It’s Thanksgiving Day and your family is seated around the dinner table, enjoying ample portions of turkey, stuffing, mashed potatoes and cranberry sauce. Amid the cacophony of chatter, laughter and clinking silverware, your Uncle Bob suddenly lurches to his feet, his face beet-red as he clutches his throat and gasps for air.

Someone immediately dials 9-1-1 as your Aunt Janice rushes to his aid. She clutches Bob from behind, balls up her fist in his abdomen, leans him forward slightly and gives him a few quick, upward thrusts just above the navel. Within seconds, a large chunk of white meat sails across the dinner table. A sense of collective relief spreads through the room at the disaster that was narrowly averted.

For more than three decades, the gold standard for treating a choking victim who is still conscious has been the “Heimlich maneuver” — a first-aid procedure made famous by its namesake, Ohio chest surgeon Dr. Henry Heimlich, and by countless depictions in movies and television shows. According to the Heimlich Institute of Cincinnati, the maneuver has saved tens of thousands of people.

The American Red Cross, however, recently changed its first-aid protocol to de-emphasize the use of the Heimlich for treating a conscious choking victim. According to Mike Higgins, manager of community preparedness education at the northern Vermont chapter of the American Red Cross, the new protocol recommends calling 9-1-1, then giving the person several sharp blows to the back, right between the shoulder blades, with the heel of the hand. If this doesn’t clear the obstructed airway, “abdominal thrusts” should be tried next, alternating with repeated back blows, until the person breathes freely or loses consciousness.

The American Red Cross now teaches both procedures as part of its CPR and first-aid classes, and is currently revising the informational posters, pamphlets and wallet cards it gives out to restaurants and the general public. And, in keeping with the advice of most national emergency-responder agencies, the Heimlich maneuver is no longer advised as useful or beneficial for helping a near-drowning victim.

Why the switch? According to Higgins, the Red Cross reviews its first-aid protocols every five years, and it determined recently there’s no evidence the Heimlich maneuver works better than back blows. Interestingly, the Red Cross doesn’t even call it the “Heimlich maneuver” anymore, but uses the more anatomically descriptive “abdominal thrusts.” Higgins explains that the name was changed to reflect how the procedure works physiologically.

But according to someone who’s also quite familiar with the procedure, and with Dr. Heimlich himself — his son, Peter Heimlich — the change is a result of growing questions about the maneuver’s safety and effectiveness, as well as the credentials of Dr. Heimlich himself. Bluntly put, the younger Heimlich has repeatedly accused his father of being “a fraud” and “one of history’s great medical charlatans,” while also dismissing his lifetime’s medical research as “completely bogus.” Peter Heimlich also accuses his father of stealing credit for the maneuver, which he claims was actually invented by another researcher.

If someone is choking, your first instinct is to give the Heimlich Maneuver.

And why not.

It’s ingrained in our minds.

The Heimlich Maneuver’s been taught for over 40 years.

But, new research shows you’re not supposed to react to a choking person that way.

Surprised?

Even Red Cross Instructors, like Laural Harder say it didn’t feel right.

“I did question it. I was a little surprised,” says Harder.

Harder says now, you’re supposed to use 5 back blows first.

Peter Heimlich has a Web site, http://medfraud.info, dedicated to skewering his father’s medical accomplishments. He also has waged a campaign that takes aim at his brother’s political career, often contacting the news media and medical officials using pseudonyms.

“He went to a great deal of trouble to disguise his identity,” said Bob Kraft, spokesman for Hank Heimlich.

In 2001, there was a family argument, Kraft said. At that time, in a telephone conversation, Kraft said, Peter Heimlich told his father, “I am going to destroy you.”

Peter Heimlich refused to answer questions, but his attorneys said their client’s goals are pure.

“Basically, he wants the record to be straight,” Peter Heimlich attorney Lou Sirkin said.

“His motivation is not to demean his family in any way,” said Jennifer Kinsley, also a Peter Heimlich attorney.

The family considers the matter private.

“It’s a subject that gives me great pain,” Jane Heimlich said. “I hope you will understand that I would prefer not to discuss it.”