CITATION: Hillis v. Meineri, 2017 ONSC 2845

COURT FILE NO.: 4869/09

DATE: 2017 05 09

ONTARIO

SUPERIOR COURT OF JUSTICE

BETWEEN:

Lynn Hillis

Plaintiff

– and –

Dr. Massimiliano Meineri and Dr. Reza Ghaffari

Defendants

Stephen J. MacDonald and Jill M. Edwards, for the Plaintiff

Eric S. Block and Kosta Kalogiros, for the Defendants

HEARD: June 8 - 11, October 20 – 23, November 24 – 26, 2015, January 21, February 22, June 27 and September 30, 2016

REASONS FOR JUDGMENT

COATS J.

A. OVERVIEW

[1] This medical malpractice case arises from the care and treatment provided to the Plaintiff, Lynn Hillis, by the Defendant anaesthetists, Dr. Reza Ghaffari and Dr. Massimiliano Meineri, during a procedure that took place at the Toronto General Hospital on December 15, 2008. The main issue is whether or not each of the two Defendants met the standard of care of a prudent anaesthetist in the circumstances. The quantum of damages was resolved prior to trial and I heard no evidence regarding damages and make no decision regarding same. Ms. Hillis was previously known as Ms. Othen.

B. UNDISPUTED FACTS

[2] The following is a brief summary of the facts as agreed upon by the parties. Where the parties’ versions of events differ, those differences will be highlighted when analyzing the relevant issues. There are undisputed facts that I have chosen not to include in this section as they are more appropriately dealt with in the context of my analysis of the case.

I. Background

[3] In October 2008, Ms. Hillis was diagnosed with endometrial cancer. She was 46 years old. Ms. Hillis’ medical history prior to the cancer diagnosis included chronic pain, migraines and fibromyalgia. She also had gastroesophageal reflux disease. She was taking prescription medication to manage her pre-existing ailments and pain.

[4] Following the diagnosis of cancer, in November 2008, Ms. Hillis met with Dr. Rosen, a surgeon at Toronto General Hospital, in order to schedule surgery. Ms. Hillis signed a Consent to Treatment form at this meeting. Ms. Hillis testified that she informed Dr. Rosen of the prescription drugs she was taking. Dr. Rosen is not a party to this matter and was not called to testify.

[5] On December 8, 2008, Ms. Hillis met Dr. Naughton, an anaesthesiologist, and a nurse for a pre-operative/pre-admission assessment. Ms. Hillis advised that she had malignant hyperthermia and also provided a list of her medications and dosages and provided her medical history. Dr. Naughton gave Ms. Hillis instructions on which medications she should take and not take on the morning of the surgery. Dr. Naughton is not a party to this matter and was not called to testify.

[6] A Pre-Admission Assessment Report was created following Ms. Hillis’ pre-operative assessment and anaesthetic consultation. It was available to Dr. Ghaffari and Dr. Meineri in advance of the procedure. It contained a comprehensive overview of Ms. Hillis’ clinical history, including matters of specific pertinence to the general anaesthetic such as her medical history, her allergies and her malignant hyperthermia.

[7] It is uncontroverted that both Dr. Ghaffari and Dr. Meineri reviewed Ms. Hillis’ available electronic medical records, including the Pre-Admission Assessment Report, in advance of the procedure.

[8] As set out above, Ms. Hillis has a condition called malignant hyperthermia. Dr. Noble, the expert for the Defendants, described malignant hyperthermia as follows:

It’s a genetic disorder that results in a patient responding to inhaled anaesthetics, excluding Nitrous Oxide, and, it results in the body’s biochemistry going berserk, and so, instead of taking the oxygen and energy substrates and producing energy in the body, it produces heat – thus, hyperthermia – and if heat is not counteracted and stopped, the patient will die.

[9] Dr. Esufali, the expert for the Plaintiff, described malignant hyperthermia in a similar manner. He described it as a hypermetabolic disorder of the skeletal muscle and that patients with the disorder can have a life-threatening reaction when exposed to volatile anaesthetics and the drug succinylcholine. As a result, it is uncontroverted that people with malignant hyperthermia sensitivity are not given volatile anaesthetics such as desflurane, sevoflurane or halothane.

[10] Both Dr. Esufali and Dr. Noble agree that a patient with malignant hyperthermia cannot receive any inhaled (gas) anaesthetic other than nitrous oxide. Nitrous oxide is known not to trigger the life threatening reaction. Ms. Hillis therefore received nitrous oxide and intravenous drugs (TIVA).

[11] Ms. Hillis was also a chronic opioid user due to chronic pain. Ms. Hillis’ opioid use and her malignant hyperthermia were the two main factors that Drs. Ghaffari and Meineri took into consideration in planning the anaesthesia that would be delivered to her during the procedure. Both experts agreed these were appropriate considerations.

II. Total Intravenous Anaesthesia (TIVA)

[12] Due to Ms. Hillis’ malignant hyperthermia, it was determined by Drs. Ghaffari and Meineri that the appropriate method of delivering anaesthetic was through Total Intravenous Anaesthetic (“TIVA”). The experts agree that this determination was correct.

[13] TIVA delivers general anaesthetic through the bloodstream rather than through ordinary inhaled anaesthetics. As set out above, nitrous oxide, via inhalation, can be given in addition to TIVA because nitrous oxide is not known to trigger the same dangerous reactions as other inhaled anaesthetics in patients with malignant hyperthermia.

[14] It is more difficult to monitor the amount of anaesthetic when using TIVA as compared to monitoring with anaesthetic gases. With ordinary inhaled anaesthetics, an anaesthetist can detect the level of anaesthetic using an “end tidal” monitor. This measures the level of inhaled gas in each breath. The amount of gas in each breath indicates the concentration level in the brain. With TIVA, the anaesthesia is administered directly into the bloodstream. At the time of Ms. Hillis’ procedure, there was no way to immediately measure the level of anaesthesia in the blood. Blood plasma concentrations of anaesthesia cannot be measured during a surgery with TIVA, unlike the situation with anaesthesia gases where concentrations can be measured almost instantly.

[15] A patient receiving TIVA may be required to be paralyzed during the surgery as well. This can be problematic because the paralytic or muscle relaxing drugs that are given to patients can affect the anaesthetist’s ability to monitor patient responses. Paralytic agents may limit a patient’s perceivable signs of awareness, such as increased frequency in breathing (ventilatory movements) or changes in muscle tone. If a patient is paralyzed during surgery the anaesthetist has to rely on less reliable signs that the anaesthetic may be light such as changes in heart rate, changes in blood pressure, whether the patient is sweating and whether the patient is tearing. These are called sympathetic responses. Both Dr. Noble and Dr. Esufali agree that approximately 20 per cent of patients experiencing awareness under anaesthetic will not have an increase in blood pressure or heart rate. Ms. Hillis did not have an increase in heart rate or blood pressure or tearing or sweating. It is uncontroverted that Ms. Hillis showed no sympathetic signs of awareness during the surgery.

[16] The experts agree that the goals of a general anaesthetic are to achieve unconsciousness, to achieve amnesia, to achieve analgesia and to achieve muscle relaxation. The overall goal is to get the patient safely and alive through surgery, without awareness, without pain, and without memory of the event. Dr. Noble also spoke of the goal of anxiolysis (not being anxious) and acknowledged that if a patient is unconscious, the patient is not anxious. Unconsciousness usually gets rid of hormonal responses created by adrenalin and leads to hemodynamic stability.

[17] The experts describe a balanced anaesthetic in the TIVA context. Balanced anaesthetic involves the anaesthetist administering a variety of drugs – hypnotic sedatives, which produce unconsciousness (Propofol is a hypnotic sedative); narcotics that provide analgesia (Fentanyl is a narcotic); benzodiazepines that provide amnesia and muscle relaxants that provide muscle relaxation. Dr. Noble described a balanced anaesthesia as follows:

A. Balanced anesthesia is a mechanism where you try to combine anesthetic agents so they give you all of unconsciousness, amnesia, anxiolysis and analgesia, and, muscle-relaxants. It requires, if you’re going to stick with TIVA – intravenous agents only – it requires multiple agents to do that, and each of these agents play with each other. They – if you, if you use only Propofol, for example, you’ll have to use very high doses. If you use, if you try to use only Fentanyl, you’d have to use extremely high doses. All these agents are assisted with the addition of the other agents. There is this synergy between them and it is that balance that results in anesthesia, unconsciousness, amnesia, analgesia and muscle-relaxation.

Q. And so, when an anesthetist is administering a balanced anesthesia, what happens if one of the multiple agents being used is brought down or reduced?

A. Um, depends which one, obviously, which effect you’re going to lose, but, you will lose something of that effect, and, you can overcome that problem by using, either another drug or more of another agent.

[18] Dr. Esufali described balanced anaesthesia in a similar manner.

[19] Although not every TIVA patient or type of procedure requires the use of paralytic agents, it was required in Ms. Hillis’ case. The doctors needed to ensure that she would not, for example, buck or cough. Even small movements during surgery could cause problems to the organs and blood vessels.

[20] It is uncontroverted that the infusion of Propofol was administered through an infusion pump. Dr. Ghaffari’s undisputed evidence is that the pump had three knobs – one for the patient’s weight, one for the infusion rate amount (micrograms per kilograms per minute, which I will refer to as mics/kg/min) and a knob for any bolus amount.

III. The Surgery

[21] Ms. Hillis’ surgery was initially scheduled for December 19, 2008, but was moved up to December 15, 2008.

[22] Dr. Ghaffari and Dr. Meineri were the anaesthetists assigned to the surgery. Dr. Ghaffari was to be present at the surgery administering the anaesthesia, and Dr. Meineri was to act in a supervisory role.

[23] On December 15, 2008, Ms. Hillis underwent a robotic-assisted laparoscopic hysterectomy and bilateral salpingo-oopherectomy. This surgery involved the removal of her uterus, fallopian tubes and ovaries to treat and prevent the spread of cancer. Ms. Hillis’ surgery began at approximately 8:00 a.m. and was completed at approximately 10:40 a.m.

[24] Before and during the surgery, Dr. Ghaffari was present in the operating room with Ms. Hillis. Dr. Meineri attended the operating room at the beginning of the procedure but did not stay in the room during the surgery.

[25] A number of drugs were administered during the course of Ms. Hillis’ procedure, the doses of which are undisputed with the exception of the Propofol infusion rate as discussed below.

[26] The rate of nitrous oxide being administered relative to the amount of oxygen being simultaneously administered results in a percentage of nitrous oxide. In Ms. Hillis’ case, the initial percentage of nitrous oxide was calculated to be 53 per cent. At approximately 8:45 to 8:50 a.m., the nitrous oxide percentage was reduced to 17 per cent. This reduction occurred because the surgeons complained to Dr. Ghaffari that Ms. Hillis’ bowels were becoming distended. It is undisputed that the reduction occurred and the percentage calculations are not disputed. It is also undisputed that decreasing the nitrous oxide was an appropriate response to the surgeon’s complaint. There are aspects of the reduction, including the speed and the amount of the reduction, that are disputed which are detailed below.

IV. Ms. Hillis’ Intra-Operative Awareness

[27] Following the surgery, Ms. Hillis made her medical team aware that she had experienced a period of awareness during surgery, known as “intra-operative awareness.” She had what Dr. Esufali described as explicit memory. She could recall events that happened during surgery without any prompting or any questions.

[28] Ms. Hillis described her experience during her testimony. She described being prepped for the surgery and falling asleep, and then waking up in the operating room. She said she didn’t know what was going on and described being in extreme pain. Ms. Hillis felt the surgeons inside her stomach and heard them talking. She described trying to move, open her eyes and scream but being unable to get the attention of the doctors. She said that while she was awake she felt like she was being ripped apart. She could not move or scream because she had been, as Dr. Esufali describes, maximally paralyzed with paralytic agents due to the nature of her surgery.

[29] Both Dr. Ghaffari and Dr. Meineri visited Ms. Hillis after learning of Ms. Hillis’ intra-operative awareness. The Defendants accept and acknowledge that Ms. Hillis experienced “intra-operative awareness.” This fact is undisputed.

[30] Ms. Hillis left the hospital the morning after the surgery, on December 16, 2008. She had a follow-up appointment with Dr. Meineri on January 13, 2009.

V. Dr. Ghaffari

[31] Dr. Ghaffari received his medical degree in 1998 from the Azad University of Medical Science in Tehran, Iran. He then maintained a general practice until 2002, when he sought specialty training in anaesthesiology and intensive care medicine at Tehran University of Medical Sciences. He completed this training in 2005, obtaining his anaesthesiology degree. From September of 2005 to November of 2006 he worked as an assistant professor and anaesthesiologist in Tabatabai Hospital, Baqmalek Khousestan, Iran.

[32] Dr. Ghaffari came to Canada to commence clinical Fellowships in various subspecialties of anaesthesiology through the University of Toronto. From February of 2007 to February of 2008 he did a Fellowship in liver transplant and surgical oncology at Toronto General Hospital. From February of 2008 to October of 2008 he did a neurosurgery and spine anaesthesia Fellowship at Toronto Western Hospital. In October of 2008 he began a cardiac anaesthesia and intensive care Fellowship at Toronto General Hospital. This is the Fellowship he was in at the time of Ms. Hillis’ surgery.

[33] Dr. Ghaffari completed the Pre-Entry Assessment Program (“PEAP”) in the first three months of his Fellowship in Toronto, which meant he was as qualified as any Canadian trained Fellow and was permitted to work as any other Fellow in Canada.

[34] As set out above, at the time of Ms. Hillis’ procedure, Dr. Ghaffari was completing his Fellowship in cardiovascular anaesthesiology and intensive/critical care. His clinical practice at the time was spent between cardiac-related anaesthetic procedures and non-cardiac anaesthetic procedures.

VI. Dr. Massimiliano Meineri

[35] At all material times Dr. Meineri was a staff anaesthesiologist at Toronto General Hospital. He had been there since 2006. Among other things, Dr. Meineri served as an Assistant Professor of Anaesthesia at the University of Toronto, Faculty of Medicine and was involved in the teaching and supervising of Fellows, Residents and students. He also had associate-staff and consultant roles at the Kensington Eye Institute and the Centre for Addiction and Mental Health.

[36] Dr. Meineri graduated from medical school in 1999 from the University of Torino, in Turin, Italy. He subsequently pursued a specialization in anaesthesia and intensive care through the University of Torino. He completed this specialization in 2003. He then practiced as a staff anaesthetist in the division of cardiovascular anaesthesia and intensive care at San Giovanni Battista Hospital in Turin, Italy.

[37] In 2004, Dr. Meineri came to Canada to complete a cardiovascular anaesthesia Fellowship at the University of Toronto. At the time of completing his Fellowship in 2006, he also obtained certification in peri-operative transesophageal echocardiography through the National Board of Echocardiography in the United States.

[38] It is uncontroverted that Dr. Meineri was assigned by the scheduling coordinator to Ms. Hillis’ December 15, 2008 procedure. He was also staffed to a simultaneous transesophageal echocardiography with another Fellow. This echocardiography procedure required Dr. Meineri’s hands-on involvement. Dr. Ghaffari was the Fellow assigned to Ms. Hillis’ procedure. Dr. Meineri had worked with Dr. Ghaffari before Ms. Hillis’ procedure.

C. PLAINTIFF’S THEORY OF THE CASE

[39] The Plaintiff’s theory of the case is as follows:

▪ Drs. Ghaffari and Meineri failed to meet the required standard of care in their treatment of Ms. Hillis;

▪ Drs. Ghaffari and Meineri were negligent in their treatment of Ms. Hillis; and

▪ The negligence of Drs. Ghaffari and Meineri either caused or materially contributed to Ms. Hillis’ intra-operative awareness.

[40] It is the Plaintiff’s position that the evidence establishes, on a balance of probabilities, that the standard of care for Ms. Hillis’ treatment was not met by Drs. Ghaffari and Meineri.

[41] The Plaintiff’s expert witness, Dr. Esufali, opined that Dr. Ghaffari administered an inappropriately low dose of Propofol to Ms. Hillis, and that he failed to properly compensate for the lowering of the nitrous oxide dose being administered to Ms. Hillis. Further, it is the Plaintiff’s position that Dr. Meineri failed to meet his standard of care by not properly supervising Dr. Ghaffari before and during Ms. Hillis’ procedure.

[42] In support of her argument, the Plaintiff argues that the Defendants have offered no probable alternative explanation for the Plaintiff’s awareness. The Plaintiff asserts that Dr. Meineri and his colleagues’ opinion after reviewing Ms. Hillis’ charts was that an insufficient amount of anaesthesia had been administered during her procedure.

D. DEFENDANTS’ THEORY OF THE CASE

[43] The Defendants’ theory of the case is as follows:

▪ Drs. Ghaffari and Meineri met the required standard of care in their treatment of Ms. Hillis;

▪ If the standard of care is found not to have been met, any error in treatment would constitute an error in judgment and would not rise to the level of negligence; and

▪ Even if the standard of care was not met, the treatment of Ms. Hillis by Drs. Ghaffari and Meineri was not the cause of her intra-operative awareness.

[44] The Defendants’ position is that the evidence of Dr. Esufali relies on the benefit of hindsight to establish that the appropriate standard of care was not met by the Defendants in their treatment of the Plaintiff. The Defendants’ position is that they were both engaged in an honest and intelligent exercise of judgment, acted reasonably and considered the correct parameters in providing anaesthesia to Ms. Hillis. Dr. Meineri’s position is that he met the standard of care for supervision of Dr. Ghaffari.

[45] It is the position of the Defendants that the administration of TIVA anaesthetic is entirely a matter of clinical judgment and that Dr. Ghaffari exercised the appropriate judgment during his treatment of Ms. Hillis. The Defendants submit that Dr. Ghaffari’s treatment decisions were made based on pre and intra-operative clinical observations. Specifically, the Defendants claim the following:

▪ The Defendants considered all the right facts in formulating an anaesthetic plan;

▪ The Defendants had fulsome knowledge of all facts necessary to exercise their clinical judgment;

▪ The treatment of Ms. Hillis required the continuous exercise of clinical judgment;

▪ The determination of specific doses for any given anaesthetic is a clinical judgment call, within established therapeutic ranges; and

▪ Dr. Ghaffari was in the best position to exercise clinical judgment and make treatment decisions.

[46] The Defendants’ position is that the Plaintiff has not met her burden of proof in establishing causation. Their position is that the evidence put forward by the Plaintiff, and in particular the evidence of Dr. Esufali, is insufficient to establish causation under either the “but for” or “material contribution” tests.

E. ISSUES

[47] There are two main issues to be decided in this case.

▪ Did Drs. Ghaffari and Meineri fall below the standard of care owed to Ms. Hillis?

▪ Did the treatment provided by Drs. Ghaffari and Meineri cause or materially contribute to Ms. Hillis’ intra-operative awareness?

F. THE LAW

I. Standard of Care

[48] The Plaintiff bears the burden of proving that the Defendants were negligent. The Plaintiff’s onus is not affected by Ms. Hillis’ sympathetic circumstances: Lapointe v. Hôpital LeGardeur, 1992 CanLII 119 (SCC), [1992] S.C.J. No. 11, at para 77.

[49] The quantum of damages has been agreed upon between the Parties. As such, to succeed against the Defendant physicians, the Plaintiff must prove on a balance of probabilities that: (a) the Defendants owed Ms. Hillis a duty of care; (b) the Defendants breached the standard of care in their treatment of the Plaintiff; and (c) the Defendants’ breach or breaches of the standard of care were the actual and legal cause of the damage the Plaintiff suffered.

[50] The Defendants acknowledge that they owed Ms. Hillis a duty of care.

[51] To meet the standard of care, a physician must exercise the degree of skill and care expected of a normal, prudent physician of comparable training and experience in the same circumstances. The Ontario Court of Appeal in Crits and Crits v. Sylvester et al. (1956), 1956 CanLII 34 (ON CA), 1 D.L.R. (2d) 502, at para. 13 (Ont. C.A.), aff’d 1956 CanLII 29 (SCC), [1956] S.C.R. 991, described the expected standard as follows:

Every medical practitioner must bring to his task a reasonable degree of skill and knowledge and must exercise a reasonable degree of care. He is bound to exercise that degree of care and skill which could reasonably be expected of a normal, prudent practitioner of the same experience and standing, and if he holds himself out as a specialist, a higher degree of skill is required of him than of one who does not profess to be so qualified by special training and ability.

[52] The Supreme Court of Canada similarly described the standard of care as follows in ter Neuzen v. Korn (1995), 1995 CanLII 72 (SCC), 127 D.L.R. (4th) 577 (S.C.C.) at para. 46, adding that the standard is higher where the practitioner is a specialist:

It is well settled that physicians have a duty to conduct their practice in accordance with the conduct of a prudent and diligent doctor in the same circumstances. In the case of a specialist…the doctor's behaviour must be assessed in light of the conduct of other ordinary specialists, who possess a reasonable level of knowledge, competence and skill expected of professionals in Canada, in that field. A specialist…must exercise the degree of skill of an average specialist in his field. [Citations Omitted.]

[53] Conduct of physicians who are alleged to have been negligent should be reviewed in the context of the knowledge that they ought to have reasonably possessed at the time of the alleged negligence. Courts must not use the benefit of hindsight to judge doctors too harshly who have acted according to the prevailing standards of professional knowledge: ter Neuzen, at para. 47.

[54] The standard of care is not a gold standard; rather, it is the average among similar peers. This is set out in Wilson v. Swanson, 1956 CanLII 1 (SCC), [1956] S.C.R. 804, at p. 817:

The test of reasonable care applies in medical malpractice cases as in other cases of alleged negligence…[t]he medical man must possess and use that reasonable degree of learning and skill ordinarily possessed by practitioners in similar communities in similar cases...

[55] Drs. Ghaffari and Meineri are specialists, and as such, should be held to a higher standard of care than generalists: ter Neuzen, at para. 46.

[56] An error in judgment will not constitute negligence: Wilson v. Swanson, at p. 812.

An error in judgment has long been distinguished from an act of unskillfulness or carelessness or due to lack of knowledge. Although universally-accepted procedures must be observed, they furnish little or no assistance in resolving such a predicament as faced the surgeon here. In such a situation a decision must be made without delay based on limited known and unknown factors; and the honest and intelligent exercise of judgment has long been recognized as satisfying the professional obligation.

[57] Whether a physician was negligent or simply made an error in judgment is determined on a case by case basis having regard to the particular facts. This is set out at para. 42 of Dean v. York County Hospital et al., [1979] O.J. No. 348 (Q.L.) (Sup. Ct.) as follows:

Diagnosis is, above all, an exercise of the physician’s judgment based on his training, experience and, perhaps, intuition. It is trite to say that a physician is not liable for injuries flowing from errors of judgment (as opposed to actual negligence). The real difficulty lies in determining whether injurious behaviour by a physician was negligence or merely an error in judgment and it is the facts in each case which will determine the answer to this crucial question.

[58] In Crits, supra, at paras. 15-16, the Ontario Court of Appeal adopted the language of Denning L.J. in Roe v. Minister of Health and emphasized that misadventure is not medical negligence:

In approaching a problem such as this it is well for a Court to caution itself, as was done by Denning L.J. in Roe v. Minister of Health et al.; Woolley v. Same, [1954] 2 Q.B. 66 at 83, [1954] 2. All E.R. 131, where that learned jurist stated: "It is so easy to be wise after the event and to condemn as negligence that which was only a misadventure. We ought always to be on our guard against it, especially in cases against hospitals and doctors. Medical science has conferred great benefits on mankind, but these benefits are attended by considerable risks. Every surgical operation is attended by risks. We cannot take the benefits without taking the risks. Every advance in technique is also attended by risks. Doctors, like the rest of us, have to learn by experience; and experience often teaches in a hard way. Something goes wrong and shows up a weakness, and then it is put right."

I also subscribe to the concluding words in his judgment at p. 86 where he says: "But we should be doing a disservice to the community at large if we were to impose liability on hospitals and doctors for everything that happens to go wrong. Doctors would be led to think more of their own safety than of the good of their patients. Initiative would be stifled and confidence shaken. A proper sense of proportion requires us to have regard to the conditions in which hospitals and doctors have to work. We must insist on due care for the patient at every point, but we must not condemn as negligence that which is only a misadventure."

[59] The Ontario Court of Appeal in Tacknyk v. Lake of the Woods Clinic, [1982] O.J. No. 170 (Ont. C.A.), at para. 29 has clarified that the standard of care expected of the medical profession must be realistic and reasonable. A physician is not the insurer of a patient’s health and well-being.

[60] The conduct of a physician is judged in light of the medical knowledge that ought to have been reasonably possessed at the time of the alleged act of negligence. As held by the Supreme Court in ter Neuzen, supra, at para. 34:

[T]he conduct of physicians must be judged in the light of the knowledge that ought to have been reasonably possessed at the time of the alleged act of negligence. As Denning L.J. eloquently stated in Roe v. Ministry of Health, [1954] 2 All E.R. 131 (C.A.), at p. 137, "[w]e must not look at the 1947 accident with 1954 spectacles". That is, courts must not, with the benefit of hindsight, judge too harshly doctors who act in accordance with prevailing standards of professional knowledge...

