Sparks v Hobson

[2018] NSWCA 29

Court of Appeal

Supreme Court

New South Wales

• Summary available
• Amendment notes

Medium Neutral Citation:

Sparks v Hobson; Gray v Hobson [2018] NSWCA 29

Hearing dates:

6 and 7 November 2017

Decision date:

01 March 2018

Before:

Basten JA at [1];
Macfarlan JA at [107];
Simpson JA at [239]

Decision:

(1)   Dismiss Dr Sparks’ appeal with costs;
(2)   Allow Dr Gray’s appeal;
(3)   Set aside orders 1 and 2 made at first instance so far as they relate to Dr Gray;
(4)   Judgment for Dr Gray on the respondent’s claim against him.
(5)   Order the respondent to pay Dr Gray’s costs of the proceedings at first instance and on appeal;
(6) Grant the respondent a certificate under the Suitors’ Fund Act 1951 (NSW) in relation to Dr Gray’s appeal.

Catchwords:

NEGLIGENCE – medical negligence – respondent became paraplegic as a result of surgery – principal anaesthetist’s attempts to address respondent’s continuing high carbon dioxide levels during operation were unsuccessful – whether head surgeon and principal anaesthetist negligent in failing to terminate operation earlier than occurred – roles and responsibilities of head surgeon and principal anaesthetist

 

NEGLIGENCE – medical negligence – peer professional opinion – Civil Liability Act 2002 (NSW) s 5O – whether necessary that at the time of the alleged negligence there was an established practice which was widely accepted as competent medical practice – McKenna v Hunter & New England Local Health District [2013] NSWCA 476; (2013) Aust Torts Rep 82-158 considered

NEGLIGENCE – medical negligence – inherent risk – Civil Liability Act 2002 (NSW) s 5I – whether risk of neurological injury was inherent risk of surgery that could not have been avoided by the exercise of reasonable care and skill

Legislation Cited:

Civil Liability Act 2002 (NSW), ss 5B, 5 I, 5 O; Pt 1A, Div 6
Interpretation Act 1987 (NSW), ss 34, 35

Cases Cited:

Adeels Palace Pty Ltd v Moubarak; Adeels Palace Pty Ltd v Bou Najem (2009) 239 CLR 420; [2009] HCA 48
Bolam v Friern Hospital Management Committee [1957] 1 WLR 582; [1957] 2 All ER 118
CEMEX Australia Pty Ltd v Takeovers Panel (2009) 177 FCR 98; [2009] FCAFC 78
Dobler v Halverson (2007) 70 NSWLR 151; [2007] NSWCA 335
Elliott v Bickerstaff (1999) 48 NSWLR 214; [1999] NSWCA 453
Federal Commissioner of Taxation v St Helens Farm (ACT) Pty Ltd (1981) 146 CLR 336 at 410; [1981] HCA 4
Garcia v National Australia Bank (1998) 194 CLR 395; [1998] HCA 48
Holmes a Court v Papaconstuntinos [2011] NSWCA 59
Gett v Tabet (2009) 254 ALR 504; [2009] NSWCA 76
Harrison v Melhem (2008) 72 NSWLR 380; [2008] NSWCA 67
Hunter and New England Local Health District v McKenna; Hunter and New England Local Health District v Simon (2014) 253 CLR 270; [2014] HCA 44
McKenna v Hunter & New England Local Health District; Simon v Hunter & New England Local Health District [2013] NSWCA 476; (2013) Aust Torts Reports 82-158
Ingram v Fitzgerald [1936] NZLR 905
Montgomery v Lanarkshire Health Board [2015] 1 AC 1430
Naxakis v Western General Hospital (1999) 197 CLR 269; [1999] HCA 22
Paul v Cooke (2013) 85 NSWLR 167; [2013] NSWCA 311
Qidwai v Brown [1984] 1 NSWLR 100
Rogers v Whitaker (1992) 175 CLR 479; [1992] HCA 58
Rosenberg v Percival (2001) 205 CLR 434; [2001] HCA 18
Sidaway v Board of Governors of the Bethlem Royal Hospital [1984] 1 QB 493
Sidaway v Board of Governors of Bethlem Royal Hospital [1985] AC 871
Sydney South West Area Health Service v MD [2009] NSWCA 343; (2009) 260 ALR 702
The Nominal Defendant v Buck Cooper [2017] NSWCA 280

Category:

Principal judgment

Parties:

CA 2017/165207
Dr Christopher Sparks (Appellant)
Brendan Hobson (Respondent)

  CA 2017/168320
Dr Randolph Gray (Appellant)
Brendan Hobson (Respondent)

Representation:

Counsel:
CA 2017/165207
R Cheney SC / K Burke (Appellant)
P Menzies QC / R de Meyrick (Respondent)

 

CA 2017/168320
M Windsor SC / S Woods (Appellant)
P Menzies QC / R de Meyrick (Respondent)

   

Solicitors:
CA 2017/165207
Avant Law (Appellant)
Grieve Watson Kelly (Respondent)

  CA 2017/168320
Norton Rose Fulbright Australia (Appellant)
Grieve Watson Kelly (Respondent)

File Number(s):

CA 2017/165207; 2017/168320

 Decision under appeal 

Court or tribunal:

Supreme Court

Jurisdiction:

Common Law

Citation:

[2017] NSWSC 589

Date of Decision:

17 May 2017

Before:

Harrison J

File Number(s):

SC 2013/80267

HEADNOTE

[This headnote is not to be read as part of the judgment]

Mr Brendan Hobson, the respondent, suffers from Noonan Syndrome, a genetic disorder that prevents normal development in various parts of the body. As a result of that disorder, Mr Hobson’s ability to fill his lungs with air, and hence to breathe, was restricted. Without surgical intervention, his prognosis was grave. Surgery to correct this problem was designed to take place in two stages. The first operation was successful. The second, which occurred on 17 November 2009, had to be terminated before its intended conclusion. As a result of that operation, Mr Hobson became a paraplegic.

Mr Hobson initiated proceedings claiming damages for negligence. His claims ultimately proceeded against the principal surgeon, Dr Randolph Gray, and the principal anaesthetist, Dr Christopher Sparks. Dr Gray is an experienced specialist orthopaedic/spine surgeon and Dr Sparks is an experienced specialist anaesthesiologist.

After an 11 day hearing before Harrison J in the Common Law Division of the Supreme Court, his Honour found that Drs Gray and Sparks had breached the duties of care that they owed to Mr Hobson and were liable in negligence for damages in the amount of $3,828,075. The basis of the decision against both doctors was that, in light of adverse blood gas readings for carbon dioxide obtained in the course of the operation, they should have caused the operation to be terminated earlier than occurred. His Honour held that if the operation had been so terminated, Mr Hobson would not have suffered a significant cardio-vascular collapse during the operation at about 21:30, his spine would not have been damaged and he would not have become a paraplegic.

Drs Gray and Sparks each appealed against the primary judge’s decision on liability. As well as contending that the primary judge erred in finding that they acted negligently, the appellants relied, as they did at first instance, on sections 5 I and 5 O of the Civil Liability Act 2002 (NSW).

The appellants also appealed against his Honour’s decision on damages in three limited respects. They contended that his Honour erred in the allowances that he made for past and future domestic care, and for motor vehicle expenses.

By majority (Simpson JA dissenting), the Court dismissed Dr Sparks’ appeal with costs. The Court unanimously allowed Dr Gray’s appeal.

In relation to Dr Sparks’ appeal:

(1) Breach of duty was established.

Per Basten JA at [93]: “Dr Sparks was faced with a difficult intraoperative choice. However, it was not one which required an instantaneous decision, nor one which required further information or advice. The patient’s metabolic decline was continuing despite Dr Sparks having taken every available step to alleviate the condition whilst the operation proceeded. However, whilst the operation continued, the patient was heading for cardiovascular failure. The operation was expected to last for some four hours; at 9pm the operation was only half completed, on that timescale. (The orthopaedic experts stated that it had 2-4 hours to go.) The decision to allow it to continue for 30 minutes after Dr Sparks had sought help from two experienced anaesthetists, without success, involved more than an erroneous clinical judgment; the trial judge was correct to find a breach of duty of care” (citations omitted).

Per Macfarlan JA at [181] and [182]: “Dr Sparks made an unreasonable decision to ignore a serious and imminent intra-operative danger to Mr Hobson’s well-being when Dr Sparks knew that the other risk with which he was concerned (namely the risk to Mr Hobson if the operation were not completed) did not have the same immediacy…It was not for Dr Sparks to assess the urgency of the operation and decide that it justified a serious and immediate intra-operative risk to Mr Hobson being ignored, at least not without consulting Dr Gray who, as principal surgeon, was head of the surgical team.”

Per Simpson JA (dissenting) at [359]: “The medical evidence does not…support a finding that, in failing to direct the termination of the surgery before 21:28, Dr Sparks failed to exercise reasonable care and skill. The decision Dr Sparks had to make (on a continuing basis throughout the surgery) involved the exercise of clinical judgment…The respondent bore the onus of establishing that Dr Sparks’ decision not to direct the termination of the surgery before that time represented a departure from the standard of care and skill required of a specialist anaesthetist. That onus was not discharged. The medical evidence falls well short of permitting a conclusion to that effect.”

(2) Section 5 I of the Civil Liability Act 2002 (NSW) did not provide a defence to Dr Sparks (Simpson JA dissenting).

(3) Section 5 O of the Civil Liability Act 2002 (NSW) did not provide a defence to Dr Sparks. Discussion by the Court of the correct interpretation of s 5 O.

McKenna v Hunter & New England Local Health District [2013] NSWCA 476; (2013) Aust Torts Rep 82-158 considered. Hunter and New England Local Health District v McKenna (2014) 253 CLR 270; [2014] HCA 44 referred to.

In relation to Dr Gray’s appeal:

Per Macfarlan JA at [201]: “[T]he surgery that took place on 17 November was complex, protracted and difficult. It was Dr Sparks’ role to monitor indicators of Mr Hobson’s condition during the surgery, the two main ones being Mr Hobson’s blood oxygenation and blood pressure, although other indicators were relevant. At least in respect of the other relevant indicators, Dr Gray was entitled to rely on Dr Sparks to inform him of any matter of concern without Dr Gray making any inquiry. There is no evidence that Dr Sparks did so in the period 20:50 to 21:20, and the evidence did not indicate that any matter came to Dr Gray’s notice during that time that should have caused him to make an inquiry as to Mr Hobson’s carbon dioxide level. Without such information, Dr Gray was not negligent in failing to direct termination of the operation during that period. When Dr Sparks did advise termination of the operation at around 21:25, Dr Gray promptly did so. Dr Gray’s appeal on liability therefore succeeds.”

In relation to both appeals:

The challenges to the primary judge’s damages assessment were rejected.

Judgment

1. BASTEN JA: The respondent, Brendan Hobson, was born with Noonan Syndrome, one feature of which was a serious curvature of the spine resulting in a reduced chest cavity, particularly on the left side. In the course of 2009, Mr Hobson suffered increasing breathlessness and a pattern of restrictive airways disease. Corrective surgery was undertaken which involved a two-stage operation intended to relieve the pressure on the chest cavity by straightening the spine.

2. The first stage of the operation took place on 13 November 2009, which was completed uneventfully in a surgical sense. The second stage was planned for 10 days later. However, whilst Mr Hobson was in the intensive care unit his respiratory condition deteriorated as a result of the left main airway (bronchus) becoming obstructed, with the result that pneumonia developed in the left lung. The second stage of the operation was brought forward to the evening of 17 November 2009.

