The Full Bench of the High Court (Cape of Good Hope Provincial Division) on 2 March 2007 reinforced causation as part of the onus which a plaintiff relying on lack of informed consent is required to discharge on a balance of probabilities.
By Stephanie Esterhuyse
Medical practitioners can breath a sigh of relief after the Full Bench of the High Court (Cape of Good Hope Provincial Division) comprised of HJ Erasmus J Thring J and Wagley J on 2 March 2007 reversed the court a quo’s finding on lack of informed consent in the matter of Nicola McDonald v Dr Graham Wroe (2006) 3 All SA 565 (C).
Following the judgment a quo, it was of concern to medical defence attorneys that our courts were following a trend possibly set by the House of Lords in Chester v Afshar, a matter heard by the British Court of Appeal. On page 596 of the judgment to be found at  4 All ER 587, the following is held -
“  Standing back from the detailed arguments, I have come to the conclusion that, as a result of the surgeon’s failure to warn the patient, she cannot be said to have given informed consent to the surgery in the full legal sense. Her right to autonomy and dignity can and ought to be vindicated by a narrow and modest departure from traditional causation principles.
 On a broader basis I am glad to have arrived at the conclusion that the claimant is entitled in law to succeed. This is in accordance with one of the most basic aspirations of the law, namely to right wrongs. Moreover, the decision announced by the House today reflects the reasonable expectations of the public in contemporary society.”
Nicola McDonald v Dr Graham Wroe (2006) 3 All SA 565 (C)
Fourie, J, in his judgment handed down in the High Court of South Africa (Cape of Good Hope Provincial Division) found that the defendant, a dentist, had been negligent and was liable to the plaintiff for the damages which she had suffered as a result of permanent nerve damage suffered following surgical extraction of her wisdom teeth. Despite the obvious lack of negligence on the defendant’s part as far as performing the surgery was concerned, the court held that the defendant’s negligent omission to warn the plaintiff of the risk of permanent nerve damage was causally linked to the harm ultimately suffered by the plaintiff.
The plaintiff had developed repeated bouts of pericoronitis (infection) in the area of her wisdom teeth and the defendant correctly advised her that it was necessary for her wisdom teeth to be surgically extracted under general anaesthesia. The surgery was performed on 3 October 2000. Post-operatively the plaintiff experience numbness on the left side of her face. The numbness was as a result of damage to her inferior alveolar nerve, which damage appeared to be permanent in nature. The risk of permanent nerve damage was an inherent risk arising from the surgery in that area, of which the defendant had failed to warn her prior to the surgery and when obtaining her consent to the procedure.
In her particulars of claim, the plaintiff alleged that (a) the defendant had been negligent in that he had failed to offer her the option of a referral to a specialist maxillo- facial oral surgeon for the extraction of her wisdom teeth; and (b) that he was negligent in that he had failed to inform her of the risk of permanent nerve damage to her left inferior alveolar nerve.
The defendant admitted that he had failed to inform the plaintiff of the risk of permanent nerve damage pre-operatively, but denied that the nerve damage which the plaintiff had suffered was caused by his failure to inform her of the risk of permanent nerve damage.
Causation and the law:
Fourie, J set out the relevant legal principles relating to a court’s assessment of causation and the onus of proof applicable in South African law. Page 568  to  -
“If a medical practitioner through his/her wrongful and negligent conduct causes damage to a patient, the practitioner will be delictually liable to the patient if there was a causal nexus between the conduct of the practitioner and the damage suffered by the patient. The medical practitioner cannot be liable if his/her conduct has not caused any damage.
As explained by Neethling, Potgieter and Visser, Law of Delict, 4th Ed at 173-174, the conditio sine qua non theory is used as a point of departure in order to determine initially whether a factual causal nexus between the conduct of a medical practitioner and a harmful consequence exists. If it does exist, so-called factual causation is present. The next question that arises is whether the practitioner should be held liable for the harmful events following from his conduct. Causation in the latter sense is known as legal causation.
