This is what is eventually go to happen!
In January 1983, twenty-five-year old Nancy Cruzan lost control of her car as she traveled down a Missouri road. The car overturned, and she was discovered, lying face down in a ditch, without detectable respiratory or cardiac function. Emergency medical technicians were able to restore her breathing and heartbeat, and she was transported to a hospital in an unconscious state. A neurosurgeon there diagnosed her as having sustained probable brain damage, compounded by significant oxygen deprivation. The estimated length of the period without oxygen was twelve to fourteen minutes. (Permanent brain damage generally results after six minutes without oxygen.) Cruzan remained in a coma for approximately three weeks, and then progressed to an unconscious state in which she was able to orally ingest some nutrition. In order to ease feeding and further her recovery, surgeons implanted a feeding and hydration tube with the consent of her then husband. In October 1983, she was admitted to a state hospital. Subsequent rehabilitative efforts proved unsuccessful. It became apparent that she had virtually no chance of regaining her mental faculties, and her parents—who had been appointed as her co guardians—asked the hospital to terminate the medically assisted nutrition and hydration procedures. The hospital refused to honor the request without court approval.
The United States Supreme Court upheld that ruling. It found that due process was not violated by the Missouri requirement that an incompetent person's wishes in regard to the withdrawal of life-sustaining treatment be proved by clear and convincing evidence. In the end, however, further witnesses satisfied Missouri courts that such clear and convincing evidence of her wishes did exist, and medically assisted nutrition and hydration were removed in December of 1990. Cruzan died two weeks later. Missouri now allows health care directives (though not living wills) to instruct that medically assisted nutrition and hydration be removed after a diagnosis of permanent or persistent vegetative state has been made.