Hock (Next friend of) v. Hospital for Sick Children

Between
Jessica Aaren Hock, an infant under the age of eighteen years
by her next friend Arthur John Hock and the said Arthur John
Hock, plaintiffs/respondents, and
The Hospital for Sick Children, William Williams, Dr. Salter,
W. Feteith, P. Gow, D. Willson, G.C. Mullins, Jeffrey
Smallhorn, A. Gerber and Desmon Bohn, defendants/appellants

[1998] O.J. No. 336
DRS 98-07782
Docket No. C21778

Ontario Court of Appeal
Toronto, Ontario
McMurtry C.J.O., Osborne and Charron JJ.A.

Heard: February 3, 4, and 5, 1997.
Judgment: January 30, 1998.
(81 pp.)

   Appeal by two doctors, Williams and Smallhorn, from a judgment finding them negligent for damages sustained by the minor plaintiff, Hock, while in their care.  There was a cross-appeal by the plaintiffs from the dismissal of the action against the other defendants.  Hock was born 1978 with a heart defect.  Shortly after her birth, a catheterization was conducted and showed the presence of anomalous muscle bundles in her right ventricle.  Surgery for this was not done until a child was four years old.  In 1983, Hock was admitted to the Hospital for Sick Children for surgery.  Before the operation, Smallhorn performed an echocardiogram and a catheterization, which would provide a current picture of her condition. Smallhorn concluded that Hock did not have anomalous muscle bundles in her right ventricle.  Williams then performed the operation.  While in the ICU, Hock had cardiac output problems. Both a catheterisation and echocardiogram suggested there was obstructive muscle in her right ventricular cavity.  Another operation was performed to remove tissue from the ventricle. This alleviated her condition, but she sustained brain damage as her cardiac output had been too low for too long.  An action was commenced against Williams, Smallhorn and the hospital physicians.  The trial judge found that Williams was negligent as he failed to excise sufficient tissue in the first procedure and he did not pay enough attention to repeated references in Hock's medical records to the anomalous muscle bundles.  This contributed to Hock's brain damage.  Smallhorn was negligent because he failed to inform Williams of his negative findings and because he failed to consult with Williams as to the best strategy for the operation.  The ICU doctors were not found to be negligent because they provided the appropriate level of care.

   HELD:  Smallhorn's appeal was allowed; Williams' appeal was dismissed.  The cross-appeal against the other defendants was dismissed.  Hock established that the brain damage was caused, or was materially contributed to, by Williams' impugned conduct.  There was ample evidence to support the trial judge's main finding that Williams failed to remove obstructive tissue in the first operation.  What Williams failed to do more than a mere error in judgment.  The trial judge was entitled to conclude that this failure led to Hock's brain damage since such tissue affected cardiac output.  The trial judge committed no palpable or overriding error in this analysis.  In Smallhorn's case, his obligation was to perform the pre-operative procedures and to provide his opinion to Williams. He did both and had nothing to do with Hock's care thereafter. A surgeon's review of a patient's chart before surgery was so fundamental that Smallhorn could reasonably assume that Williams would review Hock's hospital records and her pre-operative angiogram.  The trial judge's relative narrow finding of breach of duty in the case of Smallhorn was questionable.  Causation was not established for even if Smallhorn had discussed his opinion with Williams earlier, it would not have made a difference.  There was no reason to interfere with the finding regarding other defendants as the court agreed with the trial judge's analysis that the ICU physicians furnished proper care for Hock.

Statutes, Regulations and Rules Cited:

Counsel:

      The judgment of the Court was delivered by

      OSBORNE J.A.:—

OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . 3

THE TRIAL JUDGMENT . . . . . . . . . . . . . . . . . . . . .10

THE GROUNDS OF APPEAL AND THE POSITION OF THE PARTIES. . . .13

THE EVIDENCE . . . . . . . . . . . . . . . . . . . . . . . .20

      (ii) The May 26, 1983 Surgery . . . . . . . . . . . . .24

      (iii)The Pressure Readings . . . . . . . . . . . . . . 27

THE STANDARD OF APPELLATE REVIEW . . . . . . . . . . . . . .38

ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . .40

      (ii) The Duty and Standard of Care. . . . . . . . . . .52

      (iii)Causation . . . . . . . . . . . . . . . . . . . ..53

      (iv) The Liability of Dr. Williams. . . . . . . . . . .56

      (v)  The Liability of Dr. Smallhorn . . . . . . . . . .63

CROSS-APPEAL . . . . . . . . . . . . . . . . . . . . . . . .75

CONCLUSION . . . . . . . . . . . . . . . . . . . . . . . . .80

1      Jessica Hock, then four years old, sustained brain damage in May 1983, when she was a patient in the Hospital for Sick Children (the "Hospital"), for surgery to repair a congenital heart defect.  The trial judge, Hawkins J., found that two of the defendants, William Williams (a cardiac surgeon) and Jeffrey Smallhorn (a cardiologist) were negligent and thus liable to the plaintiffs for damages, which the parties agreed to in the form of a structured settlement. Drs. Williams and Smallhorn appeal from the trial judge's liability findings.

2      The trial judge dismissed the plaintiffs' action against all other defendants.  The plaintiffs cross-appeal from that decision.  The successful individual defendants were engaged in Jessica's post-operative care in the Hospital's intensive care unit ("ICU").  The plaintiffs also cross-appeal from the dismissal of their action against the Hospital which the plaintiffs submit employed ICU doctors Bohn and Mullins, both defendants against whom the action was dismissed.

3      Finally, the plaintiffs seek leave to appeal from the trial judge's order that required them to pay the costs of the successful defendants with no right to add those costs to the costs to which they were entitled from the unsuccessful defendants, Drs. Williams and Smallhorn.  During the appeal we were advised that counsel would settle the issue of costs, or seek leave to make further submission on that issue, once this judgment is released.  I will, therefore, not address the issue of costs apart from dealing with the costs of the appeal.

OVERVIEW

4      I will refer to the evidence in more detail when I consider the issues raised in the appeal and cross-appeal. For now, I propose to set out in a general way how Jessica Hock came to be at the Hospital for Sick Children on May 23, 1983 for cardiac surgery and what happened to her while she was there.

5      Jessica was born in Thunder Bay on June 22, 1978. She was periodically cyanotic and exhibited other signs of a heart defect.  She was what is commonly referred to as a "blue baby."  As a result of what was thought from the outset to be a congenital heart defect, she was referred to Dr. Neelands, who in turn referred her to the Hospital for investigation on August 3, 1978.

6      On August 3, 1978, she underwent a cardiac catheterization, a procedure designed to provide information about the anatomy of her heart.  It involved the introduction of a catheter, through a sheath inserted into her right femoral vein, into her heart and the injection of dye to enable an x-ray moving picture (an angiogram) to be taken of her heart as it beat.  As part of the process blood pressures in various regions of the heart and surrounding vessels were obtained.  These may provide useful information for diagnostic purposes.

7      In his August 3, 1978 catheterization report, under the heading "Impressions", Dr. Culham noted the presence of anomalous muscle bundles in Jessica's right ventricle.  I will refer to his report in more detail later.  He did not attach a name to Jessica's condition, however, other physicians who were involved concluded that Jessica's heart defect was Tetralogy of Fallot ("Tetralogy").  In general terms, the typical features of Tetralogy are:

8      It is common ground that no two tetralogy cases are alike.  They do, however, have common characteristics.

9      In a typical Tetralogy case, since the muscles within the right ventricle are over-worked, they become thickened, or hypertrophied.  Thus, the basic condition of the right ventricle in a Tetralogy case tends to worsen with time. The right ventricle becomes thick and somewhat plastic.

10      After the catheterization of August 1978, it was apparent that Jessica required surgery.  At that time surgery was not undertaken in Tetralogy cases until the patient was four or five years old.  In result, Jessica was sent home to await surgical intervention when she reached that age.

11      On March 29, 1982, Jessica's case was discussed at a staff conference at the Hospital.  It involved about 12 doctors, including 10 cardiologists.  The report generated by this case conference referred to anomalous muscle bundles, among other right ventricular deficiencies.  It was decided that Jessica should undergo open heart by-pass surgery in May 1983 for a total repair of her heart defects.

12      Jessica was admitted to the Hospital on Monday, May 23, 1983 for surgery scheduled for Thursday, May 26, 1983. The admitting record referred to ventricular septal defect with pulmonary stenosis (narrowing) at the valvar and right ventricular level.  The record also noted that pulmonary stenosis at the right ventricular level, "consisted mainly of anomalous muscle bundles."  This reflected the conclusions reached in 1978 following Jessica's catheterization and in 1982 at the cardio-surgical conference.

13      Dr. Williams, the cardiac surgeon assigned to operate on Jessica, testified that the routine in the cardiac unit of the Hospital was to meet every Monday morning to review patients who were scheduled for surgery during that week.  This review would include a review of echocardiograms, angiograms, and any other pertinent information.  He assumed that this meeting was held on Tuesday, May 24, 1983, since Monday the 23rd, was a holiday.  The meeting would have included Dr. Williams as well as surgical residents, cardiac staff, cardiac radiologists and representatives from Intensive Care and Anaesthesia.  During these meetings the angiogram is projected and a cardiac radiologist typically comments on the angiographic findings.  Those in attendance have a chance to ask questions.  The meetings generate no reports.   Jessica's May 24, 1983 angiogram was done after the meeting, if there was such a meeting.  Dr. Williams had no independent recollection of this meeting.

14      According to Dr. Williams, there is also a catheterization conference held each day at 8:30 a.m.  This conference involves a discussion among cardiologists about patients who are scheduled for catheterization during the day and patients who have particular problems.  Whether Jessica's case was discussed at this regular morning meeting is unclear.

15      Understandably, Dr. Smallhorn, the cardiologist responsible for Jessica's pre-operative investigations, also had no independent recollection of these regular meetings which produced no paper record that might have refreshed his memory, or even confirmed his attendance.  However, he said that he must have been present at the catheterization meeting because he was responsible for the catheterization laboratory on May 24, 1983.  He testified that Jessica's angiograms and other relevant material would have been presented to staff cardiologists and that material findings would have been discussed, likely on May 24, 1983.  He said that this information would have been passed on to the surgeons.

16      Before her surgery on May 26, 1983, Jessica underwent two pre-operative investigative procedures.  On May 23rd, Dr. Smallhorn performed an echocardiogram and on May 24th he did another catheterization.  These procedures were done to provide a current picture of Jessica's heart, to give the surgeon as much information as was reasonably available about her condition.

