KembaraXtra-Case Law- Wilsher v Essex AHA (1988)

KembaraXtra-Case Law- Wilsher v Essex AHA (1988)
1. Core Principle: Causation in Negligence

Burden of Proof: In negligence cases, the plaintiff bears the burden of proving, on the balance of probabilities, that the defendant's negligence caused the damage.
"But For" Test: The plaintiff must demonstrate that but for the defendant's negligence, the damage would not have occurred. This is a fundamental test of causation.
Multiple Possible Causes: If the defendant's negligence is only one of several possible causes of the plaintiff's damage, the plaintiff must prove that the negligence was the cause on the balance of probabilities.

2. Case Facts: Wilsher v Essex AHA (1988)

Premature Baby: A premature baby with breathing problems received supplemental oxygen.
Negligence: A catheter was misplaced (twice), leading to inaccurate oxygen level readings and, consequently, excessive oxygen administration.
Injury: The baby developed retrolental fibroplasia, resulting in near blindness.
Claim: The plaintiff argued that the excess oxygen, caused by the hospital's negligence, led to the blindness.

3. Court Decision

Failure to Prove Causation: The House of Lords ruled against the plaintiff.
Multiple Possible Causes: The court identified five possible causes of the retrolental fibroplasia, not just the excess oxygen due to the misplaced catheter. Because there were other possible causes, the plaintiff had to prove that the actions of the defendant were, more likely than not, the actual cause.
Plaintiff's Failure: The plaintiff failed to prove, on the balance of probabilities, that the defendant's negligence (excess oxygen) was the cause of the blindness, as opposed to one of the other potential causes stemming from the prematurity.

4. Distinction from McGhee v National Coal Board (1973)

McGhee Facts: A worker developed dermatitis due to the employer's failure to provide washing facilities, which increased the risk of the plaintiff getting dermatitis.
McGhee Outcome: The House of Lords found the defendant liable because the lack of washing facilities had materially increased the risk of the plaintiff developing dermatitis.
Distinguishing Factor: The court in Wilsher distinguished McGhee because McGhee involved one potential "agent" (brick dust) that could cause the dermatitis, whereas Wilsher had five potential causes for the blindness. In other words, in McGhee, the defendant's breach had materially increased the risk of the only possible cause.

5. Key Takeaways & Implications

Material Contribution vs. Wilsher: Wilsher clarified that McGhee didn't introduce a new legal principle. McGhee was decided on its specific facts, where it was reasonable to infer that the defendant's negligence materially contributed to the single potential cause of the injury. Wilsher underscores that when multiple potential causes exist, the plaintiff must still prove causation based on the balance of probabilities.
Proving Causation Can Be Difficult: Wilsher illustrates the difficulty plaintiffs face in medical negligence cases, particularly when the injury could stem from multiple factors. Plaintiffs have to prove that the negligence caused the injury.
Causation is Key: Even if negligence is established, a claim will fail if causation cannot be proven.

LAW