A set of criteria for determining when a brain is permanently nonfunctioning was formulated by an ad hoc committee at the Harvard Medical School in 1968.


Criteria for permanently nonfunctioning brain:

(1) unresponsive coma:

(1a) Coma is unresponsive when the most intensely painful stimuli do not evoke a vocal sound, withdrawal of limb, or change in respiration.

(2) apnea

(2a) If the patient is on mechanical ventilation, if the patient's carbon dioxide tension is within the normal range, and if the patient has been on room air for at least 10 minutes, then the ventilator can be turned off for 3 minutes and the patient observed for spontaneous respirations.

(3) absence of cephalic reflexes

(3a) Pupils fixed and dilated; ocular movements to head turning and cold water irrigation of the ears is absent; no blinking is seen; corneal reflexes are absent.

(3b) No evidence of postural activity; pharyngeal reflexes are absent; no evidence of swallowing, yawning or vocalization is seen.

(4) absence of spinal reflexes

(4a) No tendon reflexes are absent.

(4b) Plantar reflexes and responses to noxious stimuli are absent.

(5) flat or isoelectric EEG

(5a) Assuming proper electrode placement, functioning equipment and competent personnel.

(5b) Need to exclude any influence from the ECG.

(5c) Recording is for at least 10 minutes with over 20 minutes preferred.

(6) persistence of conditions for at least 24 hours, with no improvement.

(7) absence of drug intoxication or hypothermia

(7a) No evidence of CNS depressant drugs.

(7b) No hypothermia (body temperature < 90°F (32.2 °C)


Protocol for discontinuation of life support:

(1) The attending physician should determine the patient's condition, along with at least one other experienced physician involved in the case.

(2) The family or next of kin, and the health care professionals involved in the case should be informed.

(3) Death is declared

(4) The respirator and other life support systems are then turned off.


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