September 23, 2013

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An Even More Stringent Definition

3. Cardiopulmonary death with the requirement that all activity at the cellular level ceases. Admittedly, this is an esoteric definition. Some chemical processes inside cells continue after the body has died. In 2012, researchers at the Pasteur Institute in Paris recovered live stem cells from bodies that had been dead and kept cooled for 17 days.[5] This view has few supporters.

4. Dead, but mechanically functioning. In this scenario, a patient's heart has permanently stopped beating and he has been declared dead. He has signed up to be an organ donor. However, once the respirators are removed and the patient "dies," he is hooked up to machinery that keeps the blood pumping so that the organs remain in good condition for an impending transplant.

Brain Death, or "Legal" Death

5. Brain death with no detected brain activity. The concept of "brain death" spawns the thorny and controversial concept of "person death" -- a person is considered dead because there's no detectable brainstem activity. What makes her "her" isn't there anymore.

In 1968, the Ad Hoc Committee of the Harvard Medical School to Examine the Definition of Brain Death issued a report published in JAMA. The report, which defined "irreversible coma" as brain death, stated that "an organ, brain or other, that no longer functions and has no possibility of functioning again is for all practical purposes dead."[6]

The diagnosis can be made on the basis of unreceptivity and unresponsivity (total unawareness to externally applied stimuli); no movements or breathing (observations by physicians should last at least 1 hour); no reflexes; and a flat EEG. (Of note, currently EEG is often not used in determining brain death.)

The report also notes that all of the above tests should be repeated at least 24 hours later when there has been no change in the patient's condition.

In 1980, the Uniform Determination of Death Act (UDDA) defined "brain death," and that definition was approved by the National Conference of Commissioners on Uniform State Laws. Most states have adopted that definition: the irreversible cessation of circulatory and respiratory functions, or the "irreversible cessation of all functions of the entire brain, including the brainstem."[7]

The UDDA states that patients may be pronounced legally dead either when they meet the traditional criteria for death (the cessation of breathing and the absence of a heartbeat) or when they are diagnosed as brain dead.


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