17      Dr. Smallhorn concluded from his May 23rd echocardiogram that there was no evidence of "anomalous muscle bundles" in Jessica's right ventricle.  His catheterization report made no mention of muscle bundles, anomalous or otherwise.

18      On May 26, 1983, Dr. Williams, assisted by Dr. Feteih, undertook the surgical repair of Jessica's heart defects.  He took blood pressures following the surgery and thought that they were satisfactory.  One of the critical factual issues at trial was what, if any, muscle was excised (cut out) or divided (cut into) during this surgery.  Within a short time following surgery Jessica was taken to the Hospital's ICU.

19      Not long after Jessica's arrival in the ICU, she encountered problems with her cardiac output.  She developed junctional ectopic tachycardia ("JET"), a condition that ICU doctors thought was the cause of her low cardiac output. Persistent bouts of tachycardia, or JET, caused great concern among the ICU doctors and threatened Jessica's life.

20      Jessica's mean arterial pressure fell to an alarming level on May 27, 1983; at 11:00 p.m. on that day a doctor and nurse in the ICU noticed signs of seizure activity. Her seizures were quickly brought under control.

21      ICU physicians attempted to remedy Jessica's problems in a variety of ways.  I will refer to the particular steps taken later.  When no meaningful improvement in her cardiac output had been made by noon on May 28, 1983, in spite of the fact that her tachycardia had ended, Dr. Pelech, a resident cardiologist, decided to perform another echocardiogram.  It suggested the presence of obstructive muscle bundles in her right ventricle.  Dr. Pelech contacted Dr. Smallhorn, who decided to repeat the process.  His echocardiogram, done at about 2:00 p.m. on May 28th, also suggested obstructive muscle in Jessica's right ventricular cavity.

22      Since the possible existence of obstructive muscle in Jessica's right ventricle provided a new explanation for her low cardiac output, Dr. Smallhorn contacted Dr. Williams who came to the hospital on Saturday evening. Notwithstanding the existence of substantial risks to Jessica, Drs. Williams and Smallhorn and ICU doctors on duty decided to have Jessica taken to the catheterization laboratory around midnight on May 28th for another catheterization.  It confirmed the existence of muscle bundles in her right ventricle.  Dr. Smallhorn concluded that further surgery was necessary in order to save Jessica's life, and Dr. Williams agreed.  Thus, she was rushed to the operating room at about 4:30 a.m. on Sunday, May 29, 1983.  Dr. Williams divided (or completed the division of) her moderator band and excised tissue thought to be obstructive.  The second surgery relieved the obstruction in Jessica's right ventricle.  Her condition improved, although not as rapidly as had been hoped.  Jessica survived, but she is neurologically and developmentally impaired.  Her cardiac output had remained too low for too long.

THE TRIAL JUDGMENT

23      The trial, in which there was evidence of considerable complexity, took 26 court days.  Daily transcripts were prepared and counsel submitted written argument.  After reserving judgment, the trial judge concluded that Drs. Williams and Smallhorn, were negligent and that the plaintiffs had not established negligence in respect of the other individual defendants.  He therefore dismissed the action against all defendants except Drs. Williams and Smallhorn.

24      The trial judge's reasons are brief.  He did not refer to the evidence in any detail.  When he did refer to the evidence, he emphasized the information about Jessica's condition generated by the angiograms done on August 3, 1978 and May 24, 1983, and the cardio-surgical conference of March 29, 1982.  He highlighted references made, and not made, to anomalous muscle bundles.

25      When he considered what Dr. Williams did during Jessica's May 26, 1983 surgery, he concluded that "... the best evidence of the procedures carried out to be the reports generated at that time."  He noted that in the reports generated by Jessica's first surgery there was no reference to the division of her moderator band, or to the excision of any muscle or tissue.  He also noted that Dr. Williams' reporting letter to Dr. Izukawa dated May 26, 1983 also made no reference to dividing or incising Jessica's moderator band, or to the excision of tissue and that no tissue was sent to the Hospital's pathology department for analysis.  He then concluded:

26      Quite clearly, the trial judge found that Dr. Williams did not half divide Jessica's moderator band or remove obstructive muscle during the first operation.  He concluded that Dr. Williams did not pay sufficient attention to repeated references to anomalous muscle bundles in Jessica's medical records.

27      When the trial judge dealt with Dr. Smallhorn's liability, he emphasized that the purpose of the pre-operative echocardiogram and catheterization was "... to assist the surgeon [Dr. Williams] to understand the probable and possible problems to be encountered during the surgery."  He concluded that Dr. Smallhorn breached the duty of care that he owed to Jessica by not informing Dr. Williams of his "negative findings" before the May 26th surgery.  Dr. Smallhorn's findings were "negative" in that he had concluded that Jessica did not have anomalous muscle bundles in her right ventricle. This finding differed from earlier reports that referred to anomalous muscle bundles.

28      When he dealt with causation in respect of Dr. Williams' negligence, the trial judge expressed the opinion that Dr. Williams' failure to excise "sufficient tissue" in the first operation was the cause of Jessica's brain damage, I assume on the basis of evidence that Dr. Williams' failure to excise obstructive muscle caused or materially contributed to her extended low cardiac output.  The trial judge did not deal separately with causation as it related to his finding of negligence against Dr. Smallhorn.  One has to assume that he found that Dr. Smallhorn's failure to alert Dr. Williams to the earlier anomalous muscle bundle findings (not his failure to detect anomalous, or obstructive, muscle bundles) contributed to Dr. Williams' failure to remove obstructive muscle during Jessica's May 26th surgery.

29      The trial judge concluded that the ICU doctors, five of whom were defendants, provided an appropriate level of care when Jessica was in the Hospital's ICU.  This conclusion is challenged on the cross-appeal.  I take it from the trial judge's brief reference to this liability issue that he found that the ICU doctors who treated Jessica had no reason to think that her low cardiac output might be attributed to residual obstructive muscle in her right ventricle.  It is clear that the trial judge found that, in the circumstances, the specific remedial efforts undertaken in the ICU were appropriate in both selection and timing.

30      Since Dr. Williams and Dr. Smallhorn were jointly represented, and did not claim over against each other, the trial judge did not apportion liability as between them.

THE GROUNDS OF APPEAL AND THE POSITION OF THE PARTIES

31      The appellants raise the issue of the reasonableness of the trial judge's finding that both Drs. Williams and Smallhorn were negligent.  They submit that these findings are not supported by the evidence.  They further submit that in Dr. Williams' case the trial judge failed to make allowance for the reasonable latitude to be accorded a surgeon in exercising his professional judgment in the course of surgery.  They also take issue with the trial judge's failure to consider evidence bearing upon the applicable standard of care, an issue the appellants contend the trial judge did not address.  They further contend that the trial judge misapprehended the defence position and evidence material to it.  In addition to their attack on the reasonableness of the trial judge's findings of negligence against Drs. William and Smallhorn and their general contention that the trial judge misapprehended or failed to consider the defence position and evidence that supported it, the appellants take issue with the sufficiency of the trial judge's reasons for judgment.  They contend that his failure to make essential findings of fact and his failure to give reasons for findings that he did make, give rise to a miscarriage of justice.

32      The appellants emphasize that the plaintiffs' case at trial was that Dr. Smallhorn's diagnosis (no anomalous muscle bundles) was wrong and that his error led to Dr. Williams' failure to excise obstructive muscle in the May 26, 1983 operation.

33      The appellants' position is that Dr. Williams was aware of the existence of "muscle bundles" in Jessica's right ventricle before he operated on her on May 26th, 1983.  He viewed these muscle bundles to be part of the spectrum of Tetralogy of Fallot and thus he rejected the label "anomalous muscle bundles".  The appellants contend that during the May 26th surgery Dr. Williams partly divided the moderator band, in addition to closing the VSD, patching the infundibulum, removing some muscle tissue and enlarging the pulmonary valve. The appellants contend that excision and division of muscle tissue are functional equivalents and that the choice is a matter of surgical judgment.

34      The appellants submit that Dr. Williams achieved a complete Tetralogy repair.  Although Dr. Williams acknowledges that dividing the moderator band is not usually done to relieve obstruction in Tetralogy cases, the appellants submit that what Dr. Williams did during the May 26th surgery represented the reasonable exercise of surgical judgment, a feature of this case that the appellants submit the trial judge ignored.

35      It is accepted that the cause of Jessica's brain damage was a prolonged period of low cardiac output -- an inadequate flow of blood in the post-operative period following her May 26th, 1983 surgery.  One of the critical issues at trial was what caused her prolonged low cardiac output.  The appellants contend that her tachycardia, or JET, a life threatening condition (20 to 50% of those who have JET do not survive) caused her low cardiac output.  The appellants also submit that how much muscle tissue to excise in a Tetralogy case is a matter of surgical judgment and that without JET and other complications affecting Jessica's already compounded and surgically traumatized right ventricle any muscle tissue left in Jessica's right ventricle would not have caused cardiac output problems.  The respondents contend that Dr. Williams' failure to excise obstructive muscle caused Jessica's injuries and that there was ample evidence to support the trial judge's finding on that issue.

36      The appellants explain the residual obstruction disclosed on the May 28th and 29th echocardiograms to catheterization on two bases.  First, they submit that had Jessica not developed JET, any residual muscle that remained in her right ventricle after her May 26th surgery would not have affected her cardiac output.  Second, they say that the extent of the residual muscle, part of which they contend was excised during Jessica's May 29th surgery, was the product of the cumulative effect of the trauma caused by the first surgery, the potential for increased muscle obstruction brought about by inotropic drug therapy and swelling resulting from cardioversion and renal failure. One defence expert, Dr. Cornel, said that the combination of post-operative circumstances could have lead to what he described as "dynamic obstruction". Such an obstruction could make an existing muscle prominent and produce on a transient basis, an obstructive muscle which, combined with other factors (including JET), could account for Jessica's low cardiac output and her brain damage.

37      The appellants submit that Jessica's low cardiac output was caused by her tachycardia (however it is to be labelled), which had a direct negative impact on her cardiac output.  They emphasize the fact that Jessica's right ventricle was compromised going into her May 26th surgery, traumatized during the surgery, and aggravated to an extent by the treatment that she received in the ICU to control JET, a life threatening form of tachyarrythmia.  These compounding features, according to the appellants, compel the conclusion that nothing Dr. Williams left behind at the time of the May 26th surgery caused her low cardiac output.

