At the extreme end of the spectrum of unconsciousness, is coma. Whatever the cause, whether head injury, a stroke, a tumour or a drug overdose, the condition is characterized by the unresponsiveness of the patient to any of the usual methods employed to stimulate consciousness, while, at the same time, vital organs can be kept functioning so that the casualty does not die.
A coma may last for a few hours, days or, in some cases, years. Advances in medical science have meant that some people in a deep coma who would have automatically died even a few decades ago can now be kept alive by artificial means until virtually the time they would have died a ‘natural’ death if it had not been for their injury. Breathing and heartbeat can be taken over by a machine, and fluid and nutrients introduced intravenously.
This has, naturally, raised various ethical issues. There are many recorded cases of patients who have come out of a coma several years after they first lost consciousness. Often, the stimulus has merely been the playing of a favourite song, or a recorded message from an admired celebrity. But what of the patient who has been in a coma for ten years or more, for whom the regaining of consciousness seems less and less likely? Should they be kept on a life-support system indefinately? Is it just that other people may be denied treatment that would improve the quality of their life because of the cost of keeping one person alive who is not aware of the fact? All these questions, and others, need to be faced with increasing urgency by both the medical profession and society.