Testing for Death
State law may impose additional criteria, such as the qualifications of the physician who determines brain death or the need for confirmation by a second examiner. The physician who determines brain death must carefully examine the patient and document the results.
Ancillary tests, such as EEG, cerebral angiography, nuclear scan, and transcranial Doppler imaging, may support the diagnosis of brain death, but they are not required unless there is uncertainty about the clinical diagnosis or when the apnea test cannot be done.
Brain death is not a reversible physiologic state. According to the AAN, "In adults, there are no published reports of recovery of neurologic function after a diagnosis of brain death using the criteria reviewed in the 1995 American Academy of Neurology practice parameter."
Neonates, Infants, and Children
Guidelines for the determination of brain death differ slightly in neonates, infants, and children because of their immature nervous systems compared with adults. In particular, a second examination and apnea test are required to confirm brain death after an observation period, usually 12-24 hours. Brain death guidelines for neonates, infants, and children were recently updated by the Pediatric Section of the Society of Critical Care Medicine, Section on Critical Care of the American Academy of Pediatrics, and the Child Neurology Society. This update includes a useful checklist for brain death documentation.
Other Transplant Scenarios
A "vegetative state" most commonly occurs from traumatic brain injury, hypoxic-ischemic neuronal damage, or brain infarction or hemorrhage with thalamocortical damage. These patients manifest sleep/wake cycles and preserved cranial nerve reflexes.
By definition, patients in a vegetative state are not brain dead and may recover awareness. After 1 year in a vegetative state, the prognosis for recovering awareness is very poor. Whether vital organ transplantation may be ethically undertaken in people who exist in a persistent vegetative state requires a different discussion than one limited to brain death.
Patients with severe spinal injuries or end-stage muscle disease on life support who are "neurologically aware" and choose to terminate life support may ethically donate their organs, according to the United Network for Organ Sharing. This decision does not require the determination of brain death and is a distinct clinical scenario.
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Cite this: Brain Death: You're Legally Dead Despite Your Beating Heart - Medscape - Sep 23, 2013.