[61] Furthermore, the Court should not attribute to a physician knowledge that the physician did not have: (see Grass (Litigation Guardian of) v. Women’s College Hospital, (2005), 2005 CanLII 11387 (ON CA), 75 O.R. (3d) 85, (C.A.). at paras. 105-106.

[62] A physician must be judged based upon the information available to him or her at the time of treatment: ter Neuzen, supra, at para. 34; Bafaro v. Dowd, [2008] O.J. No. 3474 (Sup. Ct.), at paras. 24 – 26, 30, aff’d. 2010 ONCA 188, 260 O.A.C. 70. The standard of care cannot be elevated such that physicians are expected to take action based upon the worse-case scenario. This is set out in Cardy v. Trapp, [2008] O.J. No. 4547 (Sup. Ct.), at paras. 37-39 as follows:

It would be wrong to require a physician to practice to a standard that anticipated a worse case scenario as the risk and elevate the standard of practice accordingly. We know the standard of practice applied has a degree of risk. We know now that additional communication and checks could have prevented the delay in obtaining a diagnosis. But the court must be careful not to rely upon the perfect vision afforded by hindsight. [Citations omitted.]

…It might well have been helpful if [the defendant doctors] had conducted their practices to such an elevated standard, but this court is unable to find that they were obliged to so do and that their failure to do so constituted negligence.

[63] A finding of negligence cannot be based merely on the consequences of medical treatment to a patient. The law requires reasonable care, not infallibility, and recognizes that reasonable physicians make mistakes: Felix v. Red Deer Regional Hospital Centre, 2001 ABQB 545, [2001] A.J. No. 877 (Q.L.), at para. 80. Physicians are not guarantors of the results of their treatment, and, in medicine, adverse outcomes are often unpredictable or unavoidable even where the medical care has been reasonable. In Lapointe v. Hôpital LeGardeur, supra, at para. 28, the Supreme Court held:

…[C]ourts should be careful not to rely upon the perfect vision afforded by hindsight. In order to evaluate a particular exercise of judgment fairly, the doctor’s limited ability to foresee future events when determining a course of conduct must be borne in mind. Otherwise, the doctor will not be assessed according to the norms of the average doctor of reasonable ability in the same circumstances, but rather will be held accountable for mistakes that are apparent only after the fact.

[64] The Supreme Court has confirmed that it is important that the trier of fact not focus on whether a specific positive act constituted fault, but rather on whether the physician behaved similarly to a reasonably prudent and diligent fellow professional in the same circumstances. This is set out in St-Jean v. Mercier, 2002 SCC 15, [2002] 1 S.C.R. 491, at para 53, as follows:

To ask, as the principal question in the general inquiry, whether a specific positive act or an instance of omission constitutes a fault is to collapse the inquiry and may confuse the issue. What must be asked is whether that act or omission would be acceptable behaviour for a reasonably prudent and diligent professional in the same circumstances. The erroneous approach runs the risk of focusing on the result rather than the means. Professionals have an obligation of means, not an obligation of result. [Emphasis in original.]

[65] A plaintiff’s case which applies an outcome-based retrospective approach and attempts to work backwards from the result to prove negligence is fundamentally flawed in law and contrary to repeated admonitions in the case law. “Nothing is to be imputed to the defendant that is not clearly proved against him. Post hoc, ergo propter hoc has no place in our law”: Gent and Gent v. Wilson, 1956 CanLII 128 (ON CA), [1956] O.R. 257 (C.A.), at 256. In Brics v. Stroz et al., [2002] O.T.C. 171 (Sup.Ct.), at para. 72, the Court warned against the danger of applying hindsight in the medical negligence context:

In assessing the conduct of the physicians, the law is careful to avoid viewing the facts from the frequently more enlightened perspective of hindsight. By the time of trial, with the abundance of time to review and analyze the issues, it may be that the physician might have taken additional precautions at the time of the treatment. The case, though, must be judged from the perspective of the knowledge the physician had at the time of treatment...

[66] It is legally insufficient for an expert to simply criticize a defendant physician’s conduct without specifically testifying that the impugned conduct fell below the standard of care. In Campbell v. Hess, (unreported) (June 8, 1994) (Ont. Gen. Div.), cited in Dowd, supra, at para. 36, Ferrier J. emphasized the following:

I note particularly that although Dr. Wigle [the cross-claimant’s expert] stated that he himself would not have discontinued the Coumadin, he did not state in his evidence that [the Defendant Doctor] fell below the standard of care for a cardiologist in March 1989 in the circumstances that presented themselves. Thus Dr. Wigle did not give opinion evidence concerning the standard of care; it can be argued that the inference can surely be drawn from his evidence that that is his view. It may well be his view but such an important piece of evidence, that is an expert opinion on the standard of care, in my view, ought not to be left to a conclusion drawn by inference in the case of a negligence claim against a professional specialist.

[67] In other words, it would be an error in law for the Court to form a conclusion regarding a physician’s breach of the standard of care without specific expert opinion supporting that conclusion. This principle is most compelling in a case such as this where the medical issues are complicated and both parties have had ample opportunity to lead expert opinion.

[68] The standard of care is not determined by what an expert would himself do in a particular situation. The Supreme Court emphasized this principle in Wilson, supra, at p. 818, as follows:

A great deal of the medical evidence was read to us at the hearing and I have again read all this evidence with care. I shall not attempt to review it in detail but I am satisfied that the only portion of Dr. Kemp's evidence which might be considered as prima facie evidence of negligence on the part of appellant is that portion relating to certain pre-operative tests which Dr. Kemp claimed he would have made. Dr. Kemp, who was the last witness to testify, stated that had the patient been his patient, before making a clinical diagnosis as to the probable character of the stomach lesion, he would have had certain tests made, including a test of the gastric juices and a blood count and that in addition he would have had fresh x-rays taken and a report from a radiologist. All that this proves, of course, is that Dr. Kemp would have made these additional tests, or had them made, not that other doctors would consider it necessary to do so.

[69] In Bafaro v. Dowd, supra, at para. 36, the Court held:

To the extent that an expert testifies as to what he himself would do in a situation, rather than what the standard of care requires, his testimony does not establish the standard of care nor demonstrate that the defendant doctor breached a standard of care.

[70] It is therefore insufficient for an expert to testify as to his or her own likely actions, without also expressly opining on the reasonableness of the actions taken by the defendants as compared to what is required by the standard.

[71] In R. v. Abbey, 1982 CanLII 25 (SCC), [1982] 2 S.C.R. 24, at p.46, the Supreme Court held that “[b]efore any weight can be given to an expert’s opinion, the facts upon which the opinion is based must be found to exist”

[72] The onus throughout the proceeding is on the Plaintiff and the standard of proof is on a balance of probabilities.

II. Causation

[73] Causation can be established if Ms. Hillis can establish on a balance of probabilities that Drs. Ghaffari and/or Meineri caused or materially contributed to her intra-operative awareness.

[74] If a physician is found to have breached the standard of care, a plaintiff’s claim will still fail unless the plaintiff establishes that the breach of the standard caused the plaintiff’s injury. If a breach of the standard does not cause the injury, the physician is not liable: Clements v. Clements, 2012 SCC 32, [2012] 2 S.C.R. 181, at para. 37; see also Cottrelle v. Gerrard (2003) 2003 CanLII 50091 (ON CA), 67 O.R. (3d) 737 (C.A.), at para. 36; leave to appeal refused, [2003] S.C.C.A. No. 549.

[75] Causation cannot be assessed or proven in the abstract, and must be specifically linked to the act or omission said to have breached the standard. As Laskin J.A. stated for the Court of Appeal in Chasczewski v. 528089 Ontario Inc, 2012 ONCA 97, 287 O.A.C. 266, at para. 15 as follows:

…[I]t is the defendant’s particular substandard act or omission that must be shown to have caused the harm; therefore, it is necessary to identify that act or omission to determine what, if any, connection it has to the harm at issue. In other words, causation can only be assessed in the context of a breach of the standard of care.

[76] Causation is established when the Plaintiff proves on a balance of probabilities that the defendant caused her injury (in this case, awareness). In the vast majority of cases, the governing test is the “but for” test and this test is set out in Resurfice Corp v. Hanke, 2007 SCC 7, [2007] 1 S.C.R. 333, at para. 21-22 as follows:

First, the basic test for determining causation remains the “but for” test. This applies to multi-cause injuries. The plaintiff bears the burden of showing that “but for” the negligent act or omission of each defendant, the injury would not have occurred. Having done this, contributory negligence may be apportioned, as permitted by statute.

This fundamental rule has never been displaced and remains the primary test for causation in negligence actions...

[77] No suggestion has been made by the Plaintiff that a different test ought to be applied. In this case, the question is whether, but for Dr. Ghaffari and Dr. Meineri’s alleged breach of the standard, Ms. Hillis would have suffered awareness during her procedure on December 15, 2008.

[78] If, on a balance of probabilities, the Plaintiff fails to prove that the Plaintiff’s injuries would have been avoided had the standard not been breached, causation is not established.

[79] In Aristorenas v. Comcare Health Services (2006), 2006 CanLII 33850 (ON CA), 83 O.R. (3d) 282 (C.A.), at paras. 54, 63-64, 75-76, the Court of Appeal has confirmed that causation requires actual evidence on the issue, and that the “robust and pragmatic” approach to evidence does not permit the Court to make a finding of causation in the absence of actual evidence:

[54] The “robust and pragmatic” approach is not a distinct test for causation but rather an approach to the analysis of the evidence said to demonstrate the necessary causal connection between the conduct and the injury. Importantly, a robust and pragmatic approach must be applied to evidence; it is not a substitute for evidence to show that the defendant’s negligent conduct caused the injury.

[76] Eschewing scientific certainty does not eliminate the need for any evidence to support causation. If causation can be inferred in the absence of any proof, then it is indistinguishable from reversing the burden of proof, something Sopinka J. clearly disapproved of in Snell.

[80] The mere possibility of a causal connection between the alleged negligence and the damage caused is insufficient. As the Ontario Court of Appeal stated in Rothwell v. Raes, (1990), 1990 CanLII 6610 (ON CA), 2 O.R. (3d) 332 (C.A.), at para 8:

“the onus is not met simply by demonstrating that there is the possibility of some causal connection.”

[81] It is insufficient for the Plaintiff to speculate, or to ask the Court to speculate, about what could have happened but for the physician’s actions – he or she must lead sufficient evidence to establish, on a balance of probabilities, that but for the physician’s alleged negligence, a better or different outcome would have resulted (see Cottrelle, supra, at paras. 25-26, 36, Rothwell, supra at para. 8, and Salter v. Hirst, 2011 ONCA 609, 107 O.R. (3d) 236, at paras. 14-15; leave to appeal refused, [2011] S.C.C.A. No. 503.

[82] Proving that the Plaintiff has suffered a loss of chance is not sufficient to establish causation. It is not enough to show that a physician’s actions increased the risk of injury to the plaintiff or reduced his or her chance at recovery or a better outcome. This is set out in Laferrière v. Lawson, 1991 CanLII 87 (SCC), [1991] 1 S.C.R. 541, at para. 157 as follows:

Overall, then, not only do I question the independent recognition of a lost chance in all but the exceptional classical cases (such as the case of the lottery ticket), but I can certainly see no reason to extend such an artificial form of analysis to the medical context where faults of omission or commission must be considered alongside other identifiable causal factors in determining that which has produced the particular result in the form of sickness or death. As far as possible, the court must consider the question of responsibility with the particular facts of the case in mind, as they relate concretely to the fault, causation and actual damage alleged in the case. While probabilities are unquestionably a part of the assessment of these elements in the finding of responsibility, I am very reluctant to remove the analysis from the concrete to the probabilistic plane.

G. ANALYSIS

[83] In my analysis below, I will first address the factual findings that I have made with respect to the Propofol infusion rate and Ms. Hillis’ pre-operative opiate use. I will then move to the question of whether Drs. Ghaffari and Meineri met the appropriate standard of care in their treatment of Ms. Hillis and after the standard of care analysis, deal with the issue of causation.

I. Fact Finding

1) Overview

[84] There are two major factual points that the parties disagree upon: (1) the rate at which Dr. Ghaffari administered the Propofol infusion; and (2) the manner in which Ms. Hillis’ pre-operative opiate use was taken into account by Dr. Ghaffari.

2) Propofol Infusion Rate

[85] The Propofol infusion rate during Ms. Hillis’ procedure is of the utmost significance in determining whether the standard of care was met by Drs. Ghaffari and Dr. Meineri, and whether the anaesthetic dosages were the cause of her intra-operative awareness.

Positions of Parties

[86] The Plaintiff’s position on the Propofol infusion rate is that it was set by Dr. Ghaffari at 50 mics/kg/min at the beginning of surgery (around 8:02 to 8:03 a.m.) and was never raised. Alternatively, it is the Plaintiff’s position that the infusion rate was initially set at 50 mics/kg/min and was increased incrementally as indicated by the three up arrows on the Anaesthetic Record. The three up arrows are at approximately 9:15 a.m., 9:50 a.m. and 10:20 a.m.

[87] The Defendants’ position is that the Propofol infusion rate was set at 50 mics/kg/min only for the first few minutes of the procedure, and was turned up to 100 mics/kg/min immediately after Ms. Hillis was intubated at around 8:10 a.m. Further, they state that the infusion rate was raised incrementally as indicated by three up arrows on the Anaesthetic Record; first to 125 mics/kg/min, then to 150 mics/kg/min, and finally to 175 mics/kg/min. The Defendants acknowledge that Dr. Ghaffari does not have an independent recollection of the procedure and rely on his description of his usual practice to support their position.

[88] As set out above, Dr. Ghaffari did not have an independent recollection of the Propofol infusion and relied on his usual and routine practice. He said he started the infusion pump with an infusion rate of 50 mics/kg/min before putting the patient to sleep. He then administered 2 mg of Versed and 150 mics of Fentanyl via injection. He then injected the induction medications to put Ms. Hillis to sleep and place her in the anaesthetic state. This involved a single injection of Propofol (150 milligrams), 60 mics of Rocuronium and an injection of Fentanyl. This was done around 8:05 a.m.

[89] By 8:10 a.m., after she received the induction dose, Ms. Hillis was intubated (a breathing tube was inserted in her airway) and an inhaled gas mixture of nitrous oxide and oxygen set at 1.5 litres/min of nitrous oxide and 1.3 litres/min of oxygen (53 per cent nitrous oxide) was commenced.

[90] Dr. Ghaffari ensured, among other things, that Ms. Hillis was appropriately positioned for the procedure and that her eyes were lubricated and taped shut. He gave the surgical staff an acetaminophen suppository that was administered rectally to Ms. Hillis.

[91] What is disputed is Dr. Ghaffari’s evidence that he increased the infusion rate of Propofol from 50 mics/kg/min to 100 mics/kg/min immediately after Ms. Hillis was intubated.

Anaesthetic Record

[92] The parties do not dispute what is written on the Anaesthetic Record with respect to the Propofol infusion rate.

[93] The Propofol infusion rate is recorded with a variety of notations made by Dr. Ghaffari. First, in the spaces indicating the first hour of the procedure, Dr. Ghaffari has handwritten “infusion 50 [mics]/kg/min.” Following this notation is a line that continues until the end of the procedure just before 10:45 a.m. Along the line are the three up arrows described above. The first appears just before 9:15 a.m., the second just after 9:45 a.m. at around 9:50 a.m. and the third between 10:15 and 10:30 a.m. at around 10:20 a.m.

[94] It is acknowledged by the Defendants that the increase Dr. Ghaffari claims occurred immediately after intubation is not noted on the Anaesthetic Record.

Findings on Propofol Infusion Rate

[95] The Plaintiff suggested at trial that the line drawn across the Propofol infusion portion of the Anaesthetic Record was a continuous line drawn at the beginning of the procedure, reflecting a continuous infusion rate of 50 mics/kg/min for the duration of the procedure. I disagree. In order for this to be true, Dr. Ghaffari would have had to know the exact time that the procedure would end. There has been no evidence led to support this claim and so I find that the line was made by Dr. Ghaffari in increments and is simply reflective that the Propofol infusion was continuous. The line has no bearing on my findings as to what the infusion rate was at various points during Ms. Hillis’ procedure.

[96] There was a suggestion made by the Plaintiff that the up arrows may or could have been added to the Anaesthetic Record after the procedure was completed. There was no evidence at all that this occurred and I make no such determination.

[97] In his testimony, Dr. Ghaffari described the Propofol infusion pump as incrementally increasing each time the anaesthetist would turn it clockwise. He described the increments on the pump for the Propofol infusion rate as being 50, then 100, then 125, then 150, then 175, then 200. There was no evidence led to dispute these being the increments that were available on the pump.

[98] Dr. Ghaffari testified that the up arrows on the chart were indicative of increases in the Propofol infusion rate. He explained why he used the arrows rather than a more detailed notation.

I maybe have to do a better charting for this Propofol, but, but this is the, this is the changes that, in some cases, that they are not able to tolerate the increase – we have to put it down again, quickly; and put it up again – so, and because there is a little room here, we, we, not always we are able to write down all the numbers of the increase or decrease, so, I just put a little arrow to go up; it shows in that particular time frame, I increased it.

[99] Dr. Ghaffari said that when he went to check the pump after learning of Ms. Hillis’ intra-operative awareness, it was set at 175 mics/kg/min. Thus, his position was that each arrow must have represented an incremental increase of 25 mics/kg/min.

[100] I am satisfied that the up arrows carried some meaning, and based on Dr. Ghaffari’s testimony of the set-up of the pump, I find that each up arrow represented an incremental increase based on one clockwise turn of the infusion pump.

[101] The defence position was that the Propofol infusion rates were as follows:

▪ From 8:00 a.m. until no later than 8:10 a.m., the rate was 50 mics/kg/min.

▪ From no later than 8:10 a.m. until approximately 9:15 a.m., the rate was 100 mics/kg/min.

▪ From approximately 9:15 a.m. until approximately 9:50 a.m., the rate was 125 mics/kg/min.

▪ From approximately 9:50 a.m. until approximately 10:20 a.m., the rate was 150 mics/kg/min.

▪ From approximately 10:20 a.m. until the end of the procedure at approximately 10:40 a.m., the infusion rate was 175 mics/kg/min.

[102] Dr. Ghaffari acknowledged that the chart does not reflect the defence position that there was an increase in the Propofol infusion rate from 50 to 100 mics/kg/min at about 8:10 a.m.

[103] In explaining the inconsistency between what was written on the chart and his own version of events, Dr. Ghaffari did not rely upon an independent recollection of his actions during Ms. Hillis’ procedure. Rather, he argued that it was his daily practice to switch the infusion rate to 100 mics/kg/min immediately after intubating the patient, saying “exactly after the airway, I turn and increase my Propofol; that’s every day, the first thing that I do.” The defence put this forward as an invariable practice argument.

[104] Dr. Ghaffari described his use of the Propofol infusion pump at the beginning of the procedure as follows:

When the patient was in the room and I was giving the pre-medication, before the induction, I put the Propofol infusion on 50mcg to make sure that the pump is working; make sure that the drug is getting into the patient and I make sure that I don’t see any bad reaction or any allergic reaction on the patient. Then, as soon as the tube was in, I turn and put it onto, onto 100 mcg – that’s my daily practice that I do…

[105] Dr. Ghaffari also described the timing of the infusion rate being changed from 50 mics/kg/min to 100 mics/kg/min. He said, “[a]nd again, this, this is all in the first 15 minutes; not, not after, because the re-, writing is, the infusion is taking too much ti-, longer and it’s going forward…”

[106] The invariable practice of a professional can be given significant weight by the Court: Bafaro v. Dowd, supra, at para. 29. However, I find that, given the inconsistencies between the contemporaneous written record and Dr. Ghaffari’s evidence of his invariable practice, the written record is more reliable in this case. I also find that Dr. Ghaffari had not been administering anaesthesia unsupervised for a significant enough period of time such that what he describes as his ordinary practice should be given deference.

[107] The Defendants rely on Dickie v. Minett, 2012 ONSC 4474, 221 A.C.W.S. (3d) 1010, aff’d 2014 ONCA 265, 239 A.C.W.S. (3d) 243, as support for their proposition that it is appropriate for the court to accept a doctor’s explanation for his lack of recollection and to rely on his evidence of invariable practice. While it is true that the Court of Appeal accepted that it was appropriate for the trial judge to rely on invariable practice in that case, I find that Dickie can be distinguished from the immediate case in a number of ways.

[108] First, in Dickie, the oral surgeon defendant had been practicing as a fully licensed oral surgeon for over 20 years at the time of the wisdom tooth extraction surgery in question. During those 20 years, the defendant estimated that 30% of his practice was comprised of wisdom tooth extractions, with between 20 and 30 extractions being performed per week. In contrast, Dr. Ghaffari’s experience as an anaesthetist was limited.

[109] From 1998 until 2002, Dr. Ghaffari worked as a general physician in Iran. From 2002 until 2005, Dr. Ghaffari completed his residency in anaesthesiology and intensive care medicine at Tehran University of Medical Sciences. Dr. Ghaffari confirmed that he was always under the supervision of a hospital physician during this time period. Dr. Meineri described an anaesthetic resident as “an anaesthetist in training.”

[110] From September 2005 until November 2006, Dr. Ghaffari worked as Assistant Professor and Anaesthesiologist in Tabatabai Hospital. During this time, Dr. Ghaffari was the staff anaesthetist. Dr. Ghaffari testified that during his time working as an anaesthetist in Iran, approximately 10 per cent of his cases were Total Intravenous Anaesthesia (TIVA).

[111] Between February 2007 and January 2009, Dr. Ghaffari was an anaesthetic Fellow at Toronto General Hospital. From February 2007 until February 2008, Dr. Ghaffari completed a Fellowship in liver transplant and surgical oncology. From February 2008 until October 2008, Dr. Ghaffari completed a Fellowship in neurosurgery and spine anaesthesia. Beginning in October 2008 and continuing until January 2009, Dr. Ghaffari was a Fellow in the cardiac anaesthesia and intensive care unit. It was during this last Fellowship that Ms. Hillis’ procedure occurred.

[112] Dr. Ghaffari was supervised for the entire period of his residency from 2002 to 2005. He then had about 14 months of unsupervised work as an anaesthetist. As set out above, Dr. Ghaffari started his Fellowship in Toronto in February of 2007. According to his evidence he did surgeries on his own after the PEAP was completed and by the second year of his Fellowship or after finishing the first year of his Fellowship. This would have been around approximately February of 2008. Ms. Hillis’ procedure was 10 or 11 months later.

[113] In any event, at the time of Ms. Hillis’ procedure, Dr. Ghaffari had been unsupervised in his practice for only about two years cumulatively (24 to 25 months).

[114] Dr. Ghaffari completed his Practice Ready Assessment examinations in June of 2009, and it was not until that time that Dr. Ghaffari was licensed to practice as an anaesthesiologist on his own. Prior to that time, under the terms of his Fellowship, Dr. Ghaffari was required to at least review his anaesthesia plan with the staff anaesthetist who was supervising him.

[115] Dr. Ghaffari estimated that in Iran, he would administer between 1500 and 2000 general anaesthetic cases per year. Dr. Ghaffari estimated that TIVA anaesthesia made up about 10 per cent of those cases. Further, Dr. Ghaffari estimated that since coming to Canada in 2007, approximately 5-10 per cent of his non-cardiac cases involved TIVA. Dr. Ghaffari agreed that since coming to Canada, the majority of his experience involved non-TIVA anaesthesia.

[116] However, robotic-assisted hysterectomies were new to Toronto General Hospital at the time of Ms. Hillis’ procedure, and Dr. Ghaffari was unable to confirm that he had ever performed anaesthesia with such a procedure prior to December 15, 2008.

[117] Quite simply, for all these reasons, I find that Dr. Ghaffari did not have sufficient experience working independently for the Court to be satisfied that he had established an invariable practice, let alone an invariable practice entitled to deference.

[118] Further, In Dickie, the oral surgeon’s contemporaneous notes were supportive of his stated invariable practice. Similarly, in other cases put forward by the Defendants, the invariable practice of a doctor was accepted by the court as it complemented the notes taken contemporaneously to a procedure: O’Connell v. Williams, [2001] O.T.C. 666; Suwary (Litigation Guardian of) v. Women’s College Hospital, 2011 ONCA 818, [2011] O.J. No. 5895. In contrast, Dr. Ghaffari relies on his evidence of invariable practice to explain away his inaccurate charting and the inconsistency of his version of events with Dr. Meineri’s letters as discussed below. I find that Dr. Ghaffari has not provided convincing evidence of his invariable practice. His oral testimony is not compelling in the face of contradictory contemporaneous notes. As set out above, the Anaesthetic Record prepared by Dr. Ghaffari during the surgery reflects the infusion rate of 50 mics/kg/minute for the first hour of the surgery. There is no note or notation of any kind whatsoever of what Dr. Ghaffari claimed was his invariable practice.

[119] Aside from the lack of evidence supporting Dr. Ghaffari’s claim of invariable or usual practice, there are some other elements of the written chart and evidence that add to the reasons for my rejection of the defence position that the infusion pump was turned from 50 mics/kg/min to 100 mics/kg/min immediately after induction of the patient and my acceptance of the written Anaesthetic Record.

