There used to be just one condition for a diagnosis of human death: irreversible cessation of breathing and heartbeat. In the 1970s, when organ transplantation was becoming more common and there was an increasing need for donor organs, doctors decided on another criterion for death: brain death, which isn't really death at all.
A patient certified as brain dead can be expected to be on a ventilator to enable him to breathe. He will breathe in oxygen and breathe out carbon dioxide. His heart will be beating. His body will be warm. If he is given liquids, he will urinate. He will digest food. If he is not turned regularly, he will develop bed sores. If he is not correctly positioned, he could develop pneumonia. If the patient is a pregnant woman, she can bring a baby to term. But a diagnosis of brain death allows the patient to be declared dead and his or her body used for donor organs.
The question of brain death is in the news once more with the story of an American woman who gave birth to twins almost a month after being declared brain dead, and with the remarkable - and unusual - story of Steven Thorpe. Seventeen-year-old Steven, from Kenilworth in Warwickshire, was in a car crash with two friends, one of whom was killed. He had serious injuries, and four doctors declared him brain dead. Doctors wanted to switch off life support and told his parents "You need to start thinking about organ donations." His parents refused.
They contacted a GP, who called in a neurosurgeon she knew. The neurosurgeon detected faint signs of brain activity. Two weeks later Steven woke up. Within seven weeks he was out of hospital.
There is one more thing that potential organ donors should be aware of. Potential donors, and next-of-kin whose permission is sought for organ removal, are led to believe that life support will be switched off and then the organs removed. In fact, life support is not switched off until after the organs are taken. (The only hearts, livers and pancreases that are used for transplantation are taken while the heart is still beating.) The fact that potential organ donors and next-of-kin are not told that vital organs are removed before life support is switched off is immoral.
As one former consultant cardiologist has put it, "The uncomfortable fact is that the brains of the so-called 'brain dead' are not truly and totally dead and the diagnosis does not exclude the possibility that some donors may retain or regain some form or degree of consciousness during the surgical removal of their vital organs. We just do not know."
Tests for brain death do not and can not prove lack of awareness.