38      In respect of Dr. Smallhorn, the appellants' position is that he did not breach the duty of care that he owed to Jessica, but if he did, his failure to confer with Dr. Williams before Jessica's May 26, 1987 surgery, as found by the trial judge, made no difference.  The appellants note that the trial judge made no finding of causation in respect of Dr. Smallhorn.  The causation question in respect of Dr. Smallhorn boils down to the question whether, assuming Dr. Smallhorn had a duty to confer with Dr. Williams about the "best strategy" and to alert Dr. Williams to the earlier anomalous muscle bundle findings, did Dr. Smallhorn's breach of those related duties contribute to Dr. Williams' failure to excise obstructive muscle on May 26th?  That question cannot be answered without analyzing what Dr. Williams did, and did not do, during the May 26th surgery and then determining what, if any, connection existed between Dr. Williams' acts or omissions, and Dr. Smallhorn's conduct before the surgery. The appellants submit that there was no evidence to support the trial judge's finding that Dr. Smallhorn had a duty to consult with Dr. Williams to determine the best surgical strategy.  They emphasize that the plaintiffs' case at trial was based on Dr. Smallhorn's allegedly negligent diagnosis, not his failure to discuss the negative findings with Dr. Williams.

39      The plaintiffs' cross-appeal focuses on Jessica's post-operative care.  The plaintiffs submit that the trial judge failed to consider evidence going to the general issue whether the defendants (respondents in the cross-appeal) responsible for Jessica's post-operative care acted reasonably in the circumstances by assuming, without any meaningful consultation with the surgical staff, that Jessica's ongoing dangerously low cardiac output was caused by her tachycardia, or JET.  The cross-appellants contend that mechanical causes for Jessica's low cardiac output should have been ruled out before other treatment was undertaken, or at the very least taken into account before noon on May 28, 1983, when Dr. Pelech did the echocardiogram that suggested the presence of residual muscle bundles in Jessica's right ventricle might explain her low cardiac output.  The cross-appellants submit that the May 28th echocardiograms should have been done sooner.  They rely on evidence that an echocardiogram and angiogram done on May 27, 1983 would have revealed the same obstruction indicated in the May 28th echocardiograms, and confirmed by the May 29th angiogram.  The result of all of this, according to the cross-appellants, is that the second surgical intervention should have occurred earlier and before Jessica sustained "residual post-operative neurological damage", as it was put in her discharge summary.  They further submit that the particular remedial efforts undertaken in the ICU on the assumption that tachycardia, or JET, was the cause of her low cardiac output were counter-productive and thus inappropriate.

40      The cross-appellants also raise the issue of the defence's failure to call a number of witnesses, including Dr. Hesslein (concerning the nature, significance and frequency of Jessica's tachycardia); Drs. Freedom, Hesslein and Zeitlin (concerning the reasonableness of the ongoing treatment Jessica received in the ICU to the point of her second surgery on May 29, 1983); and Drs. Wilson and Gerber (concerning their evaluation of Jessica's condition on May 27, 1983).  The plaintiffs submit that the trial judge (who did not refer in his reasons to witnesses who were not called) ought to have drawn an adverse inference from the defence's failure to call some or all of the witnesses to whom I have referred above. They submit that the trial judge should have found that the evidence of these witnesses would have been adverse to the defence position in respect of the identified issues that broadly related to the adequacy of Jessica's care in the ICU between May 26, 1983 and May 28, 1983 when she was taken from the ICU for catheterization.

THE EVIDENCE

41      I will set out here some of the evidence that I consider to be significant in light of what I think are the critical factual issues.

42      To begin, I should comment briefly, and somewhat unscientifically, on the anatomy of the heart.  The heart consists of four main chambers.  The right atrium receives de-oxygenated blood from the body.  The right ventricle receives blood from the right atrium through the tricuspid valve.  Blood propelled into the right ventricle flows through the infundibulum, an outflow tract or channel, located in the main channel of the right ventricle above the apex of the ventricle.  The blood proceeds through the infundibulum to the pulmonary valve, into the main pulmonary artery, which in turn branches into the right and left pulmonary arteries.  Blood from the right ventricle proceeds eventually through those arteries into the right and left lungs where it receives oxygen and is relieved of carbon dioxide.  The left atrium receives oxygenated blood from the lungs and the left ventricle receives blood from the left atrium, through the mitral valve.  Blood is then pumped into the aorta, and on to the body where it provides nourishment.

43      The heart is positioned with the right ventricle facing forward and almost on top of the left ventricle; that is to say the ventricles do not sit literally side to side. The infundibulum, a channel in the right ventricle through which blood flows on its journey to the lungs where it is oxygenated, is tubular and has four walls.  The back wall is referred to as the infundibular septum.  The infundibulum's left side wall is referred to as the septal band and the infundibulum's right side wall is referred to as the parietal band.  The front wall is referred to as the anterior or free wall.  The lower extent of the infundibular chamber is referred to as the inferior margin of the infundibular septum and at the upper extent of the infundibular chambers is the pulmonary valve.

44      The moderator band, which is found in the main chamber of the right ventricle (below the infundibulum), arises from the septum and passes forward to attach to the front wall of the ventricle.  It provides some support for the front wall of the ventricle.  Trabecular muscles are located toward and in the apex (bottom) of the right ventricle.  They are muscles that occur in groups which often cross each other, thus forming very small cavities.  These muscles are not normally implicated in the obstruction of required blood flow within the ventricle.

      (i)  Pre-operative Investigations

45      As I have noted, in 1978 when Jessica was about six weeks old, she underwent a cardiac catheterization and angiography.  Through a cut down on her right groin a catheter was guided into her right heart, pulmonary arteries and also into her left atrium and left ventricle.  The report of Dr. Culham (a radiologist) noted, under the heading "Impression":

Jessica returned to her home in Thunder Bay after the August 3, 1978 catheterization.

46      Jessica was examined at the Hospital on February 6, 1979, August 7, 1979, February 26, 1980 and March 3, 1981. The provisional diagnosis continued to be Tetralogy of Fallot. There were no further references to anomalous muscle bundles in the records of these examinations, but nothing in the Hospital records suggested that there was any disagreement with Dr. Culham's anomalous muscle bundles "impression."

47      Jessica's case was reviewed at a cardio-surgical conference on March 29, 1982.  The conference report, signed by Dr. Izukawa, stated:

48      It is clear that the 1982 cardiac conference took no issue with Dr. Culham's assessment of Jessica's 1978 angiogram.  The 1982 conference report was sent to medical and cardiac records.

49      Jessica was admitted to the Hospital on May 23, 1983 for surgery scheduled for May 26, 1983.  Dr. Smallhorn performed an echocardiogram on May 23rd and a catheterization on May 24th.  In his report on her echocardiogram he noted, "There was no evidence of any anomalous muscle bundles in the right ventricle."  His report of Jessica's angiogram is silent on the subject of anomalous muscle bundles.  The box for muscle bundles on the Hospital's standard catheterization form was left blank.  Dr. Moes, the cardiac radiology resident, noted in his report concerning the May 24th angiogram, "... [t]he right ventricle does show an accentuated trabeculated pattern ..."  An admitting note stated that her August 3, 1978 catheterization showed a ventricular septal defect and pulmonary stenosis at the valvar and right ventricular level. The note added, "[t]he latter [pulmonary stenosis at the right ventricular level] consisted mainly of anomalous muscle bundles."  A further Hospital record titled "Clinical Antenatal History" also referred to anomalous muscle bundles.

      (ii) The May 26, 1983 Surgery

50      Dr. Williams was assigned to perform remedial open heart surgery on May 26th, 1983.  He had no specific recollection of the details of the May 26th surgery.  His evidence was based, in part, on the written records of the surgery and by his reconstruction of what he thought he did on May 26th.

51      Dr. Williams said that before he operated on Jessica on May 26th he had reviewed her May 24th angiogram. His evidence on this point was specific, however, he acknowledged that he had no actual recollection of it.  In light of the fact that more than a decade had elapsed from surgery to trial this is not surprising.  In any case, in assessing Jessica's condition before her surgery, Dr. Williams said:

52      Dr. Williams testified that on May 26th he incised Jessica's infundibulum past the valve into the main pulmonary artery.  He patched her ventricular septal defect (the hole in her heart) and looked for an atrial septal defect.  He found none.  He said that he half-divided her moderator band and patched her infundibulum in order to make the narrowed channel larger.  In the end, the hole in Jessica's heart had been patched and her right ventricle outflow tract had been made more efficient by enlarging it. This latter aspect of the surgery involved surgical adjustment and expansion of her pulmonary valve and her infundibulum. The incision in her infundibular chamber extended up to the pulmonary valve and down to a point about one centimetre below the lower end of the infundibular septum (below the os infundibulum -- the mouth of the infundibulum).  The total length of the incision was about 3.5 centimetres from the pulmonary valve.

53      As I have said, the moderator band is a muscle band located below the infundibulum.  Dr. Williams testified that it was not possible to inadvertently divide it.  He disagreed with Dr. Carr, the plaintiffs' main expert witness, who had suggested in his evidence that Dr. Williams might have inadvertently divided Jessica's moderator band.  However, Dr. Williams acknowledged that the division of the moderator band is not a usual procedure in this kind of surgery.  The moderator band is not typically obstructive since it is situated below the narrowest point in the right ventricle and generally runs parallel to the flow of blood in the right ventricle.

54      Dr. Williams could not recall when he half divided Jessica's moderator band during the May 26th surgery. He thought it was probably after he had patched her ventricular septal defect and looked for a suspected (but non-existent) atrial septal defect.  He said, "I think I divided half of the moderator band trying to preserve its function while leaving some of the muscle mass which was encroaching on the right outflow tract."

      (iii)      The Pressure Readings

55      When he had completed his May 26th surgery, Dr. Williams used a needle catheter to measure pressures in Jessica's right ventricle and pulmonary artery.  He did this to confirm that pressure in Jessica's right ventricle was at an acceptable level, that is that he had achieved a full repair of Jessica's Tetralogy defects.  He looked for the presence, or absence, of an acceptable pressure gradient across the area of repair.  In theory, if there was a significant difference in systolic pressure from one relevant area to another, this might well point to the existence of an obstruction.

