Brain Failure and Brain Death

Abstract

Brain failure consists of a wide spectrum of central nervous system pathologies with many different neurologic manifestations. The causes of brain failure include several disease processes that result in decreased supply of blood and oxygen to the brain or metabolic derangements that affect the central nervous system. Brain failure usually results in some altered level of consciousness. Brain failure and brain death result in several pathophysiologic changes. The definition of brain death is controversial and evolving. However, clear guidelines to determine brain death have been established. These guidelines state that three cardinal findings be present to establish brain death: (1) coma or unresponsiveness, (2) absence of brainstem reflexes, and (3) apnea. Several clinical parameters must be met when these findings are made. Adjunctive studies such as four-vessel cerebral angiography, electroencephalography, and nuclear brain scintigraphy can help make a diagnosis of brain death. When brain death is established, suitability for organ transplantation should be evaluated. After obtaining consent, potential organ donation should be optimized for possible donation. This review contains 2 figures, 3 tables, and 69 references. Key Words: brain failure, brain death, consciousness, coma, death, delirium, organ donation