CRITERIA AND TESTS FOR DETERMINING BRAIN DEATH

Determination of brain death confirms the irreversible cessation of all functions of the entire brain, including the brainstem.^[10] Irreversibility means that no treatment may be reasonably expected to change the condition. The responsible disorder may be thought of as structural, and it does not result from functional and potentially reversible causes such as drug intoxication, hypothermia, or metabolic or endocrine disturbance. The passage of time is also an essential component in determining that a lesion is irremediable. Although testing all functions of the brain is conceptually impossible, the cessation of all functions of the brain is practically determined by loss of consciousness, loss of brainstem responses, apnea, and confirmatory tests, including the lack of electroencephalographic activity.

Loss of Consciousness and Unresponsiveness

The patient should be in coma and scored as 3 on the Glasgow Coma Scale. Motor responses of the limbs or facial muscles to painful supraorbital pressure should be absent. Motor responses (i.e., the Lazarus sign) may occur spontaneously during apnea testing^[62] and are considered to have a spinal origin. This sign is often observed during hypoxic or hypotensive episodes. Other spontaneous movements from spinal origin are observed.