56      The procedure of taking post-surgical pressures is somewhat intrusive and irritating.  In layman's terms, it involves plunging a pressure needle into the patient's surgically repaired, closed heart.  Thus, according to Dr. Williams, surgeons thus do not take unnecessary pressure readings.  When Dr. Williams undertook this process on May 26, 1983, he obtained a right ventricular pressure recorded as 34. It was accepted by all concerned, including Dr. Williams, that this reading was wrongly recorded and that the proper reading was 43, consistent with the anesthetist's record.  Jessica's May 26th pulmonary artery pressure was 33.  The pressure gradient was satisfactory and no further readings were taken. The pulmonary artery -- right ventricular pressure gradient suggested that there was no lingering obstruction with which to be concerned.  This assumes that the pressure taken in Jessica's right ventricle on May 26th was taken below any residual obstructive muscle.  Dr. Carr made this clear in his evidence.  He emphasized that there was an obstruction "just below" Jessica's os infundibulum and that a pressure taken above that level would not be revealing.

57      Dr. Cornell, a defence expert, testified that post-operative pressures of 43 in Jessica's right ventricle and 33 in the pulmonary artery indicated that Dr. Williams had achieved a good repair.  To put it another way, the pressures would suggest that there should be no concern about the existence of any residual obstructive muscle.

58      I should note here that a quite different story in respect of pressures emerged from the May 28, 1983 post-operative catheterization.  The two pressures taken revealed a pressure gradient of 44 between the apex and the infundibulum.  Dr. Smallhorn accepted that this gradient suggested that there was a residual obstruction in Jessica's right ventricle.  In summary form, the pressure readings from before Jessica's first surgery to after her second surgery, are set out in the chart below.  [See Note 1 below]

   Note 1:  There are 2 procedures for obtaining blood pressure measurements in the heart and surrounding blood vessels:

              3-Aug-78  24-My-83  26-My-83   28-My-83  29-My-83

59      It is accepted that pressures obtained by the cardiac surgeon after surgery provide important information to ICU doctors because they provide evidence of the adequacy of the surgical repair.  It is also accepted that the reliability of pressure measurements are dependent upon where the pressures are taken.  How reliable post-operative pressure are was a subject addressed at some length in the evidence.  Dr. Soder, a defence witness, stated that a negative pressure gradient is a factor that would be of concern to a cardiac surgeon in that it would suggest that something is wrong.  He said that a positive pressure gradient is something less significant than the actual performance of the surgically repaired heart because the information provided by the process depends upon where the pressures are taken.  Dr. Duncan, another defence witness, added another wrinkle to the debate. He pointed out that a pressure needle can become entrapped in muscle.  This can lead to an inordinately high, and unreliable, reading.  Drs. Williams and Smallhorn said that post-operative pressure readings are useful to determine if a complete repair has been achieved.  Dr. Smallhorn's evidence on this issue differed somewhat from his examination for discovery evidence.

              (a)  General References

60      Not long after she was admitted to the ICU there were indications that Jessica's cardiac output was low.  If cardiac output is unduly low, the body's vital organs are not supplied with enough nourishment -- oxygenated blood.  With a prolonged state of low cardiac output, vital organ systems will eventually shut down and permanent damage and death may occur.  Brain damage is within the spectrum of damage that can occur if cardiac output is too low for too long.  Low cardiac output may also have an adverse effect on heart rhythm and rate.

61      Under normal circumstances the heart's rhythm is controlled by a heart centre called the "sinus node."  When in sinus rhythm the atria contract a split second before the ventricles thus enhancing the pumping power of the ventricles. This was referred to as the "atrial boost."  If the heart is not in sinus rhythm, and loses the atrial bost, it is less efficient and cardiac output drops.

62      The terms tachycardia and tachyarrhythmia refer to an excessively fast heart rate and may suggest a heart rhythm disturbance.  It was Jessica's heart rate, not her heart rhythm, which was of great concern while she was in the ICU.  The convergence of intermittent tachycardia and her loss of sinus rhythm presented serious problems to the ICU staff.

63      The evidence, particularly the defence evidence, is replete with references to Jessica having a form of tachycardia called junctional ectopic tachycardia (JET).  The trial judge made no specific reference to JET in his reasons, however, he did observe that Jessica experienced tachycardia. JET's cause is not clearly established.  It is difficult to control and if sustained it may lead to hypotension, shock and death.  It is a species of tacharrythmia where there is an abnormal focus of the electrical conductive activity of the heart.  Dr. Carr, in describing JET, and its abnormal focus, said, "It's a focus that shouldn't be firing off."  He also said some children with JET have low cardiac output before they develop JET and that that low cardiac output is "another factor promoting JET."

              (b)  Jessica's Progress in the ICU

64      When Jessica came to the ICU a nurse noted that she was "very cool" peripherally and that her lips were slight cyanosed (blue).  She went into junctional rhythm shortly after admission to the ICU.  With the onset of tachycardia at 7:20 p.m. on May 26, 1983, her condition continued to decline. By 11:00 p.m. on May 26th, her mean arterial pressure had fallen to a dangerous level.  Later, her urine output was inappropriately low.  This, according to Dr. Carr, the plaintiffs' expert, was a sign of inadequate renal perfusion.

65      In the early morning of May 27, 1983, Jessica's blood gas readings suggested metabolic acidosis.  This was as a result of her low cardiac output since oxygen-deprived cells produce lactic acid.  Her acidosis was apparent resolved by a dose of bicarbonate.

66      Throughout Jessica's tachycardia period, the ICU doctors treated her aggressively with drugs, electric shock (cardioversion), atrial pacing, sequential pacing and paired ventricular pacing.  Paired ventricular pacing differs from sequential pacing because the electrical impulse in paired pacing is applied to the ventricles.  Thus, during paired pacing, there is a loss of what I referred to earlier as the "atrial boost."

67      When Jessica returned briefly to sinus rhythm during the early morning of May 27th, paired pacing was discontinued.  Unfortunately, she soon returned to junctional rhythm and experienced a further drop in cardiac output.  This was not accompanied by tachycardia.

68      Jessica's tachycardia ended by mid-day on May 27th.  However, she remained in a low cardiac output state during the rest of May 27th and into the morning of May 28th. An ICU progress note made during the afternoon of May 27th indicates that there was some improvement but she continued to have low cardiac output despite the suppression of junctional rhythm and tachycardia.  At midnight on May 27th, Dr. Gerber noted:  "cardiac output deteriorated continuously although no more sinus rhythm problems any more, blood pressure lowish, urine output decrease ..."

69      Throughout the post-operative period and up to noon on May 28, 1983, ICU doctors assumed that Jessica's problems were related to her tachycardia, or JET.  It was their position at trial, accepted implicitly by the trial judge, that they had no reason to think otherwise, since there was no indication that Jessica had undergone anything other than a complete repair of her Tetralogy.

70      At about noon on May 28, 1983, Dr. Pelech, a resident cardiologist, apparently on his own, decided to do an echocardiogram.  This echocardiogram suggested potentially obstructive muscle in Jessica's right ventricle.  This provided an explanation for her continuing cardiac output problems that had not been considered before.  Dr. Pelech contacted Dr. Smallhorn who came to the Hospital and did a second echocardiogram at about 2:00 p.m. on May 28th.  That echocardiogram also confirmed the possible presence of potentially obstructive muscle in Jessica's right ventricle. Dr. Smallhorn said that the echocardiogram caused him to be "suspicious" that there was residual muscle in Jessica's right ventricle.  The echocardiogram note was:  "There appears to be a muscle bundle in the mid-RV's cavity."  The recorded provisional diagnosis was, "Post-operative T of F Ano musc Bundle"; that is, post-operative Tetralogy of Fallot anomalous muscle bundle.  It is not clear who prepared that note.

71      Because of the seriousness of her condition and the new evidence of a residual muscle obstruction, Jessica was taken to the catheterization laboratory at midnight on May 28, 1983.  Her catheterization was done shortly after midnight on May 29th.

72      The angiogram confirmed Dr. Smallhorn's suspicions.  When he was asked to comment on the May 29th angiogram, he said:

73      Dr. Smallhorn's report of the May 29th angiogram stated that it "demonstrated large amount of muscle bundles in the mid-right ventricular cavity."  The box on the standard form part of the angiogram report for muscle bundles was ticked.  The same box on the same form that was completed at the time of Jessica's May 24, 1983 pre-operative angiogram was not ticked.

74      Dr. Moes, a senior cardiac radiologist, reviewed Jessica's May 29th angiogram and reported that it disclosed thick muscle bundles.  When he described their location he wrote:  "Within the right ventricle at the os infundibular level there are thick muscle bundles which may be causing some outflow tract obstruction ..."

75      Dr. Pelech prepared a schematic diagram of Jessica's heart on which he recorded pressures taken during the catheterization.  It indicates that the pressure proximal to the suspected obstruction (below it) was 84/18 and the pressure distal to the suspected obstruction (a pressure taken in the Jessica's infundibulum) was 40/18.  He labelled Jessica's condition "double chambered right ventricle."  This label suggested the existence of a specific condition Jessica did not have, or perhaps no more than Dr. Pelech's impression that mid-ventricular muscle bundles made her right ventricle look like it had two distinct chambers due to anomalous muscle bundles.  In Dr. Carr's opinion, the pressure gradient of 44 provided "overwhelming evidence of the existence of an obstruction."  Dr. Duncan, a defence expert, accepted the pressure gradient provided evidence of an obstruction that was significant enough to justify recommending that Jessica be operated on once again.

76      Jessica was rushed to the operating room at 4:30 a.m. on May 29, 1983.  Her life hung in the balance, but from the standpoint of the quality of her life, it was too late.

77      On May 29, 1983, Dr. Williams removed the outflow patch (put in place in the previous surgery) and inspected Jessica's right ventricle.  He saw "thick muscle bands on both the septal surface and the anterior free wall surface."  He testified that he excised these muscle bands and completed the division of the moderator band.  He then resutured the patch to its original position and Jessica was weaned from the CP by-pass.  Post-operative pressure readings were satisfactory.

78      The records of Jessica's second surgery do not refer to her moderator band.  I refer to this because Dr. Williams testified that he relieved the obstruction by completing the division of the moderator band and by excising a small amount of tissue.  The handwritten progress notes referable to the May 29th surgery describe the operation as, "Resection of R.V. muscle bund."  In his re-examination, what Dr. Williams did during the second surgery became more confused.  After he was asked about the removal of tissue during Jessica's first surgery, done on May 26th, his trial counsel turned to the second operation and asked him whether he excised any muscle during that operation.  Dr. Williams said, "I think we did not take out muscle in the second operation.  I think we incised the moderator band and some septal bands."  The matter was not taken further, once counsel for the plaintiffs objected and the trial judge upheld the objection.

79      Following the May 29th surgery, two pieces of tissue were sent to pathology.  No tissue was sent to pathology after the May 26th surgery.

