QUICK-CHILLING people by pumping an icy slurry into their lungs could help
them survive a heart attack or stroke.
The chief cause of death or injury during heart attacks and strokes is oxygen
starvation in parts of the brain. But even when the oxygen supply is restored,
many cells surrounding injured areas continue to die. Medics have thought for a
long time that if they can cool a person by a few degrees, they can reduce such
secondary injuries.
But cooling people by wrapping them in a cold blanket, or placing bags of icy
water against their scalp, doesn鈥檛 work quickly enough. So Lance Becker of the
University of Chicago Hospitals and his colleague Terry Vanden Hoek wondered if
it was feasible to get something really cold straight into the lungs鈥攖he
largest body cavity.
Advertisement
The team suspended tiny, smooth ice particles in perfluorocarbon, an inert
fluid that also carries bubbles of oxygen. This allows patients to continue
breathing as the fluid reaches their lungs. The ice-making technique came from a
team at the Argonne National Laboratory in Illinois, which has patented a
technique for making ultra-smooth ice particles tens of microns across.
Becker and Vanden Hoek plan to pump the ice slurry down the windpipe via a
tube into the lungs to cool blood through the lung membranes. The hyper-cooled
blood then flows directly to the brain.
Donald Marion, a neurologist at the University of Pittsburgh, says he鈥檚
worried that patients鈥� lungs could be damaged by the ice particles in the fluid.
But Becker says that perfluorocarbon is already used regularly to deliver
concentrated oxygen to newborn babies鈥� lungs. 鈥淏ut of course we鈥檙e worried about
this,鈥� he says. He鈥檚 now testing the idea on pigs.