Irreversible cessation of all functions of the brain including the cortex and the brain stem. This definition of whole brain death has been endorsed by the American Medical Association and the American Bar Association, and is law in 46 states. Thirty-six of these states have adopted some version of the Uniform Determination of Death Act, which includes whole brain death as a legal determination of death. Criteria for diagnosis rest on three principal abnormalities: (1) severe coma of known cause; (2) absent brainstem reflexes; and (3) sustained apnea. If brain death criteria are satisfied, the patient is legally dead and no further treatment or permission to treat is necessary. The body may remain on the respirator until donated organs can be harvested. [Sources: Halevy, A, Brody, B, "Brain Death: Reconciling Definitions, Criteria, and Tests," Annals of Internal Medicine 119 (1993): 519-25. Plum, M, "Clinical Standards and Technological confirmatory Tests in Diagnosing Brain Death," in The Definition of Death: Contemporary Controversies, eds., Younger, SJ, Arnold, RM, and Schapiro, R. (Baltimore: The Johns Hopkins University Press, 1999), 34-65.]
The development of the concept of brain death and its clinical diagnosis was largely the result of issues related to organ transplantation. Because all human life is of intrinsic value in the Catholic tradition, death must be determined before organs can be transplanted:
The determination of death should be made by the physician or competent medical authority in accordance with responsible and commonly accepted scientific criteria . . . . Organs should not be removed until it has been medically determined that the patient has died. In order to prevent conflict of interest, the physician who determines death should not be a member of the transplant team (Ethical and Religious Directives, Part Five, nn. 62 and 64).