3. The procedure was expected to take some four hours, commencing shortly after 7pm. However, the senior anaesthetist, Dr Christopher Sparks, requested the surgeons to terminate the procedure at about 9.25pm, when the patient’s blood pressure and oxygen levels had dropped dramatically. Once the wound had been closed the patient, who had been in a prone position on the operating table, was returned to a supine position, whereupon his condition improved. Nevertheless, there had been a severe ischaemic collapse in his spinal column resulting in paraplegia.

4. The operation was later completed successfully, but Mr Hobson did not recover the use of his lower limbs.

5. Mr Hobson commenced proceedings against the hospital and various members of the team who operated on him, alleging negligence in various respects. In November 2016 a trial was conducted before Harrison J in the Common Law Division. On 17 May 2017 judgment was delivered for the plaintiff against the principal surgeon, Dr Gray, and the principal anaesthetist, Dr Sparks. Mr Hobson was awarded damages. [1] The particular of negligence which was upheld with respect to both practitioners was the failure to terminate the operation no later than 9.15pm that evening.

   1. Hobson v Northern Sydney Local Health District [2017] NSWSC 589 (“Hobson”).

6. Both the medical background and the procedural background have been fully explained in other judgments. For the reasons given by Macfarlan JA, it is clear that, with respect to the single particular of negligence which was upheld, the primary responsibility lay with the anaesthetist, Dr Sparks. I agree that the finding of negligence on the part of Dr Gray was not justified and Dr Gray’s appeal should be allowed.

7. The situation with respect to Dr Sparks has led to differing conclusions. The following reasons address the case against Dr Sparks and the basis on which he has challenged the decision below.

8. Much of the relevant material was set out clearly and comprehensively by the trial judge in reasons the bulk of which are not the subject of challenge on this appeal. Despite the complexity of the medical evidence, the number of experts called and the somewhat variable course taken on behalf of the plaintiff during the trial, the issues raised on the appeal are circumscribed; the trial judge rejected some 13 particulars of negligence in respect of which there is no notice of contention. [2] It is convenient to commence by identifying the relevant grounds of appeal.

   2. The judge upheld one, saying there were 15, which is not clear from the pleading: Hobson at [6].

Dr Sparks: grounds of appeal

9. Dr Sparks pleaded seven grounds of appeal, six of which related to liability and the seventh to aspects of the assessment of damages.

10. Grounds 1 and 2 alleged error in the application of s 5O of the Civil Liability Act 2002 (NSW), set out in the next part of these reasons. It is convenient to set the grounds out in full.

“1. The primary judge erred in failing to find, pursuant to section 5O of the Civil Liability Act 2002 (NSW), (“the Act”) that the appellant did not incur a liability in negligence, in circumstances where:

a.   the appellant adduced expert evidence to the effect that he acted in a manner that (at the time the service was provided) was widely accepted in Australia by peer professional opinion as competent professional practice;

b.   that evidence was not challenged; and

c.   the primary judge did not find that the peer professional opinion is irrational and could not, for that reason, be relied on.

2.   The primary judge erred in failing to determine the standard of care according to the evidence of what was, in 2009, widely accepted in Australia by peer professional opinion as competent professional practice.”

11. The syntax of ground 3 was obscure, but it appeared to be directed to s 5I of the Civil Liability Act. In short, it alleged that the respondent suffered harm as a result of the materialisation of an inherent risk which could not be avoided by the exercise of reasonable care. The risk was identified as “risk of suffering spinal cord ischemia”.

12. Ground 4 alleged that the judge failed to identify “the risk of harm” against which the appellant ought to have taken precautions. Ground 5 alleged that the judge had wrongly held there was a breach of duty merely because the risk of harm could have been avoided by doing something in a different way. Ground 6 asserted in broad terms that the time for terminating the procedure was a matter of clinical judgment for the anaesthetist and that allowing the operation to proceed for some 15 minutes after the last moment at which it should reasonably have been terminated (as identified by the trial judge) did not constitute a breach of duty.

13. Grounds 1 and 2 are central to the appeal and it is convenient to turn to the operation of s 5O of the Civil Liability Act.

Civil Liability Act, s 5O

14. Both appellants appealed from the rejection by the trial judge of their respective defences based on s 5O of the Civil Liability Act. There are a number of reasons for addressing the defence separately in each case. First, Dr Gray originally pleaded the section with five particulars, three of which appeared to be directed to s 5I. Neither of the other two potentially relevant particulars addressed the termination of the operation. [3] Dr Sparks, by contrast, originally pleaded the section, but without any particulars at all. [4] Secondly, although both appellants addressed the issue in written submissions at trial, they did so in somewhat disparate terms. [5] Thirdly, the nature of each defence case turned primarily upon the evidence of the expert witnesses practising in the field of the particular specialist.

    3.    Defence to third amended statement of claim (Dr Gray), 14 November 2016, par 40.

    4.    Amended defence (Dr Sparks), 10 November 2016, par 23.

    5.    Fourth Defendant’s outline of submissions, 21 November 2016, pars 124-140 (Dr Sparks); Second Defendant’s outline of submissions, 22 November 2016, pars 195-202.

15. Before addressing these separate circumstances it is convenient to consider the scope and operation of s 5O. The section is located in Pt 1A of the Civil Liability Act dealing with “Negligence”. The Part does not constitute a comprehensive statement of the principles governing the tort of negligence, but identifies in separate divisions a number of specific principles. Section 5O appears in Div 6, entitled “Professional negligence”. The primary principle is stated in subs (1), but it is convenient to set out the whole of the section, including the subsidiary provisions:

5O   Standard of care for professionals

(1)   A person practising a profession (a professional) does not incur a liability in negligence arising from the provision of a professional service if it is established that the professional acted in a manner that (at the time the service was provided) was widely accepted in Australia by peer professional opinion as competent professional practice.

(2)   However, peer professional opinion cannot be relied on for the purposes of this section if the court considers that the opinion is irrational.

(3)   The fact that there are differing peer professional opinions widely accepted in Australia concerning a matter does not prevent any one or more (or all) of those opinions being relied on for the purposes of this section.

(4)   Peer professional opinion does not have to be universally accepted to be considered widely accepted.

16. The section envisages a conflict in the evidence as to whether the defendant’s conduct was accepted by his or her peers as “competent professional practice.” In order to establish negligence, there will usually need to be expert evidence called by the plaintiff to the effect that the defendant failed to exercise reasonable care and skill in providing a relevant service. Under the general law, the defendant would seek to challenge that evidence by calling expert opinion to a contrary effect. For the plaintiff to succeed, the court would need to be satisfied on the probabilities that the appropriate standard was that for which the plaintiff’s experts contended. That position has been varied by s 5O(1); although expressed in the passive voice (“if it is established that …”), it has been broadly accepted that the section provides a defence. [6]

    6. Dobler v Haloverson (2007) 70 NSWLR 151; [2007] NSWCA 335 at [60] (Giles JA); Sydney South West Area Health Service v MD [2009] NSWCA 343; (2009) 260 ALR 702 at [21]-[25] (Hodgson JA), [51] (Allsop P), [58] (Sackville AJA).

16. Despite the common acceptance of the provision as a “defence”, that characterisation gives rise to difficulty. To be a defence carries the implication that the plaintiff must establish breach according to the general requirements of s 5B of the Civil Liability Act, following which the practitioner bears the burden of establishing that his or her conduct amounted to “competent professional practice” in the terms of s 5O(1). The heading of the section (“Standard of care for professionals”) indicates its purpose. Although the heading is not part of the Act, [7] it may be taken into account as extrinsic material in construing the provision, in accordance with s 34(1) of the Interpretation Act. In any event, it is tolerably clear that the provision sets a standard. However, if the standard is met, it follows that the conduct was not negligent.

    7. Interpretation Act 1987 (NSW), s 35(2)(a).

17. Accordingly, once s 5O is invoked, arguably the general exercise required by s 5B becomes otiose. There can only be one standard against which to judge the conduct of a professional defendant, although that standard may depend upon the resolution of conflicting evidence called by the plaintiff and the defendant. It is only if one takes the plaintiff’s evidence in isolation that a two-stage process, involving the assessment of the plaintiff’s claim followed by assessment of an affirmative defence, will arise. However, in a practical sense, that is not how the dispute should be determined. Rather, a judgment will be given based on all of the evidence. Nor is the exercise helpfully clarified by speaking of shifting burdens of proof. The question for the trial judge is ultimately whether the plaintiff has established that the conduct of the defendant failed to comply with the relevant standard of care. This approach is consistent with Dobler and is not to say that a plaintiff must seek out and negative opinions inconsistent with those of the experts on whom he or she relies. [8] Beyond that proposition, Dobler did not turn upon the onus of proof. [9]

    8. Dobler at [61].

    9. Dobler at [55].

18. This approach obtains support from an understanding of s 5O in its historical context. Prior to the enactment of s 5O, Australian courts identified the standard of care in medical negligence cases according to the principles set out in Rogers v Whitaker:[10]

“In Australia, it has been accepted that the standard of care to be observed by a person with some special skill or competence is that of the ordinary skilled person exercising and professing to have that special skill. But, that standard is not determined solely or even primarily by reference to the practice followed or supported by a responsible body of opinion in the relevant profession or trade.”

10. (1992) 175 CLR 479 at 487; [1992] HCA 58 (citations omitted).

20. This statement rejected the approach then applied in the UK[11] by reference to a direction given to a jury by McNair J in Bolam v Friern Hospital Management Committee. [12] As Lord Scarman explained in Sidaway v Board of Governors of Bethlem Royal Hospital:[13]

“The Bolam principle may be formulated as a rule that a doctor is not negligent if he acts in accordance with a practice accepted at the time as proper by a responsible body of medical opinion even though other doctors adopt a different practice. In short, the law imposes the duty of care: but the standard of care is a matter of medical judgment.”

11. Cf now Montgomery v Lanarkshire Health Board [2015] 1 AC 1430.

12. [1957] 1 WLR 582 at 587.

13. [1985] AC 871 at 881.

21. Lord Scarman himself preferred a different approach: [14]

“In my view the question whether or not the omission to warn constitutes a breach of the doctor's duty of care towards his patient is to be determined not exclusively by reference to the current state of responsible and competent professional opinion and practice at the time, though both are, of course, relevant considerations, but by the court's view as to whether the doctor in advising his patient gave the consideration which the law requires him to give to the right of the patient to make up her own mind in the light of the relevant information whether or not she will accept the treatment which he proposes.”

14.    Sidaway at 876.

22. Australian authority, as explained by Gleeson CJ in Rosenberg v Percival,[15] adopted the dissenting view of Lord Scarman by which “the relevance of professional practice and opinion was not denied; what was denied was its conclusiveness.” The Australian approach was not confined to cases of warnings and medical advice; it extended to diagnosis and treatment. [16]

    15. (2001) 205 CLR 434; [2001] HCA 18 at [7].

    16. Naxakis v Western General Hospital (1999) 197 CLR 269; [1999] HCA 22 at [21] (Gaudron J), [47] (McHugh J), [81] (Kirby J).

23. However, the language of s 5O differs from Bolam, which referred to a practice accepted as “proper” by a “responsible body of medical men”. Lord Scarman also referred to “responsible and competent professional opinion”. The differences may not have practical significance.

24. In Dobler, Giles JA stated :[17]

“Section 5O may end up operating so as to determine the defendant’s standard of care, but the standard of care will be that determined by the court with guidance from evidence of acceptable professional practice unless it is established (in practice, by the defendant) that the defendant acted according to professional practice widely accepted by (rational) peer professional opinion.”

