Warmed From Inside Out : Hypothermia Victims--Doctors Cheating Death

Not many years ago, rescue workers who found people in snowbanks or floating in cold water would take one look at the victim’s blue-gray pallor, icy skin, stiffened limbs and undetectable heartbeat--and call the coroner.

But since the 1970s, when a few daring doctors became convinced that such victims could be revived despite the classical signs of death, the list of individuals who have been brought back to life has grown steadily.

The most recent case was that of a 2-year-old Milwaukee boy named Michael, who last month wandered out of doors in weather that was 22 degrees below zero, wearing only his pajamas. He was found lying in the snow with no heartbeat, respiration or other apparent signs of life.

Administering the kind of high-tech medicine that allowed them to slowly warm his internal organs and restore their normal functioning--in essence, warming him from the inside out--physicians at Milwaukee’s Children’s Hospital managed to save Michael, and now expect him to recover with no major problems.

Michael’s case was dramatic, but his condition--hypothermia--is not uncommon, even in milder climates such as Southern California’s. Hypothermia occurs when the temperature of vital internal organs drops 3 degrees Fahrenheit below normal.

In famine-stricken Ethiopia, for example, 40-degree nights can induce hypothermia easily in thin, undernourished people who lack both sufficient warm clothing and natural body fat to keep them warm, according to Neil Ross, a University of Rhode Island authority on hypothermia.

The same problem exists for homeless people in the United States who spend the night on the cold pavement or ground.

The elderly, even those who live in houses or apartments, are exceptionally vulnerable to hypothermia, experts say, because heat control centers in the brain lose their sensitivity with age. Older people who do not eat regularly or are on medications that reduce the ability to sense cold are especially vulnerable.

‘Can Die at 65’

“Even in Los Angeles, you can die of hypothermia at 65 degrees,” Ross said.

Experts now agree that restoring normal body temperature in a manner that does not trigger lethal physiological reactions is the most ticklish stage of revival in people who are hypothermic.

The problem is to find ways to rewarm the body while avoiding a complication called cardiac fibrillation. Lowering the heart’s temperature more than a few degrees can cause it to fibrillate, or lose its ability to pump blood. The result is heart failure and sudden death.

In the past, before researchers had learned as much as they now know about hypothermia, rescuers sometimes unknowingly performed treatments that killed rather than cured.

During World War II, for example, doctors in the British Royal Navy became puzzled when sailors, dunked in the cold waters of the North Sea after their ships had been torpedoed, would seem healthy and happy for an hour or so after rescue--then die.

Alcohol Suspected

Today, it’s still not clear why these so-called post-rescue relapses happened, but it is suspected that the Royal Navy’s habit of immediately giving survivors a tot of rum may have been a factor.

John Bernhartsen, chief of boating safety for the U.S. Coast Guard, tells a story of how a British warship once rescued 200 German sailors from their sunken vessel and, according to custom, gave each a shot of rum. An hour or two later, nearly half of the Germans were dead.

Bernhartsen said it is suspected that the depressant effect of alcohol on the nervous system may have caused too quick a reversal of the survival reflex that occurs whenever the body experiences hypothermia. Because the peripheral parts of the body lose heat very quickly, the reflex kicks in to shut off the flow of blood to the skin, legs and arms and shunts the blood to the heart, lungs and brain.

If the circulation to restricted areas returns to normal too quickly, the danger is that the warm blood in the internal organs will flow to the cooler peripheral parts of the body, become cooled and return to the heart as cold blood, causing it to fibrillate.

Warm Fluids

It is partly because of physiological findings such as this that Michael’s doctors focused on warming the heart, lungs and brain first before concentrating on his arms and legs. These techniques consisted of flowing warm fluids into Michael’s abdominal cavity, warm air into his lungs and by pumping his blood through a heart-lung machine to warm it before passing it back into Michael’s circulation.

If they had warmed his outside first, said Dr. Thomas Rice, one of the physicians, the lactic acid that is released from surface areas under those circumstances could have triggered fibrillation in the boy’s cold heart.

