Brain Death

I'm glad we had a lecture on brain death. I think many people have some idea of what brain death means, but it's certainly an opaque topic. Brain death is a state equivalent to death. It is morally and legally permissible for a physician to withdraw life support from a brain dead patient; in fact, it may be ethically wrong to maintain a brain dead person on life support (unless they are awaiting organ donation). So what is brain death? Brain death is a state in which a person has no clinically measurable neurologic function. This requires the brainstem to be completely lost. The patient should have no pupillary, corneal, oculovestibular, or gag reflexes. They should be apneic (no breathing) and have no response to painful stimuli. They should not be on neuromuscular blockers or sedatives; their temperature should be normal. Sometimes an EEG is taken to document lack of brain activity (this criterion varies by state). There have been no cases of a person meeting brain death criteria later regaining consciousness. They can donate organs.

On the other hand, a person in a persistent vegetative state can appear awake. They may open their eyes, make movements, and demonstrate sleep-wake cycles. However, they are unconscious and unaware; there is no sign they can respond to outside stimuli. There are extremely rare cases of patients in persistent vegetative states that later regain consciousness. For this reason, these patients are not dead and it would be unethical for a physician to withdraw life support without consent.