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Ice slurry gives brain the big chill. |
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Engineers Ken Kasza (left) and John Oras prepare a batch of ice slurry for the next brain cooling test. They are developing a portable device to pump the slurry. |
‘Big Chill’ puts a freeze on heart attacks |
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An Argonne technology originally designed to cool urban buildings may have a new life saving lives of cardiac arrest victims. Coronary heart disease, which often leads to cardiac arrests, is the No. 1 cause of death in America. It claims more than 250,000 lives every year. Researchers in Argonne’s Energy Technology Division and the University of Chicago’s Emergency Resuscitation Center are employing the cooling to decrease the devastating effects of sudden cardiac arrests. Using a five-year, $4-million grant from the National Institutes of Health, researchers are expanding work on the medical application of ice slurry—a mixture of ice and salt water that may be injected into the lungs for rapid blood cooling to sustain the heart and brain cells after cardiac arrests. Ice slurry is an equal mix of ultra-small—equivalent to the diameter of a human hair—ice particles and salt-water liquid carrier. “In the United States alone,” said Roger Poeppel, Energy Technology Division director, “sudden cardiac arrests strike about 1,000 people a day, and the survival rate is at best 2 percent to 4 percent. If we can improve survival rate by just 1 percent, we will save the lives of 10 people every day.” People who suffer cardiac arrests outside of the hospital have a lower recovery rate. Brain cells start dying rapidly 10 to 12 minutes after an arrest because of lack of blood flow to the brain. In 1999, Ken Kasza, a senior mechanical engineer who leads the research at Argonne, and Poeppel worked with collaborators Lance Becker and Terry Vanden Hoek from the University of Chicago Hospitals to develop the Emergency Resuscitation Center to investigate brain cooling using ice slurry to improve recovery rate. When cells cool, their metabolism and their chemical processes slow dramatically. Because external cooling works too slowly, the team is studying injecting ice slurry into the body to induce rapid internal cooling. Ice slurry’s high cooling capacity would cool critical organs rapidly. In the procedure, slurry would be inserted into the lungs, cooling the surrounding blood. Medics must perform chest compressions to circulate the cooled blood, allowing it to reach the brain and preserve brain cells. The ice slurry slowly melts in the body and is removed with a suction device on the end of the endotracheal tube. Data collected by the Argonne-university team has shown that the ice slurry can cool the brain by 10.8 degrees Fahrenheit within 10 minutes. The brain remains chilled for an hour, which in real life would give doctors more time to revive normal heart, blood flow and brain activity. This, hopefully, will reduce or stop brain damage. Kasza and Becker said if the ice slurry procedure is eventually approved, it will still be secondary to defibrillation. Other challenges still remain for the slurry and cardiac arrest treatment. For example, researchers still need to find the optimal cooling level of ice slurry, the correct timing and protocols, the appropriate toxicity levels, and to determine how much of the brain survives after ice slurry is used. “We hope to see the medical application of slurry used by first responders as a common procedure in the next three to five years,” Kasza said. “With this funding and support, we’ll be able to answer the questions to get us to that point.” Also see: http://www.anl.gov/OPA/logos21-1/ice01.htm. For more information, please contact Evelyn Brown. |