Two new studies show that by cooling the body just a few degrees, doctors can improve the chances of survival of heart attack victims. The studies published in this week's New England Journal of Medicine also show the treatment can reduce or prevent brain damage.
In a European study, researchers used ice packs and circulating cold air to cool the bodies of heart attack victims. In the study, involving 275 subjects in five countries, patients were chilled from the normal 37 degrees celsius to 34 degrees celsius for 24 hours. A similar study, involving 77 patients, was conducted in Melbourne, Australia.
In both studies about half of those whose bodies were chilled had what doctors described as favorable outcomes. They survived the heart attacks and had less brain damage than might otherwise have been expected or none at all. "The mild cooling, being simple and safe… won't do any harm. It may do some good," said Peter Safar of the University of Pittsburgh Medical Center, a pioneer of body cooling as a way to prevent brain damage.
He commented on the studies in an editorial in the New England Journal of Medicine. "Cooling of any organ will, of course, reduce the oxygen requirement which is one reason why is protects and preserves and resuscitates," he said.
But Dr. Safar said a more likely reason chilling appears to protect the brain from damage when the heart stops is it halts the release of harmful chemicals that destroy brain cells.
Dr. Safar thinks body chilling ought to be a standard part emergency heart attack care.