[120] Dr. Ghaffari testified that, due to the quick sequence of events at the beginning of the procedure, he did not chart the infusion rate until after turning the pump to 100 mics/kg/min and after having turned Ms. Hillis over to the surgeons for the procedure to begin. Dr. Ghaffari wrote the Propofol infusion rate of 50 mics/kg/min to cover almost the entire first hour of the procedure until the commencement of the infusion “line” drawn into the chart beginning just before 9:00 a.m. I find Dr. Ghaffari’s explanation for this illogical. Given the sequence of events he described, this does not make sense. I cannot see why Dr. Ghaffari would write the incorrect infusion rate across the entirety of the first hour of the chart after he had already turned the pump to 100. It is not just that he didn’t make note of the alleged increase. He charted what he says was the initial rate for the first ten minutes across the first hour of the procedure.

[121] Further, if his practice is, as he claimed, to start at 50 mics/kg/minute and then turn it to 100 mics/kg/min before charting, it is less understandable why he would write 50 if he intended to write 100, and as he claimed, he would routinely have already turned it to 100.

[122] As discussed above, Dr. Ghaffari testified that the up arrows in the chart represent incremental increases in the Propofol infusion rate, and I have no reason to disbelieve this testimony. As such, if Dr. Ghaffari increased the infusion rate at approximately 8:10 a.m. he could have placed a further up arrow at approximately 8:10 a.m. He did not do so. This would have been consistent with his charting of the other increases. It was not done. It would have been simple to do. The absence of this up arrow around 8:10 a.m. supports that the increase did not occur.

[123] Further, in cross-examination Dr. Ghaffari acknowledged that the only thing he had not charted was his claimed initial increase in the Propofol infusion rate immediately following induction of Ms. Hillis. Compared to the rest of Dr. Ghaffari’s testimony with respect to various drug dosages administered throughout the procedure, as well as Ms. Hillis’ charted vital signs, the chart is accurate. I note particularly that Ms. Hillis’ blood pressure was charted at a fairly high frequency, with tick marks indicating changes in blood pressure every five minutes. It does not make sense to me that Dr. Ghaffari could accurately and frequently chart so many other elements during the procedure but would inaccurately write out the Propofol infusion rate over the first hour of the procedure. The Anaesthetic Record is otherwise completely accurate. It is therefore reasonable to rely on the written record of the Propofol infusion rate.

[124] Dr. Ghaffari testified that the chart was “accurate, but not complete.” With respect, Dr. Ghaffari cannot characterize the chart as accurate. His evidence was that the infusion rate was turned from 50 to 100 mics/kg/min at approximately 8:10 a.m. yet the chart shows 50 mics/kg/min from 8:00 a.m. to 9:00 a.m.

[125] Dr. Ghaffari would have inevitably looked at the Anaesthetic Record throughout the procedure as he made many more entries on the Record including the three up arrows on the very same line of the Record. It is inconceivable to me that he would not notice his error of writing 50 mics/kg/min over the first hour of the procedure on the line marking the Propofol infusion rate if it was an error.

[126] Further, both Dr. Ghaffari and Dr. Meineri made notes on Ms. Hillis’ patient chart (not to be confused with the Anaesthetic Record) under “Interdisciplinary Clinical Notes.” Dr. Meineri made a note in the chart on the day of the procedure, December 15, at 4:30 p.m. Dr. Ghaffari wrote a note the following morning, December 16, at 8:00 a.m. Although both notes discussed Ms. Hillis’ intra-operative awareness, neither note dealt with the dosages that Ms. Hillis had received during her procedure or the Propofol infusion rate.

[127] In my view, if Dr. Ghaffari and Dr. Meineri had reviewed the anaesthetic chart and noted such a glaring inaccuracy in charting, they would have made a note contemporaneously to the procedure, rather than first presenting their explanations for the chart several years later after Ms. Hillis’ action against them had been commenced.

[128] This suggestion was put to Dr. Ghaffari in cross-examination and he agreed that both he and Dr. Meineri could have made a note contemporaneously to the procedure.

Q. I’m not talking about the anesthetic chart; I’m talking about ‘her’ chart – you made a note to her chart after you found out about this problem – a hand-written note to the chart…

A. Correct.

Q …right? And so did Dr. Meineri, right?

A. Yes

Q. And there would have been nothing stopping you from making a further hand-written note to the chart…

A. Yes.

Q. …based upon what you say was the total amount of the Propofol, right?

A. Yes.

Q. There would be nothing stopping you from doing it?

A. Maybe we have to do that, but, we had to do that but we didn’t do it.

[129] Dr. Ghaffari said his practice was to put the infusion rate for Propofol at 50 mics/kg/min initially to ensure the pump was working, to confirm there was no blockage in the IV line and to rule out any adverse reactions to Propofol As I have outlined above, Dr. Ghaffari’s evidence on his usual practice is not entitled to deference. Further, Ms. Hillis was not allergic to eggs and therefore was not allergic to Propofol.

[130] Dr. Ghaffari put forward as evidence that the syringes that he filled with Propofol prior to the procedure were indicative of the overall amount of Propofol infused, and that the amount in the syringes supported the defence position on the infusion rate.

[131] Dr. Ghaffari gave evidence that there were three syringes filled prior to the procedure, and that each of the syringes held 60cc’s, or 600 milligrams, of Propofol, meaning that there was a total of 1800 mg of Propofol prepared for infusion during Ms. Hillis’ procedure.

[132] The Defendants submitted that the amount of Propofol put into the syringes in preparation for the procedure was important because the amount left in the syringes at the end of the procedure would have bearing on the findings of the overall infusion rate. However, the Defendants did not provide evidence of how much Propofol was left in the syringes at the conclusion of the procedure. As a result, the amount of Propofol put into the syringes in preparation for the procedure has no bearing on my findings of fact.

[133] In his testimony, Dr. Meineri described his recollection of the day of Ms. Hillis’ procedure. Dr. Meineri clarified that the purpose of his visit to the operating room was to check on Dr. Ghaffari, to make sure he had no problems with the induction of anaesthesia, to sign the chart and to ensure that Dr. Ghaffari and others had his pager number to use if any issues arose during the procedure.

[134] In describing the timing when he entered the operating room, Dr. Meineri gave conflicting evidence as to whether Ms. Hillis had already been intubated or not. During his examination for discovery, which was read into court, Dr. Meineri gave different accounts of the timing when he walked into the room:

▪ “I walked into the room after Ghaffari induced general anaesthesia and intubated the patient.”

▪ “When I walked into the room, the patient was just being intubated…”

[135] During the same examination, Dr. Meineri was asked when he signed the chart and he answered, “She was actually fully under and the endo tracheal tube, the breathing tube, was in place.”

[136] During his examination in chief, Dr. Meineri gave the following description of the timing:

▪ “I went to check with Dr. Ghaffari, and, as I walked into the room, the patient was just being intubated.”

[137] The particular time that Dr. Meineri entered the operating room is not of significant importance. It is understandable that years after the procedure actually took place it would be difficult to remember very specific details of Ms. Hillis’ case. However, I have highlighted this inconsistency to illustrate the difficulty in relying on Dr. Meineri’s independent recollection to support Dr. Ghaffari’s evidence that at approximately 8:10 a.m. the infusion rate was turned up to 100 mics/kg/min.

[138] Dr. Meineri said that he stayed in the operating room for approximately ten to fifteen minutes. Dr. Ghaffari testified that Dr. Meineri was in the room between five and ten minutes.

[139] Dr. Meineri testified that, while in the operating room, he looked at the monitors, checked and signed the chart and left. Dr. Meineri stated that, at that time, he and Dr. Ghaffari did not discuss the dosages and that he left it entirely to Dr. Ghaffari to determine the drugs to be used and the dosages to be given. During his examination in chief, Dr. Meineri described his observations at the time of the procedure as follows:

I walked in, and everything looked fine, so, I looked at the screen – at the anaesthetic screen – with all the vital parameters, and I don’t recall anything abnormal. Ah, I looked at the anaesthetic machine, and I looked at the, ah, ah , pressure traces, and, the monitor, and watched the intubation, and, so, it was normal. I looked around, there was a, there was a pump and it was with Propofol, and there was the IV, the IV bag, and, ah, I saw the chart, and I asked Dr. Ghaffari if everything was fine – he said ‘No problems’ – I, and so, then, I, I signed the chart and I left.

[140] Dr. Meineri testified that he did not recall having any concerns at the time. When asked to describe the status of the Propofol infusion pump, Dr. Meineri said that although he couldn’t remember what it had been set to, it “didn’t stand out [or] look abnormal.” He said that if it had been abnormal, he “would have obviously told something to Dr. Ghaffari.” Dr. Meineri testified that when he was in the operating room, he “saw that the TIVA was dosed as accurately as possible for this specific patient.” As set out above, Dr. Meineri’s independent recollection of his attendance in the operating room that day is imprecise. I cannot rely on his evidence that he can’t recall anything “abnormal” as supportive that the infusion rate was at 100mics/kg/min. This is particularly so when nothing was noted in writing in regard to infusion rate by Dr. Meineri in the immediate time after his becoming aware that Ms. Hillis experienced awareness, as noted above.

[141] After the procedure was over, Dr. Meineri then Dr. Ghaffari were informed of Ms. Hillis’ intra-operative awareness. Dr. Meineri went to see Ms. Hillis and discussed what had happened. After Dr. Meineri met with Ms. Hillis, Dr. Meineri and Dr. Ghaffari met to review the Anaesthetic Record together and discuss the possible cause of Ms. Hillis’ awareness. Dr. Meineri testified that at that time, Dr. Ghaffari informed him about what happened during the procedure.

[142] When asked if he observed anything odd or unusual in the Anaesthetic Record when it was being reviewed by Dr. Meineri and Dr. Ghaffari together, Dr. Meineri said that he told Dr. Ghaffari that the amount of Propofol given to Ms. Hillis was on the lower side to begin with, where the Propofol infusion rate was recorded as 50 mics/kg/min. Dr. Meineri said that he would have expected a slightly higher initial dose of Propofol, and indicated that the dose he would expect would be about 100 mics/kg/min.

[143] Dr. Meineri recalled that Dr. Ghaffari said he started the infusion rate at 50 mics/kg/min even before giving Ms. Hillis the induction dose. Dr. Ghaffari told Dr. Meineri that he then increased the amount to 100 mics/kg/min. Dr. Meineri relies on Dr. Ghaffari’s explanation in order to establish that the infusion rate was set at 50 mics/kg/min and immediately increased to 100 mics/kg/min.

[144] The fact that Dr. Meineri had to seek clarification from Dr. Ghaffari about the infusion rate as recorded in the Anaesthetic Record indicates to me that Dr. Meineri did not take note of the infusion rate at the time that he was in the operating room. It is not possible to reconcile Dr. Meineri’s apparent concern about the written record with a first-hand observation of the infusion rate. This was still the same day as Ms. Hillis’ procedure. Memories were fresh.

[145] Dr. Ghaffari testified as follows in explaining his recollection of the rate of Propofol infusion:

I’m confirming that the beginning, starting dose, was 100, and the finishing dose was 175, and there was three clicks – three arrows – here, and, by any calculation, this is every increase is 25. I may say, at that time, that I don’t remember because I don’t exactly recall, you know, if, if, if this arrow is representing two clicks or one, but, if there is three clicks and it has gone from 100 to 170 [sic], that means each click is two, twenty-five, is 25 microgram. So, that is the way that I calculate it, but, if you ask me to exactly remember the number of the 125 on the machine that you clicked it to there, it’s too far to remember it now for me. But, I, I can tell you that the finishing, I went downstairs and checked my machine, with my colleague, and it was 175. That’s my answer.

[146] There is no written record that Dr. Ghaffari went to check the pump after becoming apprised of Ms. Hillis’ period of awareness. This is not reflected in any note made by either Dr. Meineri or Dr. Ghaffari after meeting with Ms. Hillis concerning the awareness episode. Further, this is not reflected in documents Dr. Meineri authored post-surgery. This evidence is simply not reliable. The written Anaesthetic Record is reliable and it indicates 50 mics/kg/min for the first hour of the procedure.

[147] Even if the finishing dose was 175 mics/kg/min, which I have not found, this doesn’t mean that the rate was turned to 100 mics/kg/min right after intubation. As set out in paragraph 145 above, Dr. Ghaffari did not recall if each up arrow meant two clicks or one. Two clicks (rotations on the infusion pump) would be an increase of 50 mics/kg/min represented by a single up arrow.

[148] Further, Dr. Ghaffari testified he and a colleague went to check. I was not told who the colleague was. Dr. Meineri was clear he did not go to check.

[149] Dr. Meineri testified he recalled Dr. Ghaffari telling him he checked after becoming aware that Ms. Hillis had awareness and the pump was at 175 mics/kg/min. Dr. Meineri wrote documents that did not include this information in the month after the procedure despite the fact that the documents made mention of the infusion rate. It is inconceivable and illogical that he would recall this specific part at trial and not within the month after the procedure.

[150] In terms of the written documents prepared post-surgery, Dr. Meineri completed a written “Operative/Invasive Incident” report following Ms. Hillis’ procedure. The report provides limited information; however, under “Reason for Operative/Invasive Incident” it states “Light Total Intravenous Anaesthesia.” When questioned about this notation, Dr. Meineri said that it was entered into the report because it was the only explanation that they had for the awareness. If Dr. Meineri knew at the time that Ms. Hillis’ infusion has been increased as Dr. Ghaffari described to an end rate of 175 mics/kg/min it is not reasonable that he would describe this as light. Neither expert came close to suggesting 175 mic/kg/min of a Propofol infusion rate could be viewed as light or one that started at 100 mics/kg/min immediately after infusion and increased to 175 as light.

[151] Dr. Meineri also wrote two letters following the incident. First, he dictated a letter to Dr. Rosen on January 16, 2009. Subsequently he wrote a letter to Whom It May Concern, February 10, 2009.

[152] Dr. Meineri testified that he wrote the January 16 letter in order to tell Dr. Rosen what he had found during the course of his review of Ms. Hillis’ case. Dr. Meineri said that he intended the letter to be accurate and complete. He said that the main purpose of the letter was to summarize the situation and to let Dr. Rosen know that he had seen Ms. Hillis again and was dealing with the consequences of her intra-operative awareness.

[153] Prior to writing the letter, Dr. Meineri met with three members of the Department of Anaesthesia: the Chair, the Site Chief and the Chair of Quality Control. Dr. Meineri references these individuals in his letter collectively as “My Group.” Dr. Meineri explained that the Group physically reviewed Ms. Hillis’ chart.

[154] A portion of the January 16 letter considers possible explanations for Ms. Hillis’ intra-operative awareness and states as follows:

I reviewed the case with my Group and we feel that reviewing the anesthetic chart, it is likely for Mrs. Othen to have had an episode of awareness. Although the blood pressure and heart rate were stable and there weren’t any signs of awareness during the procedure given the amount of anesthetic drugs she received through her IV and her history of chronic pain and preoperative use of opioids, we feel that the amount of anesthetic she received was not enough for her to keep her asleep.

[155] It is clear from the letter that Dr. Meineri and the “Group” concluded that Ms. Hillis had received an inadequate amount of anaesthesia during her procedure. Dr. Meineri explained the discrepancy between his position at trial and the position reflected by the letter by saying that he and the “Group” had reached that explanation out of a process of elimination. Essentially, he said that upon review of the Anaesthetic Record, they were unable to find any other explanation for Ms. Hillis’ awareness, and so concluded that the reason must have been the doses of anaesthesia that she received.

[156] Dr. Meineri said that in reaching their conclusion, the Group was unable to clearly ascertain the exact amount of Propofol that was given to Ms. Hillis using the chart alone because the specific doses weren’t clearly reported. Dr. Meineri testified that the Group “all agreed that there [was] no other explanation for Ms. Hillis’ awareness.” This letter was written a month after the awareness incident. If Dr. Meineri knew from Dr. Ghaffari that the anaesthetic chart did not accurately reflect the Propofol infusion rate, why would this not be considered by the Group? Why would they consider the Chart without considering what Dr. Ghaffari had supposedly told Dr. Meineri – both that the charting did not reflect the alleged initial increase from 50 to 100 mics/kg/min and that Dr. Ghaffari had checked the pump and the final infusion rate was 175 mics/kg/min..

[157] The February 10 letter was written by Dr. Meineri for inclusion in Ms. Hillis’ medical file. He said that he intended for the letter to be as accurate as possible and agreed that he could easily consult the chart in preparing for the letter. In the letter, Dr. Meineri described the doses of anaesthetics given to Ms. Hillis as follows:

Induction of anesthesia was achieved with Propofol 150 mg, Versed 2mg, Fentanyl 250 mg, followed by Rocuronium 50 mg.

Maintenance of anesthesia was accomplished with Propofol infusion 50-100 mcg/Kg/h and Hydropmorphone 2 mgs IV bolus given soon after intubation.

[158] When questioned about the reference to “maintenance of anaesthesia,” Dr. Meineri testified that he got the figure from the chart and from what he remembered of the discussion with Dr. Ghaffari. He characterized the 50-100 dosage as the “initial dosage at which the pump was set on the Propofol.”

[159] In my view, the use of the word “maintenance” is important as it contradicts Dr. Meineri’s characterization of 50-100 as an “initial” dose. When asked about this apparent contradiction, Dr. Meineri said that he “wasn’t precise enough because [he] didn’t specify the doses that were given from Propofol during the whole operation.” He also said that “what [he] meant is that this is the…initial setup of the pump,” and that he “didn’t think that the specific doses which [he] reported [in the letter] were absolutely important.”

[160] I find Dr. Meineri’s explanation to be tenuous. As was pointed out by counsel for the Plaintiff, the initial incident report and the January 16 letter to Dr. Rosen were consistent in pointing to inadequate anaesthesia as the explanation for Ms. Hillis’ awareness. The February 10 letter purports to explain the dosages given to Ms. Hillis during the procedure and to advise on future dosages to be given, but does nothing to account for the Defendants’ position at trial that the initial infusion rate went from 50 to 100 mics/kg/min quite quickly. If Dr. Meineri was told by Dr. Ghaffari on the day of the surgery and immediately after they became aware that awareness had occurred, that Dr. Ghaffari had immediately increased the infusion rate to 100 mics/kg/min after intubation, then subsequently maintained with three increases to a total of 175, why would Dr. Meineri not get this right in the February 10 letter? The letter was written less than two months after the awareness episode. It is inconceivable that he wouldn’t recall what he had been told by Dr. Ghaffari two month later but recall it accurately at trial.

[161] This was an important letter. It was to be considered by future anaesthetists if Ms. Hillis required anaesthesia in the future. Ms. Hillis’ future well-being was at stake. It is inconceivable that Dr. Meineri would not have accurately described the maintenance dose of Propofol if he had been told it by Dr. Ghaffari or accurately set out the 175 mics/kg/min was the highest infusion rate at the end of the procedure, had Dr. Ghaffari told him this.

[162] Later in the letter, Dr. Meineri includes a list of recommendations, one of which suggests “Propofol continuous infusion > than 200 mcg/Kg/min if tolerated.”

[163] This notation provides some support for the Defendants’ position that the Propofol infusion rate was incrementally increased as indicated by the up arrows on the Anaesthetic Record. I have accepted Dr. Ghaffari’s evidence that the up arrows reflect increases in the infusion rate. It would not make sense for Dr. Meineri to recommend an infusion rate of greater than 200 mics/kg/min if the overall rate of infusion was 50 mics/kg/min throughout the procedure. On this point, I accept Dr. Meineri’s explanation that he suggested the dosage because the Propofol rate was close to but under 200 and that he would recommend “to be safe, if tolerated and if indicated, to shoot high.” This does not however provide support for Dr. Ghaffari’s evidence that the end rate was 175. This is not noted in this letter.

[164] Dr. Meineri had four opportunities to provide a written explanation that the Anaesthetic Record was an inaccurate representation of the actual Propofol infusion dosages given to Ms. Hillis on the day of her procedure: a brief note he wrote in her chart on December 15, 2008, the “Operative/Invasive Incident” report, the January 16, 2009 letter to Dr. Rosen and the February 10, 2009 incident report letter for inclusion in Ms. Hillis’ chart.

[165] Despite these opportunities, Dr. Meineri failed to provide a written account that offers any explanation of Ms. Hillis’ intra-operative awareness aside from inadequate anaesthesia. In fact, in testimony he agreed that the only explanation that he had for Ms. Hillis’ awareness was that the dose of Propofol was inadequate.

[166] Thus, Dr. Meineri’s evidence does not support Dr. Ghaffari’s claim that the Propofol infusion rate was increased from 50-100 mics/kg/min towards the beginning of the procedure, around 8:10 a.m.

[167] I am satisfied that, in this case, fact finding must be based on the written record. This finding is made for three principal reasons: (1) as a result of my finding that there is no evidence to support the Defendants’ claim of invariable practice; (2) due to my findings regarding the tenuous nature of Dr. Ghaffari’s claim that he turned the infusion pump to 100 mics/kg/min at approximately 8:10 a.m.; (3) due to my finding that Dr. Ghaffari’s evidence that he checked the pump after the procedure is not reliable; and (4) because Dr. Meineri’s independent recollection is unreliable and inconsistent with his contemporaneous notes.

[168] I find as a fact that the Propofol infusion rate was as follows:

▪ From just after 8:00 a.m. (around 8:02 to 8:03 a.m.) until approximately 9:15 a.m., the rate was 50 mics/kg/min.

▪ From just before 9:15 a.m. until approximately 9:50 a.m., the rate was 100 mics/kg/min.

▪ From approximately 9:50 a.m. until approximately 10:20 a.m., the rate was 125 mics/kg/min.

▪ From approximately 10:20 a.m. until the conclusion of the procedure at approximately 10:40 a.m., the rate was 150 mics/kg/min.

[169] These findings are supported by the written record. The Anaesthetic Record indicates an initial infusion rate of 50 mics/kg/min, followed by three up arrow notations. Dr. Meineri and Dr. Ghaffari made notes on Ms. Hillis’ medical chart immediately after the procedure and did not indicate anything to contradict or correct the Anaesthetic Record. Further, Dr. Meineri filed an Operative/Invasive Incident report that indicated “light total intravenous anaesthetic.” His letter from January 2009 indicated that inadequate anaesthesia was the reason for Ms. Hillis’ awareness, and the letter from February 2009 offered no other explanation. Significantly, none of these written records in any way support Dr. Ghaffari’s evidence of the infusion rates or his claimed invariable practice.

[170] I want to be clear that I am not in any way suggesting that Dr. Ghaffari or Dr. Meineri could or should have altered or added to the Anaesthetic Record in anyway after finding out about Ms. Hillis’ awareness. This would have been inappropriate. This is different than making notes to the file of events and discussions occurring after as those events occurred. The awareness was an incident within the hospital. It resulted in an Operative/Invasive Incident reporting. Dr. Meineri met with a Group to review the incident. If there were facts known at the time relevant to the incident and review and reporting this should be documented. It was critical to know what infusion rate of Propofol was administered to Ms. Hillis. If the Anaesthetic Record was inaccurate I would expect to see that noted in a written record. It wasn’t.

3) Opiate Use

[171] In addition to the Propofol infusion rate used by Dr. Ghaffari during the procedure, there is disagreement between the parties as to whether and how Ms. Hillis’ pre-operative opiate use was taken into consideration in planning her anaesthesia for the procedure.

[172] It is undisputed that, at the time of the procedure, Ms. Hillis had a prescription for M-Eslon, a type of morphine used to treat her chronic pain. It is also undisputed that her prescription for the M-Eslon was for a dosage of 90mg, three times per day. This dosage is noted in the Pre-Admission Assessment Report and in the Interdisciplinary Clinical Notes signed by the pharmacist.

[173] What is in dispute and has bearing on this case is two-fold. First, the amount of M-Eslon that Ms. Hillis told Dr. Ghaffari she took on the morning of the procedure is disputed. Second, the parties disagree about whether Dr. Ghaffari correctly accounted for Ms. Hillis’ pre-operative opiate use when he administered her anaesthesia.

[174] Whether Dr. Ghaffari correctly accounted for Ms. Hillis’ pre-operative opiate use is a matter to be explored within the standard of care analysis laid out later in this decision. For the time being, it is necessary to establish how much M-Eslon Ms. Hillis told Dr. Ghaffari she was taking daily at the time of the procedure.

Positions of Parties

[175] Ms. Hillis does not have an independent recollection of meeting with Dr. Ghaffari on the morning of the procedure, let alone a recollection of specifically what she told him during that meeting with respect to her opiate use. However, Ms. Hillis was adamant during testimony that she would not have described her daily opiate use as anything different than what was prescribed to her. When challenged on cross-examination that she had told Dr. Ghaffari that she’d taken 30 mg of M-Eslon the morning of the surgery, Ms. Hillis said:

No. There’s no way. I took my 90 milligrams. I would never take something less than what I’m supposed to take, and then tell a doctor totally wrong amounts when I’m going under, under for surgery. That’s insane.

[176] Ms. Hillis testified that she had been on the 90 mg three times daily dose of M-Eslon since at least the year 2000.

[177] The Defendants submit that Ms. Hillis actually told Dr. Ghaffari that she was taking a total of 30 to 60 mg per day of M-Eslon at the time of the procedure.

