- The end of life. The cessation of life (these common definitions of death ultimately depend upon the definition of life, upon which there is no consensus.)
- The permanent cessation of all vital bodily functions (this definition depends upon the definition of "vital bodily functions.")
- The common law standard for determining death is the cessation of all vital functions, traditionally demonstrated by "an absence of spontaneous respiratory and cardiac functions."
- The uniform determination of death. The National Conference of Commissioners on Uniform State Laws in 1980 formulated the Uniform Determination of Death Act. It states that: "An individual who has sustained either (1) irreversible cessation of circulatory and respiratory functions, or (2) irreversible cessation of all functions of the entire brain, including the brain stem is dead. A determination of death must be made in accordance with accepted medical standards." This definition was approved by the American Medical Association in 1980 and by the American Bar Association in 1981.
Reference: MedicineNet.com. Definition of Death. Internet. September 28, 2009. Available at http://www.medterms.com/script/main/art.asp?articlekey=33438
A state of prolonged irreversible cessation of all brain activity, including lower brain stem function with the complete absence of voluntary movements, responses to stimuli, brain stem reflexes, and spontaneous respirations.
Reversible conditions which mimic this clinical state (e.g., sedative overdose, hypothermia, etc.) are excluded prior to making the determination of brain death.
Reference: DeCS. Health Sciences Descriptors. Internet. Accessed September 28, 2009. Available at http://decs.bvs.br/I/homepagei.htm