All human death is brain death: The legacy of the Harvard criteria.

Fifty years ago, the ad hoc committee of the Harvard medical school provided the influential first guidance on confirming death using neurological criteria (DNC). Now 70% of countries have a legal or professional framework enabling DNC. While there is virtually universal acceptance of a three staged approach to the clinical diagnosis of brain death, international variation in practice continues. The need to develop international consensus and standards is essential in the future if public and professional confidence in the diagnosis is to be maintained and increased. The legacy of the Harvard ad hoc committee has been a continuing development of our concepts of human death. There is a growing acceptance that ultimately all human death is brain based whether diagnosed using neurological criteria or using circulatory criteria after cardiac arrest.