While the court found that, initially, the defendant’s care met the requisite standard, he later engaged in tunnel vision by continuing to assume that the plaintiff’s complaints were due to a traumatic SAH that was the result of the plaintiff hitting her head, even though he knew that in a significant minority of patients SAH was caused by a life-threatening condition, such as an aneurysm. The court was critical of the defendant for “seeking refuge” in investigations such as an X-ray and CT scan that neither supported nor ruled out his diagnosis, and failing to obtain the necessary input from a neurologist or a neurosurgeon. This would have led to surgery to avert the rupture of the plaintiff’s aneurism and avoid her permanent injury.
Causation in Delayed Diagnosis Cases
Causation can be particularly challenging for a plaintiff to prove in cases involving delayed diagnosis. In order to succeed in a claim, the plaintiff needs to prove that delay was a “but for” cause of their injury. In other words, the plaintiff must prove that had the condition been diagnosed and treated sooner, the injury would likely have been avoided. If earlier diagnosis and treatment “might” have avoided the injury, that is simply a loss of chance which is not compensable.
The issue of loss of chance arose in Cottrelle v. Gerrard.9 The plaintiff, a long-time diabetic, developed a sore between her toes. She called the office of the defendant, her family physician, and was prescribed a cream. The physician did not speak directly with the plaintiff. About a month later, the plaintiff saw her doctor. He examined her foot and prescribed a topical steroid. Just over a month after that, the plaintiff awoke to a throbbing pain between her toes and went to the ER where she was diagnosed with an ulcer and prescribed a course of antibiotics.
When the plaintiff saw the defendant doctor again a few days later, he made an appointment for her to see a skin specialist but gave no further instructions or warnings. Before she had an opportunity to see the specialist, the condition of her foot deteriorated, becoming painful, turning a darker colour and developing an odour. She was taken to the hospital and was found to have developed gangrene, which was spreading. She eventually required amputation below the knee. Examination of the amputated limb revealed severe atherosclerosis (obstruction of the arteries) which had inhibited the plaintiff’s ability to fight the infection.
At trial, the judge found that the defendant was negligent in failing to adequately examine the plaintiff’s foot and failing to monitor her condition. The judge found that his actions were a material cause of the plaintiff’s injury as he denied the plaintiff a “window of opportunity” to save her leg. The ruling was overturned, with the Ontario Court of Appeal finding that the trial judge erred with respect to the legal test for causation, and that the evidence demonstrated that it was likely that even if the defendant had met the standard of care, the plaintiff would have lost her leg. Both the plaintiff’s and defendant’s experts agreed that had the plaintiff received aggressive treatment in the form of IV antibiotics when her foot deteriorated, she may not have suffered the loss of her leg. Due to her pre-existing atherosclerosis, however, no expert testified that it was more likely than not that the leg could have been saved even with proper diagnosis and treatment. The Court of Appeal reiterated that proving that adequate diagnosis and treatment would have afforded a chance of avoiding the unfavourable outcome is not sufficient to establish liability unless that chance surpasses the threshold of “more likely than not.”10
