Lowering Body Temperature After Cardiac Arrest

Hypothermia (lowering the body temperature to subnormal levels) after cardiac arrest became standard practice in adult and neonatal critical care in the early 2000s, but its benefits in children were unknown. To answer this question, University of Utah Health researcher J. Michael Dean, MD, and colleagues conducted two randomized trials (in-hospital and out-of-hospital) at 38 U.S. and international sites, comparing hypothermia with normothermia-maintenance of normal body temperature-after cardiac arrest. Over 4,000 children were screened and 624 participated in the trials. In both trials, researchers found no benefit from hypothermia versus normothermia. Previous trials had observed frequent fever in the patients who were not treated with hypothermia after cardiac arrest. Dean and colleagues introduced an important innovation in their trials: active treatment of participants in the normothermia group with temperature control mattresses to prevent fever. This unique approach yielded the key insight that, after cardiac arrest, it is the prevention of fever, and not the induction of hypothermia, that plays a critical role in determining the ultimate health and neurological outcomes of survivors.