Ipp JA and I agreed. On reflection, this passage may be open to misunderstanding. It is true that s 5O will not be engaged unless there is evidence of a widely accepted professional practice supporting the defendant’s conduct, but where there is such evidence, unless it can be rejected by the trial judge, it will fix the relevant standard; there cannot be two legally supportable standards operating in the one case.

17. Dobler at [61].

25. There remains a question as to the extent to which the trial judge has a discretion to reject evidence of a widely accepted professional practice. The judge may dismiss “peer professional opinion” as “irrational”, in accordance with subs 5O(2). By contrast, the older cases, while tending to use transferred epithets, refer to opinions of responsible and competent practitioners in the field. It may be that the reference in s 5O to “peer professional opinion” is to be so understood. But then it is difficult to understand how an irrational opinion could qualify as a relevant peer opinion.

26. More importantly, the provision raises the possibility of a negative inference, namely that the court may not reject an opinion even though satisfied that it is unreasonable (though not irrational), or otherwise not one the court would itself adopt. Such a general negative inference should not be inferred; there will be other questions which will arise.

27. First, there will be a question as to whether the evidence of one or two experts can satisfactorily establish opinions which are “widely accepted” in circumstances where such a view is contradicted by other evidence. No doubt evidence of “general professional opinion”, in addition to the personal opinion of the expert, is admissible in such circumstances. [18]

    18. Cf Qidwai v Brown [1984] 1 NSWLR 100 at 102, dealing with misconduct of a medical practitioner in a professional respect.

28. Secondly, it will be a matter for the court to assess the significance of particular evidence. Evidence may be at a greater or lesser level of generality. At a high level of generality it may readily be accepted that an opinion is widely held amongst peers of the practitioner. However, the standard so identified may not assist greatly in resolving the particular case. On the other hand, the more particular the opinion, based on the specific circumstances of the case, the more difficult it may be to establish an opinion which can be described as “widely accepted” among fellow practitioners. Accordingly, whether or not evidence of medical opinion is properly described as conclusive in a particular case will depend upon a range of factors and not merely the fact that it can properly be described as not irrational.

29. Subsections (3) and (4) do little more than explain what might otherwise readily have been inferred, namely that for an opinion to be “widely accepted” it need not be “universally accepted” and, if not universally accepted, there must be more than one opinion and may be more than one which is widely accepted. If the court is satisfied that the defendant’s conduct is considered competent according to widely accepted peer professional opinion, that opinion provides a standard against which to assess the claim.

30. At trial, both practitioners raised s 5O as a defence. Counsel for the plaintiff treated the reasoning of this Court in McKenna v Hunter & New England Local Health District [19] as an effective answer to the defence. In McKenna Macfarlan JA stated that: [20]

“To establish a defence under s 5O a medical practitioner needs to demonstrate, first, that what he or she did conformed with a practice that was in existence at the time the medical service was provided and, secondly, to establish that that practice was widely, although not necessarily universally, accepted by peer professional opinion as competent professional practice.”

On the appeal, counsel for Dr Sparks submitted that McKenna was wrong in holding that it was necessary to demonstrate the existence of “a practice” extant at the time of the conduct in question.

19. McKenna v New England & Hunter Local Health District [2013] NSWCA 476; (2013) Aust Torts Rep 82-158 (“McKenna”).

20.    McKenna at [160] (emphasis in original).

31. Although it is uncertain how this reasoning in McKenna will operate in particular cases, there is a risk in reformulating the statutory language. To speak of “a practice” adopted by a group of professional persons suggests a regular course of conduct adopted in particular circumstances. By contrast, the phrase “competent professional practice” is apt to cover the whole gamut of professional services provided by the practitioner, whether or not the particular circumstances have arisen sufficiently often to result in an established practice. For example, although opinions may differ as to the conclusion to be drawn, there is no grammatical or semantic difficulty in describing an argument run by counsel in a novel case as demonstrating competent or incompetent professional practice. The same judgment may be offered about the failure of counsel to call a defendant in a criminal trial, where no settled practice exists. Where an acquittal depends on establishing an affirmative defence and there is no other evidence to support the defence, it may be described as incompetent professional practice not to call the defendant who could have given such evidence. Where an opinion is given and challenged, it will be supported (or attacked) not by reference to some established practice, but by reference to how an assessment of the circumstances (which may be unique) would be undertaken by a knowledgeable and experienced practitioner.

32. There are other reasons for thinking that the reference to “competent professional practice” does not require evidence of “a practice”. First, it is the “manner” in which the defendant acted which must be the focus of the opinion. Secondly, if it were necessary to establish a practice, one might expect subs (3) to refer to “opinions … concerning that practice”, rather than “opinions … concerning a matter”.

33. To take an example closer to the present case (but still hypothetical) an anaesthetist might allow an operation to proceed on the basis that two indicators remained within acceptable limits but a third indicator did not. An expert might express an opinion that such conduct was not competent practice, not because he or she had experienced the same circumstance in the past, or had read about it in a textbook, but because basic principles of human physiology led to that conclusion.

34. Accordingly, although the language used in McKenna may well sufficiently describe many circumstances in which s 5O is invoked, I would not understand it as a general proposition as to the constraints imposed by s 5O(1).

35. If that understanding is too restrictive and it is necessary to go further, I would not follow McKenna. The decision in McKenna having been overturned in the High Court,[21] the reasoning of the majority in this Court is no longer binding. As Kirby J noted in Garcia v National Australia Bank:[22]

“It is fundamental to the ascertainment of the binding rule of a judicial decision that it should be derived from (1) the reasons of the judges agreeing in the order disposing of the proceedings; (2) upon a matter in issue in the proceedings; (3) upon which a decision is necessary to arrive at that order. Thus, the opinions of judges in dissent are disregarded for this purpose, however valuable they may otherwise be.”

21. Hunter and New England Local Health District v McKenna (2014) 253 CLR 270; [2014] HCA 44 (“Hunter Health District”).

22. (1998) 194 CLR 395; [1998] HCA 48 at [56].

36. When the decision of an intermediate court of appeal is overturned by the High Court, the reasoning of the majority is no longer dispositive, even if the High Court does not directly reject it, as it did not with respect to the interpretation of s 5O in McKenna, having determined the appeal on a different point.

37. There is some irony in the fact that the primary support for this conclusion is often sourced to a brief statement by Aickin J in dissent in Federal Commissioner of Taxation v St Helens Farm (ACT) Pty Ltd [23] stating:

“I should add that there is no basis on which one point in the judgment of a primary court should be regarded as authoritative where the judgment is reversed on other grounds.”

23. (1981) 146 CLR 336 at 410; [1981] HCA 4.

38. Given that the reasons of the intermediate court in a case where the decision has been reversed are no longer dispositive, they are analogous to the reasoning of a dissenting judge. Allsop P explained in Holmes a Court v Papaconstuntinos [24] that dissenting judgments “may contain valuable discussions of legal principle”, but that is “a different thing to being taken as an exposition of the common law to be applied.” The same proposition applies with respect to discussion of statutes.

    24. [2011] NSWCA 59 at [3] (Beazley and Tobias JJA agreeing).

39. The position would, of course, be quite different if the High Court, despite reversing the decision in this Court in McKenna, had approved the reasoning with respect to s 5O. The reasoning would not then form part of the ratio, but it would clearly obtain the authority of dicta of the High Court. However, that did not happen in the present case. The High Court held that the plaintiff must fail on the basis that there was no duty of care owed to relatives of the deceased. The Court continued:[25]

“Consideration of those other issues, about ss 5B, 5O, 43 and 43A of the [Civil Liability Act], should await a case in which it is necessary to examine them.”

25. Hunter Health District at [12].

40. While the reasoning of this Court in McKenna as to the scope and operation of s 5O is not to be disregarded, there is no obligation on this Court, as a matter of precedent, to follow it. For the reasons set out above, in my view it is too restrictive. [26]

Civil Liability Act, s 5I

26. See CEMEX Australia Pty Ltd v Takeovers Panel (2009) 177 FCR 98; [2009] FCAFC 78 at [94]-[95] (Ryan, Jacobson and Foster JJ).

41. Dr Sparks also called in aid the exclusion from liability for the materialisation of an inherent risk, as set out in s 5I of the Civil Liability Act. The section provides:

5I   No liability for materialisation of inherent risk

(1)   A person is not liable in negligence for harm suffered by another person as a result of the materialisation of an inherent risk.

(2)   An inherent risk is a risk of something occurring that cannot be avoided by the exercise of reasonable care and skill.

(3)   This section does not operate to exclude liability in connection with a duty to warn of a risk.

42. The scope and operation of the provision has been the subject of careful consideration in earlier decisions, including Paul v Cooke. [27] The apparently simple language of the provision is fraught with difficulties.

    27. (2013) 85 NSWLR 167; [2013] NSWCA 311.

43. On one reading of subs (2), that which “cannot be avoided” by the exercise of reasonable care is the “risk”; the alternative reading is that it is the materialisation of the risk which cannot be avoided by exercise of reasonable care. To speak of “avoiding” a risk is meaningful in some circumstances, but not in others. Ordinary usage would suggest that it is the occurrence (the materialisation of the risk) which may or may not be “avoided”. Context suggests that that is the intended meaning because the provision only operates where a person has suffered harm as a result of the “materialisation of an inherent risk.”

44. The next problem stems from the use of the words “cannot be” avoided. A risk is less than a certainty; it may be quantified in a particular case at, say, 25%. In three out of four cases the harm will not materialise and in one sense “can” be avoided. However, the section should be understood as referring to the exercise of skill having no causal consequence in terms of the outcome. Thus, in a sense, the provision may be read as operating where the skill of the surgeon does not affect the risk of an adverse outcome.

45. Of course, the application of s 5I will only arise in circumstances where (staying with the medical example) the patient has had an adverse outcome, in which case liability will depend upon establishing negligence and causation. Assuming negligence, the plaintiff will fail if she cannot demonstrate a causal connection between the negligence and the harm. In that case, s 5I is not required by the defendant; if causation is established, s 5I is not engaged.

46. Rogers v Whitaker is often cited as a paradigm of an inherent risk. The patient had an operation on her right eye, which resulted in her losing her sight in her left eye as a result of a condition known as sympathetic ophthalmia. Evidence suggested that the risk materialised in fewer than one in 10,000 cases. The operation had been carried out with the required skill and care. Rogers itself involved a failure to warn and thus s 5I would not have applied. [28]

    28. Civil Liability Act, s 5I(3).

47. There may be cases, of which Paul v Cooke was one, where negligence may be conceded and the case will turn on causation. However, as Leeming JA explained, where s 5I is raised, “it unquestionably remains for the plaintiff to establish s 5D legal causation, and the logical consequence of so doing may (and often will be) to negate s 5I.”[29]

    29. Paul v Cooke at [80].

48. This is not a case where the risk of harm was less than 50%, so that, had the negligence not occurred, the operation would have been conducted on a different occasion when, on the probabilities, the harm that in fact occurred would not have occurred.

49. Section 5I has no application in the present case. The risk which accompanied the surgery was the neurological collapse of the spinal column which in fact occurred. There is no doubt that if the operation had ceased at a point in time before the collapse occurred (which was probably shortly before the operation in fact ceased) the risk would not have materialised; the harm would not have occurred. That result would have been achieved in the exercise of reasonable care and skill. The question for the determination of the Court was whether the continuation of the operation involved a failure to exercise reasonable care and skill. Because the definition of “inherent risk” in s 5I assumes that the exercise of reasonable care and skill would not affect the outcome, it is not clear how the section was said to be engaged in the present case.

