Causation is a well-established principle in medical negligence claims, requiring a plaintiff to prove that the defendant’s breach of the standard of care caused or contributed to their injury. Recently in Hemmings v. Padmore, the Supreme Court of Canada (the SCC) clarified that factual causation and remoteness are distinct inquiries in the negligence analysis that must be considered separately. The decision provides helpful guidance on how courts should approach each stage of the causation analysis, particularly in professional negligence claims.
The SCC reaffirmed that a plaintiff alleging negligence must establish four elements: (1) that the defendant owed the plaintiff a duty of care, (2) that the defendant breached that duty, (3) that the plaintiff suffered damage, and (4) that the damage was caused, both in fact and in law, by the defendant’s breach. The SCC further emphasized that the fourth element engages two distinct inquiries: factual causation and remoteness of damage.
The case arose from the delivery of Sophia Hemmings’ child at Scarborough Hospital. During an emergency C-section, Ms. Hemmings suffered a cardiac arrest following anesthetic complications. Although she was successfully resuscitated, she sustained severe and permanent brain damage. Ms. Hemmings and her family commenced an action against several of her treating healthcare practitioners, including Dr. Jamensky, the on-duty anesthesiologist at her delivery. The trial turned entirely on liability.
At trial, the judge found that the attending anesthesiologist, Dr. Jamensky, breached the standard of care by intubating Ms. Hemmings (the Intubation Breach) and in converting to general anesthetic (the Conversion Breach) before all other reasonable options had been attempted. The trial judge further held that the Intubation Breach and the Conversion Breach directly caused Ms. Hemmings cardiac arrest and found that, but for the administration of general anesthesia, the cardiac arrest would not have occurred.
These findings engage the doctrine of factual causation. To establish factual causation, a plaintiff must prove, on a balance of probabilities, that the defendant’s conduct caused their injury. In other words, the plaintiff must demonstrate that ‘but for’ the defendant’s negligent act, the injury would not have occurred. The SCC further explained that the “but for” test is to be applied in a common sense fashion, taking into account all of the evidence before the court, as well as any inferences that may reasonably be drawn from that evidence.
Establishing factual causation, however, does not end the inquiry. The SCC clarified the law of remoteness by reviewing its historical development and confirmed that the doctrine of remoteness asks a distinct question: whether there is a sufficiently close connection between the defendant’s wrongful conduct and the plaintiff’s injury to justify imposing liability. As the SCC explained, remoteness turns on reasonable foreseeability; that is, whether the plaintiff’s injury was a reasonably foreseeable consequence of the defendant’s negligence. For professional defendants, foreseeability is assessed based on the skill and knowledge of a reasonable practitioner in the same position. The risk of injury must be a ‘real risk’ or probability, not a mere possibility.
Applying these principles, the SCC upheld the finding of liability against Dr. Jamensky, concluding that there was sufficient evidence to conclude, on a balance of probabilities, that the conversion to general anesthetic (the Conversion Breach) caused the cardiac arrest. It further found that reasonable efforts to sedate Ms. Hemmings would likely have been successful, allowing her to remain on regional anesthetic. In reaching its conclusion on causation, the SCC held that Conversion Breach was sufficiently connected to the resulting harm.
The SCC’s decision in Hemmings v. Padmore reinforces that establishing liability in negligence requires more than proving that a defendant’s conduct factually caused the injury. Courts must also determine whether the injury was a reasonably foreseeable consequence of the negligent act. By clearly distinguishing these two principles, the SCC has provided valuable guidance for litigants and practitioners navigating complex negligence claims.
These principles are particularly important for prospective plaintiffs evaluating whether to bring a medical malpractice claim. The SCC’s clarification of the distinct inquiries of factual causation and remoteness serves as a reminder that both play a critical role in determining the viability of a claim.
About the Author: Maya Stanton joined Soloway Wright as an associate in 2026 after completing her articles with the firm. She obtained her Juris Doctor from the University of Ottawa’s French Common Law Program, where she graduated on the Dean’s Honour List. Maya practices within the litigation group, with a focus on medical malpractice, personal injury, commercial litigation and employment law.
DISCLAIMER: This article is for general information purposes only and is not (and should not be construed as) legal advice. The information contained herein summarizes only certain aspects of the subject matter and is not a comprehensive review of applicable law. All of the foregoing is subject to legal and accounting advice based on the particular circumstances of each potential client.
