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Brain Death

Brain death is part of the medical description of death in the modern world and informs medical ethics. Death is medically determined by checking for heart-beat, unaided respiration, and reflex actions (gagging, blinking, pupil dilation, grimacing). If the body is only recently declared deceased, many of the still living organs can be removed and transplanted, while the brain quickly decays. This decay begins once oxygenated blood stops reaching the brain in adequate amounts (this is called "ischemia", the condition suffered by tissues and organs when deprived of adequate nutrients and oxygen carried in blood). Though people are not always brain dead when they are declared dead, the brain will eventually die without life-support from the rest of the body or from life-support technology. Life-support does not always keep the brain alive though. The term "respirator brain" describes the decay of a brain that has mostly died while the rest of the body is kept alive. Terri Shiavo is the most recent, well-known case of a person whose body was mostly still alive, but whose brain's most vital functions had ceased (as evidenced by recent autopsies).

Death is thus an ambiguous process in which a body can collapse into stillness and silence and be considered dead, although most of the organs and cells of the body continue to live for a time. In addition, life can be extended beyond what is medically defined as death because a person can recover from extended heart, reflex, and respiration cessation as well as benefit from life-support that replaces bodily failure. The death of the brain is a more important factor to consider in whether a person is alive or dead because the brain dies in different parts and stages, having different effects on bodily and mental existence (indicating a clear relationship between the self and the brain). People with respirator brains have never fully returned to their normal selves. Those selves can be said to have died when the brain did, as the collected functioning organs of the entire brain maintain the normal functioning of the rest of the body through which the self is experienced. Without a fully functioning brain that helps the body to live, the sense of self is reduced. What matters in the case of Terri Shiavo is that the sense of self in this woman was greatly reduced - if it was there at all - because significant parts of her brain were dead and her body was atrophied. Medical technology can reverse bodily collapse and keep a body alive when it cannot otherwise live, but the lives of those on life-support can result in ethical ambiguity. This is because such a life can defy easy definitions of selfhood and illustrates that the medical definition of death is more a matter of admitting medical limitation: death is a matter of being beyond the help that available medicine currently offers (and may thus be postponed if a person has access to better medicine).

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