Drowning, Not Hypothermia, Linked to Icy-Water Deaths
The heat of August may seem like a strange time to be talking about winter drownings, but new research suggests that rescuers may be taking a wrong approach in their attempts to revive people who have fallen into icy ponds and lakes. Conventional wisdom holds that such victims typically die of hypothermia, a cold-induced stoppage of the heart, and most first aid is now directed at restoring normal body temperatures. But new results from Britain and Sweden indicate that victims actually die from drowning and that clearing the lungs of water should be a first priority.
Researchers from the University of Portsmouth in England and the National Defense Research Establishment in Harsfjarden, Sweden, recruited 10 healthy adults to swim for 90-minute periods in water at temperatures of 77 degrees, 64 degrees and 50 degrees Fahrenheit. Their heart activity, oxygen consumption and internal body temperatures were monitored throughout the swims.
All swimmers completed the full 90 minutes at 77 degrees, and eight completed the time period at 64 degrees, but only five at 50 degrees, the team reported in Saturday’s Lancet. The researchers found that as the swimmers’ bodies were progressively chilled, they began to lose muscle coordination. The team concluded that continued swimming would lead to the swimmers’ inability to keep their heads out of the water and that they would drown before the heart could be stopped by hypothermia.
Infection Risk Low in Pig-Donor Research
The biotechnology industry has been developing genetically engineered pigs that could serve as organ donors for humans in a process called xenotransplantation, but critics have argued that the process will expose humans to pig viruses that could cause unprecedented epidemics of disease. A new study in last Friday’s Science appears to suggest that the risk is lower than critics predict.
A team of government, academic and industrial researchers studied 160 human patients who have been directly exposed to pig tissues, including pig islet cell grafts, pig skin grafts and extracorporeal (outside the body) perfusion of blood through pig spleens, livers and kidneys. They examined blood and tissue from the humans looking for traces of the porcine endogenous retrovirus, which is believed to represent the greatest risk of cross-species transmission of infective agents.
They found no trace of the pig virus in humans and concluded that proposed clinical trials of xenotransplants should proceed as scheduled.
Want to Quit Smoking Forever? Go on a Diet
Kicking the smoking habit is often associated with an increase in weight, but it doesn’t have to be that way, according to Swedish researchers. In fact, women who consume a low-calorie diet at the same time they are quitting smoking not only lose weight, but also have a greater success rate for losing the nicotine habit.
Dr. Tobias Danielsson and his colleagues at the Karolinska Hospital in Stockholm studied 287 female smokers between 30 and 60 who had quit smoking once before but had started up again because of weight gains. Half used a nicotine gum for smoking cessation and consumed a low-calorie diet. The rest used only the gum.
The researchers reported in Saturday’s British Medical Journal that after 16 weeks, half of the dieting group had stopped smoking, compared with 35% of those who did not diet. The latter group had an average weight gain of 3.4 pounds, while the dieting group had an average loss of 4.5 pounds. At the end of a full year, 28% of the dieting group were still not smoking, compared with 16% of the non-dieters.
School Seeks Victims for Ski-Injury Study
Have you had a skiing or ski-boarding accident? If so, researchers from the Johns Hopkins School of Public Health in Baltimore would like to hear from you for a study about the specific circumstances that increase a person’s risk of injury. Participants answer a series of questions about the details of the fall they had and its consequences.
To participate, go on the Web to https://www.injury-study.org.
CPR Device Improves Chances of Survival
The use of a hand-held suction device--similar to a plumber’s plunger--during cardiopulmonary resuscitation can more than double the chances of surviving a cardiac arrest, according to French researchers. Dr. Patrick Plaisance of Lariboisiere University Hospital in Paris arranged a test in which paramedics used standard CPR and the new device on alternate days. The suction device increases the inflow of blood into the heart when compression is not being applied to the chest to force blood out of the heart.
They reported in Thursday’s New England Journal of Medicine that the one-year survival rate among 377 heart attack victims who received conventional CPR was only 2% and that among 373 patients on whom the suction device was used was 5%.
Plaisance suggested that less-compelling results reported in previous studies probably resulted from poor training of the paramedics who used the devices.
Secondhand Smoke Linked to Strokes
A new study suggested Tuesday that breathing in other people’s cigarette smoke makes nonsmokers 82% more likely to suffer a stroke. The study by researchers at the University of Auckland in New Zealand is the most rigorous to date and also indicates that the dangers of smoking are much worse than originally believed.
Current estimates of how smoking increases the risk of various diseases are dramatically understated because the ill effects of secondhand smoke inhalation are not taken into account, the researchers reported in the August issue of Tobacco Control.
The study examined 521 stroke patients in Auckland and compared them with 1,851 randomly selected healthy people matched by sex and age to see the effect of smoking and secondhand smoke on the chances of suffering a stroke. None of the subjects was older than 74.
Overall, smokers were four times more likely to suffer a stroke than nonsmokers. But when the nonsmokers exposed to secondhand smoke were excluded from the equation, smokers were six times more likely to have a stroke.
Researchers had previously believed that people who quit smoking eventually reduce their stroke risk back to normal levels, and that is what the Australian team found--if they didn’t take passive smoking into account. But when they did factor it in, they found that ex-smokers still had twice the normal risk of stroke two years after quitting.
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Medical writer Thomas H. Maugh II can be reached at thomas.maugh@latimes.com.
