Science-- there's something for everyone

Tuesday, November 8, 2011

Therapeutic hypothermia for a heart attack


Yesterday, I wrote about warming, now a story about cooling.  Patients who underwent therapeutic cooling following a heart attack fared better than controls, according to a study by doctors at the Mayo Clinic.  Over two and half times as many hypothermia-treated patients survived their cardiac arrest as patients who had not been drastically cooled.

Therapeutic cooling is the process of lowering the body temperature to a point where metabolism is slowed down.  This can be done by applying cold packs externally or by IV fluids. The target body temperature of this process is 32–34 °C (90–93 °F).   The hope is that such treatment can prevent the brain damage that often results from lack of blood flow following cardiac arrest.  However, doctors were concerned that the extreme cooling could delay post-heart attack awakening, a critical component of continued diagnosis and treatment.  This did not turn out to be a problem.  Of the 227 patients in the study (128 treated with hypothermia and 99 controls), all awakened within the same time frame, and the cooled patients had a significantly higher survival rate.

Sudden cardiac arrest is the leading cause of death in U.S.  With current treatments, only 7% of victims survive.  Perhaps if patients can be immediately cooled down, that percentage might go up.