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earlier you can do cooling, the better,” lead author Maaret Castren, a professor of emergency medicine at the Karolinska Institute in Stockholm, said in a statement released at the time. Side effects of treatment included three nosebleeds and 13 cases in which noses froze and turned white; normal color spontaneously returned in patients who survived.
The American Heart Association has recommended therapeutic hypothermia after out-of-hospital cardiac arrest since 2003. Patients who survive to hospitalization are cooled so their internal body temperature is between 89.6 and 93.2 degrees (32 to 34 degrees centigrade) for 12 to 24 hours. Although scientists don’t fully understand why cooling is effective, they believe it slows the metabolism of the brain, arresting destructive biochemical reactions and reducing the need for oxygen that the stricken heart can’t supply. In cardiac arrest, the heart loses its ability to effectively pump blood throughout the body. It can be caused by a heart attack or by ventricular fibrillation, in which the heart uselessly twitches instead of contracting.
In the BeneChill study, all patients who survived to hospitalization received therapeutic hypothermia in the hospital.
Barbut founded BeneChill in 2004 specifically to develop and commercialize a cooling device that ambulance crews could use in the field. The focus was not the entire body, but the brain. “That is the target organ we have to cool,” Barbut says, “and as close to time zero as possible.”
The company looked at delivering coolant through the lung before settling on the nose because of its proximity to the brain. The back of the nasal cavity sits under the middle of the brain, Barbut says, separated from the organ by a thin plate of bone. Barbut says it took the company a long time to formulate the coolant, which she describes as a volatile liquid that lowers the brain temperature as it evaporates.
In the recent study, lowering temperatures by less than three degrees made all the difference. Cooled patients had an average temperature of 93.56 degrees (34.2 centigrade) on arrival at the hospital, compared to 95.9 degrees (35.5 centigrade) for those not treated with the BeneChill device. Temperature was measured at the eardrum. Patients who received cooling and CPR within six minutes of their collapse had the best outcomes. Cooling made little difference when resuscitation efforts were delayed 10 minutes or more.
BeneChill, a venture-backed company, has enough money to finance operations through the end of 2010, Barbut says. The device will go on sale in Europe next March but no date has been set for introducing it in the U.S. Barbat complained the company has been “going back and forth for almost two years now” with the FDA to obtain permission to market the device. The company has filed what is known as a 510K application, which is typically used to obtain marketing clearance for a device that is similar in function to one already approved. A decision from the agency is expected in the spring.
Barbut said the regulatory situation was sensitive and declined to provide many details. But if the FDA rejects the BeneChill device, the company may simply end its pursuit of the U.S. market. “If the Europeans buy it and use it,” she says, “there will be little incentive to do something in the U.S.”