80      In his letter to Dr. Izukawa dated May 30, 1983, Dr. Williams reported on the May 29th surgery.  He wrote that he "completed" the division of Jessica's moderator band and excised "some of the parietal muscle bands" during the May 29th operation.

81      The second operation seems to have been successful in that it saved Jessica's life.  She did not encounter the same difficulty after this operation that she did after her first operation; although her improvement was slow, she did progress, but, as I have said, with brain damage.

THE STANDARD OF APPELLATE REVIEW

82      The statutory basis for appellate intervention is found in s. 134 of the Courts of Justice Act, R.S.O. 1990, c. C.43.  The relevant parts of s. 134 are:

83      An appellate court will not retry the case or interfere with the trial judge's findings of fact, and conclusions reasonably supported by those findings, unless the record reveals palpable and over-riding error that affected the trial judge's findings.  See Delgamuuk v. British Columbia, a judgment of the Supreme Court of Canada, released December 11, 1997; Lewis v. Todd, [1980] 2 S.C.R. 694; Stein v. The Ship "Kathy K", [1976] 2 S.C.R. 802.  Deference must be accorded to the trial judge's assessment of the evidence of expert witnesses.  See N.V. Bocimar S.A. v. Century Insurance Co. of Canada, [1987] 1 S.C.R. 1247.

84      If the trial judge's findings are not supported by the evidence, or if the trial judge draws unreasonable inferences from the evidence, conclusions based on those findings and inferences cannot stand, since they are not supported by the evidence and are thus speculative.  The trial judge's failure to consider essential evidence may constitute an error in law and justify appellate intervention.  If error is found, the appellate court will necessarily consider the effect, if any, of the error, that is whether it can reasonably be said that the error did not constitute a substantial wrong or miscarriage of justice.

85      If the trial judge is found to have committed reversible error s. 34(1)(a) of the Courts of Justice Act permits the appellate court to substitute the decision that should have been made.  In many cases an appellate court, confined to a consideration of somewhat sterile transcripts, will not be in a position to substitute its decision for that of the trial judge.  In those cases the appropriate remedy will necessarily be a new trial.  See Bryars Estates v. Toronto General Hospital, a judgment of the Court of Appeal for Ontario, released September 17, 1997); Nova, An Alta. Corp. v. Guelph Engr. Co. (1989), 70 Alta. L.R. (2d) 97 (Alta. C.A.).

ANALYSIS

86      The plaintiffs' case at trial in respect of the liability of Drs. Williams and Smallhorn was largely based on the evidence of Dr. Carr, an American cardiologist.  Dr. Carr testified that the 1978 angiogram report correctly described anomalous muscle bundles.  He said that these same muscle bundles were obstructive and were left after the first surgery on May 26, 1983 but removed during the second surgery on May 29, 1983.  He emphasized that these muscle bundles were not only anomalous, that is atypical as to location or size, but were, more importantly, obstructive.  His evidence and the absence of any reference to the excision or division in records generated at, or shortly after, the May 26th surgery formed the basis of the trial judge's finding that Dr. Williams did neither when he operated on Jessica on May 26th. The plaintiffs submit that this is a critical finding of fact, and a finding that is supported by the evidence.

87      Considerable time was spent at trial dealing with the presence or absence of "anomalous" muscle bundles, and with Dr. Pelech's label, "double-chambered right ventricle" to describe Jessica's right ventricle on May 29, 1983.  Witnesses for both sides confirmed that some of the terminology was inexact.  Drs. Carr and Smallhorn both testified that "anomalous" could refer to a muscle of abnormal size.  Dr. Carr testified that some might not use the same language when describing the same cardiac structures.  Drs. Williams and Smallhorn rejected use of the term "anomalous muscle bundles" and "double-chambered right ventricle" as relevant and accurate descriptive labels; however, they admitted that such references might be found in the literature.  Dr. Duncan, a defence expert, testified that he never used the term "anomalous muscle bundles", preferring instead the term "apical right ventricular muscular hypertrophy."  There was, however, a general consensus that the important issue is not how a particular muscle is labelled, but whether it is obstructive.

88      I can readily accept the defence evidence that double-chambered right ventricle is a specific entity having certain criteria which Jessica did not match; however, I think that the distinction is more one of terminology than substance.  I reach that conclusion because Dr. Williams acknowledged that Jessica's ventricle may have had the appearance of double-chambered ventricle after her first surgery.  He also acknowledged that some might consider her ventricle as a double-chambered right ventricle; he also dismissed this as a debate involving only terminology.  He said, "I don't find that the naming of the structure is all that helpful and of course when we look inside the heart, none of them are named.  So we're relying on what we see at surgery."  In addition, Dr. Carr referred to the label double-chambered right ventricle as "almost a synonym" for anomalous muscle bundles.

89      There is no question that the August 3, 1978 and May 24, 1983 angiograms revealed large muscles in Jessica's right ventricle near her infundibulum.  Drs. Williams and Smallhorn and the defence experts prefer to refer to the muscles generally in question as "prominent muscle bundles" or "trabeculations."

90      Dr. Carr, who accepted the label "anomalous muscle bundles", stated that Tetralogy can co-exist with other abnormalities such as anomalous muscle bundles.  He emphasized how important it is for the surgeon to relieve the patient of all obstructive muscle so that cardiac output can be established post-operatively at an appropriate level.

91      In any case, Drs. Carr, Williams and Smallhorn all said that there was prominent muscle identified at and near the entrance of Jessica's infundibulum.  This muscle extended down into the main cavity toward the apex of her right ventricle.  They also agreed that the 1978 and 1983 investigations demonstrated the same findings.  The defendants insisted at trial that this consisted of enlarged or "hypertrophied" muscle which was a common element of Tetralogy.  The defence position is that since it was a typical finding in a Tetralogy case, there was no reason for Dr. Smallhorn to mention it in his report.  This accords with the evidence of Dr. Williams and Dr. Smallhorn.

92      It does not seem to me to make much difference what these muscles are called or whether their existence justified the double-chambered right ventricle label.  The defence's rejection of the descriptive term "anomalous muscle bundles" is not based on the premise that the muscles in issue did not exist.  Quite the contrary, both Drs. Williams and Smallhorn testified that the sub-infundibular muscles in Jessica's right ventricle, first referred to in Dr. Culham's August 1978 report, were consistent with the general spectrum of Tetralogy of Fallot.  Thus, the defendants' position is that the presence of these muscles was expected, so the muscles could not be said to be anomalous.

93      Dr. Carr concluded that Dr. Culham's 1978 angiogram report was correct -- obstruction at the level of the pulmonary valve, in the tube of muscle below the valve (the infundibulum) and near the mouth of the infundibulum (the os infundibulum).  At this latter point the obstruction (causing narrowing) consisted of what was originally characterized in 1978 as anomalous muscle bundles.  Dr. Carr stated that the pre-operative May 24, 1983 angiogram clearly shows the presence of the same muscle bundles, as did the August 3, 1978 and May 29, 1983 angiograms.

94      Dr. Carr said that doctors will differ in what they consider to be the boundaries of the infundibulum in any given person.  Thus, the limits of the infundibulum, at least for purposes of description, may well be somewhat inexact. When Dr. Carr was asked to comment on the 1978 angiogram report in respect of its exact wording, he expressed the opinion that Dr. Culham concluded that the angiogram revealed a sub infundibular anomalous muscle bundle and that his "query" was referable to the issue whether the muscle bundle was obstructive.

95      In respect of the location of the muscle bundle, Dr. Carr said that precision is difficult because it is not clear what was meant by the location references in the 1978 angiogram report.  In this regard he pointed out that the 1978 angiogram report referred to muscle bundle located along the septum and proximal infundibulum, i.e. away from the pulmonary valve and toward the apex, or bottom of Jessica's right ventricle.  It is clear that infundibular stenosis means a narrowing of the infundibulum which is located away from the pulmonary artery.  The os, or mouth of the infundibulum, is a precise point, however, in hospital records its location may not be identified with precision.  In his cross-examination, Dr. Carr commented on the terminology issues in this way:

96      Dr. Carr reviewed what Dr. Williams did in his May 26, 1983 surgery.  He emphasized the fact that in the operative record there was no reference to the removal or division of any tissue.  He further referred to the fact that Dr. Williams' letter to Dr. Izukawa (a cardiologist at the Hospital), which generally described Jessica's May 26th surgery, made no mention of mid-cavity muscle bundles, or to the excision or re-section of any muscle.  Nor did it refer to the division of the moderator band.

97      Dr. Carr also commented on Dr. Smallhorn's May 28th post-operative echocardiogram.  It suggested the existence of a muscle bundle in Jessica's mid right ventricular cavity.  Dr. Carr testified that these muscle bundles were the same muscle bundles that were identified by Dr. Culham in his report on Jessica's 1978 angiogram, by the 1982 cardio-conference, and by Drs. William and Smallhorn in their review of Jessica's May 24, 1983 pre-operative angiogram.

98      Dr. Carr and all experts who gave evidence on the subject said that for purposes of diagnosis, the angiogram was the "gold standard" and that the May 29th angiogram clearly revealed the presence of obstructive muscle.  In the end, he testified that the three angiograms (August 3, 1978, May 24, 1983 and May 29, 1983) all showed the same obstructive muscle at the os infundibular level.  According to Dr. Carr, the muscle in issue extended from the lower part of Jessica's right ventricle up to her pulmonary artery in a continuum.

99      Dr. Smallhorn's written report of Jessica's May 24, 1983 angiogram said nothing on the subject of muscle bundles, however, he testified that this was because he viewed the muscles to be part of the Tetralogy of Fallot package.  He said:

100      Dr. Williams, like Dr. Smallhorn, was of the opinion that Jessica's 1978 angiogram did not show anomalous muscle bundles.  He testified that in his opinion Jessica's muscle hypertrophy was not anomalous; it was part of the spectrum of Tetralogy.

101      Dr. Williams said that the May 24, 1983 angiogram showed an obstruction that was more severe than that which was evident on Jessica's 1978 angiogram.  He added that the trabecular part of Jessica's right ventricle was quite hypertrophied and that the situation in that part of her ventricle was similar to that seen in 1978.

