He was brought to the hospital with a massive heart attack, and when he did not die, his heart jolted back into motion by the full assault of the emergency code team, he lay suspended amidst machinery and slid into the dim terrain between life and death. He was not one of the famous ones: No reporters were called, no national ethicists consulted, no courts or civil liberties groups asked to intervene. He was just an intensive care unit patient with a lot of hospital equipment holding him away from death, and the only person who tended him all day long, who touched him and turned him and gazed for eight hours straight at what he had become, was his nurse.

He was on a ventilator. We were maintaining his blood pressure with medications. We were maintaining his respirations with machines. We were maintaining his urinary output with medications. In other words, we were making his body work . . .

But he did have some brain waves. So therefore legally we couldn't unplug him. And for three and a half days, his family was sitting out there. And we would turn him, you know, blood tests every hour, arterial and otherwise, to try and manage him. His arms became black-and-blue and swollen from all the pokes. We were having to get an arterial line in him so we could have some blood that way.

It just looked miserable. You feel like you're being very cruel.

They are not extraordinary anymore, these cases that so thoroughly complicate the old ideas about the saving of life and the coming of death. Nearly every month the newspapers carry some new dilemma in the difficult ethics of modern medicine. How much to intervene, when to decide against surgery, when to allow unimpeded death, how to distinguish between human life and the heart-beating stillness made possible only by machines -- these are questions that now pull a vast array of voices into the public argument.

You hear from physicians. You hear from families. You hear from attorneys who represent "right-to-life" groups, and attorneys who represent "right-to-die" groups, and judges deciding between them, and commentators reviewing the judges' rulings.

You hear almost nothing from the nurses, except as the occasional whistle-blower, who is often criticized afterward for going over physicians' heads. The nurses make no law. The nurses do not set the course of treatment, or decide when the treatment must end. The nurses make no life-or-death choices for these patients -- not publicly, anyway.

All the nurses do is cope with them, full time, over and over again.

All the nurses do is look square in the face, longer and more directly than anybody else in medicine or the law, at the effect of decisions that other people make.

The heart attack patient's nurse was a quick, dark-haired woman named Melissa Speers.

"He is called a one-to-one patient, which means you have one nurse to take care of this person. And it's an eight-hour job quite often. You go in and take care of all his vital signs, not only the obvious ones, but readings of the pressures in the arteries of the lungs and the heart, which we can do. Doing cardiac output studies on his heart . . . measure his urine output every hour . . . listening to his lungs every hour. Stethoscope. You have to sit the patient up, roll the patient over. Then you do a head-to-toe assessment.

"Start with pupilar reaction to light. Then you look for different cranial signs of nerve function. Watch for dilation . . . listen to their back, listen to their chest, listen to their abdomen . . . then, of course, you have to bathe them . . . and of course they're incontinent, stool a lot, so you spend a lot of time cleaning them up. You want to turn them at least every two hours -- these people, it's better at least every hour, because of their high risk of bedsores and pneumonia and everything else.

"Just about the time you've got all the readings and all the numbers down and you've turned him, it's time to do the readings and numbers again."

Speers is now 35, and although she still works at the large San Francisco hospital where the heart attack victim was a patient, she has moved to an administrative position. She couldn't take patient care anymore.

This part of the job, these days spent face to face with the darker side of the new technology, is much of why she says she quit.

"Burnout" is what nurses call it. There are a lot of reasons for nursing burnout: low pay, high stress, bad hours. But particularly in certain nursing specialties -- critical care, cancer care, newborn intensive care units -- ethical anguish has become a special weight of the past decade. Nursing schools, which once threw ethics into some broad single humanities course, if the subject was raised at all, have begun offering classes that let students discuss realistic case studies in ethical uncertainty.

A documentary film called "Code Gray," in which nurses caught on duty discuss real dilemmas facing them on the job, is being used for discussion among students and working nurses alike. Whole textbooks are now offered to help nursing students work through the moral difficulty of daily practice, and at a recent American Society of Law and Medicine-sponsored national conference in Los Angeles, a full day's agenda was devoted to discussion of the nurse's role and responsibility in ethical controversies.

"The ethical problems in nursing have just about mushroomed in the last five years," says Catherine Murphy, a Boston nursing professor who chairs the American Nurses Association's Committee on Ethics. "It's one of the most severe problems facing us now. We're on the front line in most of these cases . . . It's only the nursing staff who spends all that time with the patient."

"There may be a very strong, direct conflict between what the nurse thinks should be going on and what she's actually doing," says Christine Mitchell, a Boston nurse who served as associate producer and commentator on the film "Code Gray." "She's got, basically, moral schizophrenia."

