Working toward a new tool to determine brain death

Canada is faced with an organ shortage: some 4 500 patients are currently on the transplant list and, each year, approximately 260 people run out of time waiting for an organ to become available. What can be done to improve the situation? Michaël Chassé, researcher at the CHUM Research Centre and clinical professor in the Faculty of Medicine and École de santé publique at Université de Montréal, believes that the solution partly lies in the better diagnosis of brain death.

In many cases, doctors cannot confirm a patient’s death, and this delay in the organ donation process ultimately alters the quality of the organs.

A clinical examination cannot always reliably confirm neurological determination of death, since conditions such as hypothermia, extensive facial injuries and paralysis can prevent physicians from assessing a patient’s reflexes (e.g. no breathing or pupil response). They may then recommend a scan to check for blood in the brain but the images do not indicate whether there is blood flow in the brain stem—a sure sign that a patient is alive. In many cases, doctors cannot confirm a patient’s death, and this delay in the organ donation process ultimately alters the quality of the organs.

Michaël Chassé is focused on determining whether CT perfusion imaging, a tool currently used for stroke patients, could help solve problem. He reprogrammed the machine and set out a new protocol to analyze a cohort of 300 Canadians in a deep coma. He will compare the diagnoses based on the scans with the physicians’ clinical conclusions.

CT perfusion imaging generates a series of brain images. By following blood flow in real time, like a film, it may be possible to confirm beyond doubt that a patient has suffered brain death. The tool would support physicians in cases in which a clinical diagnosis is difficult to make or a scan is mandatory, as in some western Canada hospitals.

A number of organizations, including Canadian Blood Services and the World Health Organization, have expressed interest in the study, since the findings will serve to update the recommendations for the neurological determination of death.