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Causation and Negligent Omissions

Causation and Negligent Omissions: Ghiassi v Singh, 2018 ONCA 764

A common issue faced by plaintiffs in medical malpractice actions is proving causation in the face of a negligent omission such as where a medical provider fails to conduct indicated testing. In such situations, the plaintiff cannot prove to a certainty what the test would have shown, because the test was never done. How do the courts analyze causation in such cases? This issue was recently considered by the Ontario Court of Appeal in Ghiassi v Singh, 2018 ONCA 764 [Ghiassi]. 

In Ghiassi, the infant plaintiff was born on December 22, 2005. At 9:00 PM on December 25, 2005 the defendant nurse noted that the plaintiff was slightly jaundiced. She reported the jaundice to the incoming shift nurse at 7:00 AM the next morning. At 8:45 AM that nurse took a blood sample. The lab report at 10:00 AM indicated that the plaintiff had a higher than normal level of bilirubin in the blood (severe hyperbilirubinemia). The reported bilirubin level was only slightly less than the threshold for critical hyperbilirubinemia. Critical hyperbilirubinemia carries the potential to cause long-term neurological injury. 

At 11:00 AM the infant was put under lights to reduce the bilirubin concentration in his blood (phototherapy). His bilirubin level dropped slightly, but by 3:00 PM he began to display signs of neurological injury. He developed a severe brain injury as a result of his hyperbilirubinemia. 

The trial judge found that the defendant nurse breached the standard of care by failing to report the onset of jaundice at 9:00 PM on December 25, 2005 to the resident pediatrician on duty. The trial judge then had to consider what a reasonably competent resident would have done had the defendant nurse met the standard of care. The trial judge considered the evidence of the plaintiff’s expert who opined that a competent resident would order a blood test at the next handling episode, as well as the evidence of another resident who testified, and found that a reasonable resident would have ordered a bilirubin test at 12:00 AM on December 26, 2005. The trial judge found that, had that been done, phototherapy would have been commenced by 2:15 AM and the infant would have avoided the brain injury.

The defendants appealed, arguing that, because the plaintiff’s expert testified that the entire medical staff on the unit lacked competence, it was an error for the trial judge to conclude that the resident on duty would have met the standard of care. The Ontario Court of Appeal rejected this argument and held that the defendant nurse could not escape liability by pointing at another medical practitioner’s hypothetical negligence. 

The appellants also argued that the trial judge erred in inferring causation in the absence of expert evidence that the plaintiff would not have developed a brain injury had phototherapy been commenced at 2:15 AM on December 26, 2005. In Ghiassi, the defendants did not call their own expert evidence on causation but argued that the plaintiffs had failed to prove causation. The plaintiff’s expert was not asked whether phototherapy initiated at 2:15 AM would have prevented the brain injury and it was not until closing argument that the defendants argued that, even if the defendant nurse reported the jaundice at 9:00 PM, phototherapy would not have been commenced until 2:15 AM. 

The Court of Appeal held the trial judge was entitled to draw an inference of causation from her findings of fact, including that:

  • Expert evidence established that the brain injury would have been avoided had phototherapy been initiated at 12:00 AM on December 26 2005;
  • Phototherapy effectively blunts the rise and reduces the level of bilirubin;
  • The plaintiffs bilirubin declined after phototherapy was initiated; and
  • The plaintiff was still neurologically intact at 11:00 AM on December 26, 2005 and did not display signs of neurological damage until 3:00 PM.

The trial judge did not speculate or act as her own expert. The only expert evidence available, combined with the evidence of how the plaintiff’s condition progressed, provided a solid factual foundation for an inference of causation. 

The Court of Appeal further held that, if there is a gap in the evidence about what would have happened had phototherapy been initiated at 2:15 AM, that gap was produced by the defendant nurse negligently failing to order the blood test. The defendant nurse was not entitled to rely on a lack of evidence produced by her own negligence.

The approach used by the trial judge in Ghiassi is not a new approach to causation. It is merely the appropriate application of the robust and pragmatic approach to factual causation as set out by Sopinka J in Snell v Farrell, [1990] 2 SCR 311. This approach permits a trial judge to draw an inference of but for causation in the absence of scientific proof after weighing all the evidence.

By Iman Jomha