Evidence and findings at trial

50. There were five methods adopted for the monitoring of the patient’s condition during surgery. These were (a) blood pressure, (b) oxygen levels in blood, (c) CO2 levels in blood, (d) exhaled CO2 levels and (e) spinal cord monitoring. The last (spinal cord monitoring) was abandoned, but that proved to be only indirectly relevant to breach of duty; it may conveniently be addressed first. Dr Sparks based his decision-making on the first two parameters; a critical question was whether he should have paid greater attention to the CO2 levels.

(a)   spinal cord monitoring

51. It is convenient to consider first the significance of the spinal cord monitoring. The importance of such monitoring arose from the fact that part of the arterial blood supply to the spinal cord had been diminished through the first procedure. An episode of low blood pressure (hypotension) was liable to place the spinal cord at risk through loss of blood supply. A number of criticisms were made of the monitoring procedure. First, it was important to obtain a baseline reading. The neurophysiologist responsible for the monitoring, Associate Professor Jim Lagopoulos gave evidence that he arrived at the theatre after the procedure was already underway. He said that a normal baseline reading was not able to be established. It was common ground that at or about 8.35pm Dr Sparks administered vecuronium to improve the patient’s ventilation. The drug, a muscle relaxant, led to the discontinuation of the spinal cord monitoring as it had become ineffective.

52. There was inconsistent evidence given at the trial as to whether the readings from the monitoring were ever normal and as to whether Dr Gray or Dr Sparks was advised of the fact that they were abnormal, to the extent that they were. However, the expert evidence did not support the proposition that the surgery should have been terminated in light of the results of the monitoring. Rather, the concern focused on the fact that the monitoring ceased at about 8.35pm, when vecuronium was administered. At that stage, Dr Sparks believed that there was a problem with ventilation, and hoped that administration of vecuronium would correct the problem. The trial judge accepted that this was a reasonable step to take. He continued:[30]

“However, the significant compromise in those circumstances was that the spinal cord monitoring was immediately neutralised by its administration and any form of spinal insult that spinal cord monitoring might otherwise have been expected to highlight would remain dangerously undetected. In other words, Dr Gray and Dr Sparks were effectively trading off any concern they might have had that Mr Hobson may be neurologically compromised if the surgery proceeded in the absence of spinal cord monitoring against the possibility that he might die if the corrective surgery were discontinued.”

30. Hobson at [196].

53. The judge then considered what warnings might have been available had the spinal cord monitoring continued after 8.30pm. Dr Westbrook had given evidence that “had spinal-cord monitoring been properly established in a timely manner that there would have been advanced warning to the clinicians that spinal cord perfusion was threatened particularly during the transient, earlier episodes of hypoxaemia.” [31] Dr Michael Johnson, an orthopaedic surgeon, gave evidence that he would have “insisted that spinal cord monitoring was available.”[32] Dr Peter Heath also gave evidence of the importance of effective monitoring. In effect there was a wealth of evidence from the plaintiff’s experts that spinal cord monitoring was an important safety mechanism in circumstances where blood supply to the spinal cord was reduced by the earlier surgery, and where even transient elements of hypotension suggested cardiovascular instability which needed to be monitored. On the other hand Dr Geoffrey Askin, who was called by Dr Gray, stated:[33]

“MEP monitoring in this case would not have allowed remedial action given that the only remedial action that allowed the patient to restore blood pressure and PCO2 was to turn the patient supine. Having MEPs running during the time of the physiological crisis would not have expedited the termination of the procedure and changing the patient’s position at all. Hence, the loss of MEPs would not have changed the outcome.”

31.    Hobson at [38], par 7 of Dr Westbrook’s supplemental report of 21 October 2012.

32. Hobson at [39].

33. Hobson at [59].

54. The trial judge had extracted, at [66] and [67], lengthy extracts from the evidence of Dr Peter Silbert, a neurologist and expert in spinal cord monitoring. Dr Silbert’s conclusion was that, had spinal cord monitoring continued, it would not have detected abnormalities prior to 9.25pm, which was the time at which the collapse in other indicators led Dr Sparks to request that the surgery end. The trial judge placed weight on that evidence, and the evidence of other experts to similar effect. The consequence was that although the absence of spinal cord monitoring should have led to caution on the part of the anaesthetist and the surgeon, its presence would not have altered the outcome. This conclusion was expressed in two parts. First, at [223], the judge concluded that continuing the operation beyond 8.30pm was perfectly reasonable. Allowing that use of vecuronium was also a reasonable step, “there was … at the time no useful place for spinal cord monitoring.”[34]

    34. Hobson at [224].

55. The second stage in the argument was addressed at [243] in the following terms:

“Sixthly, there was a need to be particularly mindful of the consequences for Mr Hobson of his rapidly deteriorating ventilation by reason of the fact that spinal cord monitoring was absent or effectively neutralised. For present purposes it does not matter which it is. Indeed, I accept the opinion of Dr Silbert that he did not believe that SSEPs and MEPs would have detected significant spinal cord electrophysiological abnormalities prior to 21.25. In that sense I am not satisfied that the absence of spinal cord monitoring for whatever reason properly informs or supports a finding of negligence by either defendant. Its absence or ineffectiveness was a fact of life in the operating theatre at 20.30 and at the very point at which Dr Sparks telephoned Dr Barratt. It was however to my mind a critically significant factor that not only enlivened, but in fact heightened, the need to act conservatively and to proceed expeditiously. It told against the appropriateness of taking an expectant approach when the solution to Mr Hobson’s difficulties had not emerged or was not understood.”

(b)   measuring other conditions

56. Putting monitoring to one side, there were four other measurable parameters taken into account. Dr Sparks relied primarily on arterial blood pressure and oxygen saturation in the blood, as supporting continuation of the surgery. Until those fell below acceptable limits, he allowed the surgery to continue.

57. The challenge to his decision-making was based upon his failure to act upon the concerns raised by the other parameters demonstrating that carbon dioxide was not being removed from the blood stream. There is no doubt that the readings caused him serious concern and led to him telephoning from the operating theatre a senior colleague, Dr Stephen Barratt with whom Dr Sparks had performed a bronchoscopy at the intensive care unit during the day before the operation. It was agreed that the telephone call was at approximately 8.50pm. Dr Barratt gave the following evidence in an affidavit:[35]

“11.   Dr Sparks told me that Mr Hobson was in the prone position on a Jackson table during the surgery. In my view, if the breast plate of the Jackson Table was pressing on Mr Hobson, the cardiac compression would generate potential for hypotension.

12.   Dr Sparks expressed his concern about a high arterial carbon dioxide at the time, I think he said approximately 65 mmHg. This is about 50% more than normal. This usually means inadequate ventilation and this issue had been excluded with multiple bronchoscopies, checking for breath stacking and pneumothorax. However, at the time Mr Hobson’s end tidal carbon dioxide was only 30-25mmHg which means a significantly increased dead space ventilation. Inadequate ventilation on its own does not explain this. Therefore, I proposed to Dr Sparks that maybe a pulmonary artery was being compressed along with possible cardiac compression which would mean he would have a section of his lung which was being ventilated, but not perfused. The telephone call abruptly ended when Dr Sparks said ‘I gotta go’.”

35. Affidavit of Stephen Barratt, 12 November 2015, at Hobson [57].

58. The trial judge summarised the plaintiff’s case at trial in the following terms:

“[124]   Mr Hobson submitted that a failure to consider factors beyond oxygen saturation and blood pressure was indicative of a standard of medical practice below the standard required in Australia in November 2009 of a reasonably competent anaesthetist or orthopaedic surgeon, performing spinal surgery in the particular method adopted to treat Mr Hobson. …

[125]   Mr Hobson was in respiratory difficulty from the commencement of the surgery and the surgical team had trouble ventilating him throughout. His metabolic state, especially as reflected in his blood gasses, was also poor from the start and continually deteriorated during the surgery.

[126]   Blood gasses demonstrated a clear deterioration in Mr Hobson’s metabolic state as the surgery progressed. Samples taken at 20.08 and 20.21 had by then already demonstrated a very high carbon dioxide level despite various attempts at pulmonary ventilation with a double lumen tube. This was causing significant respiratory acidosis. From the early stages of the surgery, blood gasses disclosed evidence of an increasing lactate level suggesting inadequate organ perfusion. Blood gas samples at 20.37 and 20.51 demonstrated significant further deterioration of all parameters.

[127]   A reasonably competent anaesthetist would have concluded that Mr Hobson was suffering a profound respiratory and metabolic acidosis. Both Dr Sparks and Dr Gray were aware of this dangerous downward spiral in Mr Hobson’s metabolic state.

[128]   By 20.50 Dr Sparks had tried various means of reversing this deteriorating trend without success. In particular, maintenance of blood pressure and ventilation at reasonable levels after transient drops had failed to address Mr Hobson’s dire and deteriorating metabolic state.

[129]   As noted above, Dr Sparks spoke to Dr Barratt over the telephone at 20.50 or thereabouts. Dr Barratt correctly suggested to Dr Sparks that the breastplate of the Jackson table may have been pressing on Mr Hobson, creating cardiac and pulmonary artery compression. This meant that a section of lung was being ventilated but not perfused. Dr Sparks agreed with this analysis. Mr Hobson submitted that a reasonably competent anaesthetist would have called a stop to the surgery by this time at the latest. Had the surgery been paused or halted at that, or any earlier time, and Mr Hobson turned supine, he would not have suffered spinal cord damage.”

59. The findings of the trial judge in relation to this aspect of the case appeared as the fifth element in a series: [36]

“Fifthly, even if there was arguably no single unambiguous indication for stopping the surgery before the decision to do so was made, there were several factors which together certainly gave that indication. As Mr Hobson emphasises, the evidence of Dr Barratt, who was after all the expert to whom Dr Sparks turned when his options appeared to be evaporating, emphasises the importance of heeding several factors in combination. It is reasonably clear that Dr Barratt’s telephone input inspired the events that followed it. The attending doctors undoubtedly had access to several significant indicators of Mr Hobson’s condition, even if none taken alone pointed only in one direction. The combination of these factors provided a different perspective. The earlier indications available from Mr Hobson’s vital signs appeared to be that any deteriorations that were observed, in particular, episodes of hypoxia and hypotension occurring at or about 18.50, 19.10 and up until about 20.35, some of which were severe, were transient and recoverable but not such as to indicate that continuing with the surgery could not be justified. Up until about 20.35, Dr Gray and Dr Sparks were, in effect, permissibly taking an expectant approach, in the absence of material that indicated only one possible course of action. That position changed very shortly thereafter.”

36.    Hobson at [226] (italics added).

60. On the appeal, Dr Sparks challenged the sentence italicised above. However, that sentence could be omitted without interfering with the process of reasoning.

61. The judge then set out in some detail Dr Westbrook’s evidence, together with the responses of Dr Forrest and Dr Manasiev. He referred to Dr Sparks’ own evidence and to the expert evidence of two orthopaedic surgeons in the following terms:[37]

“As I have earlier noted, the orthopaedic surgeons in their joint report indicated that the surgery should have ceased ‘when the anaesthetists reached the stage that they were unable to maintain satisfactory cardio respiratory parameters’. The orthopaedic surgeons made no precise reference to a time when the surgery should have ceased. Satisfactory cardio respiratory parameters were not being maintained by 20.30.”