As though that were not confusion enough, Mitchell says, a major thrust of nursing education in recent years has been emphasizing to nurses that their single most important mission is trying to act in the patients' best interests, and that they are different from doctors -- not subservient to them. "It's much easier for the nurse to avoid moral responsibility than it is for the attending physician, as long as she sees herself as an instrument of someone else's will," Mitchell says. But nurses learn just the opposite, she says. "All their nursing education is geared to telling themselves they are not someone's instrument."

And Melissa Speers was required, every day of the heart attack patient's hospital stay, to do what she deeply believed was not even remotely in his best interests. This is how she coped: She tried to keep him as comfortable as possible. She spoke to him whenever she had to touch or turn him, assuming that there was the faintest possibility he could still hear. She sang while she was bathing him -- "Stardust," she thinks it was, since he was in his sixties. And when he had been kept away from death for three full days, she and his other nurses asked his family to come into his room and watch what they had to do.

"We'd have them come and sit there in the room while we were performing these things on this person," she says. "We have a tendency to try and keep the family in as little pain as possible, and sometimes that's a wrong thing to do. I think you're denying them access to the person. I think you're denying them access to reality. The lay population has no idea of what can go on, what technology we have available."

It was the man's teen-age son who finally broke, she says. "About the third day he broke down crying, and I walked in, and he says, 'He's dead, isn't he?' . . . And I said, 'Well, he's not dead, but he's somewhere between -- he's not living.' And he just broke down and had a good cry, and I sat there and held him and let him cry. And he goes, 'Well, I don't think we should do this any more.' "

So the heroics stopped, Speers says. The patient stayed hydrated, with medications to keep his blood pressure up, but without more elaborate treatment his heart failed again. "We did have a 'no code' order on him by that time," she recalls, meaning physicians, with the approval of family members, ordered the hospital staff not to resuscitate him again. "So we just quietly let him go," she says. "Turned off the monitor and let the family be there with him."

Speers knows physicians also have a hard time with situations like these -- but at least they have an effect on the course of treatment. "The nurses don't. You have sort of no say in it." And she began to wonder sometimes what she was doing in the hospital at all. "I kind of felt that there became many times when I was not even being an advocate for the patient in performing these heroic acts . . . it's like there just is a refusal to believe that death is a part of living. You kind of forget that. The old, 'If you have it, you should use it.' And I don't think that's necessarily true. I think we have a real gap between our technology and our ethics, and that really bothered me. I've had patients say, 'Be my friend and kill me.' "

An elderly woman in Frances' intensive care unit in San Francisco was being kept alive after a heart valve replacement by constant resuscitation with an emergency drug. "It was physician-ordered, but the nurse is the one who administers the drug," Frances says. "It was steadily downhill. And the only thing that was really intact was her mind, and she made it perfectly clear that she wanted us to stop. In fact, in the end, I remember having to do CPR on her. And the feeling I had doing CPR -- she was so fragile, her ribs cracked. I just felt that I was brutalizing this poor woman. At least she was no longer conscious during those last few minutes. But it required a lot of compromise about my feeling about performing in an ethical manner."

She is 33, and has spent her entire nursing career as an intensive care unit nurse. She, like most of the other nurses who agreed to talk about this, has asked that her full name not be used. "When you have an adult, an elderly adult, who is not confused, who is lucid, and who reaches a point where they shake their head at you when they see you, or they turn from you -- when they all along have been cooperative, and have laid there while they get i.v.'s put in and that sort of thing -- and suddenly they reach a point where they try to pull everything out -- you know that you're going against that person's will. And that's real tough. In the case of this woman, yes, we started having to tie her hands down, so she wouldn't pull the tubes out of her mouth. None of us got into nursing because we like to tie people up."

Sometimes it is physicians who force the worst dilemmas on her, she says -- physicians who will not accept death, physicians who will not talk to nurses or ask their advice. Sometimes it is just the legal and ethical quagmire of the times. And sometimes she finds physicians' attitudes appalling and then comes to believe they were right -- she is remembering how she recoiled when she told a doctor how near to death a leukemia patient seemed to be, and the doctor said, "It doesn't matter what the patient or his wife wants -- we're going to treat him aggressively." But the patient recovered and is still alive and watching his young children grow up.

This is the case that still haunts Mary. She is a slender, 26-year-old Los Angeles neonatal intensive care unit nurse, which means her days are spent with seriously ill or disabled babies generally less than a month old. The baby she is remembering arrived in Mary's unit with respiratory distress; he was premature, born at 33 weeks, the first son of an attorney and a corporate vice president.

"What happened was, the baby didn't do very well," Mary says. "Three days and the baby was doing worse. Five days and the baby was doing worse. And instead of the settings on the ventilator going down, the settings on the ventilator were going up -- more oxygen, higher pressure, a higher rate, have to breathe for the baby faster."

