WASHINGTON (AP) - Suspended animation may not be just for sci-fi movies anymore: Trauma surgeons soon will try plunging some critically injured people into a deep chill - cooling their body temperatures as low as 50 degrees - in hopes of saving their lives.
Many trauma patients have injuries that should be fixable but they bleed to death before doctors can patch them up. The new theory: Putting them into extreme hypothermia just might allow them to survive without brain damage for about an hour so surgeons can do their work.
In a high-stakes experiment funded by the Defense Department, the University of Pittsburgh Medical Center is preparing to test that strategy on a handful of trauma victims who are bleeding so badly from gunshots, stab wounds or similar injuries that their hearts stop beating. Today when that happens, a mere 7 percent of patients survive.
Get cold enough and "you do OK with no blood for a while," says lead researcher Dr. Samuel Tisherman, a University of Pittsburgh critical care specialist. "We think we can buy time. We think it's better than anything else we have at the moment, and could have a significant impact in saving a bunch of patients."
If the dramatic approach works, it will spur some rethinking about that line between life and death, says Dr. Arthur Caplan, a University of Pennsylvania bioethicist who is watching the research.
But before the first candidates get chilled, the scientists face a hurdle: The law requires that patients consent to be part of medical experiments after they're told the pros and cons. That's impossible when the person is bleeding to death. There won't even be time to seek a relative's permission.
Go even a few minutes without oxygen and the brain in particular can suffer significant damage. Doctors have long sought to use hypothermia in medicine since discovering that cooling can slow the metabolism of the brain and other organs, meaning they can go without oxygen for longer periods. Donated organs are chilled to preserve them, for example. And people whose hearts are shocked back into beating after what's called cardiac arrest often are iced down to about 90 or 91 degrees, mild hypothermia that allows the brain to recover from damage that began in those moments between their collapse and revival.
But the CPR that buys time during more routine cardiac arrest doesn't help trauma patients who've already lost massive amounts of blood. Injuries are the nation's fifth-leading killer, and hemorrhage is one of the main reasons, says Dr. Hasan Alam of Massachusetts General Hospital, who is collaborating with the Pitt study.
Enter deep hypothermia, dropping body temperature to around 50 degrees. It has worked in dogs and pigs, animals considered a model for human trauma, in experiments over the past decade conducted by Tisherman, Alam and a few other research groups.