231 pp., $5.95.

HOW COULD the author of The Andromeda Strain and Dealing write something like Five Patients? After all, Five Patients is supposed to be a serious expose of hospital mismanagement, AMA intransigence, and technological innovations in medicine, isn't it? Actually, author-doctor Michael Crichton has performed no mysterious feat- Patients is just as conversational and dramatic as his other novels; it is written for the ignorant layman and contains just enough intelligent information to fool the reader into thinking that the compelling mystery he is reading is a technical account of hospital life.

In typical Crichton fashion, the book simulates accurate situations. Dealing talks about real-life facts of dope traffic and real human relationships. Patients similarly contains accurate descriptions of some hospital cases and even contains a few serious editorial points. But on the whole Patients resembles a magic act more than serious journalism: There is an air of revelation, mystery, and well-kept secrets throughout the book as "The Hospital Explained" pops out of the sleeve, flashes before the audience briefly and then disappears behind the back once more. People in the medical field, or anyone who knows hospital routine, will find the trick stale and superficial-they know as much as the magician-but the marks go wild.

There are a lot of serious faults in present-day medical care and delivery. The large hospitals are going through convulsive changes as the medical profession redefines its role to fit modern needs. The huge size of the problem and the large amount of money required to tackle it are delaying most hospitals from making the necessary rapid changes, but a revolution in health care is not far off: Decentralized medical delivery units will begin to serve the entire community; health organizations will provide comprehensive facilities and financing for medical care; medical practice itself will be reorganized as groups of specialists become coordinated, as nurses and nonprofessional health workers take over routine hospital treatments and even diagnoses; the strategy of disease treatment will change as chronic, addictive, and social psychological diseases are identified; and new methods of medical research will apply technological advances to health care while reevaluating patient-doctor relationships. Much of this will take place in he next few years.

MICHAEL CRICHTON, as a fourth-year student at Harvard Medical School, spent a lot of time in Mass. General Hospital. The MGH complex is better equipped and more innovative than most hospitals in this country and is thus generally able to adapt to changing conceptions of health care. Along with the other health care workers in the hospital, Crichton was in the midst of the practical turmoil of a hospital facing rapid change. Crichton, already a successful fiction writer by his senior year, decided to write about this experience. It's a good idea, really; it's just too bad that Crichton played to the public appetite and wrote a book which hides simple technology in the mystique of medical miracles and too bad that Crichton got carried away with the drama of medical cures at the expense of discussion of serious aspects of the health care problem.

Crichton's drama follows five patients (surprise!) whose bodies find their way into the hospital for various reasons. Patient one is a construction worker who is rushed into the emergency ward after an accident. His heart has stopped and the medical teams try bravely to save his life, but fail. Following a dramatic account of the medical effort, Crichton offers a heavy dose of "what this all means" in the context of a changing hospital system. "What this all means" unfortunately has little to do with modern health care and has even less that is not so obvious as to be trivial.

Crichton uses the example of this guy's death to illustrate modern hospital technology. Sort of.

Crichton uses the example of this man's death as opposed to the painful operations of the last century, and hospital procedure has therefore been transformed. Moving quickly along, Crichton suggests that hospitals are larger now than they were before, that they now are clean, that there is now a wide variety of drugs to use in medicine (a great improvement over 1821 when snakeskins were part of the pharmacopoeia-a substance of doubtful value, according to Crichton) and that in general medical care is now more complex.

That's the end of chapter one, and fortunately the book goes a little uphill from there. The climb is excruciatingly slow, however, as Crichton continues to belabor obvious common sense facts and describes the medical cases in technical banalities.

THERE are a few worthwhile passages. A section on hospital costs is interesting: Part of a hospital bill is reprinted showing the incredible expenses involved in health care, and Crichton adds an intelligent, if brief, comment on forms of health insurance. It's in this section, too, that Crichton takes a swing at the AMA with an attack that has been quoted by reviewers who think Crichton is a serious Harvard Medical student:

For the past forty years, the American Medical Association has worked to the detriment of the patient in nearly every way imaginable; It is a peculiarity of this organization that it has worked to the detriment of physicians, as well.

Another useful section describes some of the computer diagnostic and history-taking apparatus that the MGH is now using.

Crichton even occasionally attempts to discuss the serious aspects of the health care revolution, but consistently keeps his arguments superficial; Patients must be excused as pure entertainment. Medicine holds a certain mystique for many readers, and fictional suspense can be fun; Crichton has thrown together some fictional medicine and a lot of dramatic suspense, added just enough facts to prove that he once was a med student, and come up with Patients, a book that offers the casual fiction reader a quasi-intellectual form of entertainment.

Crichton, now living in La Jolla, California, has abandoned a medical career and is writing full-time. Before reading Patients, the reader should take the hint. Crichton is his own best critic.