37. Hobson at [240].

62. Before turning to the evidence of Dr Barratt, on whom the trial judge placed some weight, it is convenient to return to the evidence given by Drs Westbrook and Forrest addressing their joint report. Dr Westbrook had set out in his affidavit and a chart annexed to the affidavit the evidence of steadily deteriorating metabolic conditions and their consequence. In responding to questioning from the plaintiff’s counsel he stated: [38]

“So – well, so the carbon dioxide level at 19.13 was, as I say, 64, well – well above the upper limit of normal of 48. Subsequently it went [to] 69, so it steadily increased until it really reached a peak at 20.51. But even at 20.37 and 20.21 it was up to 70 which was, as I say, well above the normal limits. Now, the consequence of that is that the patient had become increasingly [acidotic] and that was further aggravated by what’s referred to as a metabolic acidosis. That – so that was an accumulation of acids in the blood stream most likely due to inadequate perfusion of other organs. So by 20.37 the patient had a pH of 7.027 which really is a serious acidosis, a mixed metabolic and respiratory acidosis, the consequences of which are depressed myocardial function and other depressed cellular functions in the body.

MENZIES: Could that lead to some result adverse to the patient at that point?

WESTBROOK: Well, if – certainly were it to continue to deteriorate which it – of course it did at 20.51 and 21.01, the pH was even lower and at 21.13 lower still. That, coupled with the compression of the great vessels in the chest, you know, there was an inevitable deterioration towards to the eventual collapse at … 21.20 or thereabouts. I think … the problem for the anaesthetist is they didn’t have anything they could do to improve the situation. They were doing everything they possible could in terms of ventilation of the lungs, in terms of maintaining h[a]emodynamics. And despite these measures, the acidosis was deteriorating.

MENZIES: You’ve already expressed an opinion that, in the light of that deterioration …, that the collapse that occurred [at] 21.33 or thereabouts was inevitable at some point. … When did that inevitability arise? Or put another way, in as much as it was inevitable and you’ve already said the surgery should have been stopped, at what point then do you say the surgery should have been stopped?

WESTBROOK: I – I mean I think at 2021 things were looking pretty grim but certainly at 2037 with a pH of 7 and an increasing lactate I – it’s my view the surgery should have been abandoned at that point.”

38.    Tcpt, 14/11/16, p 264(27).

63. Dr Forrest agreed that with “a benefit of hindsight I think you couldn’t argue that [it] would have been preferable to abandon the surgery earlier than … the time that it was abandoned.” [39] He was challenged as to whether that conclusion could only be advanced with hindsight. He referred to the steps which were taken, the difficult choice the doctors were required to make given the possible effects of abandoning the surgery, and the attempts made to correct the underlying cases of metabolic acidosis. He continued: [40]

“Now, that in fact proved to be unsuccessful, because his carbon dioxide continued to climb, so as his carbon dioxide reached a level of over a hundred at – at – 2051. And I think really, the key to this is that – is that the difficulty in ventilation was already one of the key factors that was aggravating his metabolic acidosis because as carbon dioxide climbed, that led to an increase in his pulmonary-vascular resistance, which is the – basically the impedance against which the right ventricle has to eject. That in turn led to a reduction in right-ventricular function, right-ventricular performance, which decreases pulmonary blood flow. And of course, pulmonary blood flow is exactly the same as your cardiac output, so ultimately that right-ventricular dysfunction led to the cardio-vascular collapse that occurred around 2130.”

39.    Tcpt, p 265(24).

40.    Tcpt, p 265(50).

64. It is then necessary to return to the oral evidence of Dr Barratt, upon which the trial judge placed significant weight.

65. Dr Barratt was cross-examined about the conversation he had with Dr Sparks over the telephone. His evidence was that the conversation took place at about 9.30pm, but it was accepted that the phone call occurred just prior to 9pm. He agreed that the discussion had included the possibility of cardiac compression generating the potential for hypotension with the consequence that critical organs might not be adequately perfused. The discussion had included Dr Sparks’ concern about high arterial carbon dioxide and the fact that he had checked that the patient was properly ventilated “but he still could not explain the problem.” The cross-examination continued: [41]

    41.    Tcpt, 08/11/16, pp 103-104

“Q. So your response was that probably, or maybe, a pulmonary artery was compressed along with possible cardiac compressions, it means his lung was being ventilated but not perfused?

A. That is exactly correct.

Q. What is ventilated but not perfused mean?

A. It means that there is inability to eliminate carbon dioxide from the lung because there’s no blood going through the alveolus and all this air is just coming into the lung and can’t take the carbon dioxide out so the carbon dioxide is going to build up.

Q. And the consequence of that is what?

A. A carbon dioxide level of 65 is not a problem physiologically but for that to happen, you have to be pressing on a pulmonary artery in such a significant way that it’s going to impede [cardiac] output and organ perfusion.

Q. And the consequence of that is what? … If uncorrected?

A. Critical end–organ ischemia.

…

Q. And the consequence of that in a longer term sense if these organs are damaged was what?

A. Well, a low [cardiac] output state could damage the brain, the spinal cord, the kidneys, or the liver, for instance, potentially.

…

Q. Doctor Sparks told you that the various metabolic indicators were critical?

A. Yes, yes.

Q. Despite, apparently, adequate blood pressure and blood oxygen levels. That was one of his dilemmas, wasn’t it?

A. Yes, yep.

Q. Then in those circumstances, it really wasn’t appropriate, was it, to look at the blood pressure and oxygen levels alone when making a decision whether to persist or abandon surgery?

A. I agree with that statement.”

66. The trial judge’s conclusion, based on that evidence was expressed in the following terms:[42]

“It is important not to lose sight of the fact that Dr Sparks and Dr Gray were confronted with what was patently a distressing and fraught intraoperative emergency. It is difficult to over-emphasise just how awful it must have been at that time for all concerned. It is clear that Dr Sparks had attempted all of the anaesthetic manoeuvres in his armoury to correct the problem without apparent success. Criticism of these doctors in those circumstances may seem harsh. However, it is not in question that stopping the surgery when no obvious answer to the problems confronting the doctors was presenting itself would have avoided the damage. We know with hindsight that postural adjustment from prone to supine produced immediate resolution of these problems. That was something which in my opinion Dr Sparks and Dr Gray should have foreseen and acted upon. Failure to do so amounted to a want of reasonable care. It was in my view not appropriate to take the risk that something that could not be explained would or might somehow spontaneously resolve or improve. It is no answer to insist that the surgery was lifesaving in circumstances where Mr Hobson’s respiratory difficulties at or after 20.30 had deteriorated below his pre-operative condition in ICU.”

42. Hobson at [242].

67. Finally, the judge considered that the absence of spinal cord monitoring “heightened the need to act conservatively and to proceed expeditiously. It told against the appropriateness of taking an expectant approach when the solution to Mr Hobson’s difficulties had not emerged or was not understood.”

68. So far as Dr Sparks is concerned, and without reference to s 5O of the Civil Liability Act, in my view that conclusion was sound.

Application of s 5O

(a)   approach adopted at trial

69. For reasons set out above, the proper course in a case where s 5O has been pleaded and has been the subject of evidence is to determine first the standard of care to be applied, before assessing the alleged negligence against that standard. The trial judge did not take that approach but rather, in accordance with what was understood to be the appropriate course at the time, considered s 5O as a defence to be addressed after findings had been made on the plaintiff’s case. That indeed was the manner in which counsel for Dr Sparks dealt with the matter in written submissions at trial.

70. Counsel for Dr Sparks asserted that where there is evidence to demonstrate that the defendant acted in a manner which was widely accepted by peer professional opinion as competent professional practice, that opinion determined the standard of care and the expert evidence was conclusive. [43] Counsel further asserted that the approach adopted by this Court in McKenna should not be followed as it was inconsistent with the reasoning in Dobler. However, if McKenna were to be followed, it was submitted that the conduct of the defendant in exercising judgment as to the time for cessation of the operation constituted a “practice”. The submissions simply relied upon the evidence of Dr Forrest as establishing the defence. In oral submissions, there was reference to the reasoning in McKenna, but no further attempt to grapple with the evidential requirements of s 5O.

    43.    Fourth defendant’s outline of submissions, 21 November 2016, par 133.

71. In these circumstances, it is unsurprising that the trial judge dealt with the matter by way of a defence, noting the paucity of evidence in support of it. Having already rejected the views of the defendants’ doctors as to whether the conduct of the practitioners was negligent, the judge considered that the defence under s 5O had also effectively been rejected. [44]

    44. Hobson at [259].

72. It is correct to say that the reasoning of the trial judge did not address the submission that Dr Forrest’s evidence could not be rejected unless it was shown to be irrational. Nor did it expressly address the proposition that Dr Forrest’s opinion was “conclusive” as to the relevant standard of care. Grounds 1 and 2 in Dr Sparks’ notice of appeal rely on these matters as demonstrating error.

73. On the appeal, Dr Sparks’ written submissions identified the evidence relied on in support of the s 5O test as that of Dr Forrest (called in Dr Sparks’ case) and the evidence of Dr Manasiev, called for Dr Gray but who expressed opinions as to the conduct of both Dr Gray and Dr Sparks. It was submitted that the opinions were unchallenged.

74. As Simpson JA explains, the trial did not proceed smoothly. The pleadings left much to be desired as to detail; parties were joined and then removed; the plaintiff’s case was recast on more than one occasion, and the evidence of the experts was, inevitably in these circumstances, not always clearly directed to the issues as they finally emerged. The task of the trial judge in these circumstances was fraught with difficulties. Nevertheless, it is apparent that s 5O was relied upon by Dr Sparks and was not correctly disposed of at trial. It is therefore necessary for this Court to address the evidence.

75. Despite the conclusion reached above that the proper approach where s 5O is relied upon is to consider all the evidence in order to reach satisfaction as to the relevant standard of competent professional practice, to adopt such a course on this appeal would be impractical for two reasons, both of which operated at the trial. First, one cannot seek to identify a standard of competent professional practice in the abstract; the standard must relate to the specific ways in which negligence is alleged. Because the pleadings of the plaintiff bore limited resemblance to the case ultimately presented for determination, the plaintiff’s case provided a moving target for the defendant. (Although there were grumbles in Dr Sparks’ written submissions at trial, no issue of procedural unfairness was raised on appeal.) Secondly, the reasoning of the trial judge followed the structure presented by the parties. It would not be possible to recast that reasoning on appeal to comply with a structure not presented at trial.

(b)   expert opinion evidence – anaesthetists

76. The primary evidence relied upon by Dr Sparks was that of Dr Forrest, an expert anaesthetist called by Dr Sparks. In his principal report (the only report which addressed this issue) the final question and answer were as follows: [45]

    45.    Report of Dr Forrest, 26 October 2013, pp 5-6.

“5.   Did Dr. Sparks, in his anaesthetic management of Mr Hobson, act in a manner that was widely accepted in Australia by peer professional opinion as competent profession practice, at the time the service was provided?

Yes.

Mr Hobson was a high-risk patient who required major emergency surgery on his spine, in the prone position.

From the preceding, Dr. Sparks identified the critical issue of the patient’s bronchial compression preoperatively. …

However, it proved very difficult to effectively ventilate the patient in the prone position, despite the trial of a variety of different ventilation techniques. These difficulties were likely due to the patient’s pre-existing pneumonia and bronchial compression, which were significantly aggravated by the use of the prone position for surgery.

The patient was appropriately monitored intraoperatively, and the anaesthetic drugs, dosages and fluid administration were also appropriate.

