A 'Slurpee' That Could Save Your Life

Nov. 18, 2008 -- By crushing and shaving the sharp edges off tiny ice crystals, scientists in Chicago have created a slurry that can be pumped into veins, arteries and the lungs. The life-saving, Slurpee-like slurry rapidly cools the body from the inside out, giving doctors more time to treat patients while staving off harmful complications, saving lives.

"What you end up with is not what you'd get from the local 7-11," said Ken Kasza of the Argonne National Laboratory in Illinois. "With a Slurpee you get the liquid but not the ice. In our slurry you get the liquid and the ice."

Protective cooling, as rapidly cooling the body to prevent inflammation, acidosis and other problems is called, has been around unintentionally for thousands of years. It explains why, when a person falls into a frozen lake or river and doesn't breathe for as long as 90 minutes, they can be successfully revived with little or no brain damage.

For decades scientists have artificially induced localized and universal hypothermia using cooling blankets, cold, liquid saline solutions and packed ice chunks, in surgical patients to protect them.

Related Content:

These techniques are effective, but slow. Speed is critical for protective cooling. Pumping iced saline directly into veins, arteries and lungs lets doctor cool organs much more quickly than cooling externally, increasing survival rates and the time doctors have to treat a patient. During a surgery, that could mean having more than two hours to operate on a patient, instead of the 30 minutes currently available for some procedures.

"The fact that we have high ice loading means that we can absorb many times more heat than with cold saline," said Kasza. "That means that the amount of coolant needed to reduce body temperature is reduced dramatically."

Kasza's Argonne colleague, Yue Wu (Ryan), ran initial tests of the ice, compared with cold saline during an angioplasty, and found the slurry is about five times more effective at cooling the body.

In large animals, the scientists were able to at least triple the window of time to treat a heart attack, from 10 to 15 minutes for a heart attack, up to 30 and 45 minutes. The scientists think they could extend that time even longer; they discontinued the experiments early to ensure that all animal survived. The scientists are currently seeking FDA approval to test the ice slurry on humans.

The Argonne National Laboratory and University of Chicago scientists created their life-saving slurry by first freezing large chunks of saline solution into a clear, solid mass. Then they mechanically ground up the ice using a special, propriety method that turns the sharp, crystalline ice into round, smooth balls.

The tiny, icy spheres, small enough to fit through a 1-mm-wide catheter, can then move around one another and not become stuck, like what can happen in a 7-11 Slurpee, allowing for a quick brain freeze. The table-top-sized machine can produce about three to four liters of ice slurry at a time, more than enough to treat a patient.