Cooling the body appears to prevent brain damage after cardiac arrest

Cooling the body just a few degrees appears to prevent brain damage in people who survive cardiac arrest but are left unconscious. <br><br>If treated quickly enough, cardiac arrest can be reversed and

Wednesday, February 20th 2002, 12:00 am

By: News On 6

Cooling the body just a few degrees appears to prevent brain damage in people who survive cardiac arrest but are left unconscious.

If treated quickly enough, cardiac arrest can be reversed and the heart restarted with electric shock. But doctors have not figured out how to stop the brain damage that begins minutes after blood flow stops.

Researchers in Europe and Australia tried lowering body temperatures, using cold air and ice packs on cardiac arrest victims who were comatose when they reached the hospital.

The patients who were chilled had a better recovery, according to their research, reported in Thursday's New England Journal of Medicine. The European study also found mild hypothermia increased the patient's chances of survival.

``Now we have at least a tiny little tool ... which might help,'' said Dr. Fritz Sterz, who led the European study in five countries. ``This gives a new hope and a new attitude toward these patients.''

The treatment is now used at Vienna General Hospital, where he works, and was used as recently as Tuesday in the case of a 48-year-old man.

Dr. Peter J. Safar of the University of Pittsburgh Medical Center said there is enough evidence now to make the treatment routine in the United States.

``It's pretty clear-cut now. This should immediately go into guidelines for regular use,'' said Safar, whose lab did some of the animal tests that renewed interest in the approach.

Cooling for cardiac arrest _ but at much lower temperatures _ was tried in the 1950s but abandoned because of serious side effects.

Safar said cooling works by reducing the brain's need for oxygen while suppressing the chemical processes that kill brain cells.

The technique is also being tested for stroke and brain injuries, and Safar said other uses warrant study, such as spinal cord injury.

In the European study of 275 patients, half were chilled with circulating cold air and ice packs from a normal 98.6 degrees to between 89.6 and 93.2 degrees for 24 hours. Fifty-five percent of the cooled group had a favorable outcome compared with 39 percent of the group that did not get the treatment. The death rate at six months was 41 percent in the cooled group and 55 percent in the group that was not cooled.

The researchers in Melbourne, Australia, used ice packs, and cooling was started by paramedics. Forty-three of 77 patients were chilled to 91.4 degrees for 12 hours. Forty-nine percent of the treated group recovered well enough to go home or to a rehabilitation center, compared with 26 percent of the patients who were not chilled.

Dandenong Hospital's Dr. Stephen A. Bernard and his colleagues calculated that patients were five times more likely to recover with mild hypothermia than without.

``What we were eager to demonstrate was that we could get people home again, rather than just simple improvement in survival,'' he said.

Researchers in both studies said quicker, more efficient ways to cool patients are needed. Several devices are being developed, and Bernard said he is testing ice-cold liquids given intravenously.