How do we define death? Canada now has clear clinical guidelines

Brain-based definition of death becomes the central concept of the new Canadian guidelines


Montreal, May 31, 2023 - Clinical practice surrounding the determination of death after arrest of circulation or neurologic function in Canada is now supported by new guidelines. Recently published in a special issue of the Canadian Journal of Anesthesia along with 28 evidence reviews and supporting manuscripts, the 2023 Clinical Practice Guideline provides a unified brain-based definition of death and defines the clinical criteria for its determination.

Sam David Shemie

This work, led by Dr. Sam Shemie at the Research Institute of the McGill University Health Centre (RI-MUHC), was a partnership between the Canadian Critical Care Society, Canadian Blood Services and the Canadian Medical Association, and is the result of the contributions of a large multidisciplinary panel.

The new definition describes death as the permanent cessation of brain function, observable by the absence of consciousness and brainstem reflexes including the ability to breathe independently. It applies to all people in all circumstances.

“While the concepts used until now in current medical practice refer to two distinct forms of death – brain death and cardiac death – the new guidelines contain a single, brain-based definition of death,” says Dr. Shemie, an associate investigator in the Cardiovascular Health Across the Lifespan Program at the RI-MUHC, a specialist in Pediatric Critical Care Medicine at the Montreal Children’s Hospital of the MUHC and a professor of Pediatrics at McGill University. “It’s important to understand that cardiac death is indeed brain death, since the arrest of circulation stops brain blood flow, which in turn leads to the rapid loss of brain function.”

“In the end, it comes down to one simple truth: the only organ that we can neither artificially support nor replace is the brain. And when the brain completely stops working, the person is dead,” he adds.

The guidelines also include updated criteria for death determination after devastating brain injury or circulatory arrest that replace previously published Canadian recommendations. These criteria are critical for ensuring the legal and ethical practice of deceased organ donation.

More clarity for professionals, and for families

Promoting consistency in practice, the new guidelines minimize risk for diagnostic error, foster trust and integrity in the health system, and address legal and ethical challenges. They also provide guidance for how to compassionately communicate with families during the tragic loss of a loved one.

“How we inform and counsel families who have a loved one in the intensive care unit at high risk of mortality is essential. Families need to understand that risk, and that we are doing everything we can to reverse the life-threatening condition,” says Dr. Shemie, who is also a medical advisor in deceased organ donation at Canadian Blood Services. “We need to educate them about the fundamental ways the body functions, as well as the mechanisms of death, in clear and consistent language. What is also important is to take into account the time they need to process their emotions and perform rituals that accompany transitions from life to death.”

As the guidelines specify, when a person is mechanically ventilated, families can sometimes feel a conflict between what they see (the chest rising) and feel (warm body temperature), and what is happening.

“In those cases, it can be helpful and convincing for the family to observe the brain death examination, so they can witness the absence of consciousness, motor response and brainstem function, and the inability of the person to breathe without mechanical support,” further explains Dr. Shemie

Building consensus

Dr. Shemie was a co-lead of the World Brain Death Project that led to the publication of Determination of Brain Death/Death by Neurologic Criteria in JAMA in 2020, which aimed at standardizing brain death globally. Endorsed by many world federations of critical care, as well as pediatric, neurosurgery, neurology and regional intensive care societies, it provided a basis for the work to be done in Canada.

“Until now, definitions of death varied in Canada from province to province. Adopting one unified definition will help improve death determination practices and enhance trust and integrity in the deceased donation and transplantation system, especially where there is no legal definition of death and where the courts base their judgments on accepted medical practice,” explains Dr. Shemie.

A 60-person multidisciplinary panel contributed to this work, bringing together critical care nurses and physicians (adult and pediatric), radiologists, neurologists, neurointensivists, anesthesiologists, ethicists, lawyers, patient families and public partners, as well as methodologists from across Canada.

The 2023 Clinical Practice Guideline is endorsed by the Canadian Medical Association, Canadian Critical Care Society, Canadian Blood Services, Canadian Neurological Sciences Federation (representing the Canadian Neurological Society, Canadian Neurosurgical Society, Canadian Society of Neurophysiologists, Canadian Association of Child Neurology, Canadian Society of Neuroradiology and Canadian Stroke Consortium), Canadian Association of Emergency Physicians, Canadian Anesthesiologists Society, Canadian Association of Critical Care Nurses, Nurse Practitioners Association of Canada, Health Canada Organ Donation and Transplant Collaborative, Canadian Donation and Transplantation Research Network and the Canadian Cardiovascular Critical Care Society.


About this work

Shemie, S.D., Wilson, L.C., Hornby, L. et al. A brain-based definition of death and criteria for its determination after arrest of circulation or neurologic function in Canada: a 2023 clinical practice guideline. Can J Anesth/J Can Anesth (2023).


A list of all project outputs and publications is available here.

This project was made possible through a financial contribution from Health Canada.

About the Research Institute of the McGill University Health Centre

The Research Institute of the McGill University Health Centre (RI-MUHC) is a world-renowned biomedical and healthcare research centre. The institute, which is affiliated with the Faculty of Medicine of McGill University, is the research arm of the McGill University Health Centre (MUHC) – an academic health centre located in Montreal, Canada, that has a mandate to focus on complex care within its community. The RI-MUHC supports over 450 researchers and around 1,200 research trainees devoted to a broad spectrum of fundamental, clinical and health outcomes research at the Glen and the Montreal General Hospital sites of the MUHC. Its research facilities offer a dynamic multidisciplinary environment that fosters collaboration and leverages discovery aimed at improving the health of individual patients across their lifespan. The RI-MUHC is supported in part by the Fonds de recherche du Québec – Santé (FRQS).

Media contact

Fabienne Landry
Communications coordinator, research
McGill University Health Centre
[email protected]