102      Except for the evidence of Dr. Duncan, the defence evidence does not seem to me to be in serious conflict with Dr. Carr's testimony on the issue of the location of the obstructive muscles.  Dr. Smallhorn stated that the os is at the lower end of the infundibulum and runs onto the trabeculaseptomarginalis which contains trabecular muscle. Dr. Williams testified that hypertrophic muscle could be seen on the May 24th angiogram extending into the apex and fusing with Jessica's heavily trabeculated apex.  He agreed that there was thickening or hypertrophic muscle at the level of Jessica's os infundibulum.  Dr. Cornell, another defence expert, said that he saw very prominent muscle bundles, not anomalous muscle bundles, on the August 23, 1978 and May 24, 1983 angiograms.  He said that the May 29, 1983 angiogram revealed prominent muscle at the mid ventricular level.  He stated that the structures overlap.  Dr. Moes, a cardiac radiologist, concluded in the main body of his report, that the May 29th angiogram revealed muscles at the os infundibular level.  Dr. Cornell said that his observation and Dr. Moes' report were not inconsistent, "... because the junction between the mid cavity and the infundibulum is the os infundibulum."

103      Dr. Duncan's evidence was the most favourable to the defence.  He located the muscle bundles furthest from Jessica's infundibulum.  He stated that the muscle bundle was in the trabecular part of Jessica's right ventricle.  He labelled the muscles in issue as, "apical right ventricular muscle hypertrophy".  He saw no obstruction on the May 29th angiogram.  It was this angiogram that led Drs. Williams and Smallhorn to conclude that the second operation was necessary to relieve the mid-ventricular obstruction.

104      Dr. Duncan also accepted that it was "possible" that the same muscle band lead to Dr. Pelech's schematic diagram (based on his reading of the May 29th angiogram) and his diagnosis "double chambered right ventricle".

105      Dr. Duncan did not think that the results of the two May 28th echocardiograms supported the decision to take Jessica for catheterization.  On this point, he said:

106      When Dr. Duncan was reminded Dr. Smallhorn (and Dr. Williams) had reached a different conclusion after viewing the May 28th echocardiograms, Dr. Duncan deferred to Dr. Smallhorn:  He said:

107      Dr. Duncan agreed that Dr. Culham's report on Jessica's August 3, 1978 angiogram and Dr. Moes' report on her May 24, 1983 angiogram were not in conflict.  He accepted that the two cardiac radiologists were reporting similar features, using different terminology.

108      In any case, Dr. Williams who actually saw the subject muscle bundles (twice on the trial judge's findings) referred to the obstruction in this way:

When he was asked to be specific about the location of the residual obstructive muscle, he placed the muscle about a centimetre below the os infundibulum.

109      He explained, however, that muscle that is not obstructive pre-operatively may become obstructive.  He said:

110      Dr. Williams testified that the residual muscle he saw on the May 29th angiogram was too far down in the body of the ventricle to be obstructive.  On cross-examination, when he was referred to the two echocardiograms done on May 28th, the observations of other doctors, the response of the doctors to their observations, what was disclosed on the May 29th angiogram and the pressure readings taken during the May 29th catheterization, he retreated somewhat from his no obstructive muscle bundle position.  He accepted that Jessica had an interior muscle bar beneath the surgical patch, that is, well above the apical part of her heart.  After he was referred to the opinions of Drs. Smallhorn, Moes, Pelech and Cornel, he gave this evidence:

111      On the basis of Jessica's May 29th angiogram, Dr. Smallhorn agreed that further surgery should be undertaken.

112      Against this background of that evidence, I turn to consider the trial judge's findings of liability against Drs. Williams and Smallhorn.

      (ii) The Duty and Standard of Care

113      There is no doubt that all of the individual defendants owed a duty of care to Jessica while she was in the Hospital in May 1983.  In my opinion, the real issue at trial was the standard of care and, more particularly, its application.  What did the appellants, Drs. Williams and Smallhorn, have to do to discharge the duty of care that they owed to Jessica was the central trial issue.  Similarly, what the other individual defendants had to do to discharge the duty that they owed to Jessica was the central trial issue in respect of all of the remaining defendants.

114      A physician's conduct will be measured against the standard of the average practitioner in the speciality area of which the physician is a member, or claims to be a member.  Thus, a higher level of skill and performance will be demanded from a specialist than from a general practitioner. However, the conduct of both will be measured against practices accepted as appropriate by the law's invention, in this case the reasonable cardiac surgeon, cardiologist and intensivist.  See Fleming, The Law of Torts, 8th ed. (1992), at p. 104; Holmes v. London (City) Hospital Board (1977), 17 O.R. (2d) 626 at 637 (H.C.J.).

     (iii) Causation

115      Even if one or more of the defendants fell below the applicable standard of care, to establish negligence in the legal sense, the plaintiffs must establish that Jessica's brain damage was caused, or materially contributed to, by the defendants' impugned conduct.  It is clear that her low cardiac output led to Jessica's brain damage.  Thus, the core causation issue, an issue of fact, is what caused her low cardiac output.

116      The courts have come to recognize that causation in medical negligence cases is difficult to establish because evidence material to that issue is typically in the hands of the defence.  Sopinka J. considered this issue in Snell v. Farrell, [1990] 2 S.C.R. 311.  In Snell, the trial judge had reversed the burden of proof on the causation issue in circumstances that I need not detail beyond noting that neither expert was able to state with certainty what had caused the plaintiff to lose the sight in her eye.  Sopinka J. considered whether, as a matter of policy, where the defendant had materially increased the risk of injury and where the injury sustained fell within the ambit of that risk, the burden of proof should shift to the defendant on the causation issue.  This shift in the burden of proof had been endorsed by Lord Wilberforce in McGhee v. National Coal Bd., [1973] 1 W.L.R. 1 (H.L.).  Sopinka J. rejected this approach, although he accepted the difficulty plaintiffs sometimes have in establishing causation in medical negligence cases.  He concluded that to reverse the burden of proof on the causation issue could result in compensating plaintiffs where there was no "substantial connection" between the injury and the defendant's allegedly negligent conduct.  Instead, he modified the causation burden that plaintiffs in medical negligence cases had previously borne.  Rather than reversing the burden of proof on causation, he accepted that in some cases the plaintiff's evidence may result in the trier of fact drawing an adverse inference if the defence does not lead evidence to the contrary.  He said at pp. 329-30:

117      He went on to the refer to the role of experts. He said at p. 330:

118      Sopinka J. accepted Brennan J.'s statement in Sentilles v. Inter-Caribbean Shipping Corp., 361 U.S. 107 (1959) that causation must in the final analysis be determined by the trier of fact:

119      The Supreme Court of Canada considered the causation issue further in Athey v. Leonati, [1996] 3 S.C.R. 458.  In that case, there were two distinct possible causes of the plaintiff's injury.  Major J. made it clear that the plaintiff need not establish that the defendant is the sole cause of the plaintiff's injury.  He said at p. 467:

120      In summary:

      (iv) The Liability of Dr. Williams

121      The trial judge resolved the factual dispute about whether Dr. Williams removed obstructive muscle or divided (incised) Jessica's moderator band on May 26th.  [See Note 2 below]  He found that Dr. Williams failed to resect obstructive muscle in the first operation that he did resect in the second operation.

   Note 2:  In his examination in chief, Dr. Williams was somewhat obscure in his reference to Jessica's moderator band. He said:  "In Jessica, I think I divided half of the moderator band."

122      In reaching the conclusion he did on Dr. Williams' liability, the trial judge specifically recognized, "... that surgery calls for the exercise of judgment and that no surgeon is always right or always successful."  The trial judge noted, in the passages that he quoted in his reasons, that there were five references by Dr. Williams to the removal of tissue (resection or excision) and two to cutting into tissue (incision or division).  He compared what Dr. Williams said he did during the May 26th surgery with records generated at the time of the surgery.  He also noted that following Jessica's May 26th surgery, no tissue was sent to pathology for analysis.  He said:

123      The trial judge found that the defence had not explained why the tissue that was removed during Jessica's second surgery was not removed during her first surgery.  In my view, it is implicit in that finding that the trial judge rejected the defence theory that a "dynamic", and perhaps transient, obstruction may have developed after the first surgery due to tissue swelling and inotropic drug therapy.

124      Having concluded that Dr. Williams excised no tissue on May 26th, the trial judge turned to the issue of causation.  He found that Dr. Williams' failure to excise obstructive muscle caused Jessica's brain damage.  He put it in this way:

125      The trial judge did not set out the chain of causation; however, it is clear that he concluded that Dr. Williams' failure to excise obstructive muscle on May 26th caused or materially contributed to Jessica's ongoing low cardiac output.

126      The report of Jessica's May 26th surgery, under the heading of "Operative Procedure", made no reference to the excision of any tissue.  Nor did it refer to the division of the moderator band (one-half, or otherwise).  This report was signed by Dr. Feteih and initialled by Dr. Williams.  Dr. Williams' letter to Dr. Izukawa of May 26th, 1983, which describes the May 26th surgery in a somewhat general way, also made no reference to the excision of tissue or to the division of the moderator band.  There is no reference to the excision or division of tissue in the May 26th, 1983 cardiac operation sheet.  Following the May 26th surgery, no tissue was sent to Pathology as is required by law when tissue is excised.

127      Contrast the above with what was recorded and done at, and following, Jessica's second surgery on May 29th, 1983.  The May 29th operative report specifically refers to the excision of infundibular muscle bands ("these muscle bands were excised").  The cardiac operation sheet describes the operation as an "infundibulectomy" which by definition signals the excision of infundibular tissue.  Dr. Izukawa also referred to the May 29th surgery as an infundibulectomy in his reporting letter dated August 15, 1983 to Dr. Neelands.  The Hospital progress notes refer to the operation of May 29th as involving "residual muscle band obstructing R.V" and to the "resection" of the right ventricular muscle band.  The Hospital Operating Room Requisition refers to the May 29th operation as, "Resection of RT ventricular muscle bundle". Dr. Williams' letter to Dr. Izukawa, dated May 30th, 1983, about Jessica's May 29th surgery, specifically refers to the excision of tissue and the completion of the division of her moderator band.

128      In my view, there was ample evidence to support the trial judge's central finding that Dr. Williams did not remove obstructive muscle during Jessica's surgery, or partly divide her moderator band.  I see no basis upon which to interfere with that significant finding.

129      Dr. Carr testified that in failing to remove obstructive muscle bands, Dr. Williams fell below the standard of care demanded of a cardiac surgeon in the circumstances. He also specifically rejected the defence thesis that the obstructive muscle removed during the May 29th surgery was a new or "dynamic" muscle obstruction, that is one that was not present at the time of Jessica's May 26th surgery.  Even without Dr. Carr's evidence, in light of the significance of obstructive muscle bundles in Tetralogy cases, the failure to remove obstructive muscle tissue in this case provides an evidentiary base for the trial judge's finding of negligence against Dr. Williams.

