Brain death was first described by two French physicians (M.o]l.§.r§t.§.D.d G..o.u.!o..n 1.9.59.) and termed coma dépassé (a state beyond coma). They differentiated coma dépasse from coma prolongé, the latter being the condition which is now termed 'persistent vegetative state'. In 1968 the Ad Hoc Committee of the Harvard Medical School defined brain death as irreversible coma, with the patient being totally unreceptive and unresponsive, with absent reflexes and no spontaneous respiratory effort during a 3-min period of disconnection from the ventilator. The report unambiguously proposed that this clinical state should be accepted as death. A few years later M.2h.iDd§S §D.d C.h.ou..i19.Z1). suggested that in patients with known but irrepairable intracranial lesions irreversible damage to the brainstem was 'the point of no return' and that the diagnosis 'could be based on clinical judgment', thereby introducing the important concepts of etiological preconditions and a purely clinical diagnosis. Another important contribution was the memorandum issued by the CoDÍ§^§D.ce...OlM§d|C§.! Roy§]...Co!]eges..(,19Z6) which has underpinned clinical practice in the United Kingdom and many other countries ever since. This emphasized that 'permanent functional death of the brainstem constitutes brain death' and that this should only be diagnosed in the context of irremediable structural brain damage, after exclusion of certain specified conditions which might contribute to or cause the coma. This report also described the use of simple clinical tests to establish the permanent loss of brainstem function. A second memorandum in 19Z9 equated brainstem death with death itself. In the United States, guidelines issued by a governmental commission state that an individual who has sustained either irreversible cessation of circulatory and respiratory functions or irreversible cessation of all functions of the entire brain, including the brainstem, is dead ( Table.!,).
Table 1 Criteria used for the diagnosis of death in the United States
The diagnosis of death has evolved from recognition of the traditional signs (coma, absence of heart sounds, pulse, and breathing) to the diagnosis of total brain death and, in some countries, to establishing death of the brainstem. It has been suggested that death should now be conceived as a state in which there is irreversible loss of the capacity for consciousness combined with irreversible loss of the capacity to breath (and hence maintain a heartbeat) ( Pallis...and...Harley...199§). Neither would be sufficient alone. Both are essentially brainstem functions, and therefore death of the brainstem is considered by many to be equivalent to death of the individual.
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