Argonne National Laboratory via discovery.com
Scientists in Chicago have created a slurry that can be injected into the veins, arteries and lungs of critically ill patients.
The sharp edges off tiny ice crystals are shaved and crushed, and when injected, the slurry rapidly cools off the body from the inside out, giving doctors more time to treat patients.
"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."
This method of protective cooling has been used unintentionally, such as when a person falls into an icy lake or river, hasn't breathed for up to 90 minutes, yet is still able to be revived with little or no brain damage.
Scientists have also induced hypothermia in patients to protect them, but this method is slow. With protective cooling, fast results are crucial. Since pumping iced saline directly into veins and arteries, this allows doctors to cool organs quicker than doing it externally, and it also gives doctors more time for surgery on a patient.
"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."
The research was done on large animals, and the scientists found that with the slurry they were able to triple the amount of time needed to treat a heart attack (from 10-15 minutes for a heart attack up to 30-45 minutes). While the scientists discontinued the experiments on animals early to ensure they survived, researchers think they could extend this time even longer with more testing.
In order to create the slurry, scientists first froze large chunks of saline solution into a clear, solid mass. They then ground up the using a special method that turned the sharp ice into round, smooth balls. The tiny, icy spheres are small enough to fit through a 1-mm-wide catheter and are able to move around one another without getting stuck. The machine they use can produce 3-4 liters of slurry at a time, which is more than enough to treat a patient. Once injected into the body, the icy slurry melts, making the saline absorb into the body with no harm.
"We want to be able to get this stuff into the small capillaries deep in the body, heart and brain, to protect cells from dying from a lack of oxygen," said Kasza.
The scientists are currently seeking FDA approval in order to test the slurry on humans and are currently speaking with a biomedical company to market the slurry-making process.