130      The trial judge's reasons make it clear that he appreciated that surgery involves the exercise of judgment and is not always successful.  However, in light of the trial judge's findings and their implications, it seems to me that what Dr. Williams did (and did not do) during Jessica's May 26th surgery was not mere error in judgment, in the sense that he exercised a surgeon's judgment in deciding how much muscle to excise or divide.  The trial judge found that he did not excise or divide any muscle and there is evidence to support that finding.

131      Dr. Williams knew that obstructive muscle was part of the Tetralogy of Fallot package.  Indeed, it was on that basis that he and Dr. Smallhorn rejected labelling the muscle bundles first referred to in Dr. Culham's 1978 angiogram report, as anomalous muscle bundles.  In Tetralogy surgery, Dr. Williams said that:

132      Furthermore, the trial judge concluded that the muscle tissue removed in the second surgery on May 29th was present in Jessica's right ventricle on May 26th.  He said:

This finding makes it clear that the trial judge rejected the defence position that the muscle excised on May 29th because it was obstructive did not exist in an obstructive form on May 29th when he found no muscle tissue was excised or divided.

133      It is clear to me that the trial judge did not regard Dr. Williams' necessarily reconstructed assessment of what he did during the May 26th surgery to be reliable.  He commented, "in his description of what went on during the first operation, Dr. Williams strikes me as inappropriately vague."

134      A further question in respect of Dr. Williams' negligence remains.  Was the trial judge entitled to conclude that Dr. Williams' failure to excise or divide obstructive muscle bundles on May 26th, 1983 caused Jessica's brain damage?  The target muscle bundles were obstructive.   They were not excised or divided on May 26th.  There was evidence that obstructive muscle bundles can affect cardiac output (and increase the prospect of the development of tachycardia). There was also evidence that low cardiac output can lead to brain damage.  There is no doubt that Jessica sustained brain damage, probably on May 27th, sometime before, or at, 11:00 p.m. when seizure activity was noted.  In my view, the causation component of the trial judge's negligence finding against Dr. Williams is satisfied.

135      The appellants are correct in submitting that the trial judge did not review the evidence in his reasons; nor did he set out the positions of the parties.  Nonetheless, in respect of Dr. Williams, the reasons are, in my view, sufficient.  The trial judge made findings of fact essential to his conclusion that Dr. Williams was negligent -- he did not excise or divide obstructive muscle in Jessica's right ventricular cavity at the time of her first surgery and that failure caused her brain damage.  The same obstructive muscle, not removed on May 26th, was removed during the remedial surgery of May 29th.

136      Although the trial judge's reasons are somewhat sparse, I do not think it can be said that he failed to consider all of the evidence and the defence position in making the finding of negligence against Dr. Williams that he did.  Put another way, I see no palpable or overriding error. The trial judge's findings of fact in respect of Dr. Williams' negligence were findings that he could reasonably make.

137      It is apparent to me from a review of all of the transcripts that the trial judge was alert to the issues that arose throughout this trial which involved evidence of some considerable complexity.  I see nothing in the record to suggest that the trial judge failed to appreciate relevant evidence, or that he failed to appreciate, or ignored, the defence position on relevant issues.  I therefore see no basis upon which to interfere with the trial judge's finding in respect of Dr. Williams.

              (v)  The Liability of Dr. Smallhorn

138      The trial judge found that Dr. Smallhorn was negligent because he failed to discuss "his negative findings" with Dr. Williams before Jessica's May 26, 1983 surgery.  The trial judge's "negative findings" comment appears to be a reference to Dr. Smallhorn's opinion that Jessica did not have anomalous muscle bundles in her right ventricle.  This opinion was formed on the basis of his assessment of Jessica's May 23rd echocardiogram and her May 24th angiogram.

139      In his reasons, the trial judge referred to evidence that related to whether Drs. Smallhorn and Williams consulted with one another about Jessica's May 24th pre-operative angiogram and to aspects of Dr. Williams' pre-operative preparation.  On that latter issue Dr. Williams made it clear in his evidence, including evidence that the trial judge directly quoted in his reasons, that he would have reviewed Jessica's May 24, 1983 angiogram before he operated on her on May 26th.  In other evidence, not specifically referred to by the trial judge, Dr. Williams made it clear that he would have reviewed Jessica's entire chart.  This would include Dr. Culham's August 1978 angiogram report, the March 29, 1982 cardio-surgical conference report and the resident's note of May 23, 1983, when Jessica was admitted to the Hospital.  All of those records refer in some way to anomalous muscle bundles.

140      The trial judge put it in this way when he dealt with the ambit of Dr. Smallhorn's duty of consultation:

The trial judge did not go on to make a specific finding that Dr. Smallhorn's negligence caused or contributed to Jessica's injuries.

141      The trial judge's finding of negligence against Dr. Smallhorn is based on his view that Dr. Smallhorn had a duty to consult with Dr. Williams before Jessica's May 26th surgery, as the trial judge put it, to determine the "best strategy."  Since the trial judge found that Dr. Smallhorn breached this duty to consult, it would appear that he concluded that Dr. Smallhorn did not discuss Jessica's May 23rd echocardiogram, her May 24th angiogram, or the earlier references, starting with Dr. Culham's August 1978 report, to anomalous muscle bundles, with Dr. Williams.

142      There are a number of references in the trial record to the "team" approach to Jessica's care while she was at the hospital in May 1983. Dr. Smallhorn, the cardiologist, and Dr. Williams, the surgeon, were part of that team, as were all of the defendant ICU doctors and support staff. When he addressed this issue, Dr. Carr testified,

143      In the passage from Dr. Carr's evidence quoted above, Dr. Carr made it clear that the purpose of consultation between the cardiologist and the cardiac surgeon is to make sure that the surgeon knows what the cardiologist thinks he should know going into the surgery. In the circumstances, I have no difficulty in sustaining a limited finding that there was some duty of consultation generally within the "team", and further that there was no, or very limited, direct consultation between Drs. Smallhorn and Williams. Dr. Smallhorn's evidence supports the trial judge's conclusion on that issue.  Whether the specific failure to consult found by the trial judge constitutes negligence is more problematic.

144      As I have said, the appellants contend that the trial judge's particular finding of negligence against Dr. Smallhorn (no consultation with Dr. Williams) is unreasonable and not supported by the evidence.  In addition, the appellants raise the issue of causation.  They contend that there is no evidence that Dr. Smallhorn's negligence, as found by the trial judge, caused Jessica's injuries.  They submit that even if Dr. Smallhorn had a duty to discuss his "negative findings" with Dr. Williams, his failure to do so did not affect what Dr. Williams did, and did not do, during Jessica's May 26th surgery.

145      As a practical matter the discussion that the trial judge found did not take place, but should have taken place, was related to a feature of Jessica's case that Dr. Smallhorn concluded she did not have -- anomalous muscle bundles.  Although it is not entirely clear to me what the trial judge meant when he said that Dr. Smallhorn should have discussed his "negative" findings with Dr. Williams, I have assumed that he found that Dr. Smallhorn ought to have alerted Dr. Williams to the fact that he had concluded Jessica had muscle bundles, but not anomalous muscle bundles in the main chamber of her right ventricle, but that others (eg. Dr. Culham) thought differently.  I should note here that the trial judge did not resolve the evidentiary debate about the presence of anomalous muscle bundles in Jessica's right ventricle.  Since his finding of negligence against Dr. Williams related to Dr. Williams' failure to excise sufficient tissue, as distinct from anomalous muscle bundles, one might well assume that he did not accept the anomalous muscle bundle thesis.  In addition, he did not base his finding of negligence against Dr. Smallhorn on his failure to detect anomalous muscle bundles.  This also supports the conclusion (I acknowledge on the basis of what the trial judge did not say) that he did not find that the muscle tissue that Dr. Williams did not excise on May 26th was an anomalous muscle bundle.

146      I have some doubt that a reasonable cardiologist, who provided an opinion on Jessica's May 24th angiogram, which the trial judge did not find was wrong [See Note 3 below], was required to discuss an earlier finding (anomalous muscle bundles) with Dr. Williams to determine the "best strategy."  Dr. Smallhorn's obligation was to do, and provide his opinion on, Jessica's May 24th angiogram.  He did both.  He had nothing to do with Jessica's care after her May 24th angiogram until he returned to the Hospital on May 27th. His written reports on the May 23rd echocardiogram and the May 24th angiogram would not have been available to Dr. Williams before the May 26th surgery.  Thus, Dr. Williams, who said he reviewed the angiogram, may well not have known about Dr. Smallhorn's written comment in his report on Jessica's May 23rd echocardiogram, "There was no evidence of any anomalous muscle bundles in the right ventricle."  In any case, it seems to me that a surgeon's review of a patient's chart before surgery is so fundamental that Dr. Smallhorn could reasonably have assumed that Dr. Williams would review Jessica's hospital records and her pre-operative angiogram.

   Note 3:  The trial judge did not find that Drs. Smallhorn or Williams were negligent because either "... failed to diagnose the condition of the infant plaintiff." (See Statement of Claim, paras. B(g) and I(g))

147      Dr. Carr, the plaintiffs' main witness on the standard of care issues, did not say (because he was not asked) that Dr. Smallhorn breached the duty of care he owed to Jessica because he did not draw Dr. Williams' attention to the earlier anomalous muscle bundle findings or discuss the best surgical strategy with Dr. Williams in that context.  Nor was this particular ground of negligence included in the listed allegations of negligence in the amended statement of claim. Indeed, as I have said, it appears to me that the focus of the negligence alleged against Dr. Smallhorn at trial was his failure to detect anomalous muscle bundles in Jessica's right ventricle.

148      The trial judge's relatively narrow finding of breach of duty in respect of Dr. Smallhorn is, in my view, questionable; but even if it can be supported, to sustain a finding of negligence in law against Dr. Smallhorn the issue of causation must be addressed.  For reasons to follow, I do not think the evidence, taken with the trial judge's reasons, establishes that Dr. Smallhorn's negligence, as found by the trial judge caused or materially contributed to Jessica's injuries.

