The death watch: certifying death using cardiac criteria.

In the past, inadequate diagnostic instruments sometimes led to incorrect diagnoses of death, so careful and prolonged observation--the "death watch"--was required. Diagnostic instruments are now accurate and determining the presence or absence of circulation and cerebral function is easy in virtually all cases. Still, ambiguity and controversy in diagnosing death persists because the current criteria, irreversible cessation of cardiac or whole brain function, are ambiguous. Recent reintroduction of non-heart-beating organ donation has highlighted the controversy. Data on the ability to achieve restoration of spontaneous circulation are quite consistent, but they support several different sets of reasonable death criteria. This article concludes with a rejection of a fixed notion of "irreversibility" because it does not conform to current practice, is potentially deleterious to social events at the time of death, and the reversibility of cardiopulmonary arrest is dependent on available means of resuscitation. Finally, the time required to ensure irreversible cessation of cardiac function despite potential intervention is too broad to be clinically applicable and is unreasonable. Diagnosis of death should be based on the context in which it occurs because the medical means available determine what is irreversible.