ABOUT A YEAR and a half ago I nearly died in the main dining room of the Sheraton-Carlton Hotel.

I was eating a salad from the buffet when a piece of tomato slid down my throat with astonishing ease and stuck there. I could not breathe or utter a sound because my wind-pipe was totally blocked. All I could think of was: Only four minutes until brain damage.

I stood up and in the confusing seconds that followed signaled my two companions to call a waiter. My thought was he would get help - perhaps a doctor could perform an emergency tracheotomy.

Instead, the waiter ran over, wrapped his arms around me from behind, put his fist into my abdomen just below my rib cage and gave a quick upward thrust that lifted me slightly off the floor. He did it again and the piece of tomato flew out of my mouth, landing on the floor a good six feet away. I looked at it with amazement, some embarrassment and overwhelming relief that it had not been my fate, after all, to die in the Sheraton-Carlton that day because, as I discovered later, the management had trained all its waiters in the "Heimlich maneuver."

That set me off on a mission to find out why all waiters and waitresses are not trained in this maneuver. And that is how I stumbled into the middle of a medical feud between Dr. Henry Heimlich, the Cincinnati throat surgeon who originated the technique, and the American Red Cross.

Dr. Heimlich, well known in the medical community of innovations in chest surgery, had long been concerned about the number of choking fatalities and theorized that a sudden burst of air pressure up through the esophagus should expel an obstruction. He tested his theory on beagles in 1973 and found it worked. Almost immediately, Heimlich took his technique to the Red Cross, suggesting they use it cautiously at first to be sure it worked on humans.

The Red Cross, however, has not adopted and does not teach the Heimlich tehcnique, even though the maneuver has now saved thousands of people - Dr. Heimlich personally knows about of about 3,000 - and is endorsed by many public health officials and physicians. Instead,the Red Cross teaches a bastardized version of the maneuver which Dr. Heimlich charges is injuring and killing people instead of saving them. Dr. Heimlich has even forbidden the Red Cross to use his name in its materials. Consequently, the Red Cross calls its technique "the abdominal thrust."

Who's right, the Red Cross or Dr. Heimlich? The question is important because many states and cities are now adopting ordinaces requiring restaurants to instruct their personnel in proper choking first-aid. Some, like New York City, have adopted Dr. Heimlich's maneuver; others, such aas California, have gone along with the Red Cross. Others are confused: Illinois recently withheld 90,000 posters illustrating the Red Cross method because of the controversy.

Mainly at issue a choking victim on the back. For years the Red Cross has taught that a blow between the shoulder blades will loosen a stuck object. Thus, in 1976 the Red Cross adopted first-aid choking measures that combine the Heimlich maneuver and the back slap.

The reasoning was that the back slap would "loosen" the obstruction and the Heimlich maneuver would expel it. The Red Cross now recommends four back blows followed by four rapid-fire "abdominal thrusts," followed by more back blows and abdominal thrusts until the objection is expelled.

Dr. Heimlich finds the addition of the backblows outrageous. He claims there is no scientific evidence whatsoever for the effectiveness of the back slap, that it is an old wives' tale. "On the contrary," he says, "a back blow is likely to drive the object deeper into the windpipe, making it more difficult to retrieve." Further, he contends the addition of the back slaps is confusing, superfluous, a waste of precious time and even makes the "abdominal thrust" ineffective. He says the small rapid "jabs" taught by the Red Cross do not create the necessary explosive pressure of a true Heimlich maneuver.

Dr. Heimlich has numerous cases of the ineffectiveness of the back slap. In ne analysis of 910 lives saved by the Heimlich maneuver, he discovered that 135 victims had first been struck on the back without success. Of these 27 had fallen unconscious before the Heimlich maneuver saved them.

Dr. Heimlich and others have reported numerous tragedies in which back blows alone were used. In one instance a father pounded his teenage son's back for 40 minutes until the youngsters was dead. A restaurateur in Illinois says he was almost saved by the Heimlich maneuver when someone came up and slapped him on the back, forcing the food back down his throat, so the maneuver had to be repeated to save him. In Ohio, a 17-year-old boy frantically tried to save his 15-year-old brother who was choking on spaghetti by slapping him on the back; he died, although his would-be rescuer was Red Cross trained.

The Harrisburg case

Last September, a damage suit against the Harrisburg, Pa., school system was settled out of court for 352,000, after 15-year-old Gary Daniels, a retarded boy, choked on a peanut butter sandwich at school. The boy, nearly four years after the accident, is still in a coma. The suit alleged the school was negligent in not instructing teachers in the latest first-aid, including the Heimlich maneuver.

After one teacher slapped the boy on the back, he coughed up a bit of food, but soon fell unconscious and apparently suffered irreversible brain damage from lack of oxygen. Dr. Heimlich, in a deposition for the plaintiff, contended the back slap drove the food deeper into the boy's throat. After that, he said, even the Heimlich manuever, which was performed, was unable to do any good. Dr. Heimlich notes that in rare cases (he says he knows of six), notably when food is inhaled into the lungs, the Heimlich maneuver is not effective.

The boy's attorney, Richard C. Angino, says he did not make the Red Cross a party to the suit, but believes the Red Cross could be liable for negligence in future cases if it could be proved "they are promulgating procedures for which thre is no scientific basis," as Dr. Heimlich claims.

Since my accident and hearing Dr. Heimlich's arguments, I have asked the Red Cross several times for evidence on the effectiveness of its method. Its response goes like this:

The Red Cross is not a "medical" organization; therefore, it relies on "medical advice" from the National Academy of Sciences. An academy committee in 1976 recommended the procedures the Red Cross teaches, including backslapping. The Red Cross has no obligation to dispute, confirm or investigate the validity of the recommendations. By following the "consensus of the best medical advice available," supplied by the academy, the Red Cross is acting responsibly.

However, C. P. Dail, head of the Red Cross' national first-aid program, also referred me to the NAS committee report for "the evidence" on back slapping. I always look and never find it. In the report, there are 25 references that could be construed as evidence. But as Dr. Heimlich points out, 17 are unrelated to the back slap, seven provide evidence against the backslap and only one supports it. That is a study done on anesthesized baboons which Dr. Heimlich and other researches claim has no relevance to choking humans.

Dr. Heimlich repeatedly has sent letters to the academy asking for specific evidence on the effectiveness of back slapping. So has Cincinnati's Republican Rep. William Gradison on behalf of several congressmen. They don't get any satisfactory answers either. Of late, the academy replies it is "reviewing" the matter.

Surely, there must be an answer. If the Red Cross has convincing evidence somewhere on the effectiveness and safety of back slapping, it should present it, especially in light of Dr. Heimlich's persistent and persuasive attacks. A reputable organization like the Red Cross that enjoys the public trust should not hide behind bureaucratic buck-passing when lives are at stake. In the meantime, if I'm ever choking again I'd prefer my rescuer to forego the back slap. Just the Heimlich maneuver, please. CAPTION: Picture, Dr. Henry Heimlich demonstrates his method on Gov. Edward King in Boston. AP; Illustration, According to Dr. Heimlich, the backslap method promoted by this 1978 American Red Cross poster could kill choking victims rather than save them.