[178] Further, the defence argues that Ms. Hillis is regularly inconsistent in the dosage that she reports to medical professionals and that as a result her testimony on this issue is unreliable.

Findings on Opiate Use

[179] There were a number of documents submitted relevant to Ms. Hillis’ pre-operative opiate use. In addition, both Ms. Hillis and Dr. Ghaffari testified about their position on the pre-operative opiate use.

[180] The following documents were submitted as evidence relevant to Ms. Hillis’ pre-operative opiate use:

▪ Dr. Ghaffari’s note on the Anaesthetic Record, dated December 15, 2008

▪ P.A.C.U. Nursing Record dated December 15, 2008

▪ Consulting Physician’s Note from Dr. Nocent, dated March 21, 2003

▪ Recommendation from Dr. Gladstone of Gladstone Headache Clinic dated June 22, 2007

▪ Note from psychiatrist, Dr. Sarah Hales, dated May 27, 2009

▪ Record printed by Dr. Saul Stern, printed on September 29, 2010

▪ Letter from Dr. Hoffman dated February 4, 2010

▪ Consultation note dictated by Dr. Bair on December 20, 2010

▪ Note handwritten by Ms. Hillis re: medications to take the morning of the procedure

[181] Dr. Ghaffari made a note of Ms. Hillis’ dose of M-Eslon on the day of the surgery, contemporaneously to meeting with her to discuss her medication history and the anaesthesia plan and prior to the surgery. Dr. Ghaffari’s note is difficult to read, but he testified about what he had written:

…morphine – on top of morphine I wrote down ’30 to 60 mg per day’, and, under it I said, ‘M-Eslon for chronic pain’ which means that, that morphine – morphine and M-Eslon as the same – so, for chronic pain.

[182] Dr. Ghaffari was asked why he made the notation, and he answered as follows:

So, we, we have some numbers, different numbers in the chart, what – the patient was insisting that she is taking 30 to 60 mg/day at the day of surgery, and, although the patient, ahm, usually the, although we have all the prescriptions, as I said, for the chronic pain patient, the best reference at the end of the day is what patient says and what patient says she’s taking, so that’s what patient insist and said to me on the day of surgery. You see there is a little marking here – I first I was writing the dose that was on the chart, but she was insisting that she, she is taking 30 to 60 mg per day.

[183] When this encounter was put to Ms. Hillis on cross-examination, she insisted that she would not have told Dr. Ghaffari that she was taking anything other than 90 mg of M-Eslon, three times per day. She had no independent recollection of their conversation.

[184] In addition to Dr. Ghaffari’s contemporaneous note, there is also a note in the P.A.C.U. Nursing Record attached to Ms. Hillis’ chart, which, under “Patient Problems and Nursing Instructions,” includes a note that said “morphine 30-60 mg OD!” “OD” in this context, would appear to be used on the chart to refer to a “once daily” dose of morphine.

[185] In the Consulting Physician’s Note, dated March 21, 2003, Dr. Nocent makes a notation that Ms. Hillis is taking 75 mg of morphine (M S. Contin) three times per day. Three times per day is represented by the accepted medical abbreviation “TID.”

[186] This note was put to Ms. Hillis and she did not dispute that the note would have been accurate at the time that it was made. Rather, Ms. Hillis said that she “can’t remember every thing” and said “I mean, we were going back seven years. Or six and a half years.” This was a different narcotic and different drug. This contradicts Ms. Hillis’ evidence that she had been taking the same drug and dose since 2000.

[187] In his recommendation letter, Dr. Gladstone wrote the following with respect to Ms. Hillis’ chronic opiate use:

… Impression:

According to the International Headache Society Diagnostic Criteria, the only diagnosis that can be made at this time is probable chronic migraine headache and probable medication overuse headache (secondary to MS Contin and frequent triptan use). The contribution from medication overuse cannot be sorted until the medications are eliminated. As such, while she may well have chronic migraine this remains uncertain in the face of her significant medication use.

Recommendations:

3. Her headaches are unlikely to ever improve substantially while on chronic narcotics. It is well known that individuals with migraine are susceptible to medication overuse or rebound headaches. As such, when narcotics are used for other means such as fibromyalgia, this makes the situation tremendously difficult to manage. So, from a headache perspective I would like to see her off all narcotics. I do not know if this is obtainable and she might well be a chronic pain patient indefinitely.

[188] Ms. Hillis agreed at trial that Dr. Gladstone had recommended that she stop taking narcotics.

[189] In a note following Ms. Hillis’ meeting with psychiatrist Dr. Sarah Hales, Dr. Hales included a list of Ms. Hillis’ medications. The note read as follows:

Medications: CITALOPRAM 10 mg. daily, TEMAZEPAM 30 mg. q.h.s., M-ESLON 60 mg. q.a.m., 30 mg. q.afternoon and 90 mg. q.h.s. and TOPAMAX 300 mg. q.h.s., HYDROCHLOROTHIAZIDE 50 mg. daily, DOMPERIDONE 20 mg. t.i.d., RABEPRAZOLE 20 mg. b.i.d., SENOKOT, LACTULOSE and TETRACYCLINE 250 mg. b.i.d. [Emphasis added.]

[190] In the note written by Dr. Hales, the abbreviations can be taken to mean that Ms. Hillis’ M-Eslon dosages are 60 mg in the morning, 30 mg in the afternoon and 90 mg nightly. When asked if this record was correct, Ms. Hillis said “No, it’s not. I was taking 90 three times a day. They can look at my family records from Dr. Stern.”

[191] Ms. Hillis said that the “90 at night time” was correct, but “the rest is incorrect.” When asked if Dr. Hales had it wrong, Ms. Hillis responded that she did.

[192] Dr. Stern printed Ms. Hillis’ medical record on September 29, 2010. On the first page of that record, Ms. Hillis’ medications are listed, including “M-Eslon 90 mg tid Quantity* 90 x 60 mg, 90 x 30 mg, Mar 17, 2008.”

[193] The defence took the position that where Dr. Stern’s records indicated the date of March 17, 2008, it should be taken as the date from which Ms. Hillis was receiving the recorded doses. The Plaintiff took the position that the date was only referring to the date that the note was being made by Dr. Stern. The issue was not argued at length and I give no weight to the date in this record.

[194] The letter written by Dr. Hoffman dated February 4, 2010 references the medications that Ms. Hillis is taking as follows:

…However, she reported that she currently takes the following medications:

Frobatriptan 2.5 mg for migraines, which she was taking prior to the surgery but which are no longer effective. She was allowed “two a day but they don’t help now.”

Buproprion SR 150 mg one pill twice daily which she has been on for about 2 months

Citalopram currenetly [sic] 60 mg once daily which she had been on for two years prior to this incident and 10 mg prior to the surgical incident [and] 60 mg for the past three months

Morphine 90 mg at bedtime and 60 mg at lunch and 30 mg in the morning for pain, which she has been on “for a few years” prior to this incident (Oxycontin) Cesamet low dose for pain, perhaps 0.1 mg per day for “the fibro and migraines” which she has been on for about 1.5 years before the surgical incident

Domperidone for reflux and “for my stomach” which she had been on for 2 years prior to this incident

[Emphasis added.]

[195] When this document was put to Ms. Hillis in cross-examination, she argued that it was inaccurate, stating “But I wasn’t taking, I’ve never been taking 30 in the morning. No. I know what the document says, yeah. It doesn’t look good.” She also indicated that she had tried to reduce her morphine intake historically, although she did not say this in chief.

[196] Dr. Bair wrote a consultation letter subsequent to performing a colonoscopy on Ms. Hillis in 2010. The letter, dictated on December 20, 2010, notes Ms. Hillis’ medications as follows:

She is on a number of medications and had been using a proton pump inhibitor, Elavil, Senokot 4 tablets b.i.d. which is a higher dose than I would recommend verapamil, Topamax, Relpax, tetracycline, hydrochlorothiazide, domperidone 20 mg q.i.d., lactulose, Naproxen, iron supplementation, and Seroquel. The patient has also been using morphine 60 mg in the morning, 30 in the evening and [is using] TUMS on a near daily basis due to reflux type symptoms. She has intolerance to OxyContin. [Emphasis added.]

[197] When asked about Dr. Bair’s note, Ms. Hillis said:

Well I didn’t tell him what I was taking – I, I’m going to stick with what I’m saying. I take 90, three times a day, and that’s it. That’s what I’ve always been taking.

[198] Ms. Hillis provided as evidence a handwritten note that she had taken at a consultation prior to her surgery. In the note, she listed the medications that she was to take on the day of the surgery:

take morning of surgery at 6am:

m-Eslon 90 mg

novo Hydrazide 2 tablets

Ron-Rabeprazole (1) a breakfast x 2/50 (2)

No naproxen 5 days before surgery

[Emphasis added.]

[199] Dr. Ghaffari testified that despite Ms. Hillis’ insistence that she was taking 30 to 60 mg per day of M-Eslon, he “covered her, her needs up to the, the amount that was charted in the chart.” Dr. Ghaffari reiterated this when he was testifying as to what he and Dr. Meineri had discussed when reviewing Ms. Hillis’ treatment plan. He said that he mentioned to Dr. Meineri that Ms. Hillis was reporting a dosage of 30 to 60 mg per day, but that the history in the chart was “90 mg, so, we are going to cover all, all of the needs, according to the respond [sic]…of the patient for being stable.”

[200] Clearly, the evidence presented by the parties on what Ms. Hillis told Dr. Ghaffari about her pre-operative opiate use is incongruous. Ms. Hillis’ prescription for M-Eslon sets the dosage at 90 mg, three times per day. However, Ms. Hillis’ position that her dose had been consistent since at least 2000 cannot stand.

[201] Ms. Hillis was inconsistent throughout her testimony on this issue and did not convince me that she was taking the dosage set out in her prescription at the time of the procedure. As with the Propofol infusion rate, the inconsistencies in recollection lead me to rely on the written record made contemporaneously to the procedure.

[202] Dr. Ghaffari’s note on the Anaesthetic Record is difficult to read, but Dr. Ghaffari testified that he had written that Ms. Hillis was taking 30 to 60 mg per day of M-Eslon. Taking this in conjunction with the P.A.C.U. Nursing Record note which also records Ms. Hillis’ daily dose as 30 to 60 mg per day, I am satisfied and find as a fact that this is the dose that Ms. Hillis reported to the medical professionals on the day of her surgery.

[203] I find that Ms. Hillis told Dr. Ghaffari that she was taking 30 to 60 mg per day of M-Eslon at the time of her surgery.

II. Standard of Care

[204] I will begin under standard of care with the position of the parties, then describe the two experts and make some general observations regarding their testimony and summarize each expert’s evidence not specific to the four standard of care issues I will discuss in detail. I will then deal specifically with the standard of care as it relates to Dr. Meineri’s supervision of Dr. Ghaffari, then the standard of care regarding Ms. Hillis’ preoperative use of Temazepam, then the standard of care regarding Ms. Hillis’ preoperative use of narcotics, and finally the standard of care regarding the administration of Propofol.

[205] Both Dr. Esufali and Dr. Noble agree that Dr. Ghaffari and Dr. Meineri, having reviewed Ms. Hillis’ Pre-Admission Assessment Report and, in Dr. Ghaffari’s case, having conducted a pre-operative consultation with Ms. Hillis, had all of the information necessary to exercise their clinical judgment. They agree that both Dr. Ghaffari and Dr. Meineri turned their minds to the right things when they were formulating the anaesthetic plan. It is clear from the Plaintiff’s submissions that the only features of the experts’ opinions that remain in issue are Dr. Ghaffari’s dosage of intraoperative pain medication relating to Ms. Hillis’ pre-operative use of M-Eslon and Temazepam, Dr. Ghaffari’s administration and management of Ms. Hillis’ intraoperative Propofol and Dr. Meineri’s supervision of Dr. Ghaffari. I will therefore focus on these issues in the standard of care analysis and not on what is agreed to by the experts.

1) Positions of the Parties

a) Plaintiff’s Position

[206] It is the Plaintiff’s position that Drs. Ghaffari and Meineri did not meet the required standard of care in their treatment of Ms. Hillis for a number of reasons.

[207] Against Dr. Ghaffari, the Plaintiff submits that he did not meet the standard of care because:

▪ He used an inadequate amount of Propofol throughout the procedure, but especially between 8:00 a.m. and 9:15 a.m., when the Propofol infusion rate was 50 mics/kg/min.

▪ He failed to administer additional anaesthetic agents in a timely and effective manner after he reduced the amount of nitrous oxide from 1.5 (53 per cent) to .5 (17 per cent) between 8:45 a.m. and 9:00 a.m.

▪ He failed to administer a bolus of Propofol upon reducing the nitrous oxide to ensure that Ms. Hillis remained properly anaesthetized.

▪ He failed to utilize the step-down method for both the initial infusion of Propofol at the beginning of the procedure and at the point where the nitrous oxide was reduced between 8:45 a.m. and 9:00 a.m.

▪ He failed to appreciate that the reduction of nitrous oxide would have an immediate impact on the patient’s level of awareness unless counteracted by the immediate administration of another anaesthetic agent, such as Propofol.

▪ He failed to take into account the patient’s pre-operative opiate use and her use of other prescriptive pain medication in choosing both the infusion rates for the main anaesthetic agents and in respect of the intraoperative pain medication given to Ms. Hillis. He chose inadequate amounts of both. This resulted in inadequate amounts of analgesic that, in turn, exacerbated Ms. Hillis’ pain experience.

▪ The overall effect of these errors resulted in Ms. Hillis experiencing a period of awareness with pain during her surgery. This period of awareness could and should have been avoided if Dr. Ghaffari had used suitable amounts of anaesthetic agents and had administered those agents in an effective manner.

[208] Against Dr. Meineri, the Plaintiff submits that Dr. Meineri fell below the standard of care as the assigned, responsible anaesthetist for Ms. Hillis, and as supervisor of the care given by Dr. Ghaffari during Ms. Hillis’ robotic hysterectomy. Specifically, the Plaintiff argues that he did not meet the standard of care because:

▪ He did not specifically review with Dr. Ghaffari the dosages of anaesthetic agents that Dr. Ghaffari planned to use. Had he reviewed those dosages, it would have been apparent to him that they were inadequate and he would have, therefore, instructed Dr. Ghaffari to use higher doses of the anaesthetic agents, in particular, Propofol. This, in turn, would have, in all likelihood, avoided Ms. Hillis’ period of awareness.

▪ He provided no supervisory function in reviewing and overseeing Dr. Ghaffari. Dr. Meineri should have appreciated that Dr. Ghaffari had limited experience with TIVA and required a more in-depth review of his anaesthetic plan.

▪ Dr. Meineri did not appreciate Ms. Hillis’s pre-operative opiate use and had he done so, he would have instructed Dr. Ghaffari to increase the amounts of intraoperative analgesics given to Ms. Hillis.

b) Defendants’ Position

[209] The Defendants’ position is that there is a known risk of intra-operative awareness under TIVA and general anaesthesia more broadly. This risk regrettably manifested in Ms. Hillis’ case. The Defendants submit that it is easy and convenient, peering backwards with the advantage of hindsight, to try to apportion blame. Their position is that the standard of care should not be assessed retrospectively. The presence of intra-operative awareness does not mean the Defendants’ conduct or approach to Ms. Hillis’ anaesthetic was negligent.

[210] To the contrary, the Defendants argue that Dr. Ghaffari, carefully and thoughtfully administered a general anaesthetic to Ms. Hillis during her surgery. Dr. Ghaffari was required to and did use TIVA (as opposed to traditional inhaled general anaesthetic) due to Ms. Hillis’ malignant hyperthermia. He exercised his clinical judgment and administered an anaesthetic that fell within the appropriate therapeutic dose ranges and that produced reasonable anaesthetic blood concentrations.

[211] The Defendants’ position is that Dr. Ghaffari used a balanced approach to TIVA, which capitalizes on the synergistic properties of the various classes of anaesthetic agents, while making contemporaneous dose adjustments (i.e. “titrating” anaesthetic agents) and administering adjunct anaesthetic agents through the procedure based on Ms. Hillis’ real-time clinical response. They argue that Dr. Ghaffari, as the anaesthetist administering the anaesthetic, was in the best position to exercise his clinical judgment in altering Ms. Hillis’ anaesthetic doses intra-operatively.

[212] They submit that Dr. Ghaffari appropriately relied on Ms. Hillis’ real-time vital recording and his observations of Ms. Hillis’ clinical response while administering the anaesthetic and that this approach was reasonable and consistent with the standard of care, as no other reliable measurement device was available to monitor depth of anaesthesia when using TIVA.

[213] The Defendants’ position is that the Defendant, Dr. Meineri, was scheduled as the staff supervisor on Ms. Hillis’ case. He was simultaneously scheduled by the anaesthetic scheduling coordinator on a complex transesophageal echocardiogram that required his direct involvement. Because Dr. Ghaffari had demonstrated himself to be a responsible and capable Fellow, Dr. Meineri’s view was that Dr. Ghaffari could conduct Ms. Hillis’ TIVA alone. Dr. Ghaffari’s experience was precisely why Dr. Meineri was able to be staffed on two procedures.

[214] The Defendants’ position is that Dr. Meineri met the standard of care as a supervisor because he appropriately discussed Dr. Ghaffari’s anaesthetic plan with him, reviewed the status of the procedure shortly after its commencement, and otherwise made himself available for further consultation in the event Dr. Ghaffari required it. Dr. Meineri appropriately deferred clinical judgment calls regarding doses and infusion approaches to Dr. Ghaffari, as Dr. Ghaffari would be in the best position to make such decisions as the only anaesthetist with the entirety of Ms. Hillis’ contemporaneous clinical picture.

[215] In summary, the Defendants’ position is that the Plaintiff has failed to meet her burden of demonstrating that Dr. Ghaffari or Dr. Meineri was negligent in their management of Ms. Hillis’ case or that any specific breach of the standard of care caused Ms. Hillis’ episode of awareness. The expert evidence demonstrates that the standard of care was met and that, in any event, the alleged breaches did not cause Ms. Hillis’ awareness.

[216] The Defendants state that Dr. Meineri and Dr. Ghaffari are not to be judged with the benefit of hindsight and knowledge of the outcome.

2) The Expert Witnesses

Plaintiff’s Expert: Dr. Esufali

[217] The Plaintiff’s expert, Dr. Zakir Esufali, testified at length about the treatment given by Drs. Ghaffari and Meineri to Ms. Hillis.

[218] The Defendants argued in their submissions that Dr. Esufali presented as an advocate and was not a neutral expert. They state that this was revealed by his antagonistic and flippant demeanor towards opposing counsel and in his selective treatment of the evidence and literature. I disagree with this characterization of Dr. Esufali.

[219] I did not find Dr. Esufali to be argumentative. He was under cross-examination for a significant period. At times he became frustrated but this did not make him an advocate. I found Dr. Esufali to be ready to acknowledge when his evidence in chief required modification. He did calculations based on assumptions put to him by both the Plaintiff’s counsel and Defendants’ counsel. He did not overstate his experience. He readily admitted he had relied on an outdated text and adjusted and redid his calculations to reflect the updated text. He did not attempt to defend his position inappropriately. He acknowledged when he made errors. For example, he acknowledged he could have benefited from reviewing the Statement of Defence which he was not provided with. In my view, this does not undermine his evidence as he had knowledge of the positions of the Defendants from reading all of the other documents he was provided with, including their discovery transcripts. Dr. Esufali also readily acknowledged that he did not put in his report reference to the 30 – 60 mg once daily of pre-operative opiate use that had been noted in the hospital record (Dr. Ghaffari’s note on the Anaesthetic Record and the post-operative nursing note). I am not satisfied that this was indicative of him being an advocate for the Plaintiff. He also acknowledged an error in his report in referencing Dr. Ghaffari’s evidence at his examination for discovery as to the Propofol infusion rate. In my view, this is not a significant error given that my finding of fact on the Propofol infusion rate is more consistent with Dr. Esufali’s assumption and is not consistent with Dr. Ghaffari’s evidence.

[220] Further, on the critical issue of the standard of care in the infusion of Propofol, Dr. Esufali’s evidence was based on the assumption that the infusion rate was 50 mics/kg/min at least until the first up arrow. This is consistent with the factual finding I made above. This is important as Dr. Noble’s entire evidence in regard to the standard of care in the infusion of Propofol assumed an infusion rate of 100 mics/kg/min from right after intubation. This assumption was not factually correct. I will have more to say on this below under Propofol.

[221] Dr. Esufali was granted his Fellowship in the Royal College of Physicians in June of 2004. He became a staff anaesthetist at Toronto East General Hospital in July of 2004, where he stayed until May of 2006. During his time at Toronto East General, Dr. Esufali ran operating rooms on his own as well as acting as a supervisor for medical Residents. Dr. Esufali testified that during his time at Toronto East General, his practice included the use of TIVA.

[222] From May 2006 until the time of his testimony at trial in June of 2015, Dr. Esufali was a full-time staff anaesthetist at Scarborough General Hospital. During the same time period, Dr. Esufali was an associated anaesthetist at the Trillium Health Sciences Centre and the Lakeridge Health Sciences Centre, both of which he attended about once a month. Dr. Esufali has been actively involved in the teaching of medical students and Residents throughout his career as a staff anaesthetist. Dr. Esufali’s practice throughout his time at Scarborough Hospital has also included TIVA.

[223] At the time of trial, Dr. Esufali estimated that he had administered TIVA between 100 and 200 times, and that less than ten of these 100 - 200 patients had malignant hyperthermia.

[224] Dr. Esufali was qualified at trial as an expert to provide the court with opinion evidence with respect to the care and treatment of Ms. Hillis, the standard of care of a prudent anaesthetist, the standard of care of a prudent supervising anaesthetist, and generally all matters relating to anaesthesia.

[225] Dr. Esufali’s qualification with respect to the supervisory relationship between a Fellow and a supervisor was grounded in his experience as a Fellow since he had not supervised any Fellows himself. I address this issue within my findings on the supervision issue below.

[226] Dr. Esufali described the likelihood of intra-operative awareness under general anaesthesia as being about one in 1,000 or 2,000 cases. He said that the likelihood may increase with a very sick patient or a trauma patient who has lost a lot of blood.

[227] Dr. Esufali testified about a concept in anaesthesia called “Minimum Alveolar Concentration,” or “MAC.” He explained the concept as follows:

A. So if we use these MAC values, and MAC values are additives for different agents, so if we’re using nitrous oxide at say, 50%, that’s half a MAC, because we know nitrous oxide – it has a MAC of about 104%. So if you’re at 50%, you’re at half a MAC. And then if you use half of a MAC of, if you use half of a MAC of say, halothane, and you have half a MAC of one and half a MAC of another, that’s one MAC. And the MAC is equal to, is equal to the amount of anaesthetic, amount of anaesthetic that is needed to prevent any movement from skin incision in half the population.

Q. Right.

A. And then 1.2 MAC – it covers everybody, basically if you have 1.2 MAC nobody’s going to move. At one MAC, is a pretty good – if you start up and you dial up and you go to a MAC, you’re probably going to cover most people. If they move a little bit, you turn it up, right? And of course, you’ve got adjuncts. You’ve got some fentanyl, you’ve got some propofol.

[228] Dr. Esufali explained that MAC concentration levels are applicable where typical gas anaesthesia is used, but where, as in Ms. Hillis’ case, TIVA is used, it is more difficult to reliably measure whether a patient is receiving adequate anaesthetic doses. His evidence was as follows:

A. But, when it comes to intravenous drugs, intravenous drugs are, are a lot less reliable.

Q. What’s the reason for that?

A. The reason is because, is because the inhalation drugs – we have the, on the breathing circuit, we have the ability to measure the concentrations that are coming out at every breath. And so we can tell, and we can measure the MAC and we can make an estimate. If it’s an intravenous drug, we would have to draw a concentration from a patient’s arm, we’d send it to the lab, and in that time, that concentration is probably changing, and so we have no way of knowing at any one point in time, how much of that drug is in the patient. And then between patients, there’s a lot of variability.

[229] Dr. Esufali went on to explain that the difficulty in measuring is why anaesthetists tend to use nitrous oxide to complement TIVA.

…there’s a lot less, a lot less, it’s a lot less reliable when you’re using intravenous anaesthesia alone. And so that’s why, even with intravenous drugs, we tend to use nitrous oxide to, to, have at least some – a little bit of a safety net. Because you could say, okay, I’m delivering 60% nitrous oxide, I got .6 MAC, and usually awareness is prevented at around .8 of a MAC. So if you have .6 MAC of, if you have .6 MAC of nitrous oxide, and you supplement with a little bit of other stuff, you’re probably going to be okay.

Even though there is a lot of unreliability in the intravenous drugs, we do have some guidelines which, which can help us, which can help us greatly.

[230] In cross-examination, Dr. Esufali confirmed that an anaesthetist cannot safely rely on nitrous oxide alone to reach 1 MAC because it would suffocate a patient. He said that the appropriate amount of nitrous oxide to use during TIVA was 67 per cent in conjunction with Propofol or a narcotic infusion.

