Brain Death: You're Legally Dead Despite Your Beating Heart

What Is Death?

If one insists that "death" must be defined as cessation of all vital functions, including the beating of the heart, then one must return to a pre-1968 medical, social, and legal ethos. One difficulty with this point of view is that modern life-support methods may be quite successful in prolonging "life" more or less indefinitely in people who have no chance of return to consciousness.

In recognition of the implications of this new concept of brain death, the authors recommended that physicians involved in the declaration of death eschew participation in organ transplantation, "in order to avoid any appearance of self-interest..."^[3]

Practical Considerations

For organs to be useful for transplant, they must be relatively intact. Prolonged hypotension with poor organ perfusion and oxygenation at the end of life may severely damage organs, rendering them useless for transplant. Ascertainment of brain death in an individual who has previously consented to organ donation allows for planned discontinuation of life support with resultant cessation of cardiac function, in a carefully orchestrated process termed "donation after circulatory death" (DCD). Prompt assessment and determination of brain death can preserve organ viability and facilitate successful transplantation.

Although such practical considerations should not be foremost in an argument on the appropriateness of brain death criteria for transplant, the fact that organ donation is an altruistic act that may save another individual's life should not be ignored.^[2] Even the Harvard Ad Hoc Committee's 1968 article acknowledges "those in need of hospital beds already occupied by these comatose patients" as a justification for updated brain death criteria.

Current Brain Death Guidelines

The American Academy of Neurology (AAN) published a Practice Parameter for determining brain death in adults in 1995,^[4] which was updated in 2010.^[5] The 3 key features that characterize brain death are coma, absent brainstem reflexes, and apnea.^[4]

Consistent with the concepts proposed in the Harvard Ad Hoc Committee's 1968 report, the current brain death criteria do not require heartbeat cessation. Brain death does require cessation of respiration, however. In addition, the neurologic examination must not be confounded by hypothermia or drug intoxication.

The following points summarize the guidelines for brain death:

1. Establish irreversible and proximate cause of coma.

2. Neuroimaging explains coma.

3. Exclude central nervous system depressant effect.

4. No evidence of paralytic drugs.

5. Absence of severe acid/base, electrolyte, or endocrine abnormality.

6. Normothermia or mild hypothermia (core temperature > 36°C).

7. Systolic blood pressure ≥ 100 mm Hg.

8. No spontaneous respirations.

9. Pupils nonreactive to bright light.

10. Absent corneal reflexes.

11. Absent oculocephalic reflexes.

12. Absent oculovestibular reflexes.

13. No facial movement to noxious stimuli.

14. Absent gag reflex.

15. Absent cough reflex.

16. Absent motor response to noxious stimuli in all 4 limbs.

17. Negative apnea test.

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Cite this: Brain Death: You're Legally Dead Despite Your Beating Heart - Medscape - Sep 23, 2013.