Dr Henk Douw Louwrens v James Peter Oldwage

The plaintiff (Oldwage) sued the defendant (Dr Louwrens), a vascular surgeon, for medical negligence. On 5 June 2000, the plaintiff, suffering from intense pain in his right leg, consulted Dr Simons (his general practitioner), who referred him to the defendant. On 6 June 2000, the defendant examined the plaintiff and suspected the pain was caused by poor blood flow to the lower leg. On 7 June 2000, an angiogram revealed various occluded arteries in the right upper leg. The defendant diagnosed severe ischaemia requiring urgent surgical intervention and performed an iliac bi-femoral bypass operation on 8 June 2000. On 14 June 2000, the plaintiff consulted Dr Kieck (a neurosurgeon) who discovered disc degeneration at L4/5 vertebrae causing a prolapsed disc. Dr Kieck performed a laminectomy on 21 June 2000, which the plaintiff claimed brought instant relief. Shortly after, the plaintiff developed claudication symptoms in the left leg, which he alleged was caused by the defendant's surgical intervention. The central factual dispute was whether the plaintiff presented with lower back pain radiating from his back (as he claimed) or pain in the right lower leg/foot arising from a vascular problem (as the defendant and Dr Simons testified). The Cape High Court (Yekiso J) found in favor of the plaintiff on the issue of negligence. The defendant appealed to the Supreme Court of Appeal.

• Whether the defendant misdiagnosed the plaintiff's condition as vascular rather than neuralgic in origin
• Whether the defendant acted as a reasonable vascular surgeon when examining the plaintiff and not detecting neuralgic/back pain symptoms
• Whether the plaintiff gave informed consent to the surgical procedure
• Whether the plaintiff's current claudication in the left leg was caused by the defendant's surgical intervention
• Whether the defendant had a duty to warn the plaintiff of negligible risks
• The proper approach to resolving conflicting factual versions and assessing credibility
• The proper approach to evaluating competing expert medical evidence

The appeal was upheld with costs, including costs for two counsel. The order of the trial court was set aside and replaced with an order dismissing the plaintiff's action with costs, including costs for two counsel.

The binding legal principles established are: (1) In medical negligence cases involving diagnosis, a practitioner is only liable if the diagnosis is so palpably wrong as to prove negligence - the mistake must be of such nature as to imply absence of reasonable skill and care, having regard to the ordinary level of skill in the profession (Mitchell v Dixon applied); (2) A specialist must employ a higher degree of care and skill concerning matters within their field of specialization than a general practitioner, tested against what a reasonable specialist would have done under similar circumstances; (3) Where the risk of complications from a medical procedure is negligible (around 2%), a doctor has no duty to warn the patient of such remote risks, and omission to do so does not constitute negligence; (4) The standard for informed consent requires that the consenting party must have knowledge and awareness of the nature and extent of harm or risk, must appreciate and understand it, must consent to the harm or assume the risk, and the consent must be comprehensive extending to the entire transaction including consequences (Castell v De Greef applied); (5) In evaluating competing expert evidence, courts must determine to what extent opinions are founded on logical reasoning and how competing evidence stands in relation to one another in light of probabilities - simple preference where conflicting views are both capable of logical support is wrong (Michael v Linksfield Park Clinic applied); (6) When resolving conflicting factual versions, courts must evaluate credibility, reliability and probabilities; findings must be tested against objectively verifiable facts and all surrounding circumstances (Stellenbosch Farmers' Winery applied).

The Court made several non-binding observations: (1) Appellate courts have greater liberty to interfere with factual findings where they do not depend essentially on personal impressions from witness demeanor but predominantly on inferences from facts and probabilities - the appellate court with benefit of the full record may be in a better position to draw inferences regarding secondary facts (Union Spinning Mills v Paltex Dye House); (2) In comparing medical studies and practices, it is unrealistic to compare modern conditions (year 2000) with dated studies (1976 VA studies) conducted in poorly-equipped hospitals on unhealthy patient populations, especially where technology and investigations have improved enormously; (3) General practitioners would not be expected to do as in-depth investigations as specialists, which is why referrals to specialists are made; (4) The semantic difference between 'fem-fem bypass' and 'iliac bi-femoral bypass' is of medical interest only - the terminology is used interchangeably for cross-over bypass procedures; (5) Small lies and contradictions in evidence, while individually minor, cumulatively undermine credibility and make a witness's evidence appear contrived and unworthy of credence; (6) Evidence that cannot be reconciled with objectively verifiable facts (such as angiogram results or hospital records) should be treated with great skepticism.

This case is significant in South African medical negligence law for several reasons: (1) It clarifies the test for medical misdiagnosis - a practitioner is only liable if the diagnosis is so palpably wrong as to prove negligence, meaning the mistake must imply absence of reasonable skill and care having regard to the ordinary level of skill in the profession; (2) It establishes that specialists are required to employ a higher degree of care and skill within their field of specialization than general practitioners; (3) It provides guidance on when a doctor has a duty to warn patients of risks - where risks are negligible (2% or less), there may be no duty to warn; (4) It confirms the principles in Richter v Estate Hammann regarding informed consent and the doctor's dilemma in balancing disclosure of risks against frightening patients from necessary procedures; (5) It reaffirms the approach to evaluating expert evidence set out in Michael v Linksfield Park Clinic - courts must not simply prefer one expert over another but must determine the extent to which opinions are founded on logical reasoning; (6) It emphasizes the proper approach to resolving conflicting factual versions, requiring evaluation of credibility, reliability and probabilities (per Stellenbosch Farmers' Winery); (7) It clarifies when appellate courts may interfere with factual findings - they have greater liberty where findings depend predominantly on inferences from facts and probabilities rather than personal impressions of witness demeanor.