[231] During testimony, 67 per cent nitrous oxide was calculated to be .64 of a MAC, and so when Dr. Ghaffari was giving Ms. Hillis 53 per cent nitrous oxide, this was calculated to be about 80 per cent of the maximum dose of nitrous oxide. When Dr. Ghaffari was administering 17 per cent nitrous oxide, this was calculated to be 25 per cent of a maximum dose of nitrous oxide.

[232] Dr. Esufali agreed that the cumulative effect of providing all of the agents that were given to Ms. Hillis during surgery was that the requirements of each individual agent were reduced.

[233] Dr. Esufali testified that the combination of Versed, Fentanyl and the Propofol bolus injection and the Rocuronium are what put Ms. Hillis to sleep at the beginning of the procedure. He said that where Dr. Ghaffari had the nitrous oxide concentration set to 53 per cent, Ms. Hillis was receiving adequate doses of other medications in conjunction with the nitrous oxide, such that her anaesthetic needs were met. It was Dr. Esufali’s opinion that when the nitrous oxide levels were reduced, Ms. Hillis was not receiving a sufficient amount of other medication to keep her anaesthetized. This is the issue that will be discussed in detail below under Propofol and that is disputed by Dr. Noble.

[234] Dr. Esufali calculated the new concentration of nitrous oxide beginning around 8:45 a.m. to be about 16 per cent. As for the implications of reducing the concentration from 53 per cent to 16 per cent, Dr. Esufali said the following:

A. So it’s providing less analgesia, but it’s also providing, it’s also taking away, it’s also taking away amnesia. And that is the one thing that, in this case, is obviously the concern.

Q. So what effect does that have, then, on the patient?

A. So the patient, in a patient who’s paralyzed, and now, and now has far less amnesia, is now going to remember things that happened in the operating room…

[235] On cross-examination, Dr. Esufali agreed that he couldn’t say exactly how long it would have taken for the nitrous oxide levels to go down because this would depend on the flow rate of the gas, which he did not have access to. However, he was clear that from his experience, “it’s relatively quick; in the order, in the order of a few minutes." He estimated that the whole process would be five minutes or less. I will address this further below.

[236] Later, he elaborated on what it would mean for a patient to have a nitrous oxide concentration of 17 per cent (sometimes 16 and sometimes 17 was used but it makes no difference according to Dr. Esufali and Dr. Noble did not dispute this).

Q. Right. So can you put in context for us, what the 17% nitrous oxide means to a patient in the circumstances of Ms. Hillis, during this operation? What, if any…

A. Well if we go back to the concept, if we go back to the concept of minimum alveolar concentration, or MAC, which is quite well-known for the inhaled anaesthetics, and the anaesthetic gases. So 0.16 MAC, which is 17% [sic] nitrous oxide is, is in other words, in other words, 16% of an anaesthetic dose that would, it would, it would prevent, would prevent half of the patient[s] from moving to surgical stimulation. It’s only 16% of that dose. And in terms of awareness, because we always try to achieve anaesthesia, no just amnesia. However, however the, of the amount of anaesthetic you need to achieve amnesia is actually less, is actually less than how much you need to achieve anaesthesia. So if you’ve achieved anaesthesia, you don’t have to worry about amnesia.

Q. All right.

A. An, and really, as anaesthetists, our goals are to achieve anaesthesia. If you want amnesia, approximately 75% of a dose of an anaesthetic is going to give you amnesia. So if you take, if you take – so that means, so that means 75% of a MAC value of any drug is going to produce amnesia in half your patients.

Q. Right.

A. So that means .16 MAC or approximately 20% of the amnestic dose that’s going to produce amnesia in half the patients…

Q. Yes.

A. …is what she got.

Q. Yes.

A. She only got 20% of an amnestic dose that’s going to produce – if you take the amnestic dose that’s actually going to produce amnesia in half the patients, she only got 20% of that dose.

Q. What’s the implication, then, as far as...

A. Well the…

Q. …as far as awareness is concerned.

A. So the implication is, is I mean she was, she was well under the spectrum of amnesia. I mean she was easily aware, if she only had the nitrous oxide on board. Now she had the propofol infusion, albeit at a small rate, and she did not have many other adjuncts, in this time between 9:00 o’clock and 10:00 o’clock. She really didn’t have much else in terms of things for her amnesia.

[237] While discussing the appropriate Propofol concentration range during cross-examination, Dr. Esufali explained the literature as follows:

[T]he actual original literature on Propofol infusions, show that 3 to 4 ‘mics’, 3 to 4 ‘mics/ml’, if you combine, if you come out with 67 percent Nitrous Oxide, or, or a potent narcotic... That combination is able to provide a satisfactory anaesthesia in 50 percent of the patients…

[238] Dr. Esufali agreed to the following question put to him on cross-examination with respect to a reasonable starting infusion of Propofol:

Q. And, what I’m getting at is, you’ll agree with me, it’s reasonable, as a starting, prospective proposition to give a patient a dose which will, through the various research and theories, result in a 3 to 4 mcg/ml plasma concentration, and then, to use your skills as an anaesthetist to watch how that patient reacts and dictate what you’re going to do next, right?

A. Yes.

[239] As part of Dr. Esufali’s opinion, he reviewed the anaesthetic doses received by Ms. Hillis during a 2003 breast reduction and abdominal liposuction in comparison with the 2008 procedure. Dr. Esufali said that the 2003 procedure would have been a less painful surgery than Ms. Hillis’ 2008 procedure, and thus the requirement for pain medication would have been increased in 2008.

A. And I think, I think the biggest thing that I’d calculated here that – if you take, if you take, if you take 80% of a full anaesthetic as the dose you need to produce amnesia, in 2003 in the whole operation, she received 63% of the amnestic dose from the nitrous oxide. So two thirds of the amnesia came from the nitrous oxide. And she got – and all the other agents were the same – pretty well. They were pretty close. And in 2008, she only, in 2008 for approximately two thirds of the operation, she only got… 21% of an amnestic dose. And so the other 80% of the amnesia had to come from somewhere else. And considering she got the same amount of all the other drugs, if not a little less, that would – it’s a clear explanation.

Q. Clear explanation for the fact that…

A. It’s a clear explanation why in 2003 there was not awareness, and in 2008 there was.

[240] Dr. Esufali was asked in his examination in chief to review his conclusions with respect to the factors involved in Ms. Hillis’ intra-operative awareness.

A. I said, ‘In summary factors that contributed to Ms. Othen’s episode of awareness under anaesthesia are as follows: Number 1. Failure of Dr. Ghaffari and Dr. Meineri to appreciate Ms. Othen’s greatly increased demand for anaesthesia.’

A. That relates to her pre-operative use of, her pre-operative use of, of chronic opioids. Which was 90 milligrams three times a day, a very high dose. And the fact that she was on temazepam, a benzodiazepine, and also the fact that she was very, she was also a very young patient.

A. Number 2. Failure of Dr. Ghaffari and Dr. Meineri to use appropriate benzodiazepines and narcotics. So I mean, I think the benzodiazepine…use was initially sufficient, the 2 milligrams, but I think especially when the nitrous oxide was decreased, further benzodiazepines should have been administered, and I’ve already talked about the narcotics. How it was definitely for a patient who is not narcotic naïve. I think that the narcotic that was given was definitely too low.

Q. Next.

A. Failure of Dr. Ghaffari and Dr. Meineri to administer TIVA correctly. So, so that would relate to the failure to use a step-down infusion model, and also the failure when giving increases in propofol concentration to also administer a bolus so your plasma levels don’t have, you don’t have a lag period before they’re at that next concentration you want to achieve.

A. So the failure of Dr. Ghaffari and Dr. Meineri to appreciate the greater patient variability, the greater patient variability with TIVA as compared to traditional anaesthetics. And what that means is, unlike our dialed in anaesthetics in the anaesthesia machine, the – we have no way of knowing at any one point in time, what the plasma level of these, of the propofol is, so we need to be, so we need to, to appreciate that, and to, and to perhaps even give more than you, even give more than an…average dose and you can always cut back a little if you need to, but just to know that if I give a certain dose, you know, the plasma concentration may not be – and in this case, it’s reasonable to think a higher dose is also expected because of a young patient who is going to clear the…propofol very quickly from her plasma... And last one was, failure of Dr. Ghaffari and Dr. Meineri to administer a relatively larger dose to make sure that Ms. Othen received a complete anaesthetic, especially since there was no reason not to do so. There was no instability in terms of blood pressure. And there was no problem with oxygenation. It could have been very safe to give, you know, to give a higher dose, and especially with our drugs, especially with our drugs these days, nausea and prolonged awakening are not, are extremely small issues, because these drugs do have short half-lives.

[241] Dr. Esufali never claimed that intra-operative awareness could be avoided with 100 per cent certainty, and he agreed that “an anaesthesiologist’s obligation is to honestly, and intelligently exercise his or her medical judgment, in the circumstances.”

[242] Dr. Noble also testified that at the time of Ms. Hillis’ surgery in 2008, there was no way to avoid awareness with 100 per cent certainty.

[243] As set out above, in terms of the totality of information that an anaesthetist looks to obtain about a patient prior to a procedure, Dr. Esufali agreed that factors may include height, weight, medication use, social history, dental information, comorbidities, past anaesthetic procedures and allergies. Dr. Esufali further agreed that the Pre-Admission Assessment Report dated December 8, 2008 contained all of the relevant pieces of information available at the time that Drs. Ghaffari and Meineri would need to formulate an anaesthetic plan.

[244] Dr. Esufali agreed that “the doctor who is meeting with, listening, and making observations, he or she is in the best position to make an exercise of clinical judgment when formulating a plan.”

Defendant’s Expert: Dr. Noble

[245] The expert for the Defendants, Dr. William Noble, also testified about the treatment given to Ms. Hillis by Drs. Ghaffari and Meineri.

[246] Dr. Noble received his Diploma of Anaesthesia from the University of Toronto in 1969. He became a Fellow of the Royal College of Physicians of Canada in 1969 and retired on July 1, 2007. He was involved in the clinical practice of anaesthesia for almost 40 years, with the entire time of his practice at St. Michael’s Hospital at the University of Toronto (“St. Mike’s”). His career involved both teaching and practicing anaesthesia.

[247] From 1975 to 1983, Dr. Noble was the Director of the ICU at St. Mike’s. From 1980 to 1986, he was the Director of the Department of Anaesthesia, and from 1982 to 1992, Dr. Noble was the Director of Research for the Department of Anaesthesia University of Toronto.

[248] Dr. Noble testified that he worked with Residents or Fellows “constantly” throughout his career and that he was involved in their training. When asked how many Fellows he had worked with in his career, Dr. Noble estimated that he worked with 100 to 200 Fellows. He said that he was working with Fellows up until when he stopped his clinical practice in 2007. Dr. Noble described his role with Fellows as “in a very similar role…[as] between Meineri and Dr. Ghaffari.”

[249] When asked how he kept up-to-date with developments in the area of anaesthesia, Dr. Noble explained that because he was a Professor Emeritus, he had full access to the University of Toronto medical library. Further, he said that he continued to go on rounds for a period after he retired and has continued to read journals, and that his involvement in medical-legal cases requires him to research materials and remain updated. Dr. Noble said that after retirement he kept in regular contact with practicing colleagues.

[250] Dr. Noble also sat as an editor for the Canadian Anaesthetist’s Society Journal, which is an academic peer-reviewed journal. He has authored and coauthored numerous publications in peer reviewed journals and made many presentations over the course of his career.

[251] He said that he has previously been qualified as an expert in medical-legal proceedings and that he has authored reports on behalf of both plaintiffs and defendants.

[252] Dr. Noble testified that to his knowledge, there was no change to the standards with respect to administering anaesthetic using TIVA between his retirement date and the date of Ms. Hillis’ procedure. Further, he said that there was no change to the standard with respect to supervising Fellows during that time period.

[253] When asked how often he would use TIVA, Dr. Noble explained:

A. …I would like to divide that into two kinds of TIVA. There was the cardiac anesthesia – I was heavily involved in cardiac anesthesia, and, and most of those during my career were done under a TIVA, because inhaled anesthetics depress the heart too much and the patient wouldn’t tolerate it. But, there was a second form of TIVA which, the case we’re reviewing today, involves, which is to do with Malignant Hyperthermia, and, those two are different, and I was involved in both kinds of procedures.

Q. And, so, of all the TIVA that you’ve done – mindful of both categories – what percentage of TIVA that you’ve conducted would have been in that non-cardiac category?

A. It would be low, and I’m, again, I, I’m going to estimate, 10 to 20 percent?

[254] Dr. Noble was qualified as:

[A]n expert anaesthesiologist, qualified to opine on the standard of care of an anaesthesiologist in the Province of Ontario, in the year 2008, and, in particular – and in particular, with respect to the formulation of and administration of a TIVA general anesthetic, and the supervision of Fellows in a tertiary care centre.

[255] Dr. Noble summarized his opinion as follows:

Q. And, in summary, very briefly, what is your opinion?

A. That Dr. Meineri and Dr. Ghaffari met the standards of care required in giving the anaesthetic to Ms. Hillis in 2008.

Q. And, in summary, what is your opinion with respect to the supervision provided by Dr. Meineri?

A. That is also met the standard of care. It is a usual mechanism to create a, an opportunity for the recently trained, fully trained person to gain some confidence in his skills.

[256] With respect to the number of cases in which awareness under anaesthesia occurs, Dr. Noble said that it would be one in 1,000 patients.

[257] Before summarizing the non-contentious parts of Dr. Noble’s testimony there are some general observations regarding his testimony. These general observations are most relevant when I compare Dr. Esufali and Dr. Noble’s evidence on the administration of Propofol.

[258] First and foremost as set out above, Dr. Noble based his entire testimony on the standard of care in the administration of the Propofol on the assumption that Dr. Ghaffari raised the Propofol infusion rate from 50 mics/kg/min to 100 mics/kg/min immediately after Ms. Hillis had been intubated and in the first ten minutes of the procedure. This assumption permeates his evidence on the standard of care on the administration of Propofol. This assumption is inconsistent with my finding of fact above and this is significant and critical to my analysis. I will detail this below under the Propofol heading.

[259] I am also concerned that Dr. Noble confirmed in his oral testimony that he had put in his written report an assumption, that to maintain anaesthesia Propofol was infused at 50-170 mics/kg/min (two hours were at Propofol 100 mics/kg/min) in combination with nitrous oxide and oxygen. There was no evidence at the trial by any witness that there were two hours of Propofol infused at 100 mics/kg/minute under any scenario. This is inconsistent with the Anaesthetic Record and Dr. Ghaffari’s own evidence.

[260] A further concern, again specific to Propofol, was that Dr. Noble confirmed in cross that in his April 16, 2015 report he had stated “To compensate for this N2O reduction Dr. Ghaffari increased Propofol four times ...” Dr. Ghaffari’s own evidence was that after the nitrous oxide reduction he only increased the Propofol infusion rate three times. Dr. Noble responded by saying that what he was trying to imply was that “all of these things would compensate for the decrease in nitrous oxide” including the initial increase he assumed happened just after intubation and before the nitrous oxide was decreased. After several more questions he acknowledged the number was three which the plain reading of his report suggests is the correct number. The Defendants submitted Dr. Esufali was defensive and argumentative. However, in my view, Dr. Noble was less willing to acknowledge inaccuracies in his reports.

[261] I also found Dr. Noble’s assumption regarding Ms. Hillis’ pain experienced during her awareness to be problematic. Dr. Noble acknowledged in cross that he had written the following in his August 17, 2012 report:

Dr. Ghaffari and Dr. Meineri were restricted in their GA choices by Ms Othen’s problems. Analgesia was well managed by the choice of laparoscopic surgery (less pain), N20 and morphine to which was added fentanyl and hydromorphone. As a result, according to the post operative note, Ms. Othen’s main complaint was not of pain but that she could not move her finger or open her eyes and being awake.

[262] When asked about this and whether it contradicted a previous note in his report that summarized that Ms. Hillis had reported being in “excruciating pain”, Dr. Noble stated the following:

A. The patient who is in excruciating pain is hardly going to tell you all of the difficulties she had moving her fingers and not being able to open her eyes. Those kind of things would be very low on her problem list, and she would – excruciating pain would be the first and last words of what was her difficulty in the OR; would be my expectation. Doesn't prove that that's so, that's just my expectation.

A. But what I'm trying to do with that sentence is discriminate between pain and other complaints, and clearly, she has multiple complaints; I am not saying she doesn't have pain. Don't misinterpret what I am saying. I am saying that, if a reasonable person who is not experienced in anesthesia had an inability to move, couldn't communicate, was paralyzed – if all of those things were true – and she also had excruciating pain, what I'm trying to point out is, that there is a difference between those things. That excruciating pain would override all of the other symptoms that she is complaining about. I have no idea whether she had pain or all of these other symptoms. I believe she did have awareness under anesthesia and my difficulty is in understanding how she could be in excruciating pain, with the blood pressure, heart rate record, with the doses of narcotics that were given to her, but, is it possible? Absolutely. It certainly is possible. I am not denying she had pain.

[263] This suggests he did not accept as an assumption Ms. Hillis’ description of being in excruciating pain. In fact he says he is not absolutely certain whether she had pain or not. This minimized other evidence in this case. In Dr. Meineri’s letter to the surgeon, Dr. Rosen, dated January 16, 2009, Dr. Meineri described that “She felt pain for having something stuck in her abdomen but she could not move.”

[264] This note in Dr. Noble’s report understates Ms. Hillis’ evidence at her examination for discovery and particularly that the first thing she remembered after falling asleep was extreme pain in her stomach. She described it as “extreme tearing in my stomach,” “someone was inside me ripping, ripping me apart. It was excruciating. It was burning and burning and burning and burning.” When confronted with this Dr. Noble said:

A. Pain is a phenomena which, when you're having it, it could be all of those things, but, it is conceivable as well, that, and, and so, if it were all of those things, my expectation is – and it may be wrong; I'm not denying that – my expectation is, all the other things would become nothing in her memory, that is, she wouldn't remember not being able to move, she couldn't wiggle, she couldn't talk, she couldn't do any of those things because this was such an overriding – that's what she's describing – an overriding symptom; she couldn't do anything else but think of it. That is why, added to my knowledge – my personal experience with patients with awareness under anesthesia – that the ones that I had were aware, but they did not have pain, and so, I tried to put these two stories together. Was it possible that the person who examined her first would have the best crack at this; by that I mean, discriminating between pain and, and all the other symptoms that, that constitute awareness under anesthesia. The first person who asks that question can set it up, and, the patient will either say, 'Hmm, you know...' – and I have experienced this – '...you know, I don't really think I did have pain, but I had all these other symptoms,' and there is the problem.

A. I'm not denying that. I agree with you, but that's a memory, not – because we have, we have, in the examinations by – that was Dr. Meineri, I think – page 132, we have all these other symptoms. She, she remembered she woke up, she couldn't move a finger – well, on a scale of things I would remember, if I'm in excruciating pain, not being able to move my finger is hardly in that scale, and that's my problem. Please be aware, I am not saying she did not have pain; I am not saying she did not have excruciating pain. I'm trying to discriminate between the two possibilities.

[265] Dr. Noble acknowledged that the statement in his report was a mischaracterization of Ms. Hillis’ evidence and he said he was trying to explain why it’s possible that she didn’t experience as much pain as she is stating. This appears incompatible with Ms. Hillis’ description and her description was not contested by anyone – not by Dr. Ghaffari, not by Dr. Meineri and not by way of cross-examination of Ms. Hillis at trial. Dr. Noble indicated that he made this note in his report based on Dr. Meineri’s note to Dr. Rosen. If he did, he appears to have ignored other evidence describing Ms. Hillis’ pain.

[266] Dr. Noble further stated as follows with respect to Ms. Hillis’ complaints of pain:

A. The totality of the record, as you've stated, and I put it into my experience with these kinds of patients, and I said, it's possible that she did have this excruciating pain, but it's also possible that she expected to have it, because she couldn't move and all this terrible surgery was going on, and a normal person might very well come to the conclusion that pain was there, and it was excruciating, and imagine what's happening to her in the OR, and that would be how she would describe it.'

[267] He agreed this was speculation on his part and that it completely ignored what Ms. Hillis had reported, consistently and repeatedly.

[268] Returning to the overview of Dr. Noble’s evidence, Dr. Noble did not seem to take issue with Dr. Esufali’s description of MACs. He noted, as did Dr. Esufali, that the concept of using MACs to measure concentration is applicable only to inhaled anaesthesia and can’t be applied to intravenous anaesthesia. In comparing MACs to TIVA, he said the following:

It’s awful, because there’s no way you can measure the level that is in the blood, in a patient under a TIVA. You can take a sample – and, all, all these research studies do take samples – but it takes hours to get the result, and effectively, you’re anaesthetic’s done before you get the results, so, it’s of no use to you as a clinical person.

[269] This is virtually the same position as Dr. Esufali’s evidence.

[270] Dr. Noble said that the use of TIVA to administer anaesthetic in a person with malignant hyperthermia was required in order to keep with the applicable standard of care, and that TIVA is the only way that a person with malignant hyperthermia can receive general anaesthesia. As set out above this is undisputed. Dr. Esufali’s testimony is the same.

[271] Dr. Noble described the administration of balanced anaesthesia using TIVA as follows:

A. Balanced anaesthesia is a mechanism where you try to combine anesthetic agents so they give you all of unconsciousness, amnesia, anxiolysis and analgesia, and, muscle-relaxants. It requires, if you’re going to stick with TIVA – intravenous agents only – it requires multiple agents to do that, and each of these agents play with each other. They – if you, if you use only Propofol, for example, you’ll have to use very high doses. If you use, if you try to use only Fentanyl, you’d have to use extremely high doses. All these agents are assisted with the addition of the other agents. There is this synergy between them and it is that balance that results in anesthesia, unconsciousness, amnesia, analgesia and muscle relaxation.

Q. And so, when an anesthetist is administering a balanced anesthesia, what happens if one of the multiple agents being used is brought down or reduced?

A. Um, depends which one, obviously, which effect you’re going to lose, but, you will lose something of that effect, and, you can overcome that problem by using, either another drug or more of another agent.

[272] When asked about the implications that TIVA has on awareness under anaesthesia, Dr. Noble explained that awareness is more common under TIVA than under an inhaled anaesthetic technique. In order to address this issue, he said that a reasonable anaesthesiologist “would select [his] dosages of drugs carefully, trying to put them in a range that literature would support.” He explained that, because a muscle relaxant is used in a laparoscopic surgery such as Ms. Hillis’, the anaesthetist would need to monitor the patient for awareness, signs of which would be “limited to following blood pressure, heart rate, whether the patient is sweating, and whether they’re tearing.” He described all of these symptoms as a “sympathetic response” of the patient. Again this is undisputed.

[273] When asked how a reasonable anaesthetist in 2008 would monitor for these sympathetic responses, Dr. Noble suggested that monitoring heart rate and blood pressure are standard, but that the anaesthetist would also want to follow closely, looking for “signs of elevation; feel the skin of the patient; looking for sweating and tearing. In this particular patient, you’d also be interested in temperature.”

[274] Dr. Noble said the reasonable anaesthetist in this situation would also be “looking at your drug infusion system, to make sure it is, in fact, working properly; that if, that the tube has not got kinked; that your IV has not gone interstitial…meaning…it’s gone outside of the vein.”

[275] Finally, with respect to any further signs of awareness, Dr. Noble said that an anaesthetist would be looking for signs of movement, but that those signs would be unlikely unless the dosage of Rocuronium was inadequate.

[276] When asked about Dr. Esufali’s view that up to 20 per cent of patients experiencing awareness would not have an increase in blood pressure or heart rate, Dr. Noble said that in his view, this number was correct but that the “problem with it is that most of the patients you have awareness under anaesthesia have a reason for it, other than awareness. They are probably on some sort of medication that slows the heart rate… [or] drops blood pressure.” He said that “Ms. Hillis didn’t have that; she wasn’t on those kinds of medication, so, you should be able to rely on [signs of awareness].”

[277] Dr. Noble described his opinion of the pharmacological actions required to anaesthetize a patient in accordance with the standard of care:

To create anaesthesia, you want the patient to be unconscious. I, I’ll leave out which drugs do which at the moment. You want the patient to be unconscious. You also want amnesia. You must understand, amnesia will be present if the patient is unconscious, so, what I want is unconscious. You can talk about anxiolysis, but the same comment is made, if your unconscious you’re not anxious.

…You also need analgesia – pain relief. You also want muscle-relaxation, and, if you create unconsciousness, usually, you’re got rid of the hormonal responses because they’re usually created by adrenalin, so, usually, if you’ve done the one, you’ve got the other, but it’s from the stimulation of surgery.

[278] Dr. Noble was also asked about the anaesthetic requirement with respect to sympathetic or hormonal responses and his answer was as follows:

A. Is to choose the right drugs to give to create that set of circumstances and also the right doses of those drugs.

[279] In his testimony, Dr. Esufali referred to hemodynamic stability as one of the goals of anaesthesia. Dr. Noble described the relationship between what he was stating as the anaesthetic goals and the term hemodynamic stability:

Hemodynamic stability means you want a, that record that you see here of blood pressure and heart rate going along there, that looks like a track – those three going across – that looks like a track; that’s hemodynamic stability, and that equals, the sympathetic nervous system has not been triggered, you probably have, highly likely have, unconsciousness, analgesia, amnesia and anxiolysis.

