ABSTRACT
The concept of brain death lives at the intersection of science, religion, medicine, ethics, and law. Though the term is commonly used in clinical parlance, "brain death" is one of the most poorly understood notions among laypeople, and explaining the nuances of this subject to patients' families can be one of the most daunting tasks faced by health-care professionals. Although catastrophic neurologic injury has been recognized since antiquity, the challenges pertaining to brain death are the by-product of modern resuscitation techniques and intensive care measures that defy previously non-survivable brain damage. Particular attention must be paid to the apnea test. Properly performed, the apnea test produces acute hypercarbia, resulting in cerebrospinal fluid acidosis that stimulates respiratory centers of the brainstem. Thus, the absence of respirations confirms brainstem dysfunction. Centers vary in terms of the requirements for ancillary studies that confirm cessation of blood flow to the brain and/or the absence of cerebral electrical activity as diagnostic criteria of brain death.
