Brain death worldwide: accepted fact but no global consensus in diagnostic criteria.

OBJECTIVE To survey brain death criteria throughout the world. BACKGROUND The clinical diagnosis of brain death allows organ donation or withdrawal of support. Declaration of brain death follows a certain set of examinations. The code of practice throughout the world has not been systematically investigated. METHODS Brain death guidelines in adults in 80 countries were obtained through review of literature and legal standards and personal contacts with physicians. RESULTS Legal standards on organ transplantation were present in 55 of 80 countries (69%). Practice guidelines for brain death for adults were present in 70 of 80 countries (88%). More than one physician was required to declare brain death in half of the practice guidelines. Countries with guidelines all specifically specified exclusion of confounders, irreversible coma, absent motor response, and absent brainstem reflexes. Apnea testing, using a PCO(2) target, was recommended in 59% of the surveyed countries. Differences were also found in time of observation and required expertise of examining physicians. Additional provisions existed when brain death was due to anoxia. Confirmatory laboratory testing was mandatory in 28 of 70 practice guidelines (40%). CONCLUSION There is uniform agreement on the neurologic examination with exception of the apnea test. However, this survey found other major differences in the procedures for diagnosing brain death in adults. Standardization should be considered.