[280] Dr. Nobel also noted which drugs were used by Dr. Ghaffari to meet the goals outlined above for Ms. Hillis. He said that Versed was used to help create unconsciousness, anxiolysis and amnesia; Fentanyl was used to create analgesia; Propofol was used to create unconsciousness, anxiolysis and amnesia; Rocuronium was given to create muscle relaxation; Neostigmine and Glycopyrrolate were given to reverse muscle relaxation and stabilize the heart rate; Gravol to prevent nausea and vomiting post-operatively; the Propofol infusion to induce anaesthesia; the Dilaudid to create analgesia; and the Nitrous Oxide to provide analgesia and amnesia.

[281] Dr. Noble agreed with Dr. Esufali’s opinion that a Nitrous Oxide level of 70 per cent would be the highest that a patient could safely be given and suggested that most anaesthetists would set the Nitrous Oxide rate to 60 per cent or a little bit lower.

[282] I will briefly summarize Dr. Noble’s evidence in regard to Propofol infusion rates and add more details below. As will be more thoroughly canvassed below, I do not find that Dr. Noble’s evidence and Dr. Esufali’s evidence as to what the standard of care required for the infusion rates of Propofol varied significantly. Dr. Noble based his evidence that the standard had been met on an incorrect assumption regarding the infusion rate used by Dr. Ghaffari.

[283] Dr. Noble testified that if an anaesthetist was using Propofol alone the anaesthetist would use a Propofol infusion rate of 100 to 200 mics/kg/minute. With nitrous oxide (at about 67 per cent) the infusion rate would be 50 to 150 mics/kg/minute. Fentanyl will lower this required dose. Versed will further reduce the required dose.

[284] Dr. Noble testified that regarding the infusion rate of Propofol, anaesthetists are given advice about ranges from texts and depending on various factors, the anaesthetist might either increase the need for anaesthesia or decrease the need for anaesthesia, within the range. Such factors include pre-operative opiate narcotic use, weight and age.

[285] In terms of the surgery itself, as it relates to anaesthesia requirements, Dr. Noble described Ms. Hillis’ surgery as not mild or severe. He described it as half way in between. Dr. Esufali gave similar evidence. They both acknowledged that the nature of the surgery plays a role in the anaesthetizing of the patient.

[286] Given that the surgery for Ms. Hillis was neither mild or major, Dr. Noble testified that the standard of care required a blood concentration level of 2 to 5 mics/ml of Propofol and that the anaesthetist would start with an infusion dose, based on the literature, expected to put Ms. Hillis in this blood concentration range and monitor the situation.

3) Supervision of Residents

[287] It is uncontroverted that Dr. Meineri was assigned by the anaesthetic scheduling coordinator to Ms. Hillis’ December 15, 2008 procedure and that he was also staffed to a simultaneous transesophageal echocardiography with another Fellow (which procedure required hands-on involvement from Dr. Meineri). Dr. Meineri had worked with Dr. Ghaffari prior to December 15, 2008. He viewed Dr. Ghaffari as a very reliable Fellow.

[288] Dr. Meineri testified that the staffing process at the Toronto General Hospital was based on whether, depending on the complexity of the procedure and experience of the particular Fellow, a case could be carried out entirely by a Fellow acting independently. Staff anaesthetists would regularly be assigned to multiple procedures at once (with multiple Fellows) if at least one of the Fellows also staffed to the procedures was understood to be self-sufficient and able to practice independently, permitting the supervising staff to focus on the more complex procedure or less experienced Fellow.

[289] Dr. Meineri testified that in Ms. Hillis’ case, Dr. Ghaffari was already understood to be a sufficiently experienced and independent Fellow.

[290] Dr. Ghaffari and Dr. Meineri both reviewed Ms. Hillis’ available electronic medical records, including the Pre-Admission Assessment Report, in advance of the procedure. They both testified that they turned their minds to her history of malignant hyperthermia and her use of chronic pain medications.

[291] After Dr. Ghaffari met with Ms. Hillis on the morning of her surgery he and Dr. Meineri met, prior to Ms. Hillis being transported to the operating room. They met to discuss her anaesthetic. They discussed, among other things, Ms. Hillis’ malignant hyperthermia and the use of TIVA, in addition to Ms. Hillis’ opiate intake the morning of her surgery and the implication of this on the pain medication she would receive during surgery.

[292] There is consensus that Dr. Ghaffari and Dr. Meineri did not discuss specific drugs and doses at any time. They understood that a balanced anaesthesia approach was being used. Dr. Meineri said specific drugs and doses was something he might have discussed with a first year Resident but not a fully trained Fellow, such as Dr. Ghaffari. Dr. Meineri deferred to Dr. Ghaffari’s selection of dosages for the procedure but made himself available if Dr. Ghaffari required assistance. He was available to be paged. Sometime around 8:10 a.m., Dr. Meineri visited the operating room where Dr. Ghaffari was administering the anaesthetic to Ms. Hillis. He reviewed the monitors and the Anaesthetic Record up to that time and signed the Record and left.

[293] With this factual background, which was not really contested, the issue is whether Dr. Meineri met the standard of care of a staff anaesthetist in the supervision of a Fellow, Dr. Ghaffari.

[294] With respect to whether Dr. Meineri met the standard of care of a staff anaesthetist in the circumstances of this case, Dr. Esufali said the following:

So at the end of the day, Dr. Meineri, as a staff anaesthetist he supervises residents, he supervises medical students, he supervises Fellows, but at whatever level of training these people [under Dr. Meineri’s supervision] are, he is still the supervisor and the primary physician responsible. He’s the most responsible physician, is what they call him. So, even if it’s a Fellow, who has, who has an anaesthesia license, and the level of responsibility may go almost entirely onto the Fellow’s shoulders. It is up to the staff anaesthetist to still make sure that the plan is conducted appropriately and that plan is being adhered to, and that, and that, and that there are no variances from the plan, and any surprises need to be addressed as well. So I think in the end, Dr. Meineri is responsible, and failed to meet the standard.

[295] This is the totality of the evidence Dr. Esufali gave with regard to supervision of Fellows. Specifically, Dr. Esufali did not testify that Dr. Meineri was required to discuss dosages with Dr. Ghaffari.

[296] Dr. Noble testified that Dr. Meineri met the standard of care in his supervision of Dr. Ghaffari. The key components of Dr. Noble’s evidence in this regard are as follows:

▪ The supervisory model Dr. Meineri used is a model, commonly used in a teaching hospital.

▪ A Fellow is a fully trained and qualified anaesthetist. This is unlike a Resident who cannot be left on their own. A Fellow can be given a complete anaesthetic list that he or she can do and the supervisor can cover the Fellow from another operating room if there were a problem.

▪ Dr. Ghaffari is a Fellow anaesthetist and fully trained specialist, with or without his FRCP designation. He will discuss the case with the supervisor but it is his case to do.

▪ In 2008, a staff anaesthetist supervising a Fellow would probably have his or her own list and be in close proximity to the operating room where the Fellow was. The supervisor would discuss the case with the Fellow and hear the Fellows’ anaesthetist plan. If the plan met the standard, the Fellow would be free to go ahead.

▪ In terms of decisions the Fellow can make independently, Dr. Noble testified the Fellow can independently administer the entirety of the anaesthesia.

[297] The conclusion of Dr. Noble’s evidence on supervision is contained in the answers to two questions as follows:

Q. So, assuming Dr. Meineri, a Staff anesthetist, met with Dr. Ghaffari, a Fellow, the morning of Ms. Hillis’ procedure to discuss the anesthetic approach and permitted Dr. Ghaffari to select dose and administer the TIVA while Dr. Meineri conducted a simultaneous procedure elsewhere in the hospital, did Dr. Meineri meet the standard of care for supervising a Fellow in 2008?

A. Yes, he did.

Q. And, assuming Dr. Meineri visited the OR shortly after the induction of Ms. Hillis, reviewed the case and monitors and signed off on Ms. Hillis’ chart before leaving for the remainder of the procedure, did Dr. Meineri meet the standard of care in terms of supervising a Fellow in 2008?

A. Yes, he did.

[298] I accept the evidence of Dr. Noble in regard to Dr. Meineri meeting the standard of care required of a supervisor.

[299] The evidence supports that Dr. Meineri followed the steps Dr. Noble testified would be required of a supervisor.

[300] I prefer the evidence of Dr. Noble over Dr. Esufali on this issue as Dr. Esufali has no experience supervising Fellows. Unlike the students and Residents Dr. Esufali supervises, Fellows are fully qualified with all of the core competencies expected of an anaesthetist. Dr. Esufali’s evidence on supervision is given little weight and Dr. Noble’s evidence is preferred as Dr. Noble has had years of experience supervising Fellows. Further, Dr. Esufali did not formulate or identify any specific breach of the standard of care.

[301] Dr. Esufali’s evidence on this issue appears to impose some form of vicarious strict liability on Dr. Meineri as a supervisor. The inference being that Dr. Meineri as the supervisor and the most responsible physician is responsible for all of the actions of Dr. Ghaffari. Again, Dr. Esufali has no experience supervising Fellows. He has no basis or experience to offer this opinion other than his own experience as a Fellow and his evidence in this regard is given less weight than Dr. Noble’s evidence, which I accept. Dr. Noble did not testify as to any such responsibility. There is no evidence that it was incumbent on Dr. Meineri to discuss doses with Dr. Ghaffari and this is not implicit in the evidence from either Dr. Esufali or Dr. Noble. Dr. Noble’s evidence confirms that the particulars surrounding dosing of anaesthetist agents and the administration of TIVA need not be discussed with fully trained Fellows. I accept his evidence in this regard.

[302] I find that Dr. Meineri met the standard of care in his supervision of Dr. Ghaffari in the circumstance of this case.

[303] I add that neither Dr. Esufali nor Dr. Noble testified that the standard of care required Dr. Meineri to check the level of the Propofol infusion pump when he came into the operating room as Ms. Hillis’ procedure was starting. There is no evidence to support this alleged breach of supervision.

[304] Although I reject Dr. Esufali’s evidence on this issue it does not affect my acceptance of his evidence on the Propofol standard of care issue. Dr. Esufali readily acknowledged his lack of any experience in supervising Fellows in the qualifying stage of his evidence. He offered his opinion based on his own experience being supervised when he was a Fellow and made this clear at all times.

4) Temazepam

[305] In Dr. Esufali’s evidence in chief, he testified that Ms. Hillis’ pre-operative use of Temazepam (also known as Restoril) – a benzodiazepine – would increase her Propofol requirements or require the anaesthetist to add a little more benzodiazepine (she was administered the benzodiazepine Versed during the procedure) to the balanced anaesthesia. It is undisputed that Ms. Hillis was taking Temazepam to help her sleep. Dr. Esufali opined that a prudent anaesthetist would take this into consideration in planning for her anaesthesia.

[306] Dr. Esufali expanded on this, testifying that Temazepam is a chronic benzodiazepine and it binds receptors in the brain, GABA receptors and these receptors are the same receptors Propofol binds to so this would increase the Propofol requirements.

[307] In cross-examination Dr. Esufali was challenged on this testimony. Dr. Esufali acknowledged that he could not find such a reference in the article that he cited in support of this proposition that chronic benzodiazepine therapy is known to increase anaesthetic requirement. Dr. Esufali also acknowledged that there are different sub-units and that a benzodiazepine may attach to a different sub-unit than a steroid. He agreed that there was an authoritative article put to him in cross-examination saying that Propofol doesn’t bind to the same receptor as benzodiazepine in the brain of a rat. The study Dr. Esufali relied on initially was also based on the rat brain.

[308] Dr. Esufali agreed in cross-examination that, as the anaesthetist in the room with the patient, Dr. Ghaffari would have been in the best position to judge Ms. Hillis’ response to medication as it was administered.

[309] He further agreed that 30 to 50 per cent of receptor occupancy leads to sedation, and that for a patient to become unconscious from a benzodiazepine, 60 per cent occupancy must take place.

[310] When it was put to him that the anaesthesiologist administering the benzodiazepine knows what is happening inside a patient based on their physical reaction, Dr. Esufali agreed. The exchange went as follows:

Q. And, so that, even if there is a tolerance issue as you say, if an anaesthesiologist is providing a dose and it is seen to put the patient to sleep, or, it is seen to sedate the patient, then the anaesthesiologist knows what’s happening inside the patient based on what we know about these receptor occupancy percentages, right?

A. I would agree with that.

[311] I find that there is not sufficient cogent evidence to establish on a balance of probabilities that pre-operative use of Temazepam increases Propofol requirements. I, therefore, need not consider whether the standard of care required consideration of this aspect of Ms. Hillis’ medical history and whether this requirement had been breached.

[312] Dr. Noble’s evidence was consistent with what Dr. Esufali’s evidence was on this point when Dr. Esufali was cross-examined as such evidence was summarized above. Dr. Noble stated as follows when asked if the hypnotic drugs administered to Ms. Hillis reasonably addressed Ms. Hillis’ assumed use of 15 mg of Temazepam:

A. Yes, it did, and the, and the reason I would say that is because he, Dr. Ghaffari had the opportunity to test this concept, because, at the beginning of the anesthetic, when he's given the Versed and the Propofol, he can assess whether the patient is going to sleep or not, and she did, and therefore at reasonable doses, and therefore, these agents are doing what you expect them to do.

Q. And, in your opinion, is 2mg of Versed given an induction in keeping with the standard of care in 2008, for a patient taking 15mg of Temazepam?

A. Yes, it is.

[313] I point out that this was a minor issue raised. Neither counsel dealt with it in their written submissions.

5) Narcotics

[314] Both experts agreed that the standard of care required a prudent anaesthetist to consider Ms. Hillis’ pre-operative opiate use in planning her anaesthesia. This is uncontroverted. Initially, Dr. Esufali’s evidence was that the pain medicine doses administered by Dr. Ghaffari to Ms. Hillis fell below the appropriate therapeutic range applicable to Ms. Hillis’ balanced anaesthesia. Dr. Noble’s evidence was that it fell within the appropriate therapeutic range. After cross-examination, I find that Dr. Esufali agreed that the pain medication Dr. Ghaffari provided to Ms. Hillis did fall within the appropriate range. I, therefore, conclude that Dr. Ghaffari did not breach the standard of care in his administration of pain medication (narcotic opioid) to Ms. Hillis. I will summarize the evidence in this regard.

[315] In his testimony in-chief, Dr. Esufali opined that Dr. Ghaffari should have:

1. Administered the equivalent of at least 480 – 500 mics of Fentanyl. This was based on being at the lower end of the recommended dose for analgesia, using Fentanyl during balanced anaesthesia, in an opioid naïve patient, undergoing a moderately painful operation, such as a laparoscopic abdominal hysterectomy. This was calculated by using 4 mics/kg at the beginning of the operation, followed by 2 mics/kg per hour for two further hours of the operation. Dr. Esufali took this range from the 2000 edition of the Miller text on anaesthesia.

Or

2. Administered the equivalent of 410 to 882 mic of Fentanyl. This was based on Dr. Esufali’s assertion that a therapeutic opioid range comprised of an initial bolus (immediate injection) of 2 to 5 mics/kg of Fentanyl followed by an infusion of 0.025 to 0.075 mics/kg/min could have been used with a step-down Propofol infusion.

[316] Dr. Esufali’s evidence was that these ranges were intended to be in relation to the analgesic component of balanced anaesthesia.

[317] In cross-examination, Dr. Esufali agreed that the first range noted above (480-500) did not apply, acknowledging that it was related to an anaesthetic dose and not an analgesic dose of narcotic and that this range related to procedures where only nitrous-oxide and opioids were being used to anaesthetize a patient. Dr. Esufali acknowledged in cross-examination that there was no longer reference to this range in the then most recent edition of the Miller text published in 2005. I note both Dr. Noble and Dr. Esufali accepted the Miller text as authoritative on the subject matter of anaesthesia.

[318] Dr. Esufali also agreed in cross-examination that the second range noted above did not apply to Ms. Hillis’ procedure as it applied to anaesthetic procedures where only Propofol and opioids were used to anaesthetize a patient.

[319] Dr. Esufali agreed in cross-examination that the therapeutic analgesic dose range of Fentanyl applicable in a case such as Ms. Hillis’ was a 1.5 to 3 mics/kg loading dose followed by a 0.01 to 0.04 mics/kg/min infusion. This applied to all anaesthetic cases, including Ms. Hillis’.

[320] Using this acknowledged range and Ms. Hillis’ total body weight of 63 kg, Ms. Hillis ought to have received a Fentanyl equivalent dose of 200 mics to 600 mics over the course of the procedure. Dr. Esufali calculated that Dr. Ghaffari administered the Fentanyl equivalent dose of 375 mics.

[321] The dose administered therefore fell within the range. Dr. Esufali agreed that if the calculation were done using Ms. Hillis’ corrected body weight, the therapeutic dose range would be decreased by 8 per cent to 183 to 557 mics; if her ideal body weight were used the therapeutic dose range would be 170 to 518 mics; and if her lean body weight were used the therapeutic range would be 136 to 413 mics. Dr. Esufali agreed that the 2005 Miller text indicated that lean body mass is better for prediction of metabolic capacity than total body weight and Dr. Esufali could not dispute this independently based on his own knowledge. Regardless of which weight measure is used, the dose given by Dr. Ghaffari to Ms. Hillis as calculated by Dr. Esufali of 375 mics met the standard of care by falling within the required therapeutic dose.

[322] In Dr. Esufali’s evidence in chief he stated that a patient with chronic pain who takes chronic pain medication is going to require 25 per cent more narcotic intra-operatively. In cross-examination, Dr. Esufali acknowledged that in 2008, anaesthetists had not come to an agreement on the dosage increase necessary to counteract a patient’s past pre-operative opioid use – there was no formula or actual calculation to predict that. There was no agreed upon percentage increase. Dr. Esufali agreed that, in this respect, where to set the analgesic dose of opioids within the range was a question of clinical judgment in any particular case. He acknowledged that there was no “one size fits all” solution that set the standard of care in relation to the amount the analgesic dose needs to be increased to account for past opioid use. Even if any of the above dose ranges are increased by 25 per cent, the dose Ms. Hillis was administered still falls within the increased range.

[323] As such, Dr. Esufali’s evidence does not support a conclusion that Dr. Ghaffari breached the standard of care in his administration of narcotics to Ms. Hillis or in his consideration of her pre-operative opioid use.

[324] There is therefore no expert evidence critical of Dr. Ghaffari’s pain medication doses.

[325] Dr. Noble opined that Dr. Ghaffari’s dosage of opioids during Ms. Hillis’ case were reasonable in the circumstances and accorded with the standard of care.

[326] Dr. Noble agreed with Dr. Esufali’s evidence given in cross-examination that there is no definitive formula to determine the intra-operative opioid needs for patients who are chronic users of pain medication or have a history of using pain medication.

[327] Dr. Noble assessed the doses provided on the assumption that Ms. Hillis was taking 270 mg of M-Eslon daily. He was satisfied that the opioids administered to her over the procedure were sufficient to account for her chronic opioid needs.

[328] Dr. Noble calculated that Ms. Hillis received a 480 mics Fentanyl equivalent dose of opioids for this procedure. His number is different from Dr. Esufali’s because Dr. Esufali did not include the M-Eslon that Ms. Hillis took the morning of her surgery. Dr. Noble included the 30 mg of M-Eslon in his Fentanyl equivalent calculations. (I will comment on how Dr. Noble’s calculation compares to Dr. Esufali’s more below.) Dr. Noble explained that receiving a 480 mics of a Fentanyl equivalent dose in three hours could be extrapolated to a 1152 mg oral dose which was over three times higher than Ms. Hillis’ dose of 270 mg opioid daily intake (the level according to her own testimony).

[329] Dr. Noble used the 1.5 to 3 mics per kg range in the calculation of the appropriate dose of Fentanyl. He would have applied the ideal body weight. He testified he saw absolutely no problem with an anaesthetist using various measures of a patient’s weight (total body weight, corrected body weight, ideal body weight or lean body weight) as long as the anaesthetist realized “it’s on one side or the other side of that dose that you have decided upon.”

[330] In the end, the evidence of both experts satisfies me that there was no breach of the standard of care with regard to dosage and administration of opioids.

[331] Even if total body weight is used and even if the range were grossed up by 25 per cent (which Dr. Esufali was no longer maintaining after cross), the amount administered fell within the therapeutic range, whether she was administered a Fentanyl equivalent dose of 375 mics (Dr. Esufali’s evidence) or 480 mics (Dr. Noble’s evidence).

[332] In terms of the 375 mics versus the 480 mics, Dr. Esufali was of the opinion that in determining the dose Ms. Hillis was administered a prudent anaesthetist would not include what narcotics Ms. Hillis took the morning of her surgery pre-operatively before coming to the hospital. He didn’t include it in his 375 mics total. Dr. Noble did include it and therefore came to the total of 480 mics. It is not necessary for me to determine this issue as even using the lower number (Dr. Esufali’s number), Ms. Hillis was given narcotics by Dr. Ghaffari that put her within the therapeutic dose range.

[333] Further, when he offered his opinion that Dr. Ghaffari met the standard of care on this issue Dr. Noble assumed Ms. Hillis had taken 30 mgs of M-Eslon on the morning of her surgery. If she had taken 90 mgs, in his opinion, she would have even more Fentanyl equivalent on board and she would require less operatively. This is because he counts the pre-operative dose taken. I note my finding of fact regarding the amount of M-Elson taken closely accords with Dr. Noble’s assumption.

[334] Dr. Esufali in rendering his opinion that the narcotic administered was inadequate assumed that Ms. Hillis had been taking 270 mgs of M-Eslon a day. He did not count the dose she took that morning in his calculation of the Fentanyl equivalent Ms. Hillis received that day; however, he considered the amount of her medication she had been taking in his overall opinion as to the appropriate doses. He acknowledged that if she was taking 30 to 60 mgs of M-Eslon that would reduce her intra-operative Fentanyl dose requirements.

[335] In Dr. Esufali’s evidence he differentiated between narcotics given by injection and those given by infusion. At the conclusion of his evidence on the narcotics issue I am not satisfied that the delivery method would have affected the therapeutic range nor my conclusion that Dr. Ghaffari administered doses to Ms. Hillis within the therapeutic range. When Dr. Esufali gave his opinion in chief as to the dose for Fentanyl that should have been administered, he testified that it could be administered by infusion or injection. Dr. Noble testified that administering analgesics through intermittent injections and not infusions is a reasonable approach – there are other approaches but this is a reasonable one. I accept his opinion on this issue.

[336] For all of these reasons I find that the Plaintiff has not established that Dr. Ghaffari breached the standard of care in the administration of narcotics.

[337] I make a few concluding comments on the narcotics issue. When Dr. Esufali had put to him the therapeutic range from Miller 2005 for Fentanyl, it became clear that, depending what part of the range was selected, the dose could be higher than what Ms. Hillis received. It is therefore important to note that I accept Dr. Esufali and Dr. Noble’s evidence that what dose the anaesthetist accepts within the therapeutic dose range is a matter of clinical judgment.

[338] Dr. Esufali’s evidence confirms that Dr. Ghaffari’s analgesic opioid doses did not cause Ms. Hillis’ awareness and are not responsible for her awareness. The implication of a low dose of narcotic, he testified, is that in cases where there is pain associated with awareness, the trauma is a lot greater.

[339] As a final point on narcotics, I did not accept Dr. Esufali’s evidence given in-chief that Dr. Ghaffari breached the standard of care. I have explained why above. As will be set out below, I do accept Dr. Esufali’s evidence on the standard of care in the administration of Propofol. I did not find that Dr. Esufali modifying his opinion on the narcotics issue weakened his evidence on Propofol.

[340] His evidence on the Propofol infusion rates and blood concentrations assumed potent narcotics. Therefore, my finding that the narcotics administered were adequate does not undermine his opinion on Propofol. This will be detailed more below.

6) Propofol

[341] I accept Dr. Esufali’s evidence regarding the standard of care for the infusion of Propofol. This is in part because of my overall conclusion that his evidence on the standard of care was not meaningfully challenged and in part because important components of his evidence were similar to the evidence of Dr. Noble. I find that Dr. Ghaffari breached this standard. In this regard, I also accept the evidence of Dr. Esufali. Critical to my acceptance of Dr. Esufali’s evidence over Dr. Noble’s evidence is that Dr. Esufali assumed Dr. Ghaffari administered an infusion of 50 mics/kg/per minute in the first part of the surgery (from commencement to approximately 9:15 a.m.). This is consistent with my factual findings above. Dr. Noble assumed Dr. Ghaffari administered an infusion of 50 mics/kg/min for the first few minutes and 100 mics/kg/min from intubation to approximately 9:15 a.m. This does not accord with my factual finding. It is crystal clear from the totality of Dr. Noble’s evidence that Dr. Noble assumed that the Propofol infusion has been increased by Dr. Ghaffari to 100 mics/kg/minute right after induction, and that induction took place around 8:05 to 8:07 a.m. in forming his opinion that Dr. Ghaffari had met the standard of care. This is a significant inaccurate assumption as will be detailed below.