The management of the patient’s critical deterioration at 21:30h was appropriate, as was the decision to abandon the procedure at that time.

The anaesthetic management of Mr. Hobson by Dr. Sparks would therefore have been widely accepted by peer professional opinion in 2009 as competent professional practice.”

77. In its terms, this answer constituted an opinion that the relevant steps taken by Dr Sparks involved competent professional practice. However, it did not squarely address what became the critical issue, namely whether the failure to terminate the operation at an earlier point satisfied that test.

78. Of course, the answer to question 5 should not be read in isolation. Question 2 invited Dr Forrest to “review the blood gas readings, the blood pressure results and the tidal flow measurements” and express an opinion as to the most likely cause of the collapse at 9.35pm. Dr Forrest answered that question in the following manner: [46]

“In my opinion, the cause of Mr. Hobson’s intraoperative collapse was acute right ventricular failure (RVF).

This would account for the high central venous pressure, low oxygen saturation and low blood pressure that occurred at about 21:30h on 17 November. It would also account for the large difference in the carbon dioxide level measured in the patient’s blood and his expired breath (‘end-tidal carbon dioxide’) prior to that time, the congested (‘purple’) appearance of his head that was observed when he was turned from prone to supine and the echocardiography findings at that time (‘empty LV… RA full’).

Mr. Hobson’s probably developed acute RVF because of predisposing factors and because of the use of the prone position for his surgery.

The predisposing factors that would have contributed to acute RVF were his spinal deformity, which caused restrictive lung function and left lung collapse / infection due to bronchial compression. These factors would have caused the pulmonary arteries to constrict and thereby increased pulmonary vascular resistance (PVR). An increase in PVR causes the RV to dilate and may eventually decrease its capacity to pump blood (cardiac output).

When Mr. Hobson was turned prone, it proved very difficult to ventilate him effectively, despite confirmation of the DLT position and despite the use of a variety of different ventilation techniques. As soon as he was turned supine again, ventilation became much easier and his oxygenation, blood pressure and carbon dioxide levels rapidly normalized. The use of the prone position probably compromised his ventilation by increasing compression of the left main stem bronchus by his spine, due to the effects of gravity. His spine may also have been compressing pulmonary arteries and veins, which would also increase PVR and decrease cardiac output. Because of the difficulties in ventilation, the carbon dioxide level increased in his blood. This would also have significantly increased PVR, because raised carbon dioxide levels cause the pulmonary arteries to constrict.

The combination of increased PVR and decreased cardiac output cause the blood supply to the RV itself to fall. When the blood supply to the RV falls below a critical level, acute, severe RVF can occur. However, it is not possible to accurately predict in an individual patient if, or when this will occur.”

46.    Report, pp 3-4.

79. The next question asked whether it was appropriate and reasonable for Dr Sparks to direct that the surgery cease at about 9.30pm. He said that it was and continued: [47]

“Taken in isolation, a fall in blood pressure to 95mmHg (even from a high baseline value) would not be sufficient reason for abandoning a surgical procedure.

However at that time (about 21:30h), Mr. Hobson also had rapidly falling oxygen saturations (to less than 80%), a high CVP and severe respiratory and metabolic derangement. Hence this blood pressure signalled the onset of critical haemodynamic deterioration, which would likely have rapidly progressed to refractory cardiac arrest if surgery had not been abandoned at that time and he was not turned supine.

It was therefore appropriate and reasonable for Dr. Sparks to request that surgery be abandoned at that time.”

47.    Report, p 5.

80. Finally, Dr Forrest was asked to express his own opinion as to the standard of anaesthetic management during surgery. In concluding that the standard was reasonable, he stated:

“Mr. Hobson was a high-risk patient who required major emergency surgery at that time. He posed a very unusual and difficult anaesthetic challenge due to the significant compression of his left main bronchus by his spine and due to the requirement for prone positioning during surgery.

…

The main clinical dilemma in this case was whether surgery should have been allowed to continue given the difficulties in ventilating the patient that were encountered before the severe deterioration that occurred at 21:30h. As noted above, he patient had been difficult to ventilate prior to this time due to compression of his left main bronchus, which was exacerbated in the prone position. However, given that the patient’s surgery was considered to be sufficiently urgent that it needed to be performed out-of-hours, and given also that his lung infection would not have been expected to resolve until the compression of his left main bronchus was relieved by surgery, it was reasonable to continue the anaesthetic at that time.”

81. As with the answer to question 5, in relation to widely accepted peer professional opinion, Dr Forrest’s statement as to his own view deals with the question of earlier termination only indirectly. The final conclusion “it was reasonable to continue the anaesthetic at that time” is not precise as to the time in question. Secondly, unlike Dr Sparks, Dr Forrest, in explaining Mr Hobson’s situation, placed weight upon the raised carbon dioxide levels and their effect in causing constriction of the pulmonary arteries and therefore pulmonary vascular resistance, leading to decreased cardiac output and ultimately right ventricular failure. It was clear at some point that the only answer to those problems was to cease surgery and return the patient to a supine position, as eventually happened.

82. The submission that Dr Forrest’s views were not challenged was only partly true. In the course of his joint evidence with Dr Westbrook, senior counsel for the plaintiff obtained Dr Forrest’s agreement that there was continuous deterioration of the plaintiff’s metabolic state, and that acidosis was a harbinger of ongoing problems which could, unresolved, have proved fatal. The cross-examination ended with the following exchange: [48]

“MENZIES: … What I’m suggesting to you, for example, that if at any of those times before 2051, a decision was made to stop the surgery at that time, it’s not as if the consequence was going to be the patient was going to die in front of you, is it?

WITNESS FORREST: What the consequence would have been – and the expectation of the doctors looking after the patient at that time would have been – that because they hadn’t corrected his underlying bronchial compression, that he would continue to have ongoing severe respiratory failure, which would ultimately be – would ultimately lead to his demise because the underlying cause had not been addressed.

MENZIES: So the proposition remains the same, doesn’t it? That the semi-emergen[cy] situation as you describe it – but I’m happy with that – continued unchanged. In other words, at any time before 2125 or 2130 when the surgery was stopped, it could have been stopped with no further harm to the patient than he was already suffering. That’s right isn’t it?

WITNESS FORREST: Yes, well, that’s right. But as I’ve already said, the reason why the surgery was done in the first place at that time was because it was felt that ... (not transcribable)…would not be improved if his surgery had not gone ahead. So expectation would have been that he would have died at some point post-operatively in intensive care from… (not transcribable)… respiratory failure.”

48.    Tcpt, 14/11/16, p 268(33).

83. Neither the questions nor the answers given by the witness were entirely clear. The question to be answered by the Court is whether the evidence of Dr Forrest, taken as a whole, established the proposition that it was widely accepted peer professional opinion that it would be competent professional practice to continue the administration of anaesthetic for the purpose of surgery in all the circumstances. That required taking into account the need for the corrective surgery, and the deterioration in the patient’s condition as at about 9pm, given the expectation that it would be relieved by ceasing the operation and returning the patient to the supine position. To the extent that the evidence did address that proposition, it is by no means clear that Dr Forrest expressed a clear view about it.

84. Dr Sparks sought to obtain further assistance as to the relevant standard of competent professional practice in the evidence of Dr Manasiev. Dr Manasiev is a consultant anaesthetist and was called on behalf of Dr Gray. The doctor was asked a number of questions; question 2 was whether Dr Gray should have halted or advised “the halting of the surgery following the earlier episodes of hypoxia and hypotension … and related complications reported in the anaesthetic record between approximately 19:10 and 21:20.” [49] After dealing with two earlier events which are no longer significant, Dr Manasiev dealt with “a transient period of desaturation and relative hypotension” at 20.35. The event occurred at the time of placement of a pedicle screw in the patient’s spine. He identified three reasons for not halting the operation at that time. First, the cause was transient and, secondly, the blood pressure and saturation returned to normal values once the pressure was relieved. He continued: [50]

“Third, the decision was balanced against the apparent necessity of the operation as a potential lifesaving technique. As such, it was not warranted by Dr Sparks or Dr Gray to halt the surgery at this time and would be considered widely accepted in Australia by peer professional opinion as competent medical practice to continue the surgery.”

49.    Report of Dr Manasiev, 26 October 2016, p 3.

50.    Report, p 3.

85. After dealing with the appropriateness of halting the surgery at 21.20, Dr Manasiev noted that “the management of the ventilatory and cardiovascular parameters are primarily the responsibility of the anaesthetist.” [51] He then repeated, in relation to Dr Sparks, his opinion as to competent medical practice as at the times identified in question 2.

    51.    Report, p 4.

86. Dr Manasiev did not participate in the joint conclave of anaesthetists with Drs Westbrook and Forrest. However, he gave oral evidence at the trial. In the course of cross-examination he gave the following evidence: [52]

“Q. What are the factors, you say, that would inform competent professional practice, with respect to anaesthetists and the continuance or otherwise of a surgery?

A. Well, it’s the whole gambit of all the hemodynamic parameters that you’re looking at within a patient. Predominantly, the blood pressure and saturation, which are telling you how the organs are being perfused, but as well as that, all the attempts that are made, in this case, to improve ventilation: whether they are successful or non-successful, the response of all the blood gas analysis. It’s a complicated gambit of numbers and figures that you’re looking at.

Q. You certainly, do I understand it then, wouldn’t limit yourself to the – in a manner which excluded all the other parameters in the blood gases?

A. No, you wouldn’t exclude all the parameters, no --

Q. Because that would not be consistent with competent professional practice, in circumstances such as this in Australia, in 2009, would it?

A. You wouldn’t exclude, but you would give different parameters different weights upon the patient’s stability.”

52.    Tcpt, 14/11/16, p 294(28).

87. In his original report, Dr Manasiev did not squarely address the effect on his opinion of the evidence accepted by Dr Westbrook and Dr Forrest of the plaintiff’s continuously deteriorating metabolic state which was likely to lead to a cardiovascular collapse, if not remedied. Further, the evidence in the course of the trial progressed beyond the parameters put to Dr Manasiev for the purposes of his report. The question was not whether the events around 8.30pm should have led to the termination of the operation but whether the events around 9pm should have led to termination. No evidence was led from Dr Manasiev in relation to these further considerations.

318. It may be recognised that both Rogers v Whitaker and Rosenberg v Percival were cases in which the issue was alleged failure by the medical practitioner concerned to make appropriate disclosure of risks associated with the treatment proposed. However, it is clear that the principles stated were intended to extend to other aspects of treatment; for example, in Rogers v Whitaker, the High Court said (at 487):

“Further, and more importantly, particularly in the field of non-disclosure of risk and the provision of advice and information … it is for the courts to adjudicate on what is the appropriate standard of care after giving weight to ‘the paramount consideration that a person is entitled to make his own decisions about his life’.”

The Court made a distinction between the application of the principle in cases of alleged failure to warn or inform, and cases of alleged negligence in the administration of treatment, saying (at 489):

“Whether a medical practitioner carries out a particular form of treatment in accordance with the appropriate standard of care is a question in the resolution of which responsible professional opinion will have an influential, often a decisive, role to play; whether the patient has been given all the relevant information to choose between undergoing and not undergoing the treatment is a question of a different order. Generally speaking, it is not a question the answer to which depends upon medical standards or practices.” (italics in original)

320. In Rosenberg v Percival, Gleeson CJ added to the principle already stated, the following:

“7  … In many cases, professional practice and opinion will be the primary, and in some cases it may be the only, basis upon which a court may reasonably act. But, in an action brought by a patient, the responsibility for deciding the content of the doctor’s duty of care rests with the court, not with his or her professional colleagues.”

