The 57-year-old man entered the emergency room at 2 a.m. with a massive heart attack. By dawn he rested comfortably in the intensive care unit while his sleepy-eyed physician sat in the nurses' station typing orders for his medications into the computer terminal: diuretics to remove fluid from the body, nitroglycerin to widen the coronory arteries and digitalis to strengthen the battered heart's contractions.

But before the doctor could finish punching in his orders, a warning flashed onto the computer screen: "Alert," it read. "Tests show low potassium levels in the patient's blood. Advise potassium supplements to prevent digitalis's toxicity, which could be fatal."

"That's right," the doctor sighed, as he added potassium to the list. His weary mind hadn't considered the blood potassium levels. But the computer did.

This kind of interaction will become more common as computers like HELP -- for Health Evaluation through Logical Processing -- join the technological revolution in medicine. The first medical "smart computer" to leave the artificial intelligence lab, HELP is now dispensing advice -- or will be soon -- to doctors in community hospitals in New York, Utah and North Carolina. Control Data Corporation of Minneapolis, Minn., which began marketing HELP last January, expects to install 25 more HELP systems next year.

These systems were built to aid -- not replace -- doctors, says Dr. Jack Myers, former chairman of medicine at the University of Pittsburgh and co-creator of CADUCEUS, a computer system designed to help diagnose some 800 diseases. They are increasingly needed because "in any broad field, like internal medicine or pediatrics," he says, "the clinical knowledge base is now so vast that no single human brain can encompass it . . . and it is going to get increasingly worse in the future. We have got to have some way to store, retrieve and manipulate this great mass of medical information."

In a sense, HELP acts as a flexible checklist for doctors. The computer is programmed to react to the changing condition of the patient as the disease progresses or as new laboratory tests or information become available.

Here's how HELP works: The computer automatically collects information about the patient from a medical record entered into the computer system. This record includes the patient's history and physical exam, the doctor's and nurse's notes and data about the patient from monitoring equipment -- like an electrocardiogram -- and from laboratory test machines -- like an automatic blood analyzer or an X-ray.

HELP doesn't wait for the doctor to ask a question, notes the system's main author Dr. Homer R. Warner, chairman of the department of medical biophysics and computing at the University of Utah School of Medicine in Salt Lake. As information comes in, HELP analyzes it and immediately begins asking for more information, suggesting tests, offering a diagnosis or reacting to the doctor's treatment plan by warning of drug interactions, patient allergies or other potential problems.

The doctor doesn't have to take the computer's advice, Warner points out, but he or she will have to explain in the patient's record why the advice was ignored.

A study at LDS Hospital in Salt Lake City showed that doctors usually take the system's advice. LDS doctors changed their prescriptions 80 percent of the time after receiving a drug alert from the computer.

HELP also performs administrative jobs -- such as admissions, discharges, billing and inventory -- now assigned to traditional hospital information systems.

This total system approach led two community hospitals -- Arnot-Ogden Memorial Hospital in Elmira, N.Y. and Rex Hospital in Raleigh, N.C. -- to give HELP a try.

"It gives the poor guy out in the boondocks a little bit of help," says Dr. Gerald P. Schneider, a 62-year-old internist and the driving force behind getting HELP into Arnot-Ogden hospital last year. Doctors in Elmira don't have university experts to call on when they have a tough case, Schneider points out.

HELP's assistance is not just medical.

"It paid off big," says William Ritter, vice-president for finance at Arnot-Ogden, which spent $1.5 million to buy the first commercial HELP system. HELP already has saved the hospital $1.8 million in charges to patients which normally are lost in the shuffling of paperwork, he says. It also cut the time a patient stays in the hospital by half a day, and is expected to cut another day next year.

Despite the technological and financial advantages, HELP raises complex social and legal concerns. One of the most crucial is acceptance by physicians who worry about a machine making medical decisions.

"I would not accept the standard of care that is implicit in a computer program," says Ted Bartlett, a medical philosopher at Case Western Reserve University School of Medicine and the Center for the Critically Ill. "There is no judgement there. There is just the computation of some parameters."

Bartlett also fears that the computer could dehumanize medical care. "It leaves out how the patient feels," he says, "including pain or any of the subjective things that bring people to see doctors."

But Dr. Robert Kanich, a pathologist and vice-chairman of the computer committee at Rex Hospital -- which will turn on its HELP system in January -- disagrees. "Our goal is that the computer will free up nursing time and physician time," he says, "so that they will have more time to talk with the patient."

Asserts Phillip G. Martin of Control Data: "We try hard not to represent this thing as taking over any part of the doctor's job, which we don't think it does. We never countermand the doctor's orders regardless of whether it agrees with what we think ought to be going on."

"It has been viewed here as more of a help than a hindrance," says Arnot-Ogden's Ritter. "The doctors are very keen to know everything that they can about their patients."