[342] I find that Dr. Ghaffari used inadequate amounts of the anaesthetic agent Propofol throughout the first part of the procedure particularly when the nitrous oxide was decreased and that he failed to administer additional anaesthetic agents in a timely and effective manner after he reduced the amount of nitrous oxide from 53 per cent to 17 per cent at approximately 8:45 a.m. or 8:50 a.m.

[343] Both Dr. Noble and Dr. Esufali agree that until the nitrous oxide was reduced, Ms. Hillis had appropriate anaesthetic. Dr. Esufali explained this in his evidence. Dr. Ghaffari had started Ms. Hillis on 53 per cent nitrous oxide right after intubation. This was providing about half of a MAC of anaesthesia. Dr. Esufali said the nitrous oxide was providing half of an anaesthetic dose for about half of all people – only from the nitrous oxide. She also had the induction dose of Fentanyl and Midazolam. He described her as “good” at that point.

[344] It is undisputed that at approximately 8:45 a.m. or 8:50 a.m., Dr. Ghaffari adjusted the nitrous oxide to 17 per cent and that this level was maintained for the rest of the operation. The implication, according to Dr. Esufali, was that Ms. Hillis was receiving less analgesia and the reduction was taking away amnesia. Dr. Esufali did not criticize Dr. Ghaffari reducing the nitrous oxide level. Dr. Esufali stated it was reasonable for Dr. Ghaffari to do so given that the surgeon had told Dr. Ghaffari that Ms. Hillis’ bowel was distended and there was a potential to cause injury.

[345] Dr. Esufali was critical that Dr. Ghaffari did not do something right away to deal with the nitrous oxide decrease. Dr. Esufali testified that Dr. Ghaffari had to do something and he didn’t. Dr. Ghaffari did not increase the Propofol infusion rate to 100 mics/kg/minute until approximately 20 to 25 minutes later. Dr. Esufali testified that Dr. Ghaffari had several options – he could have increased the Propofol infusion right away; he could have given a little more Midazolam; he could have not reduced the nitrous oxide so fast or so much; he could have added a little more Versed; he could have given a bolus of Propofol and increased the Propofol infusion right away; he could have increased the Propofol infusion and then turned down the nitrous oxide; or he could have used the step-down method to administer the infusion of Propofol from the start or used the step-down method at the time the nitrous oxide was decreased.

[346] I accept Dr. Esufali’s evidence that the standard of care required Dr. Ghaffari to do something when the nitrous oxide was decreased. This is based on dose ranges and blood concentration calculations, which I will review below and because Dr. Esufali offered his overall opinion on the assumption that the Propofol infusion rate was 50 mics/kg/minute. Dr. Esufali testified that Ms. Hillis was stable throughout the surgery; her heart rate was stable and she had no hypotension. There was no reason she couldn’t have been given more Fentanyl, Propofol or Midazolam.

[347] Dr. Noble was asked if it was incumbent on an anaesthetist to increase another agent when the nitrous oxide was decreased. The question and answer is as follows:

Q. And so, doctor, it's incumbent then on the anesthetist where the Nitrous Oxide, a significant portion of the anesthetic agent, is suddenly lost to replace it with a suitable anesthetic agent, and that would, of course, suggest the increase in the Propofol, correct?

A. That would be a logical way to do it, yes.

Q. Right. Now, the difficulty with what we see charted, I suggest to you, is that the increase in Propofol - even accepting what Dr. Ghaffari says that up arrow represents – doesn't take place for, at least, another 15 to 20 minutes, that's the initiation of the up tick, correct?

A. Agreed, but, back – step back – the Propofol dose that I believe was being administered then was 100mics/kg/minute, before the first up tick, therefore the dose of Propofol given, of 100mics/kg/minute was in the patient and working. The up tick was working, but, if the 100mics/kg/minute is enough to deal with the reduction in Nitrous Oxide, added to the effect of that Propofol, is that he also gave Dilaudid, which will augment the effect of the Propofol – that was running at 100mics/kg/minute - because he gave three induction doses of Dilaudid at that point....

[348] This makes it crystal clear that his entire opinion was formed on the assumption that Ms. Hillis was receiving an infusion of 100 mics/kg/min of Propofol at the time of the nitrous oxide decrease. Dr. Noble’s evidence that Dr. Ghaffari was not required to do anything when the nitrous oxide was decreased and that the infusion rate of Propofol was acceptable was based on Dr. Noble’s erroneous assumption that at the time Dr. Ghaffari decreased the nitrous oxide the Propofol infusion rate was set at 100 mics/kg/minute. This is a critical incorrect assumption.

[349] Dr. Noble was asked in cross-examination whether he disagreed with Dr. Esufali’s opinion that at 17 per cent nitrous oxide conferred almost no protection from awareness. He answered “I wouldn’t go that far.” When asked why he didn’t take the opportunity to dispute this aspect of Dr. Esufali’s opinion he said, “I wasn’t going to quibble over that one.” I interpret this to mean he didn’t significantly disagree.

[350] Dr. Esufali’s opinion that the standard of care required Dr. Ghaffari to do something immediate when he decreased the nitrous oxide was in part based on Dr. Esufali’s evidence that when the nitrous oxide percent was changed from 53 per cent to 17 per cent the new value was reached very quickly. He said it would only take a few minutes. He was cross-examined on this evidence and confirmed he couldn’t say what the actual timeline is. He said from his experience it is very quick. He said with the flow rates from the Anaesthetic Record “it’s going to drop very quickly.” He said “His quick. It is minutes.” He said by experience “it’s relatively quick; in the order, in the order of a few minutes.” He was asked to do a sample calculation and said it would be 5 minutes or less, or if the flows were higher, it would take less time and if the flows were lower, it would take more time.

[351] In terms of the speed at which the nitrous oxide gets to a new level, Dr. Noble said that within 3.7 minutes the nitrous oxide will be at one half the difference between 54 per cent and 17 per cent and in 5 half-lives at the new level. He said it is the order of 15 minutes.

[352] In my view, their opinions on the speed at which the new level of nitrous oxide is achieved, were not different in any meaningful manner.

[353] I note that the Propofol infusion was not increased from 50 to 100 mics/kg/min until approximately 20 to 25 minutes after the decrease in nitrous oxide.

[354] Both Dr. Noble and Dr. Esufali agreed that the decrease of nitrous oxide was a substantial reduction. Dr. Noble agreed it was a significant loss of an important anaesthetic and had to be replaced and that the timing of the replacement was important. As set out elsewhere in these Reasons, at 53 per cent nitrous oxide, the nitrous oxide alone was providing about one half of a MAC of anaesthesia – it was providing half of an anaesthetic for about half of all people. Dr. Esufali explained 17 per cent is providing 0.16 of MAC, only 16 per cent of an anaesthetic dose that would prevent half of the patient population from moving to surgical stimulation. The nitrous oxide at 17 per cent was providing only 20 per cent of an amnestic dose that is going to produce amnesia in half of all patients. Dr. Esufali explained that with the decrease in nitrous oxide Ms. Hillis did not have much else on board in terms of medications for her amnesia.

[355] Dr. Noble agreed the decrease was significant. He was of the opinion that the Dilaudid (2 mg) given around 8:30 a.m. compensated for the decrease in nitrous oxide. Again, his evidence was in the context of his assumption of the infusion rate of Propofol being 100 mics/kg/minute when the nitrous oxide was decreased. This being contrary to my finding of fact. I will have more to say about the Dilaudid below.

[356] In terms of the need for an anaesthetist to do something when the nitrous oxide was decreased, Dr. Esufali testified that if an anaesthetist wants to increase the Propofol blood concentration it takes a little time after turning up the induction rate. He described the half-life of Propofol at 2 to 8 minutes and it takes 5 half-lives to reach a new concentration level.

[357] Dr. Noble gave more detail regarding the clearing of Propofol from the patient. He explained that Propofol comes out of the organs first and fastest and then out of the muscle compartment and then from the slowest compartment, which is the fat. He specifically said that the half-life that Dr. Esufali referred to for Propofol of 2 to 5 minutes was an intermediate half- life; it was not for the brain, because the brain is much faster. It was a combination of the half-life for the brain and muscle because the half-life for fat would be much slower. Dr. Noble referred to the Schuttler Study and said the half-life for Propofol for a 70 kg, 30 year old patient for the brain would be 1.33 minutes, for muscle 27 minutes and for fat 335 minutes. He said a reasonable anaesthetist would be concerned with the first one, 1.33 minutes. In 1.33 minutes the concentration of Propofol in the brain has dropped 50 per cent. If you go a second half-life, within 2.6 minutes, “you have dropped down to 25 per cent of the blood concentration.” The same analysis applies when the Propofol is increasing.

[358] I don’t think Dr. Esufali and Dr. Noble disagree with respect to the half-life of Propofol. Dr. Noble used the brain number and Dr. Esufali an intermediate number. In any event, the increase is not felt by the patient immediately, it is noteworthy to repeat that the Propofol infusion rate was not increased until approximately 20 - 25 minutes after the nitrous oxide was decreased.

[359] As Dr. Esufali explained, if the Propofol infusion rate is at 50 mics/kg/minute and the pump is turned up to 100 mics/kg/min the level of Propofol isn’t doubled right away, it takes a certain time and in the meantime the nitrous oxide “is now really low.” He described this as a small window in which there is an increased chance of awareness.

[360] Dr. Esufali testified that a bolus of Propofol could be given to affect a rapid increase in Propofol. A bolus helps the Propofol reach tissues a lot more quickly. It was not given.

[361] As set out above, I accept Dr. Esufali’s evidence that the standard of care required Dr. Ghaffari to address the decrease in nitrous oxide by doing one of the options Dr. Esufali laid out. Dr. Ghaffari did none of them.

[362] Dr. Noble testified that nothing had to be done immediately by Dr. Ghaffari when the nitrous oxide was decreased because at approximately 8:30 a.m. Dr. Ghaffari had given Dilaudid (2 mgs) to Ms. Hillis. He said this compensated for the decrease in nitrous oxide. I do not accept this evidence because the context of this evidence from Dr. Noble was the assumption that the Propofol infusion rate was already at 100 mics/kg/minute. It was in this context that he assessed the adequacy of Dr. Ghaffari taking no further steps at the time the nitrous oxide was decreased significantly.

[363] When Dr. Noble was asked why there would be a need to increase the Propofol infusion at all after the decrease in nitrous oxide if the Dilaudid made up for the decrease, Dr. Noble said, “It depends whether the Dilaudid was able to reduce the requirement for Propofol...” and “I don’t know that and nobody knows that. So you test it.” The “testing” didn’t happen until approximately 20 - 25 minutes later with the first increase of the Propofol infusion.

[364] Dr. Noble also testified that Dr. Ghaffari was not required to increase the Propofol infusion rate any sooner than he did after the nitrous oxide was decreased. I do not accept his opinion. This opinion was as well based on his incorrect assumption that the infusion rate was already at 100 mics/kg/min at the time the nitrous oxide was decreased.

[365] The Defendants by implication suggest and Dr. Noble seemed to suggest that Dr. Esufali had not fully or properly considered the Dilaudid in forming his opinion that the standard of care required Dr. Ghaffari to take action when he decreased the nitrous oxide. This specific proposition was not put to Dr. Esufali during his cross-examination. Further, Dr. Esufali clearly knew Ms. Hillis had been given the Dilaudid. He specifically referred to the Dilaudid in his testimony. I will further address Dilaudid when I review the Propofol doses and blood concentrations below.

[366] I did not take Dr. Esufali’s evidence to mean that Dr. Ghaffari had to administer a bolus of Propofol at the time the nitrous oxide was decreased. I take his evidence to mean that Dr. Ghaffari had to do one of several options Dr. Esufali outlined. Dr. Ghaffari did none of the options. He did not increase the Propofol infusion rate until approximately 20 - 25 minutes later. Dr. Noble said giving a bolus would have risked giving Ms. Hillis a Propofol overdose. I disagree. First, this opinion was rendered in the context of him assuming Ms. Hillis was already receiving an infusion of 100 mics/kg/minute when it was only 50. Second, Dr. Esufali was not suggesting a bolus at a potential overdose level. Clearly, Ms. Hillis could tolerate a higher Propofol level as Dr. Noble assumed she was safely at 100 mics/kg/minute when she was only at 50. Dr. Noble also disagreed with Dr. Esufali’s position in his reports that a bolus be given with each increase in the infusion rate of Propofol. It is clear from his answer that his disagreement assumed Ms. Hillis was already receiving 100 mics/kg/minute when the first up arrow increase was given. This is factually incorrect.

[367] Dr. Esufali also described that Dr. Ghaffari could have used the step-down method to administer the Propofol infusion for either the whole procedure or in particular to deal with the decrease in nitrous oxide. He described this as the “classical description of TIVA” – the anaesthetist administers the Propofol by starting at a higher Propofol infusion rate such as 170 mics/kg/min for about 10 minutes, then goes down to 150, then 130, then 100 and it’s done. Under the step-down method the anaesthetist is keeping the Propofol level up as opposed to starting low and raising the level which is going to take five half-lives to reach a new steady state. He said “if you start higher than you’re intending to, it’ll slowly drop, but then it’ll also reach your final end – point much sooner.” Dr. Esufali testified that this was the more standard or standard approach to Propofol infusion and was not done in this case. He described how the step-down should have been done in this case as follows:

A. Okay, so I would I have started, I would have started this, well, I mean at this point 50 mics per kilo per minute, you know, when you, you know, is fine because, you know, she’s just been induced. She has fentanyl, she has Versed, she’s paralyzed. I think that’s reasonable. It’s here, and especially the 50% nitrous oxide, she’s, you know, she’s very well covered. It’s when here, when we get to like, 16% nitrous oxide for the next, almost, yeah about two hours, and this propofol, it needs to – so I would have put this at 200 and then just looked at the hemo-dynamic response, and then gone down a little bit more, and then gone down a little bit more. And I would have done that every ten minutes, until I got, until I got to 125 or whatever it was, and I was happy.

[368] Dr. Esufali acknowledged in cross-examination that the step-down method was not the only method for Propofol infusion in 2008. I do not take his evidence as suggesting it was the only response Dr. Ghaffari could have taken to the decrease in nitrous oxide. He clearly testified Dr. Ghaffari had multiple options and explained why he had to address the decrease in nitrous oxide using one of these. I do not diminish Dr. Esufali’s evidence in any way because he testified one option was the step-down method. The step-down was the only method for the administration of Propofol referred to in the 2005 Edition of the Miller text. Dr. Noble acknowledged this in cross-examination. Dr. Noble also agreed that it is a known and effective scheme when the Propofol needs to be increased for a patient while under sedation. Dr. Noble agreed with Dr. Esufali’s evidence that in 2008 there was not a singular infusion scheme that anaesthetists were required to employ in administering TIVA to meet the standard of care. He acknowledged that a step-down method was one way to administer TIVA.

[369] Dr. Esufali testified that Ms. Hillis was hemodynamically stable when the nitrous oxide was decreased and could have easily tolerated more Propofol. He was not successfully challenged on this in cross-examination. I will address this in more detail when discussing patient variability.

[370] Dr. Esufali opined that Dr. Ghaffari failed to meet the standard of care in the administration of Propofol when the nitrous oxide was significantly decreased and there was no other adjunct given right away. A bolus was one option. Using the step-down method another option. Dr. Ghaffari took no action. This breached the standard of care. For the reasons set out above, I accept Dr. Esufali’s evidence. Dr. Ghaffari did not address the decrease in the nitrous oxide.

[371] Dr. Esufali explained that, at the time the nitrous oxide was decreased quickly and no other adjuncts given right away or other action taken it was at a period where the surgical stimulation was beginning to be high - around 9:00 a.m. to 9:15 a.m. The first induction bolus of Propofol (150 mg) given at the beginning of the procedure was “gone,” which Dr. Esufali described as out of the system and not contributing to anaesthesia. The induction dose of Fentanyl (150 plus 50 mics) given at the beginning of the procedure was at a low concentration at around 9:15 a.m. and didn’t get supplemented until later in the procedure. The decrease in nitrous oxide in this context without compensating in other ways breached the standard of care. I accept this evidence. The underpinning assertions, in terms of the state of the induction doses of Propofol or Fentanyl, were not significantly challenged in the cross-examination of Dr. Esufali. To the extent that Dr. Noble’s evidence is contrary, his evidence has to be considered in the context of his erroneous assumption of the Propofol infusion rate at the time the nitrous oxide was decreased.

[372] Dr. Noble made a comment that the induction dose of Fentanyl would last through the procedure. He never said at what concentration level. Further, both his and Dr. Esufali’s evidence on Propofol infusion rates and blood concentrations assumed the presence of potent narcotics. Dr. Noble also testified that the induction dose of Versed would last through this case. Again, he did not say at what concentration levels.

[373] Dr. Noble confirmed in cross-examination that he did not provide an opinion in his reports or testimony as to when the period of awareness took place. He said the following:

Q. And what you don't also address or attempt to provide an opinion about is, when the period of awareness took place?

A. I had, I did not address it – you're correct. I had opinions about it, but, I hadn't gone into enough detail to analyze specifically where it was. I was going at what happened and why it happened and what the problems around that are.

Q. Well, in fairness, doctor, you don't say why it happened, but, you, you do not articulate why it happened in the sense that, whether or not – you simply say, "It should have been enough, but it wasn't." But, you don't articulate why it happened, correct?

A. No, that's not quite fair, because, the, the whole paragraph about what Propofol infusion rates are needed to prevent AUA, that's all about trying to sort out the doses that investigators have come up with that would, or, are less likely to be associated with AUA, so clearly, that's what I'm concerned about. I want to make sure that the doses that were given were reasonable to try to prevent this problem.

[374] He did not provide contradictory evidence to that given by Dr. Esufali as to when the period of awareness occurred. Dr. Noble said that he could not identify the point in time as he could not find an area of weakness because the dose levels were appropriate. His assumption about the infusion rate of Propofol until 9:15 a.m. was incorrect. He added that the variability was so huge he could not identify a time where he could say this was the problem. – where he could say the drugs were inadequate. Of course, this is in the context of his incorrect assumption of the infusion rate for approximately the first hour and 15 minutes of the procedure.

[375] My acceptance of Dr. Esufali’s evidence that the standard of care required Dr. Ghaffari to take immediate action when the nitrous oxide was decreased is consistent with my analysis of both Dr. Esufali’s and Dr. Noble’s evidence on the effective levels of blood concentrations of Propofol and the appropriate dose ranges for Propofol. For the reasons above and that follow, I find that Dr. Ghaffari breached the standard of care specifically by infusing Propofol at 50 mics/kg/min from the beginning of the procedure until approximately 9:15 a.m.

[376] Both Dr. Esufali and Dr. Noble agree that the standard of care requires a prudent anaesthetist to select drug dosages carefully and to try to put the patient within the range that the relevant literature would support.

[377] Dr. Esufali’s evidence in chief was that a prudent anaesthetist would administer to a patient in the circumstance of Ms. Hillis, Propofol by infusion with a goal to achieve a blood concentration level of Propofol in the range of 3 to 4 mics/ml as part of a balanced anaesthetic technique. His evidence was unequivocal that this was the appropriate blood Propofol concentration level if the Propofol was given alongside either approximately 60 per cent nitrous oxide or a potent infusion of narcotics.

[378] Dr. Esufali was cross-examined about his evidence that the appropriate blood concentration level range was 3 to 4 mics/ml. He was cross-examined in particular about an article (Exhibit 23) which Dr. Esufali had stated in his report related to minor surgeries. Dr. Esufali acknowledged the article did not say minor surgeries and that this article was actually in this regard looking at other studies and it wasn’t known whether the other studies involved major or minor surgeries. Dr. Esufali was also cross-examined with respect to the Vuyk article he referenced in his written report (Exhibit 24). This article looked at a laparotomy not laparoscopy procedure. In my opinion, this does not weaken Dr. Esufali’s evidence. The range he put forward is a narrower range, within the range Dr. Noble testified to as the standard of care.

[379] Dr. Noble’s evidence was consistent with Dr. Esufali opinion as to how a prudent anaesthetist approaches doses. Dr. Noble confirmed that the selection of a dose is only partly a matter of clinical judgment. He explained as follows:

We are given advice about ranges, so, we have an induction dose and we’re told what that range is; we have an infusion dose and we’re told what those ranges are. And, and, so we can apply our judgment depending on the patient, themselves, as to what particular problems they have that might either increase the need for anaesthesia or decrease the need for anaesthesia, and, and, in that setting , you would choose a slightly higher, within the range, dose or a slightly lower, with the range dose.

[380] He said the type of factors that would affect the dose would be weight and age. Age was not a factor for Ms. Hillis. From an anaesthetist perspective she was young. Obese patients require less drugs to get to the same concentration in the blood than a lean patient. Ms. Hillis, Dr. Noble said, was overweight but not obese. Dr. Noble described Ms. Hillis’ past opioid use, as very relevant. As dealt with above, it increases the dose of analgesia required in what Dr. Noble described as an “unknown amount.” The type of procedure is also relevant – is it mild surgery or major or in between.

[381] In terms of Ms. Hillis’ procedure, Dr. Noble said the following about the appropriate target blood concentration level of Propofol:

...I would like to do one thing with that, because the surgical procedure here is neither mild nor major and so, instead of picking the mild numbers or the major numbers, I would average them, and that turns out to be a range of 2 to 5 mics/ml as the blood level you would like to be in for this intermediate surgical procedure.

[382] Dr. Noble clarified he was referring to the blood level of Propofol. This was his evidence on what blood level a prudent anaesthetist would target to achieve anaesthesia for Ms. Hillis and then monitor her.

[383] He amplified what a reasonable anaesthetist would do when administering TIVA as follows:

Q. And, so what could a reasonable anesthetist do when administering an anesthetic, via TIVA, to deal with this variability you've just identified?

A. Right. So, you have to look at the patient and decide what are things – so, first of all, I want to pick from the literature, wise individual's advice on what is the range of drugs that I should use – for induction; for maintenance – and, having decided on that range, then you should say, 'Well, what are the characteristics of this patient that might modify?' I want to be inside that range, but now, do I want to be at the high end, do I want to be in the middle, do I want to be at the low end – and, Ms. Hillis has reasons why you might do several things. Her opioid use says be more at the high end.

Q. Is that the case for Propofol?

A. Not as much for Propofol, although it does influence it a bit. It's not a major influence.

Q. So, sticking solely to Propofol, which is...

A. If it's just Propofol...

Q. ...what we're discussing right now?

A. ...it's weight and age, and that says, if you, if you were going to use total body weight as your, as your measure, then, you would want to start at the low end of the range, because you know that the drug result will be much higher that predicted. So, that's a way of approaching it and, sort of, I personally believe that that is the way that most anesthetists do it. The arithmetic we're going through here, you do not see anesthetists with calculators in the OR – I do have one - but, they tend to pick a dose then modify it a little bit, inside the range, and then monitor the patient's response, and depending on that patient's response, up it or down it.

[384] Dr. Noble described the limits of the range as follows:

A. That there are two limits to the range suggested by Miller. One is to prevent awareness under anesthesia, at the low end, and the other is to prevent overdose, at the high end. That's why we have that, otherwise, he would simply say, 'Let's do anything over 2mics/ml. He doesn't. He says 2mics/ml is the low; 5mics/ml is the high – I want you to be in-between those two limits.

[385] I point out that Dr. Esufali’s target range of 3 to 4 mics/ml fits within Dr. Noble’s target range of 2 to 5 mics/ml. As will be reviewed below, whether the lower end of the range is 2 or 3 is not determinative. At an infusion rate of 50 mics/kg/minute I have determined as discussed below that Ms. Hillis’ blood concentration level was below both and therefore breached the standard of care.

[386] It is crystal clear to me that when Dr. Noble was testifying as to the appropriate range that Ms. Hillis’ blood concentration level should have been between, he was assuming Ms. Hillis also had nitrous oxide (at 53 per cent initially and then at 17 per cent as this is not disputed) and appropriate narcotics on board, since it was his own conclusion that she did have appropriate narcotics/opiates on board. Dr. Noble clarified in his evidence that Dr. Esufali had said the upper end of the range for a blood concentration level of Propofol was 4 mics/ml and that Dr. Noble’s upper end was 5 mics/ml. They were talking about in the same circumstances, with 17 per cent nitrous oxide and potent narcotics. Dr. Noble stated on various occasions in his testimony that the range he put forward, 2 to 5 mics/ml, was with either nitrous oxide or a narcotic. He also testified that if Propofol alone was used the required blood concentration level would be about 12 mics/ml, which he explained is different from his evidence as to the appropriate range for Ms. Hillis’ procedure because she had nitrous oxide and narcotics on board.

[387] Both Dr. Esufali and Dr. Noble agree that there is no way to know exactly what infusion rate of Propofol leads to what level of blood concentration of Propofol in any particular patient. Both of them turned to a study by Schuttler (Exhibit 20), which I will hereinafter refer to as the Schuttler Study. Both experts referred to this as a very large study that took blood samples from patients of different weights and ages. Dr. Noble also referred to other studies but testified that he relied on the Schuttler Study because it was a large study.

[388] The Schuttler Study concluded that for a lean 50 kg adult, the minimum infusion rate of Propofol that is required to maintain 1 mic/ml blood concentration level is 40 mics/kg/min.