Rice and other experts contacted by The Times said they believe another reason for Michael’s successful revival was the extremely low temperature to which he was suddenly exposed.

The wind-chill factor where he was found was 66 degrees below zero. This caused a very rapid cooling of his body, slowing down his body’s metabolic rate and resulting in a drop in the need for oxygen by his brain and other organs. Therefore, the fact that his heart did not beat and he did not breath regularly was not so critical.

Cold Water Cases

Much of the new knowledge about hypothermia and how to reverse it has been gleaned from cases that occurred in cold water.

Technically, the definition of cold water is 70 degrees F., or 28 degrees below normal body temperature. But experts say that even colder water--how much colder they are not sure--seems to increase the chances of survival because the rate of cooling of the brain and other organs is faster.

“When I went to med school in the early ‘70s, we were taught that four to six minutes under water would result in certain brain damage,” said Dr. Martin J. Nemiroff, a Coast Guard flight surgeon and one of the nation’s leading authorities on treating cases of hypothermia. “Now, we know they have a chance after up to one hour under (cold) water.”

Nemiroff, who is stationed at the Traverse City, Mich., Coast Guard Air Station, has collected 40 cases of people who have survived after being submerged for long periods of time. Several of these cases, in which Nemiroff was personally involved, are cited by experts as turning points in medical thinking concerning the survivability of hypothermic victims.

Girl in Ocean

One case, which occurred when Nemiroff was stationed in Kodiak, Alaska, involved a 3-year-old girl who had been in the cold ocean waters for more than one hour after a fishing boat capsized.

Nemiroff said that the girl’s mother, convinced that the baby was dead, had cast her adrift. But a Coast Guard helicopter plucked the child out of the water and after a 30-minute flight, landed at a hospital where the doctors got her to respond to treatment.

Infants and small children have the best survivability in cold water, Nemiroff said, because the survival reflex that causes blood circulation to be confined to vital organs appears to be more pronounced in children than in adults. Incidentally, this reflex, called the “diving response” in sea mammals, is the reason that seals and whales can remain submerged for long periods without suffering ill effects due to oxygen deprivation.

Another hypothermia expert, Dr. Robert Pozos, chairman of the department of physiology at the University of Minnesota School of Medicine, is studying the differences between victims of hypothermia who survive and those who do not.

Small and Thin

Small people with little fat have the best chances of surviving a drowning in cold water, he said, provided someone is around to rescue them and get them to a proper medical center before too much time has elapsed.

Although all the data is not in, it appears also that individuals who gulp in the cold water quickly may have a better chance of surviving. Animal studies have indicated that this may be because the heart continues pumping blood for about five minutes after submersion. This means that the cold water that has been gulped into the lungs cools the passing blood, which in turn cools the brain and heart and enables them to survive longer without oxygen.

According to Nemiroff, it used to be thought that the treatment of such cases should focus on reestablishing the levels of minerals, called electrolytes, in the blood. Failing to do so, it was believed, was the major reason why some hypothermia victims did not revive.

But in 1977, he said, it was discovered that the electrolytes in humans are normal after drowning. Since then medical attention has focused on oxygen needs rather than electrolytes, and the success rate has improved.

Brain Damage

As with cardiopulmonary resuscitation after a heart attack, there is always a danger of resuscitating an individual whose brain has undergone a degree of damage and who will experience lifelong neurological damage.

“The problem is that we don’t know until they warm up,” Pozos said. “It depends on how cold the brain got and how long it was without oxygen.”

Pozos predicted that it will take a generation before doctors have enough information available to develop a good rule of thumb that will determine the chances of brain damage when reviving such patients.

‘When I went to med school in the early ‘70s, we were taught that four to six minutes under water would result in certain brain damage. Now, we know they have a chance after up to one hour under (cold) water.’

--Dr. Martin J. Nemiroff

Coast Guard flight surgeon