Brain death and ethical issues: Death by neurological criteria
Brain death is a medically, legally, and ethically accepted definition of human death within the United States and most other countries. Death by neurological criteria requires that clinical functions of the entire brain, including the brainstem, have suffered irreversible damage and have ceased to function completely. In adults, the most common causes of brain death include massive head trauma, hypoxic ischemic neuronal damage such as cardiopulmonary arrest, and massive intracranial haemorrhage. As referenced in the definition of death by neurological criteria, it is first necessary to identify the presence of a catastrophic structural brain lesion leading to the absence of all cerebrally-mediated responses to the environment. Available ancillary testing can be divided into two categories: those that test electrical activity of the brain and those that test cerebral blood flow. Individual institutions tend to dictate their own protocols for ancillary testing based on testing most readily available.