149      The problem is aggravated by the lack of evidence directly on point.  Nowhere in the transcript was it suggested to either Dr. Williams or Dr. Smallhorn that their failure to consult before the May 26th surgery caused or materially contributed to Dr. Williams' failure to excise or divide obstructive muscle during Jessica's May 26th surgery. Dr. Williams was not asked if he would have carried out the operation any differently had Dr. Smallhorn alerted him to discrepancies between his assessment of Jessica's right ventricle on the basis of the May 23rd echocardiogram and the May 24th angiogram and earlier assessments which referred to anomalous muscle bundles.  The lack of evidence on this issue may be explained by the fact that Drs. Williams and Smallhorn were represented by the same counsel and neither took issue with the other counsel's conduct.

150      In my view, the causation question in respect of Dr. Smallhorn cannot be answered in the absence of a determination as to what Dr. Williams knew about Jessica's condition, and opinions concerning it, going into the May 26th surgery.  This is an essential issue in respect of the causation component of Dr. Smallhorn's liability.

151      There was considerable evidence about Dr. Williams' preparation for Jessica's May 26th surgery.  I have referred to some of it.  The trial judge conspicuously limited his findings of negligence on Dr. Williams' part to his failure to excise sufficient obstructive muscle bundles on May 26, 1983.  It seems to me that had the trial judge not accepted Dr. Williams' evidence that he would have reviewed Jessica's chart and her May 24th angiogram before her May 26th surgery, he would have included Dr. Williams' manifestly inadequate preparation for the surgery as a basis for finding him negligent.

152      The record, as the trial judge put it, was "strewn with references to prominent muscle bundles, anomalous muscle bundles, muscle bundles."  If Dr. Williams reviewed Jessica's chart, in even a cursory way, he would inevitably have seen these references.  He would not have seen Dr. Smallhorn's May 23rd and 24th echocardiogram and angiogram reports which rule out, or do not note, the presence of anomalous muscle bundles.  It seems to me that the discussion which the trial judge found should have occurred would have served to emphasize Dr. Smallhorn's opinion that Jessica had potentially obstructive muscle development typical of Tetralogy of Fallot, but not anomalous muscle bundles in her right ventricle.

153      Dr. Williams testified that he made daily bedside rounds, as did his surgical residents and one cardiology resident.  Each patient was discussed.  The discussions would include comment on the patient's physical examination and a review of the patient's status.  It may be that the results of Jessica's echocardiogram and angiogram were reviewed as part of this somewhat informal procedure. All we know for sure is that these rounds were part of the Hospital routine.

154      Dr. Smallhorn testified that after angiograms were discussed at the daily morning cardiac conferences information was passed on to particular surgeons.  He did not say how this information was transmitted.  I assume that there was either direct contact between the cardiologists and surgeons, or relevant information was relayed through residents on both services.

155      Dr. Williams said that he was aware of the existence of potentially obstructive muscle bundles.  He noted before the May 26th surgery that what he saw on Jessica's May 24, 1983 angiogram was more severe than the obstruction revealed by the August 3, 1978 angiogram.  He particularly identified muscle obstruction at the lower end of Jessica's infundibulum.  He said:

156      Dr. Williams also testified that the muscle obstruction to which he referred was typical of a Tetralogy case.  This, as I have noted, was his reason for rejecting the "anomalous muscle bundles" label, but it also provides evidence that he knew about sub-infundibular muscle bundles going into the May 26th operation.  When he was asked about the muscle obstruction at the lower end of the infundibulum, in the context of whether that obstruction was new, he responded:

157      In addition, the fact that Dr. Williams noted in his operative report and in subsequent correspondence that he looked for (but did not find) an atrial septal defect suggests that he was aware of the reference to an atrial septal defect in Dr. Culham's 1978 report.  In that report Dr. Culham had listed "atrial septal defect, small" as one of his "Impressions."

158      I do not accept the submission that what Dr. Williams knew can be judged on the basis of what he did during the May 26th operation, that is not remove or divide obstructive muscle.  No one disputes that obstructive muscle is part of Tetralogy of Fallot.  Thus, when dealing with a Tetralogy case, quite apart from references to anomalous muscle bundles a cardiac surgeon would know that muscle will in almost all cases have to be excised or divided.  Indeed, Dr. Williams said that he could not think of another Tetralogy case where he had not resected muscle.  In my opinion, Dr. Williams' failure to excise or divide muscle on May 26th cannot be taken to establish that he did not know there was potentially obstructive muscle in Jessica's right ventricle.

159      An appellate court should not retry the case or make findings of fact that the trial judge chose not to make. An appellate court can, however, review the trial record, including the trial judge's reasons, particularly in a case like this where the reasons are sparse, with a view to determining whether a particular finding of fact may be assumed by necessary implication.  I think the fact that Dr. Williams reviewed Jessica's chart and her angiogram can be assumed on the basis of what the trial judge said, and did not say, in his reasons for judgment.  As I have said, had Dr. Williams not reviewed Jessica's chart before her May 26th surgery, it seems to me that the trial judge would have said so.

160      In my opinion, even if Dr. Smallhorn had discussed his opinion of no anomalous muscle bundles and the charted earlier references to anomalous muscle bundles with Dr. Williams before May 26, 1983, it would not have made any difference.  Causation is not established in respect of Dr. Smallhorn's negligence.  I would, therefore, allow his appeal and dismiss the plaintiffs' action against Dr. Smallhorn.

CROSS-APPEAL

161      On their cross-appeal, the plaintiffs take issue with the trial judge's reasons for judgment in a way generally similar to the defence attack on the reasons on the appeal from the findings of negligence against Drs. Williams and Smallhorn.

162      In addition, the cross-appellants submit that:

163      The trial judge disposed of the plaintiffs' ICU claim in short order.  He said:

164      While it would have been better had the trial judge analyzed and made findings on the discrete issues raised in this part of the appellants' claim I am not persuaded that appellate intervention is justified in the circumstances.

165      There is no doubt that once Jessica developed tachycardia those involved in her care were operating in an atmosphere of crisis.  JET was the significant problem.   To control JET, or her tachycardia, ICU doctors tried digoxin, dilantin, cardioversions, atrial pacing and paired ventricular pacing.  The defendants' submission that cardioversions and paired pacing would not have been resorted to if there were only brief spurts of tachycardia (as one might conclude from the recorded episodes of tachycardia) is consistent with the expert evidence and makes sense to me.  I note the plaintiffs' ICU expert, Dr. McNabb, agreed that cardioversions would have been undertaken because of persisting tachyarrythmia.

166      The intensity of concern among those responsible for Jessica's care in the ICU is demonstrated by their resort to paired pacing which had not been used in the Hospital before it was used as part of the treatment package to control Jessica's tachyarrythmia.

167      In the period extending from 6:00 p.m. on May 27th to 8:00 a.m. on May 28th, Jessica was relatively stable according to Dr. Bohn. Nonetheless, her cardiac output remained low, a fact that Dr. Gerber attributed to the effects of the medication and cardioversions that she had received. There was nothing at that time that pointed to another explanation such as a residual ventricular obstruction for her low cardiac output.  Put another way, those responsible for Jessica's ICU care had no reason to think at that point that she had not undergone a complete Tetralogy repair.

168      Even in cases that do not involve complications such as JET, it is relatively common following Tetralogy surgery for cardiac output to be somewhat low until the third post-operative day.  Thus, in the early period starting about 12 hours after Jessica's May 26th surgery it was not unreasonable for the ICU doctors to think that Jessica was following a normal recovery path, but one with complications.

169      In this case the ICU doctors had to respond to JET, tachyarrythmia, hypoglycaemia, acidosis and seizure activity.  In 1983, those involved in Jessica's care did not know that residual muscle obstruction could lead to JET.  Some of the more urgent problems, such as JET, had to be responded to by therapies that depressed cardiac output.  That was unavoidable.  I see nothing to suggest that the specific remedial efforts undertaken were in any way unreasonable or that the trial judge erred in reaching the conclusion he did on this issue.

170      The core issue on the cross-appeal is the contention that the focus of those responsible for Jessica's post-operative care was too single-minded -- it ignored the prospect of another explanation for her ongoing low cardiac output -- a residual obstruction. The ICU doctors, as well as Drs. Williams and Smallhorn, were not oblivious to the possibility that a residual obstruction could be the cause or a contributing cause of Jessica's ongoing difficulties. At the time, in the urgent circumstances, they thought, in my view on a reasonable basis, that residual muscle obstructions were not the cause of Jessica's problems.  Dr. Williams testified that his post-operative pressure readings were not compatible with the diagnosis of residual muscle obstruction.  There was a sufficient correlation between the ongoing disturbances in Jessica's heart rate and rhythm and her low cardiac output to cause those involved to concentrate on the arrythmia problem, not the other explanation -- residual obstructive muscles.  I see no error in the trial judge's general conclusion on this issue.

171      I think that the timing of the echocardiograms and the May 29th catheterization was a matter of judgment for the physicians involved in her ICU care.  Clearly the trial judge concluded that the timing was appropriate, or at least not inappropriate, in the circumstances with which those involved were presented at the time.

172      I see nothing clearly wrong with the extent of the involvement of Drs. Williams and Smallhorn in Jessica's post-operative care.  Dr. Williams testified that he saw Jessica twice on May 26th and 27th and on May 28th for her catheterization.  When Dr. Smallhorn returned to duty on May 27th at 5:00 p.m. he familiarized himself with Jessica's condition.  A number of ICU doctors were involved in her ongoing treatment.  There is nothing to suggest that Jessica was not the beneficiary of constant care while she was in the ICU.

173      The cross-appellants contend that the trial judge erred in not drawing an adverse inference from the defence's failure to call the doctors who I referred to earlier in these reasons.  The trial judge made no specific reference to these witnesses.  It can be assumed that he chose not to draw an adverse inference from the defence's failure to call these witnesses.  The absence of some of the witnesses was explained and in other cases it was open to the plaintiffs to call them.  Although, once again, it would have been better had the trial judge specifically addressed this issue in his reasons, I am not prepared to accede to this ground of the cross-appeal.

174      For these reasons, I would dismiss the cross-appeal.

CONCLUSION

175      I would dismiss Dr. Williams' appeal and the cross appeal.  I would allow Dr. Smallhorn's appeal and direct that the trial judgment be varied so that the action against him is dismissed.  Since judgment was reserved, we did not hear counsel's submissions on costs.  We, therefore, will not dispose of the issue of costs of the appeal and the trial until we receive counsel's submissions.  This can be done in writing.  We would ask counsel for the appellants to provide written submissions on costs within 15 days and that counsel for the respondents respond within 10 days of receiving the appellants' submission.

OSBORNE J.A.
McMURTRY C.J.O. — I agree.
CHARRON J.A. -- I agree.