December 27, 2007

Lower Body Temps Increase Blood Loss During Surgery

THURSDAY, Dec. 27 (HealthDay News) -- Even small drops in body temperature during surgery significantly increase blood loss, says a study in the January issue of Anesthesiology.

All anesthetics interfere with the body's natural ability to control its own temperature, but anesthesiologists are able to control body temperature during surgery, according to background information provided by study author Dr. Daniel I. Sessler, chairman of Cleveland Clinic's Department of Outcomes Research.

However, if surgical patients aren't actively warmed, they can develop hypothermia (decreased body temperature), which increases the risk of heart attack, infection and prolongs recovery from surgery.

Sessler said past research of a hypothermia-blood loss link has produced conflicting results. He analyzed a number of studies on hypothermia and blood loss conducted from 1966 to 2006.

"When all the studies were evaluated together, the results clearly show that even very mild hypothermia increases blood loss and transfusion requirements by clinically important amounts," Sessler said in a prepared statement.

He noted that recent evidence suggests that blood transfusions may present more risks to patients than previously thought. The findings of this study suggest that a simple way to reduce transfusion-related risks is to avoid the need for transfusion in surgery patients by preventing a decrease in body temperature.

However, there are still situations where induced hypothermia during surgery is necessary.

"In occasional patients, mostly those at risk for brain injury, hypothermia is perfectly appropriate. In these patients, physicians need to trade off the potential benefits and risks and choose the optimal approach for each individual," Sessler said.

More information

MedlinePlus has more about hypothermia.

-- Robert Preidt
SOURCE: American Society of Anesthesiologists, news release, Dec. 21, 2007
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