Hopes of helpful review of the current interpretation of the words “competent professional practice” as they appear in section 5O of the Civil Liability Act 2002 (NSW) (the Act) were dashed, as special leave to appeal was denied by the High Court of Australia (HCA) from a NSW Court of Appeal (NSWCA) medical malpractice case. This follows a review found in “Health Insights” May 2018, by Principal Nevena Brown and Associate Anna Martin of the NSWCA decision.
The HCA refused the appeal by a defendant anaesthetist, in a case that has caught the attention of the medical and legal profession and raised questions as to the interpretation of “competent professional practice” in medical negligence cases. As a result, the findings of the NSWCA stand, confirming that unchallenged peer professional evidence was not enough to defend the specialist anaesthetist from a finding of breach of duty to the patient.
By way of a recap, the case was originally brought by a patient with a rare genetic disorder which affected the development of his spine and chest, particularly on the left side, restricting his ability to breathe. He consulted an orthopaedic surgeon who advised a series of two operations, 10 days apart to strengthen the spine and improve breathing. Prior to the operation, the surgeon explained the risks to the patient, including an increased risk of ‘neurological injury including paralysis’. In particular, the surgeon explained the risk of compromised blood supply to his spine, which would increase the risks associated with the second operation.
Four days after the first operation, the patient developed pneumonia, resulting in the need to urgently perform the second operation, in life saving circumstances.
During the second operation the patient suffered circulatory collapse, resulting in reduced blood supply to his spine, and paralysis of both legs. The operation was terminated. While the operation was completed at a later date, the patient remains a paraplegic.
In the primary trial,  the anesthetist and the leading orthopaedic surgeon were both found to have been negligent in their management of the patient’s operation, and were both responsible for his injuries. The Court found that the second operation should have been terminated 15 minutes earlier than it was, and by doing so would have avoided the patient’s significant circulatory collapse and consequent paraplegia. Neither defendant had conformed to the relevant standard of care.
The surgeon and the anaesthetist each appealed against the primary judge’s decision on liability. The two specialist doctors relied on sections 5I and 5O of the Act, arguing that the judge erred in finding they had acted negligently.
The appellants also appealed against his Honour’s decision on damages in three limited respects. They contended that his Honour was wrong in the allowances made for the patient’s past and future domestic care, and for motor vehicle expenses. Unanimously, the surgeon was found not liable, but the challenges to the primary judge’s damages assessment were rejected.
The question as to whether the risk of neurological injury was, per s5I of the Act, an ‘inherent risk ‘ that could not have been avoided by the reasonable care and skill of the surgeon and anaesthetist, was found not to have applied in this circumstance.
The finding of breach of duty against the anaesthetist was established by a majority in the NSWCA of 2:1. The anaesthetist’s decision to allow the operation to continue and the failure to terminate the operation earlier were found to be a departure from the standard of reasonable care and skill, expected of a specialist anesthetist. The majority (Basten JA and MacFarlan JA) confirmed negligence by the anaesthetist, and that the trial judge was correct to find a breach of duty of care. Neither Sections s5I nor s5O were available to the anaesthetist as a defence in this case.
The Court addressed the question of whether it is necessary for the s5O defence to be available, that at the time of the purported negligence there was an ‘established practice’, that was widely accepted as ‘competent medical practice’. Counsel for the patient relied on McKenna New England & Hunter Local Health District  NSWCA 476 (McKenna) as the leading interpretation of s5O, The Standard of Care for professionals. 
To establish a defence under s5O 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.
The NSWCA majority agreed with the anesthetist’s Counsel that McKenna was wrong in finding that it is necessary to demonstrate the existence of ‘a practice’ that was in place at the time of the conduct in question. Basten JA stated that to reformulate the language of the section from ‘competent professional practice’ to ‘a practice’ was too narrow an interpretation. Not being bound by the McKenna decision, his Honour considered that the expert evidence relied on by the anaesthetist had fallen short of establishing a standard of competent professional practice widely accepted in Australia, in that it did not address the critical issue, namely whether the failure by the anesthetist to terminate the operation at an earlier point in time satisfied that test.
MacFarlan JA upheld the reasoning in McKenna, that the defendant must be able to demonstrate a specific established practice in order to rely on the s5O defence:
Expert evidence that says no more than that the expert considers the defendant to have acted reasonably, and in a way that would be widely regarded as acceptable, is insufficient to establish the existence of a ‘practice’ for the purpose of section 5O.
Simpson J (in a dissenting judgment) agreed that the McKenna interpretation was too restrictive, and that such an analysis limits the applicability of the defence to situations in which the practitioner can pinpoint an established and widely used ‘practice’ to help his /her defence. Simpson J stated that were she not (as she felt obliged) bound by McKenna, she would have would have upheld the appeal on the basis that the anaesthetist’s expert evidence was unequivocal in stating that he had acted in a manner accepted widely at the time, as ‘competent professional practice’.
During the special leave application, the HCA noted that Basten JA, not feeling constrained by McKenna, nevertheless considered the evidence had been found to be inadequate to support the anaesthetist’s defence using s5O. Mention was made of the evidence provided by a UK Anaesthetist – not an Australian practitioner as required in the Act, and he did not express a view on s5O.
Basten JA was not prepared to accept that s5O does not require a particular practice and had Simpson J not felt constrained by McKenna, Her Honour would have taken the same approach. The NSWCA’s criticism of the McKenna interpretation was unequivocal and for that reason notable. The important take away point is that in future, the McKenna approach will still need to addressed, as well as the approach discussed by Basten JA and Simpson J.
In order to apply s5O as a defence to disprove negligence, the defendant must lead substantial expert evidence to support their actions on the basis of an ‘established practice’ that was widely accepted as ’competent professional practice’ in Australia, at the time of the alleged negligence.
This article was written by Principal Nevena Brown and Lawyer Rosemary Blanden. Please contact them if you have any questions or if you would like further information.
 Sparks v Hobson  HCATrans 191.
 Sparks v Hobson: Gray v Hobson  NSWCA 29.
 Hobson v Sparks; Hobson v Gray  NSWSC 589.
 Sparks v Hobson: Gray v Hobson  NSWCA 29 at  (Basten JA, MacFarlan JA agreeing).
 McKenna New England & Hunter Local Health District  NSWCA 476 at , emphasis in original.
 The HCA had later been overturned McKenna, but on a different point of law, without approval for the Court of Appeal’s interpretation of s5O. Basten JA held the view that the s5O part of the McKenna decision was no longer binding.
 McKenna New England & Hunter Local Health District  NSWCA 476 at .