The doctors told the parents their son was doing badly, Mary says. She says the physicians suggested a new ventilator treatment to give the baby very rapid, shallow breaths. "The parents said, 'Tell us what his neurologic prognosis is,' " she says. "And so they had a neurologist come in, and he made his diagnosis, and he had his partner come in, and she made her diagnosis. And they disagreed. One said he thought the prognosis was pretty good, and the other one said she didn't think it was so good. So on a scale of one to 10, one said eight, one said three. Well, with an average of five, you know -- so the parents were like, 'We're intelligent. We don't want to have a handicapped child.' . . . So they decided they didn't want the baby to have the treatment."

Mary knows how this sounds. The treatment itself is controversial, and she knows she was not the one being asked to gamble on a child who might come home severely brain-damaged for the rest of his life. She knows how disabled children can undo adults who cannot cope; how marriages dissolve, massive debts mount up, people go into counseling.

But she also knows the wide range of possibility for children with mental disability. She knows that in cases like this, nobody spends more time with the baby -- holding, feeding, stroking to make a baby less unhappy or afraid -- than the full-time nurse. And she knows it is not the parent who must pull the tube away and then clean the mouth to wait for the baby to die.

"The nurses just couldn't stand it," she says. "I was one of them. The doctors said that if they did this treatment, the possibility of the baby living -- he had a 50-50 chance. In my book, a 50-50 is -- why even question it? You do it, because half the chance you can, and half the chance you can't. Because my whole stance was, when you become pregnant, when you become a parent, you don't have a guarantee that your child is going to be wonderful. You don't."

The parents were firm. "Two days later the parents came to our director and said, 'We want him taken off the ventilator totally. And if he lives, then he lives. And if he dies, we know he should have died.' "

A meeting was called for the hospital ethics committee, one of the multidisciplinary groups that have begun working as advisory boards to hospitals faced with ethical uncertainty. Two nurses, including Mary, argued against removing the baby's ventilator, but the committee sided with the parents, based on the neurologic prognosis and the prediction that the baby would have chronic lung difficulty if he lived.

"So the parents decided they wanted to take the baby off the ventilator," Mary says. "And they came in, I guess it was the day before it was actually done, and said, 'We don't want to be here when you do it. Just do it.'

"And the nurses were like . . . Here you are, telling us, 'Let him die, but we don't want to be here when he does it.' And one of the nurses went up to the mother and said, 'What time are we taking him off the ventilator?' And she the mother just broke down and cried."

The parents decided to stay in the unit, Mary says. "They came in, and we put a little shield, a screen, around the baby. And they unplugged him -- the physician turned the machine off, and then took him away. And they watched him for about four or five minutes, and you could see that his respirations were very poor. And they said, 'They think he's going to die within a couple minutes.' So the mom and dad came in, and the nurse took the tube out of the mouth and cleaned off the face a little bit. And they held him, and he died in his mother's arms. And the nurses cried, I think, as much as the mother did."

Mary has thought about how she might have reported this case to the state; a law signed in October by President Reagan requires state child-protective services to establish procedures for assuring that disabled newborns are not denied appropriate and medically indicated life-saving treatment. One nurse did make a telephone call, she says, but too late to keep the baby under treatment. "I felt like my hands were dirty," she says. "I washed my hands so many times that day . . . I felt like I couldn't look the parents in the eyes any more.

"And it took so much -- after the baby died, his parents were in one of the physician's offices, and I went in, and I thought about what I was going to say to them before I went in. I was going to say, 'You guys have to live with your decision, and we support whatever you do,' but I thought about that. And I thought, 'Don't lie to her -- you don't support what she did.' And then I went in and I said, 'I think you guys are strong for making the decision you did.' And I gave each of them a hug. And I went out and cried."

The guilt works the other way, too. Hope is a northern California nurse-practitioner who helped keep alive a brain-damaged baby who survived a near-drowning. The baby is now a young boy, and when she thinks about the part she played in his care, Hope feels no pleasure or pride.

"He's like a corpse," she says. "He lies there and drools, and his eyes are partially open. He's expressionless. He has no movement, except for breathing. He's motionless. He has no muscle tone. You put him one way, and that's the way he stays. You forget to close his eyelids, and they stay open . . . It's a dread. It's not enjoyable. I think that when you get in touch with how it feels, it's extremely painful . . .

"There are reasons I chose not to go to medical school, and that's part of it. I wouldn't want to be ultimately responsible. However, to have no part in the decision making, and then to be put in the group of people who are caring for that child and dealing with that family's misery, and their confusion about -- are they supposed to come and visit every day, what do they do when they're there -- if they don't come and visit they're a wreck because they've had no closure, their child didn't die . . . And you feel extremely powerless.

"And when you do it all the time -- which is why people burn out, which is when you know it's time to leave -- it stops being painful. And you start making jokes. And you start basically ignoring it. It's like trying to clean your house -- you know, you do your tasks and you don't really think about what you're doing. I don't think anybody makes cruel jokes, but people relieve their tension. Better to relieve it through humor than through rage."