[389] Dr. Esufali used this lean 50 kg adult information to calculate blood concentration levels for Ms. Hillis at various infusion rates using her corrected body weight of 58 kg. At an infusion rate of 50 mics/kg/min, Dr. Esufali in chief calculated that Ms. Hillis’ blood concentration level would be 1.08 mics/ml. This would be until almost 9:15 a.m. when I found that the infusion rate was increased to 100 mics/kg/minute. At an infusion rate of 100 mics/kg/minute, Dr. Esufali calculated, again using the Schuttler Study, that Ms. Hillis’ blood concentration would be 2.16 mics/ml and at an infusion rate of 125 mics/kg/min the blood concentration level would be 2.7 mics/ml. What is critical to my analysis is the blood concentration level at 50 mics/kg/min. The level of 1.08 mic/ml is well below the goal of 3 to 4 mics/ml testified to by Dr. Esufali and below the lowest end of the range (2 to 5 mics/ml) provided by Dr. Noble.

[390] Dr. Esufali was challenged in cross-examination as to why he did not use the 70 kg person from the Schuttler Study to do his analysis. I note that in Dr. Noble’s evidence which I will detail below, he also used the 50 kg person and grossed up the number by a percentage to account for Ms. Hillis’ weight above 50 kg. He did not use the 70 kg person. Even using the 70 kg person data from Schuttler, Dr. Esufali calculated that Ms. Hillis’ blood concentration level at an infusion rate of 50 mics/kg/min would be 1.58 or 1.59 mics/ml, again well below 3 mics/ml and still below 2 mics/ml, which was Dr. Noble’s lowest end of the range. This calculation was done using her total body weight.

[391] Specifically with respect to the timing of the awareness episode and the blood concentration levels, Dr. Esufali opined that until approximately 8:55 a.m., Ms. Hillis’ anaesthesia was adequate because even though the blood concentration was below the range, she had 53 per cent nitrous oxide and the Fentanyl and Midazolam that had been given when the procedure started as part of the induction dose and awareness would have been unlikely. He further opined that when the nitrous oxide was decreased and the Propofol did not increase at a proper rate and there were no other adjuncts added that awareness occurred, basically between 8:45 a.m. and 10:00 a.m. I accept this evidence.

[392] Dr. Esufali at all times made it clear that his evidence of a target blood concentration range of 3 to 4 mcg/ml for Propofol was based on the patient also receiving nitrous oxide at over 60 per cent or a potent dose of narcotics given by infusion. He opined Ms. Hillis received neither. My finding above that she received adequate narcotics (including the Dilaudid) does not change his opinion in any way. His opinion assumed adequate narcotics were administered and the required blood concentration level was 3 to 4 mics/ml.

[393] Dr. Noble also did blood concentrations level calculations and in my view, his evidence in this regard supports my conclusion that the Propofol infusion rate Dr. Ghaffari used until he increased it to 100 mics/kg/min at around 9:15 a.m. was in breach of the standard of care.

[394] Dr. Noble looked at a range of literature on Propofol and Propofol infusion rates and related Propofol blood concentration levels. He explained that an anaesthetist can never know what the blood concentration is of Propofol during the procedure so the anaesthetist is guided by the literature. Dr. Noble relied on the Schuttler Study to do his calculations of blood concentration levels. He describes this study as follows:

The biggest study, the most comprehensive, ah – it’s obvious that he understands pharmacokinetics very well, and he has done things that nobody else did. Figure 5 – he looked, he, he did this study on lean patients, in elderly patients, and nobody else took it apart that way, and allowed us to learn something about how these drug might affect specific patients that we have to deal with in different ways. It is statistical analysis is unbelievably complicated. If you ask me to repeat this experiment, there is no way I could possibly do it.

[395] Using the Schuttler Study Dr. Noble opined that if Ms. Hillis was receiving a Propofol infusion at a rate of 100 mics/kg/minute she would have a blood concentration level of Propofol of 3 mics/ml and this would be in the appropriate range. He used the 50 kg lean adult from the Schuttler Study. He agreed with Dr. Esufali that in this person an infusion rate of 40 mics/kg/min will produce a blood concentration of 1 mic/ml. He adjusted for Ms. Hillis total body weight being 63 kg as to her ideal body weight of 53kg and the difference was about 10 kg or 20 per cent of her ideal body weight (10 over 53). He opined that he would use the 50 kg lean person from the Schuttler Study and then adjust for Ms. Hillis’ weight above her ideal body weight. He described this as the effect of fat and answered a specific question in this regard as follows:

Q. So, for example, if you give 100 mcg/kg, the effect of fat on that is what?

A. The 20 per cent increase in fat would mean it would be 120 mics/kg/minute, because you’re using her total body weight. Since 40 mics/kg/minute produces 1 mic/ml in the blood, divide the 40 into 120 and that would state that her blood level would be 3 – 40 into 120.

[396] He clarified that 3 mics/ml would be her blood level when she was receiving an infusion rate of Propofol of 100 mics/kg/minute and he assumed that this was the infusion from the beginning of her surgery, from right after she was intubated. As noted many times above, this assumption does not accord with my factual findings. I can do the same calculation Dr. Noble did with 50 mics/kg/min Propofol infusion rate. The 50 would be increased by 20 per cent to 60 mics/kg/min and then divided by 40, which leads to a blood concentration of 1.5 mics/ml which is below both Dr. Noble’s and Dr. Esufali’s evidence as to what the therapeutic range was. This calculation of 50 mics/kg/min translating to a blood concentration of 1.5 mics/ml was done by Dr. Noble himself as part of his evidence as to why Ms. Hillis was appropriately anaesthetized before she was intubated.

[397] Dr. Noble based his calculations on ideal bodyweight. He also testified that weight was a consideration in dosage that might increase or decrease the dose within the range taken from the literature. He never gave any evidence whatsoever of any circumstances under which Ms. Hillis’ target Propofol blood concentration range would go below 2 to 5 mics/ml. In fact, he said the following applying the Schuttler Study and the 20 per cent increase due to the difference between Ms. Hillis’ total body weight and ideal body weight:

Q. ... so, assuming that 100 mcg/kg/min – 63 [her total body weight] – was put in the kilogram variance, what, how would that translate into the actual dose being experienced by Ms. Hillis?

A. Well, you, you’ve given her 3 mics/ml in the blood, and therefore, you have put her in the middle of the range you want to be at. If you recall, I want, I want it to be someplace between 2 and 5 mics/ml in the blood, because this is not mild, not a major surgical procedure – it’s a half-way in between – and that is the recommended dose.

[398] He clarified the recommended dose was 2 to 5 mics/ml in blood. As set out above, in the first hour and 15 minutes of her procedure she was not above 2 mics/ml. Using Dr. Esufali’s calculations, she was at either 1.08 or 1.58 mics/ml (the difference being whether to use the Schuttler Study’s 50 kg person or 70 kg person) or at 1.5 mics/ml using Dr. Noble’s analysis and calculations. There is no contradictory evidence from either expert. These concentration levels based on an infusion rate for Ms. Hillis of 50 mics/kg/minute fall below Dr. Noble’s low end of the range of a blood concentration level of 2 mics/ml or below Dr. Esufali’s low end of the range of a blood concentration level of 3 mics/ml.

[399] It is not necessary for me to determine whether Dr. Esufali’s blood concentration range is in keeping with the standard (3-4 mics/ml) or Dr. Noble’s (2–5 mics/ml) as the level Dr. Ghaffari administered was below the lower end of either range.

[400] At one point in his cross-examination, Dr. Noble suggested that if the nitrous oxide was reduced when the infusion of Propofol was 50 mics/kg/min that would be a low dose of anaesthesia but it would still be compatible with no awareness under anaesthesia. He never addressed this in chief. It was not canvassed any further in cross. He did not say at what time period he was considering. This bald statement does not change my analysis. It is inconsistent with his own evidence that at 50 mics/kg/min the expected blood concentration level would be 1.5 mics/ml, below the low end of the target range. Other than around the time of the bolus induction dose of Propofol, this statement is inconsistent with all of the other evidence. According to both Dr. Esufali and Dr. Noble the effect of the induction bolus of Propofol was “gone” from the brain by 8:45 a.m. – 8:50 a.m. when the nitrous oxide was decreased.

[401] This is not an issue of clinical or medical judgment. As Dr. Noble testified clinical judgment is applied by the anaesthetist to choose a dose within the range. Dr. Ghaffari’s infusion dose of 50 mic/kg/min was not within the range.

[402] Both experts spoke of “patient variability.” Patient variability, as explained by Dr. Noble, means that an individual patient’s response to anaesthetic doses are not guaranteed to accord with the literature. In other words, a patient who has been dosed based on average therapeutic ranges, and is anticipated to have a blood plasma Propofol concentration that falls within therapeutic ranges such as 3 to 4 mics/ml, may actually have a blood Propofol concentration level as low as 1 mic/ml or as high as 8 mics/ml. The Defendants argue that because of patient variability more deference is owed to the process of monitoring a patient’s clinical response and the exercise of clinical judgment.

[403] In my view, the concept of patient variability does not apply in this situation in the manner Dr. Noble described. Ms. Hillis was not dosed based on average therapeutic ranges. The infusion rate of 50 mics/kg/min was not expected by the literature to lead to a blood concentration level for her within the appropriate range. This has been demonstrated above.

[404] I also add that Dr. Esufali testified that in Ms. Hillis’ situation patient variability would have led a prudent anaesthetist to increase Ms. Hillis’ anaesthesia dose. She was young and otherwise healthy (no cardiac or respiratory issues) and could have been safely administered a fairly deep anaesthesia. Dr. Noble was asked about this in examination in-chief and in cross-examination. In his examination in chief, Dr. Noble said it was possible she might have tolerated more Propofol and possible she might not have. He said this assuming at the key time she was receiving 100 mics/kg/min when she was actually only receiving 50 mics/kg/min. Clearly, on his own evidence she could have tolerated more as he assumed she was appropriately and reasonably receiving more. Further, Dr. Noble was clear there is a range of 2–5 mics/ml blood Propofol concentration set by the literature. Her level was either 1.08 or 1.58 or 1.5, so clearly she could have tolerated more. The infusion rate was 50 mics/kg/min. Dr. Esufali talked about a bolus of Propofol being given when the nitrous oxide was decreased or an immediate increase in the infusion rate of Propofol or an increase in the infusion rate of Propofol occurring before the nitrous oxide was decreased. He was not suggesting an overdose level of medication. I understood him to be suggesting an increase within the therapeutic dose range.

[405] Dr. Noble testified in cross-examination that Dr. Ghaffari met the standard for the administration of the Propofol infusion and that patient variability and the inability to measure blood concentration levels with TIVA are the reasons for this conclusion. This ignores that Dr. Ghaffari was not providing an infusion rate to deliver a blood concentration level within the therapeutic range for at least the first hour and 15 minutes of the procedure. This was initially covered by the induction doses of medication and the nitrous oxide at 53 per cent. Then the nitrous oxide was significantly reduced and the bolus induction dose of Propofol was gone. It was at this critical time that Dr. Esufali opines that the awareness occurred.

[406] There was an issue raised as to whether the induction dose of Propofol should have been included in the calculation of the blood concentration levels at the time the nitrous oxide was decreased. It is uncontroverted that Ms. Hillis received 150 milligrams of Propofol by injection (bolus) as part of her induction dose of medications at the outset of the procedure. This was approximately 45 minutes before the nitrous oxide was decreased. Dr. Esufali testified that this induction dose “has gone.” He described it as out of the system (Ms. Hillis’) and not contributing to anaesthesia. Dr. Noble testified that with an increased infusion rate of Propofol between 100 and 170 mics/kg/min Dr. Ghaffari was providing a predicted blood level of 4.05 mics/ml using the Schuttler Study data. The infusion dose was providing 3 mics/ml and the “tail end of induction dose” the additional 1.05. The induction dose was given by bolus at about 8:05 a.m. In my view, this information does not change my analysis. First, the 4.05 mics/ml level is predicted on the infusion rate being 100 mics/kg/min in the first hour which I have found it was not. Second, accepting that the bolus of Propofol given as part of the induction dose did increase the blood concentration level of Propofol when it was administered, Dr. Esufali testified that its affect was gone when the nitrous oxide was decreased. This is consistent with the evidence concerning the half-life of Propofol as set out above. The bolus would have cleared the brain long before the nitrous oxide was decreased (1.33 minutes - the half-life x 5 = 6.65 minutes to clear the brain). Dr. Noble also testified that in the first 10 minutes of the procedure, Ms. Hillis had blood Propofol concentration of 3 mics/ml. He calculated this using1.5 mics/ml from the 50 mics/kg/minute and 1.5 mics/ml from the infusion dose. He never suggested at any point in his testimony that the one-time induction dose (150 milligrams) would still be contributing to the blood concentration level 45 minutes into the procedure when the nitrous oxide was decreased. This would be completely inconsistent with his own evidence of the half-life of Propofol in the brain.

[407] I have dealt briefly above with the issue of the Dilaudid administered to Ms. Hillis about 15 minutes before the nitrous oxide was decreased. I want to summarize my analysis on this issue. Dr. Esufali’s evidence on the appropriate blood concentration range for Propofol assumed Ms. Hillis had either approximately 60 per cent nitrous oxide or potent narcotics on board as did Dr. Noble’s evidence on the appropriate blood concentration range. They differed on whether she had adequate narcotics on board but both assumed in their evidence as to the appropriate Propofol blood concentration level and corresponding infusion range that she did. The Dilaudid (200 mg given at 8:30 a.m.) was considered as part of both of their assumptions of adequate narcotics. With the narcotics on board, including the Dilaudid, Dr. Noble testified she needed to be in the Propofol blood concentration range from 2 to 5 mics/ml and she wasn’t.

[408] Dr. Noble testified that Dr. Ghaffari had to do something to replace the decrease in nitrous oxide and since nitrous oxide is creating analgesia, the replacement would be an opioid. He testified that Dr. Ghaffari reasonably accounted for this by giving the 2 mg of Dilaudid before the nitrous oxide was decreased. Dr. Noble assumed Ms. Hillis was receiving 100 mics/kg/min of Propofol infusion at this very time. She wasn’t. She was receiving a dose below the therapeutic dose required with potent narcotics on board. The breach of the standard of care is in the infusion dose rate of Propofol being administered at 50 mics/kg/min for the first hour and 15 minutes of the procedure.

[409] Dr. Esufali was asked questions about the synergistic effects of Fentanyl and agreed that Fentanyl reduces the amount of Propofol required. This was uncontroverted. Both Dr. Noble and Dr. Esufali agreed to this. What is important is that they both assumed appropriate narcotics were in place, in the patient, when they gave their therapeutic ranges for blood concentrations of Propofol. They already factored in the benzodiazepine and its synergistic affect. They both assumed these adjunct medications were given as part of the balanced anaesthesia approach, when they gave their evidence on the therapeutic Propofol blood concentrations and related infusion rates.

[410] In the cross-examination of Dr. Ghaffari, questions were asked about what Dr. Ghaffari said about why he gave the Dilaudid at his examination for discovery and what he said were the reasons at the trial and whether the reasons were different. Similar questions were put to Dr. Noble and specifically whether Dr. Noble has attributed a reason to Dr. Ghaffari for giving the drug that Dr. Ghaffari did not allude to at his examination. In my view, this is not relevant to my analysis on the Propofol issue. As I have made clear, both Dr. Esufali and Dr. Noble in giving evidence on the appropriate target Propofol blood concentration levels assumed with these levels that the patient would have potent, appropriate narcotics on board. Even though Dr. Esufali incorrectly determined Ms. Hillis did not have appropriate narcotics on board when he looked at the Fentanyl/narcotic issue, when he looked at the Propofol issue, he gave his evidence on the appropriate range required to meet the standard of care assuming proper narcotics were on board.

[411] Counsel made submissions as to whether Dr. Ghaffari’s charting of the Propofol infusion rates breached the standard of care. Both experts gave evidence on this issue. I do not need to reconcile this discrepancy. There is no way that charting caused Ms. Hillis’ period of awareness.

[412] Dr. Noble criticized Dr. Esufali’s evidence claiming that Dr. Esufali put too much emphasis on the retrospective part of it. He referred to Dr. Esufali having seen Dr. Noble’s three reports when Dr. Esufali provided his opinion. I don’t accept this criticism. It was totally appropriate for Dr. Esufali to review all relevant documents before providing his opinion. The exercise is by necessity retrospective. Dr. Esufali is looking at Ms. Hillis’ 2008 medical reports for this procedure. This is the process. It in no way changes my analysis and findings that Dr. Ghaffari did not give a therapeutic dose of Propofol infusion as detailed elsewhere in these Reasons.

[413] It is absolutely true and Dr. Esufali acknowledged that unlike Dr. Ghaffari during the surgery or in formulating his anaesthesia plan, Dr. Esufali had the benefit of the Anaesthetic Record after it was completed as well as all post-operative consultation notes, developments and discovery transcripts. There is nothing inappropriate or unusual about this. It does not change my view of Dr. Esufali’s evidence. Dr. Esufali did note in his cross-examination that in terms of Ms. Hillis’ blood pressure and whether there was room to increase anaesthetic agents, Dr. Ghaffari did have blood pressure recordings every five minutes and he could record her blood pressure as often as he liked. He could alter an anaesthetic agent and see how the blood pressure responded. He agreed that the anaesthetist doesn’t know what the reaction of the patient will be until the dose is administered.

[414] In cross-examination it was put to Dr. Esufali that anaesthetists are not readily able to correctly identify awareness cases just using the Anaesthetic Record. Dr. Esufali agreed. In my view, this does not affect any of the analysis above. First, neither Dr. Noble nor Dr. Esufali only had the Anaesthetic Record. Each had many more documents available. Second, their evidence as to the appropriate blood concentration range for Propofol and related infusion rate did not come from the Anaesthetic Record. My finding as to the infusion rate came from the Anaesthetic Record itself and other evidence. I accept Dr. Esufali’s evidence when he responded to this and said the following:

... it’s still very possible to use pharmacologic knowledge and knowledge of the patient, in order to, in order to give you the highest chance that awareness will not occur. It’s very different.

Q. It’s not reliable looking at a record on its own, for you to determine one way or another, whether a patient has had awareness. Right?

A. Right. But I can tell you, I can tell you that, I can tell you the chance, I can tell you if there is a higher probability that a certain patient would have awareness based on the anaesthetic that was given. I can certainly do that.

[415] As both experts agree, it is possible for a patient to have an episode of awareness with no signs evident to the anaesthetist. In my view, this doesn’t change that an anaesthetist is required to meet the standard of care in choosing doses of medications to administer in a balanced anaesthetic.

[416] Dr. Esufali agreed that in Exhibit 12, an article on awareness and recall, the authors concluded “that the current results do not justify the notion that anesthesiologists are able to correctly identify an awareness case by judging the anesthetic record.” This does not mean anaesthetists are expected to meet the standard of care in the administration of Propofol.

[417] There was no evidence from either expert to suggest that Dr. Ghaffari did not monitor Ms. Hillis properly. Both experts stated that in a small percentage of patients there are no signs of awareness. I make no finding that Dr. Ghaffari failed in any way to monitor Ms. Hillis properly.

[418] For the reasons set out above, I find that Dr. Ghaffari did not meet the standard of care in his administration of the infusion of Propofol and specifically that in the period between the reduction in nitrous oxide and the first up tick in the infusion rate of Propofol (approximately 9:15 a.m.) the infusion rate was insufficient and below the therapeutic range.

III. Causation

[419] Dr. Esufali testified that awareness occurs in approximately 1 of every 1000 or every 2000 patients undergoing general anaesthetic. Dr. Noble testified that awareness occurs in approximately 1 of every 1000 patients undergoing general anaesthetic. Both experts agreed that it is not possible to guarantee to a patient that awareness will not occur despite the best of intention and that despite the honest and intelligent exercise of medical judgment an adverse event can still occur. It is within this context that I consider the issue of causation.

[420] I find that on a balance of probabilities the Plaintiff has established that the Defendant, Dr. Ghaffari, caused her injury (in this case, awareness). I am satisfied on a balance of probabilities that but for Dr. Ghaffari’s negligence in the administration of the Propofol infusion, Ms. Hillis’ injury would not have occurred. This is based on several findings which I will outline below.

[421] Ms. Hillis’ awareness did not result from unique patient variability, as offered by Dr. Noble. I have found that it resulted from the significant reduction of nitrous oxide without Dr. Ghaffari implementing any of the means available to address the decrease, such means are outlined above. He failed to administer in this critical period a Propofol infusion predicted to provide a blood concentration level within the therapeutic range.

[422] Patient variability applies when a patient is anaesthetized with levels of anaesthetic drugs considered appropriate to be within therapeutic dose ranges but nevertheless experiences awareness. This is not what happened in this case. Ms. Hillis was not given an appropriate

infusion rate of Propofol. Here there was a discrete loss of an important agent and a delay in implementing a replacement agent at the very time the Propofol infusion was too low to be within the predicted goal posts of blood concentration levels. This all resulted from Dr. Ghaffari’s actions or inactions.

[423] Dr. Esufali testified in-chief as follows:

... I think with the addition of like 50 %, or 53% nitrous oxide, and the fentanyl that was given, and the midazolam that was given, I think awareness would have been very unlikely, in this first hour here. In this first hour, I think it was unlikely. It was when the nitrous changed, and the propofol did not go up at a, at a proper rate, and there were no other adjuncts added, that I think that this is where the awareness occurred.

[424] He put the timeframe as to when the awareness occurred between 8:45 a.m. and 10:00 a.m. As set out above I accepted this evidence. I did not accept Dr. Noble’s evidence as he based his entire evidence on an incorrect assumption as to the Propofol infusion rate at the time the nitrous oxide decreased. Dr. Esufali’s evidence as accepted establishes the cause of the awareness.

[425] Dr. Esufali also testified as follows in-chief:

Q. So doctor, if the – Dr. Ghaffari had undertaken what you have previously told us about, which is the step-down model, and taken the other steps that you have told us, in your opinion, the prudent anaesthetist should have taken in these circumstances, what is your opinion as to the likelihood that this period of awareness would have been avoided by – of Ms. Hillis?

A. I think it would be much less likely.

Q. And doctor, secondly, doctor, do you have an opinion as to whether, had it been – had the (inaudible) anaesthetic been administered as you’ve indicted a prudent anaesthetist ought to have done, what’s your opinion as to whether Ms. Hillis would have been carried successfully through this surgery without a period of awareness?

A. So I think she, I think it would be much less likely that she would have had a period of awareness, and it could have been done very, very, very safely. As you can see from the anaesthetic record, at 8:00 o’clock her blood pressure was 120 over 60. Her heart rate was around 85. And at no time in the operation, at no time in the operation is there a period of instability in terms of heart rate, in terms

of blood pressure. The blood pressure never drops into an unsafe level, where you would say I can’t give more propofol. The blood pressure actually does rise a little, 100/140, even 150. So about – as much, as much as 25% up from baseline, but certainly no, there was certainly no hypotension or anything to indicate that it was unsafe to give her either more fentanyl, or more propofol, or more midazolam. Things to, things that would have all minimized, all help minimize the risk of awareness.

[426] These paragraphs must be taken together with Dr. Esufali’s opinion as to when the awareness occurred and why. He was clear in his evidence as to the cause of the awareness. I accepted the evidence. The evidence above states without the negligence the risk of awareness occurring was “less likely” and “much less likely.” Since there can never be a 100 per cent guarantee, the choice of these words is appropriate. Taken all together, Dr. Esufali’s evidence is that the low infusion rate of Propofol when the nitrous oxide was decreased without other action caused the awareness.

[427] In my view, Dr. Noble’s evidence supports this conclusion. Dr. Noble testified that awareness is more common under TIVA than it is under an inhaled anaesthetic technique. He also testified as to the purpose of the limits to the range of Propofol blood levels suggested in the authoritative Miller text as follows:

A. That there are two limits to the range suggested by Miller. One is to prevent awareness under anesthesia, a [t]he low end, and the other is to prevent overdose, at the high end. That's why we have that, otherwise, he would simply say, 'Let's do anything over 2mics/ml. He doesn't. He says 2mics/ml is the low; 5mics/ml is the high – I want you to [b]e in-between those two limits.

[428] He described the lower limit as there to prevent awareness. Ms. Hillis’ blood concentration was predicted to be below the blood concentration lower limit at the critical time. The lower limit according to Dr. Noble is in the text to “prevent awareness.” Ms. Hillis’ infusion rate was predicted to lead to a blood concentration level of Propofol which was below the lower limit and she had awareness. On the balance of probabilities the two are causally connected.

[429] This is exemplified in Dr. Noble’s further evidence in cross when he was asked about his evidence that a bolus of Propofol should not be given and why did not say this in his written report. He answered:

I made an assumption that you would understand that if you went beyond the top range, you get into trouble, just as if you go below the bottom level, you get into trouble

[430] Dr. Noble was talking about the amounts of Propofol. Dr. Ghaffari administered an infusion rate predicted to lead to a blood concentration level below the bottom level. Ms. Hillis got into trouble – the awareness. Again, causation is established.

[431] Further, Ms. Hillis’ circumstances were not those that appear to be