321. These observations, in my opinion, are particularly pertinent to the present case. It is difficult to imagine how the primary judge (or this Court) could reach a conclusion as to whether Dr Sparks’ decision to allow the surgery to continue beyond some unspecified point earlier than 21:00 or 21:15 failed to meet the standard of the ordinary skilled anaesthetist other than as informed by the evidence of witnesses with appropriate expertise.

(ii)  the Civil Liability Act

322. The relevant provisions of the CLA are s 5B, s 5 I and s 5 O. All are contained in Pt 1A of the CLA, enacted with effect from 6 December 2002. Section 5B provides as:

“5B  General principles

(1)  A person is not negligent in failing to take precautions against a risk of harm unless:

(a)  the risk was foreseeable (that is, it is a risk of which the person knew or ought to have known), and

(b)  the risk was not insignificant, and

(c)  in the circumstances, a reasonable person in the person's position would have taken those precautions.

(2)  In determining whether a reasonable person would have taken precautions against a risk of harm, the court is to consider the following (amongst other relevant things):

(a)  the probability that the harm would occur if care were not taken,

(b)  the likely seriousness of the harm,

(c)  the burden of taking precautions to avoid the risk of harm,

(d)  the social utility of the activity that creates the risk of harm.”

323. Section 5 O provides as follows:

“5O  Standard of care for professionals

(1)  A person practising a profession (a professional) does not incur a liability in negligence arising from the provision of a professional service if it is established that the professional acted in a manner that (at the time the service was provided) was widely accepted in Australia by peer professional opinion as competent professional practice.

(2)  However, peer professional opinion cannot be relied on for the purposes of this section if the court considers that the opinion is irrational.

(3)  The fact that there are differing peer professional opinions widely accepted in Australia concerning a matter does not prevent any one or more (or all) of those opinions being relied on for the purposes of this section.

(4)  Peer professional opinion does not have to be universally accepted to be considered widely accepted.”

324. Also relevant to this appeal is s 5 I, invoked by Dr Sparks, which is in the following terms:

“5I  No liability for materialisation of inherent risk

(1)  A person is not liable in negligence for harm suffered by another person as a result of the materialisation of an inherent risk.

(2)  An inherent risk is a risk of something occurring that cannot be avoided by the exercise of reasonable care and skill.

(3)  This section does not operate to exclude liability in connection with a duty to warn of a risk.”

Section 5 I

325. In Paul v Cooke Leeming JA subjected s 5 I to searching scrutiny. The meaning of s 5 I is, to my mind, obscure. Even more obscure is its purpose. It seems to me that it does little (if anything) more than restate that liability in negligence depends upon a causal connection between the negligence alleged and the harm alleged to have been suffered. In that sense, it is a statement of the obvious. What it might achieve is a short cut to a resolution of the issues: if what occurred could not be avoided by the exercise of reasonable care and skill, there is no harm resulting from whatever negligence might be shown to co-exist with or precede the damage suffered, as required by s 5B. This, perhaps, is what Leeming JA meant at [51] of Paul v Cooke, when he said:

“51 … the issue of causation, determined in accordance with s 5D, does not arise once it is determined a claim falls within s 5I …”

He held that s 5 I provides a complete answer to any claim falling within Pt 1A of the CLA. Leeming JA (with the concurrence of Basten and Ward JJA) considered that, for a s 5 I defence to be made out, what has to be shown to be unavoidable is “the risk of something occurring”, as distinct from the occurrence itself. In that case, the surgery proposed and undertaken always carried a risk of the harm that in fact materialised (intra-operative stroke), and that that risk could not have been avoided by the exercise of reasonable care and skill.

Section 5 O

326. In Dobler v Halverson, at [60]-[61], this Court held that s 5 O operates as a defence to a claim, the onus lying on the defendant to establish the relevant facts. In Paul v Cooke, Leeming JA observed that s 5 O, like s 5 I, provides a complete answer to a claim under Pt 1 A of the CLA (at [41]). It is in that sense that the section operates as a defence. For that reason, when it is pleaded, it is convenient to deal with it first.

327. In McKenna v Hunter & New England Local Health District; Simon v Hunter & New England Local Health District (2013) Aust Tort Reports 82-158; [2013] NSWCA 476 this Court held that s 5 O is directed to:

“165  … a practice, that was in existence at the relevant time, here July 2004 …”, (bold added)

and that, in the circumstances of that case, no such practice had been identified.

328. The circumstances that gave rise to the decision in McKenna may be briefly stated. In 2004 a psychiatric patient was discharged by the health authority that administered the psychiatric institution in which he had been compulsorily detained under then applicable mental health legislation. Shortly thereafter, he killed a friend (Stephen Rose) who was transporting him from NSW to Victoria.

329. Members of Mr Rose’s family who suffered consequential nervous shock sued the health authority, alleging negligence in the decision to discharge the patient. Their claims also were governed by the CLA. This Court (by majority) held that the health authority owed the plaintiffs a duty of care in accordance with common law principles, which it had failed to discharge. It was therefore necessary to consider the application of s 5 O. It was in that context that the majority construed s 5 O as set out above. On that construction, the defence failed.

330. Macfarlan JA (with whom Beazley P agreed) said:

“165  … It is unlikely, to say the least, that there would have occurred in or before 2004 a number of situations in which there were sufficient features in common with the present case to enable it to be said that there was a practice concerning how such a situation was to be dealt with by a competent medical practitioner.” (bold added)

331. An appeal to the High Court of Australia was successful on the ground that this Court erred in finding that the health authority owed the plaintiffs a duty of care; the High Court therefore did not find it necessary to address the construction of s 5 O: Hunter and New England Local Health District v McKenna; Hunter and New England Local Health District v Simon (2014) 253 CLR 270; [2014] HCA 44.

332. I consider that I am obliged to accept McKenna (in this Court) as stating the prevailing construction of s 5 O: Gett v Tabet (2009) 254 ALR 504; [2009] NSWCA 76 at [277]-[279]. But for that constraint, I would have considered that the language of s 5 O makes it plain that “competent professional [here, medical] practice” is intended to denote “the practice of a profession [here, medicine]”, and not a specific practice or method of providing the professional services in question. That construction is supported by the absence of the indefinite article in conjunction with “professional practice”, and the use instead of the adjective “competent”, which to my mind signifies professional practice in a general sense, rather than an identifiable, specific, and discrete aspect of the profession or method of providing the professional service.

333. As construed in McKenna, s 5 O can apply only in limited circumstances, where the defendant can, or seeks to, identify a discrete practice to which he or she conformed. It necessarily excludes unusual factual circumstances, such as occurred in McKenna, and such as occurred in the present case. It does not appear to me that s 5 O was intended to have such limited application. However, as I have said, I consider myself constrained to follow and apply that decision.

334. Failure by a defendant to prove the s 5 O circumstances (however that section is construed) does not conclude the matter. The onus remains on the plaintiff to establish that the defendant failed to provide the professional service in accordance with the standard of the ordinary skilled person practising that profession.

335. The claim is then to be determined by reference to s 5B of the CLA: see Adeels Palace Pty Ltd v Moubarak; Adeels Palace Pty Ltd v Bou Najem (2009) 239 CLR 420; [2009] HCA 48 at [27]. The relevant questions are:

• was there a foreseeable risk of harm arising from the conduct the subject of the claim?;

• was the risk not insignificant?;

• would a reasonable person in the position of the defendant have taken precautions to safeguard against the risk? (It is necessary for the plaintiff to identify the precautions it is alleged ought to have been taken.)

Determination

336. With those legal principles in mind, I turn to the determination of the issues raised on the appeal.

337. In seeking to apply the principles to the present case, it is worth restating, briefly, the relevant chronology. Surgery commenced at about 19:10 or 19:15. At 19:10 and 20:35 the respondent’s blood pressure dropped, but recovered. There were identifiable causes of these episodes – the insertion of the double lumen tube and the insertion of the pedicle screws. At about 20:50 Dr Sparks was sufficiently concerned by the respondent’s condition to consult two colleagues, one an anaesthetist and one a cardiac surgeon. At about 21:24 the respondent’s blood pressure again dropped, causing Dr Sparks to direct cessation of the surgery.

338. The conclusion of the primary judge was that the decision to continue beyond 20:30 was “perfectly reasonable”, but that Dr Sparks ought to have directed that the surgery cease at some time before 21:00 or 21:25. It was only in his consideration of causation, with which he dealt appropriately briefly, that the primary judge nominated 21:15 (at the latest) as the time by which surgery should have ceased. He did this in the context of noting that it was uncontroversial that the paraplegia was caused at some time after 21:15 and before 21:30.

Grounds 1 and 2: section 5 O

339. The construction given to s 5 O in McKenna played no part in the primary judge’s rejection of the defences under that section. No ground of appeal sought to call in question the correctness of the McKenna construction of s 5 O. However, if, under s 75A of the Supreme Court Act 1970 (NSW), the court were to proceed to its own consideration of the s 5 O issue, it would be necessary to determine what construction to adopt.

340. Senior counsel for Dr Sparks did suggest, during oral argument, that this Court declare that the McKenna construction is wrong. In the absence of any advance notice of that proposal, and any request for the constitution of an enlarged Bench, the suggestion must be rejected.

341. Were the construction of s 5 O that I prefer to prevail, I would uphold these grounds of appeal. Drs Manasiev and Forrest were unequivocal in their evidence that Dr Sparks acted in a manner that at the time was widely accepted in Australia by peer professional opinion as competent professional practice. No countervailing evidence was given on behalf of the respondent. Indeed, it is difficult to see how Dr Westbrook (the respondent’s only expert anaesthetist witness) could comment on peer professional opinion in Australia. He practises in the United Kingdom, and gave evidence from London. There was no evidence that he has any Australian experience.

342. Whether Dr Sparks acted in accordance with widely accepted peer professional practice is a question of fact; it is not a question of the kind referred to in Rogers v Whitaker and Rosenberg v Percival, involving determination of whether a medical practitioner failed to conform to standards of the ordinary skilled medical practitioner (in this case, practising as an anaesthetist). Under s 5 O, the task of the court is not to evaluate the merits of the competing views (if there is evidence of competing views) but to determine whether, as a factual matter, the service had the acceptance of peer opinion, even if other peer opinion was different.

343. However, adopting as I consider I must, the McKenna construction of s 5 O, and since, principally because the circumstances of this case were highly unusual, it was not possible for Dr Sparks to identify “a practice” to which he conformed, the s 5 O defence must fail. That is notwithstanding that the overwhelming medical evidence was that his conduct was in accordance with what was widely accepted in Australia as “competent professional practice”.

Ground 3: section 5 I

344. Dr Gray’s September advice to the respondent makes it plain that there was always a risk that the surgery would result in neurological injury, including paralysis. It is also clear from Dr Sparks’ reluctant agreement to participate in the operation that significant risks were involved. Although Dr Sparks did not expressly spell out what those risks were, it is a reasonable inference on the whole of the evidence that they included the very thing that happened.

345. Whether the risk of neurological injury including paralysis was an “inherent risk” for the purposes of s 5 I depends upon whether that risk could have been avoided, by the exercise of reasonable care and skill. Having regard to the primary judge’s finding that Dr Sparks was in breach of his duty of care in failing to terminate the surgery earlier than he did, the finding that, by the exercise of reasonable care and skill, the harm suffered by the respondent could have been avoided was logical and inevitable.

