The patient, only 35, had been in a persistent vegetative state for 15 years. Recently, he had developed septic bedsores and pneumonia. His kidneys were failing, and despite the feeding tube, he was losing weight. Now he was in cardiac arrest. He was dying.

But the young staff doctor had no choice. The patient's relatives, convinced that the man could communicate, had insisted that all revival efforts be made. So the doctor gave the patient a few mouth-to-mouth breaths, climbed on the bed and began vigorous chest compressions, trying cardiopulmonary resuscitation.

The patient was intubated, shocked with electric paddles and injected with epinephrine. Blood spurted as a central line was inserted into the large vein in his groin to administer medicine and fluids. EKG electrodes were placed on his arms and legs: Streams of paper spilled over the floor, as the hospital room filled with people and shouted orders.

After 15 minutes, the doctors called the time of death.

"Kneeling on that bed, doing CPR, felt not only pointless, but like I was administering final blows to someone who had already had a hard enough life," said the doctor, Daniel Sulmasy, now a New York internist, medical ethicist and Franciscan friar, recalling this experience from his internship. "Why was I forced to crack this person's ribs? Why couldn't we have let the patient die in peace?"

To be sure, extreme cases like this one are rare. But the question of who has final say over whether CPR should be attempted on a gravely ill patient — the doctor, the patient or the patient's representative — is live and unsettled in law and medicine.

Many doctors believe that their medical judgment about whether CPR will be effective in a particular patient's case and their knowledge of the havoc that CPR can wreak on a dying body should prevail. But a patient's representative, who is often a relative, may believe that every medical option should be exercised and that a miracle could be just a chest compression away. And patients' families, spurred on by TV medical dramas, often mistakenly believe that CPR is almost always effective — a notion emphatically disproved by studies.

The debate over who makes the decision raises fundamental challenges to medical integrity as well as to patients' rights, and can rub feelings raw for all concerned. Hospitals around the country and some state legislatures have wrestled with how to balance these competing values, reaching different conclusions.