Its purpose is more modest. The rapid, and near universal, acceptance of neurological criteria of death is probably attributable to three factors. First, moving the time of death to an earlier point facilitates organ transplants, and indeed makes such transplants possible. Organs, especially hearts and livers, are suitable for transplantation only if they are removed at a time when blood is still circulating. Once cardiac arrest stops circulation, rapid tissue degeneration makes the organ unsuitable for such use.
Additional considerations involve triage and allocation of scarce medical resource.
Yet a third impetus towards redefinition is an understandable desire to spare families the agony and anguish of watching a loved one experience a protracted death. The principal utility of this second standard permits declaring as dead a comatose, ventilator-dependent patient incapable of spontaneous respiration but whose heart is still beating due to the provision of oxygen via an artificial breathing apparatus. At the outset, two points must be made absolutely clear. The cerebrum controls memory, consciousness, and higher mental functioning. A patient may be in a deep coma and nonresponsive to most external stimuli but still very much alive.