346. On behalf of Dr Sparks it was argued that, as in Paul v Cooke, the primary judge erroneously focused on the potential for Dr Sparks to avoid the occurrence rather than risk of the occurrence. True it is that the risk could have been avoided by a decision not to operate at all. That, in the circumstances of the respondent’s condition, was not a realistic proposition. Once it is accepted that the respondent’s condition warranted the performance of the operation as emergency surgery, and that that surgery carried a risk of paraplegia, it seems to me that this is a rare case, like Paul v Cooke, in which s 5 I applies. I would uphold Ground 3.

Grounds 4, 5 and 6: breach of duty

347. Since satisfaction of the s 5 I criteria is a complete answer to the claim it may be unnecessary to address the remaining grounds. However, even if I am wrong about s 5 I, I have concluded that the evidence does not support the conclusion that Dr Sparks failed in his duty to exercise the skill and care required of a specialist anaesthetist by failing to take steps to ensure that the operation was terminated at any earlier stage than he did. In the present case, the answers to the first and second questions that arise under s 5B are obvious. There was a risk of harm to the respondent from the administration of anaesthesia given his respiratory condition. That risk was both foreseeable and foreseen. The risk was far from insignificant. The issue is whether Dr Sparks ought to have taken precautions against the risk, those precautions being the termination of the surgery at not later than 21:00 or 21:15. That question is to be decided by reference to the four factors set out in sub-s (2) (as well as any other “relevant thing”). In a case of alleged professional negligence “other relevant things” must include the opinions of relevant experts, as envisaged in both Rogers v Whitaker and Rosenberg v Percival as to conformity (or otherwise) with relevant standards.

348. In the light of the rather lengthy exposition of the facts above, the reasons for my conclusion that the evidence did not establish any breach of his duty of care on the part of Dr Sparks may be stated with relative brevity.

349. The central circumstance to note is the parlous condition in which Dr Sparks reasonably understood the respondent to be, pre-surgery. The medical consensus, as at 17 November, was that the respondent needed urgent surgery to ensure his survival. Although Dr Westbrook at one point challenged that view, Dr Sparks’ conduct must be assessed in the light of what he had been told by other respected medical practitioners and in the unchallenged finding of the primary judge that the decision to undertake the surgery when it was undertaken was “perfectly reasonable”. It was the ICU staff who first drew attention to the respondent’s life threatening condition. Dr Sparks was entitled (and probably obliged) to act upon the fears of those experienced medical practitioners, or at least to take them into account. Indeed, as I have noted above, his evidence was that, were the surgery not as urgent as he understood it to be, he would not have anaesthetised a patient in the condition of the respondent. That circumstance permeated his decision-making throughout the entire process, during which he was faced with the unenviable task of balancing two competing, extremely serious, risks: on the one hand, the risk that without the surgery the respondent’s survival was in doubt; on the other, the risk that the surgery itself threatened his survival. Initially, on Dr Sparks’ assessment, the former outweighed the latter. When he perceived that the balance had changed, he acted appropriately to have the surgery halted. There is no evidence to support a proposition that his assessment in this respect was erroneous, let alone negligently erroneous.

350. Not one of the anaesthetists who reported and gave evidence expressed a view that Dr Sparks’ conduct failed to reach the relevant standard. The nearest was that of Dr Westbrook who considered that the surgery should have stopped at 20:37. Even so, Dr Westbrook’s opinion was given at a time when he rejected the otherwise generally accepted opinion that the surgery was necessary to ameliorate a life threatening condition. His conclusion about the time at which it should have ceased is coloured by that, now known to be mistaken, view. Moreover, as the passage extracted above at [286] demonstrates, he based the assessment, at least in part, on “[the respondent’s] subsequent progress” – that is, on events that post-dated the decision of Dr Sparks – which nobody suggested was or should have been apparent at the time.

347. It is not now in issue that the surgery was reasonably believed to be urgent and lifesaving. The concerns of the ICU staff were expressed to Dr Gray and passed on by him to Dr Sparks. Dr Sparks independently satisfied himself of that circumstance. It was also recognised that the surgery was of a complexity that called for the assembly of a particularly skilled and experienced team of specialists, including the neurophysiologist Dr Lagopoulos. The degree of urgency, together with the need for specialised assistance, may be gauged by the fact that the operation was scheduled to take place out of ordinary operating hours. Further, it cannot be overlooked that Dr Sparks agreed to undertake the anaesthetic role only because of the perceived urgency. His evidence that, absent that urgency, he would not have agreed to anaesthetise the respondent is a further indicator of the dire situation in which the respondent was perceived to be. There is nothing in the evidence that supports doubt about that perception. That also influenced his decision to persist, and his reliance on the two most salient factors, the respondent’s blood pressure and oxygenation.

348. In this regard, reliance on subsequent events (the respondent’s recovery, and the ultimate successful performance of the second stage surgery, on 11 December) provides no answer: see Moubarak at [31]. Dr Sparks, and the entire medical team, had to work on what they knew at the time, which was that the respondent’s condition was life threatening. The finding (in [242]) that Dr Sparks and Dr Gray ought to have foreseen that “postural adjustment” from a prone to a supine position would have produced immediate resolution of the respondent’s respiratory problems, and acted on that anticipation, was largely based on what happened after the surgery had terminated and is not sustainable in the light of what is known of the respondent’s pre-surgery condition. It does not take into account the extraordinarily painful risk-balancing exercise in which Dr Sparks had to (and did) engage.

349. On behalf of the respondent, specific reliance was placed on the earlier episodes of hypotension and hypoxia as indicating that the surgery should have ceased earlier than it did. Two responses may be made to this. The first is that each episode was explicable by a specific event – the insertion of the double lumen tube, and then pressure being placed on the respondent by the insertion of “pedicle screws”. On each occasion, when the cause of the deterioration was removed, the respondent’s condition improved. The second answer is that there was no evidence that the pre-existing condition of the respondent (the condition that compelled the expedition of the surgery) had diminished. That it did on his return to the ICU says nothing about what the signs were at the time.

350. Reliance was also placed on behalf of the respondent on an answer given by Dr Barratt in cross-examination, extracted above. This was directed to Dr Sparks’ evidence that, in determining to permit the surgery to proceed, he had relied principally on the respondent’s blood pressure and blood oxygenation levels: Dr Barratt was asked:

“Then in those circumstances, it really wasn’t appropriate, was it, to look at the blood pressure and blood oxygen levels alone when making a decision whether to persist or abandon surgery?”

He agreed with the proposition contained in the question. The primary judge regarded this answer as “critical”. Dr Barratt replied that he agreed with that statement. Again, two answers may be given to the proposition. The first is that other specialist medical evidence was more favourable to Dr Sparks: Dr Forrest, asked a similar question in oral evidence, answered:

“Well, these are the parameters that are – that are used routinely in anaesthetic practice to – to guide our management and they’re not the only factors that would determine how the surgery would be conducted. But in this particular case, they would be the – the main factors that would be used to determine whether surgery should continue or not.”

355. Dr Westbrook, giving evidence concurrently with Dr Forrest, did not dissent from that answer. He had earlier said that blood gas analysis showed evidence of other serious and deteriorating problems, but agreed that those problems were reversible.

356. Dr Manasiev was asked in cross-examination what factors would inform competent professional practice with respect to anaesthetists and the continuance or otherwise of surgery. The transcript records the following answer:

“Well, it’s the whole gambit [sic – gamut] of all the haemodynamic parameters that you’re looking at within a patient. Predominantly, the blood pressure and saturation, which are telling you how the organs are being perfused, but as well as that, all the attempts that are made, in this case, to improve ventilation … it’s a complicated gambit [sic – gamut] of numbers and figures that you’re looking at.”

Ultimately, he said:

“You wouldn’t exclude, but you would give different parameters different weights upon the patient’s stability.”

357. The second answer to the proposition is that the evidence did not extend to precise identification of what other factors ought to have been considered. More importantly, no conclusion can, on the evidence, be drawn as to what decision would, on the probabilities, have been made in the light of the other considerations. In other words, there is no evident causal connection between Dr Sparks’ reliance on those two factors (to the possible exclusion of others) and the injury suffered by the respondent.

358. It has been suggested that, urgent as the surgery may have been, it was not so urgent that the respondent would have died if it were not completed within a few hours. This must be seen in the light of acceptance on behalf of the respondent (and the unchallenged finding of the primary judge) that it was reasonable to undertake the surgery at the time it was commenced, and in the circumstances in which it was commenced. A decision to terminate surgery only partly completed, after anaesthetisation of the patient, is very far from a decision to commence, or not to commence, surgery. It was not, I am satisfied, demonstrated that it was outside the bounds of proper practice for Dr Sparks to persist in his efforts to maintain the respondent’s stability in order to allow the operation to proceed to conclusion.

359. The medical evidence does not, in my opinion, support a finding that, in failing to direct the termination of the surgery before 21:28, Dr Sparks failed to exercise reasonable care and skill. The decision Dr Sparks had to make (on a continuing basis throughout the surgery) involved the exercise of clinical judgment. Although, as decided by Rogers v Whitaker, the ultimate determination as to whether the clinical judgment made came within the bounds of the exercise of reasonable care and skill expected of a competent anaesthetist lies with the court, the judgment is one which must, in this case, be guided by the evidence of other medical practitioners with the requisite knowledge and understanding of the issues involved. So much is clear from Rosenberg v Percival, and, indeed, from Rogers v Whitaker. It was not sufficient to say, although it is plainly the case, that, had Dr Sparks directed termination of the surgery prior to the respondent’s collapse at 21:28, the injury would not have occurred. The respondent bore the onus of establishing that Dr Sparks’ decision not to direct the termination of the surgery before that time represented a departure from the standard of care and skill required of a specialist anaesthetist. That onus was not discharged. The medical evidence falls well short of permitting a conclusion to that effect.

360. Dr Westbrook’s opinion that a decision “could have been taken to abandon surgery” earlier than it was abandoned is insufficient to establish that failure to make that decision lay outside the bounds of competent anaesthetic practice. For the purposes of Dr Sparks’ appeal, the evidence of the orthopaedic surgeons that the surgery should have been brought to an end “when the anaesthetists were unable to maintain the metabolic state, ie satisfactory blood pressure and oxygenation” or “when the anaesthetists reached the stated that they were unable to maintain satisfactory cardiorespiratory parameters” can be given little (or no) weight. The true import of that evidence, in the context in which it was given, was that Dr Gray was entitled to rely on the advice given to him by Dr Sparks and that the decision lay within the anaesthetic (not orthopaedic) speciality. The answer given carefully (and properly) avoided the expression of opinion by orthopaedic specialists in respect of an anaesthetic issue.

361. It follows that, in my opinion, the primary judge was in error in finding breach of duty on the part of Dr Sparks. I would uphold the appeal and set aside the judgment.

Damages

362. It follows that, in my view, it is unnecessary to determine the appeal so far as it relates to the quantification of damages. It is sufficient to record that, if it were necessary to decide those issues, I would agree with the judgment of Macfarlan JA.

363. The orders I would make are:

(1)  The appeal by Dr Gray is upheld.

(2)  The appeal by Dr Sparks is upheld.

(3)  The judgment against each defendant is set aside.

(4)  The respondent is to pay the costs of each appellant of both the trial and the appeal.

(5)  The respondent be granted a certificate under the Suitors’ Fund Act 1951 (NSW).

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Endnotes

Amendments

14 May 2018 - [214]: Formatting correction.

Decision last updated: 14 May 2018