People suffering hypothermia after immersion in cold water should be kept horizontal so their hearts work properly, doctors advised Friday.
They can also be warmed up successfully using a new invention that envelops them in warm air, another group of doctors reported.Mark Stoneham of the Stoke Mandeville Hospital in Aylesbury, southern England, studied the cases of people who had been immersed in icy seas, lakes, or rivers.
"When a person is immersed in water, he not only loses heat more rapidly than when in air at the same temperature, but also the water exerts a hydrostatic pressure effect similar to that experienced by jet pilots wearing an anti-gravity suit," Stoneham wrote in a letter to the Lancet medical journal.
"On removal from water, this hydrostatic pressure effect is lost, resulting in a rapid fall in venous return (of blood) to the heart and thus a fall in blood pressure; this is believed to precipitate sudden cardiovascular collapse."
Citing several cases in which fully conscious people were rescued from frigid waters after ship wrecks, only to collapse and die once safe, Stoneham said victims should be kept horizontal to stabilize the heart.
"Air-sea rescue crews are now being advised . . . to lift subjects from water horizontally with a modified double strop, which should help to reduce this cardiovascular collapse," he said.
Dr. P. Mair and colleagues at the University of Innsbruck School of Medicine in Austria said they had tested out a new device that re-warmed hypothermia victims with warm air, instead of the usual method of putting them into a warm bath.
"The system injects 43 degrees Centigrade (109 degrees Fahrenheit) warm air into a plastic and paper blanket," they wrote.
Nine hypothermia victims - five who suffered exposure on the streets, three who had nearly drowned and one avalanche victim - were treated with the new blanket. Six survived and three died from unrelated causes.
Mair concluded that the warm air method was easy and effective.