If Karen Ann Quinlan had been admitted to the Massachusetts General Hospital, the judge who ruled this week that she could not be taken off an artificial respirator never would have gotten to make his decision.

The reason is that Mass General Hospital, under a report from its committee on Optimum Care to the Hopelessly Ill, set up guidelines in September for the removal from expensive life support of patients whose brains no longer function.

The guidelines suggest that in a case like Quinlan's--where the patient shows no signs of recovery but is taking up valuable space in an intensive care unit--the patient should be allowed to die.

Doctors at Mass General say that the process cannot be called euthanasia, because patients like Quinlan are dead already, even if they breathe and have a pulse.

"For God's sake, that has nothing to do with what your view or my view of life is," Dr. Alexander Leaf, Jackson Professor of Clinical Medicine and director of medicine at the Harvard teaching hospital, says. "We're not talking about someone lying comfortably in bed and some brute comes along and ends their life."

But doctors at the three major Harvard teaching hospitals--Mass General, Peter Bent Brigham and Beth Israel--agree that "passive euthanasia" goes on all the time. Passive euthanasia is the death of a patient under a decision by the physician not to treat him aggressively, and it occurs through unofficial but established procedures.

Those procedures include labelling a patient "DNR," for "Do Not Resuscitate." DNR refers specifically to the prospect of cardiac or pulmonary arrest in a dying patient, and when a patient is designated DNR, it means that he is not to be resuscitated if he suffers an arrest.

"If his heart stops, you don't want ten people in the room jumping up and down trying to resuscitate him so he can live another week with his cancer," Dr. John W. Rowe, chief resident in internal medicine at Beth Israel, says.

Resuscitating a patient may cost a hospital as much as $1000, and can mean committing that patient to intensive care at even more cost.

DNR patients are usually elderly, but they are always dying, and doctors say that to prolong their lives is expensive and painful to physicians, nurses, family and the patients. The designation applies to as many as two patients on a ward of 40, they say.

DNR designation is part of what doctors say is a larger pattern of nonaggressive treatment of moribund patients. "You have a patient, 90 years old, with metastatic cancer; he's dying. What DNR means to physicians is, 'Look fellas, no heroics. Let the poor guy die in peace,"' Dr. Mitchell T. Rabkin, '51, associate professor of medicine and general director of the Beth Israel Hospital, says.

Other doctors, including Paul S. Gerber, a senior resident at Beth Israel, say that such measures saddle the physician with a painful decision, on whose life should be prolonged and whose should not.

Gerber says that the decision is a real burden, that he ends up having to "judge the quality of a patient's life."