X-Message-Number: 10902 Date: Thu, 10 Dec 1998 18:19:21 -0500 From: Jan Coetzee <> Subject: hypothermia Device speeds hypothermia recovery NEW YORK, Dec 09 (Reuters Health) -- A new armcuff device speeds the delivery of heat to the heart and internal organs of patients who develop hypothermia -- a sudden drop in core body temperature -- during surgery. ``This gives us the equivalent of an open heat-pipe that leads directly to the body's interior,'' explained device inventor Dr. Dennis Grahn, a biological researcher at Stanford University in Stanford, California. A study testing the efficacy of the apparatus, called the ``Thermo-STAT,'' was published in a recent issue of the Journal of Applied Physiology. When body temperature drops, one of the ways the body reacts is by restricting blood flow to surface areas especially prone to heat loss. However, this response can also hinder the conduction of externally applied heat (from blankets, for example) back towards the body's inner core. Most patients undergoing surgery experience temporary procedure-related declines in core body temperature. And studies have linked even mild hypothermia to an increased risk of infection and heart problems in surgical patients. But the Stanford team knew that declines in atmospheric pressure can re-open hypothermia-restricted blood vessels. Their Thermo-STAT armcuff creates a tight seal around the lower arm, while an external vacuum pump triggers a drop in air pressure inside the cuff. At the same time, warm water is pumped into the device to deliver heat to the dilated blood vessels of the arm. The re-warmed blood then returns to the heart and other organs. The investigators tested their device on 16 patients undergoing surgeries, and found that ``the combined application of heat and subatmospheric pressure to a single forearm, hand and fingers accelerated recovery from hypothermia.'' In fact, patients using the Thermo-STAT reached a stable core body temperature 10 times faster than patients warmed with traditional techniques. ``When we started these tests, we expected to get maybe double the rate of rewarming,'' said study co-author Dr. Donald Watenpaugh of the University of North Texas Health Science Center in Fort Worth. ``A 10-fold increase is really exciting.'' The researchers believe the device could have numerous applications -- from routine use in operating rooms to the treatment of victims of severe environmental hypothermia. Since the device weighs just 3 to 4 pounds, it might easily be carried by search-and-rescue and paramedic teams, they suggest. Thermo-STAT has been patented by Stanford University, and is licensed for manufacture by the Aquarius Medical Corp., of Scottsdale, Arizona. SOURCE: Journal of Applied Physiology 1998;85:1643-1648. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=10902