Rationale for revisions to the definition of death and criteria for its determination in Canada.

Clarity regarding the biomedical definition of death and the criteria for its determination is critical to inform practices in clinical care, medical research, law, and organ donation. While best practices for death determination by neurologic criteria and circulatory criteria were previously outlined in Canadian medical guidelines, several issues have arisen to force their reappraisal. Ongoing scientific discovery, corresponding changes in medical practice, and legal and ethical challenges compel a comprehensive update. Accordingly, the A Brain-Based Definition of Death and Criteria for its Determination After Arrest of Neurologic or Circulatory Function in Canada project was undertaken to a develop a unified brain-based definition of death, and to establish criteria for its determination after devastating brain injury and/or circulatory arrest. Specifically, the project had three objectives: (1) to clarify that death is defined in terms of brain functions; (2) to clarify how a brain-based definition of death is articulated; and (3) to clarify the criteria for determining if the brain-based definition is met. The updated death determination guideline therefore defines death as the permanent cessation of brain function and describes corresponding circulatory and neurologic criteria to ascertain the permanent cessation of brain function. This article explores the challenges that prompted revisions to the biomedical definition of death and the criteria for its determination and outlines the rationales underpinning the project's three objectives. By clarifying that all death is defined in terms of brain function, the project seeks to align guidelines with contemporary medicolegal understandings of the biological basis of death.