The conditio sine qua non theory, also known as the “but-for” test, requires proof on a balance of probabilities that the relevant act of commission or omission was a necessary condition of the harmful event. Legal causation is present in the event that there is a close enough relationship between the wrongdoers conduct and its consequence for such consequence to be imputed to the wrongdoer in view of policy considerations based on reasonableness, fairness and justice (see Smit v Abrahams 1994 (4) SA 1 (A) at 14A – F).”
The judgment a quo:
The court’s assessment of the evidence and its finding on causation was, however, surprising hence the concern that our courts may be following a trend possibly set in the United Kingdom by the Lords of Appeal in Chester v Afsha. Fourie J, at 575  to  held that -
“The expert witnesses are agreed that the risk of permanent nerve damage in a procedure of this nature, is less than 1%. The risk will always be present, even if the procedure is performed by a specialist surgeon. However, the expert evidence of Drs Ostrofsky and Berezowski, which I have accepted, assesses a lesser likelihood of permanent nerve damage if the procedure were to be performed by a specialist surgeon. To me the evidence conveys that although the risk of permanent nerve damage remains the same, no matter when or by whom the surgery is performed, the likelihood of that risk eventuating in the hands of a specialist surgeon, is less…
…It seems to me that the more natural and plausible conclusion on the evidence as a whole, is that had the procedure been performed by a specialist surgeon, Plaintiff would probably not have suffered the consequences which she did.
It follows, in view of my aforesaid finding, that plaintiff has proved on a balance of probabilities that the necessary factual causal nexus exists between defendant’s failure to warn her of the risk of permanent nerve damage and the consequences from which she now suffers due to the trauma caused to the inferior alveolar nerve.
This brings me to the requirement of legal causation. I am of the view, that in the circumstances of the instant case, policy considerations based on reasonableness, fairness and justice, dictate that defendant should be held liable for the harmful consequences flowing from his wrongful and negligent omission to warn plaintiff. In obtaining plaintiff’s consent to the proposed procedure, defendant failed to fully inform her of the nature and extent of the risk of permanent nerve damage, with the result that plaintiff consented thereto without appreciating the risk of permanent nerve damage. Defendant’s omission is accordingly directly linked to the harm suffered by plaintiff. To this I should add that the plaintiff’s right to bodily integrity is entrenched in Section 12(2) of our Constitution of the Republic of South Africa, 1996, which right defendant has violated by subjecting her to surgery without obtaining her informed consent.”
Fourie, J held that the defendant was liable for the damages which the plaintiff had suffered resulting from his wrongful and negligent omission to warn her of the risk of permanent nerve damage.
The appeal court’s findings:
On appeal, the Full Bench was only requested to pronounce on the court a quo’s assessment and finding on causation. The Full Bench reversed the court a quo’s finding and found in favour of the dentist.
The Full Bench unanimously rejected the court a quo’s finding as “the more natural or plausible conclusion on the evidence as a whole”.
At paragraph , the Full Bench held that –
“The defendant’s wrongful and negligent failure to warn the Plaintiff of the risk involved resulted in the plaintiff consenting to defendant performing the surgery. He performed the surgery correctly without negligence. The experts were unable to fault the manner in which he performed the surgery in any way. The harm which the plaintiff suffered, is due to a risk which is inherent in the surgical procedure in question and which can ensue without negligence on the part of the practitioner, be it a general practitioner or a specialist, who performs the procedure. The harm which the plaintiff suffered, is harm she might equally probably have suffered in any event if the surgery had been performed by a specialist surgeon. There is, therefore, no direct causal link between the defendant’s negligence (in failing to warn the plaintiff of the risk) and occurrence of the harm, unless it is shown that the plaintiff, upon being warned of risk, would not have undergone the procedure at all. That is not the plaintiff’s case.”
The full bench accordingly reaffirmed causation as an element deeply entrenched in our law of delict. A patient/plaintiff who intends relying on lack of informed consent bears the onus to prove on a balance of probabilities that (1) the medical practitioner was negligent in so far he failed to warn his patient of the particular risk or complication; and (2) the medical practitioner’s negligent omission as such caused the damages suffered.