Mitochondrial mechanisms of cell death and neuroprotection in pediatric ischemic and traumatic brain injury.
BACKGROUND Hypothermia therapy improves survival and the neurologic outcome in animal models of traumatic brain injury. However, the effect of hypothermia therapy on the neurologic outcome and mortality among children who have severe traumatic brain injury is unknown. METHODS In a multicenter, international trial, we randomly assigned children with severe traumatic brain injury to either hypothermia therapy (32.5 degrees C for 24 hours) initiated within 8 hours after injury or to normothermia (37.0 degrees C). The primary outcome was the proportion of children who had an unfavorable outcome (i.e., severe disability, persistent vegetative state, or death), as assessed on the basis of the Pediatric Cerebral Performance Category score at 6 months. RESULTS A total of 225 children were randomly assigned to the hypothermia group or the normothermia group; the mean temperatures achieved in the two groups were 33.1+/-1.2 degrees C and 36.9+/-0.5 degrees C, respectively. At 6 months, 31% of the patients in the hypothermia group, as compared with 22% of the patients in the normothermia group, had an unfavorable outcome (relative risk, 1.41; 95% confidence interval [CI], 0.89 to 2.22; P=0.14). There were 23 deaths (21%) in the hypothermia group and 14 deaths (12%) in the normothermia group (relative risk, 1.40; 95% CI, 0.90 to 2.27; P=0.06). There was more hypotension (P=0.047) and more vasoactive agents were administered (P<0.001) in the hypothermia group during the rewarming period than in the normothermia group. Lengths of stay in the intensive care unit and in the hospital and other adverse events were similar in the two groups. CONCLUSIONS In children with severe traumatic brain injury, hypothermia therapy that is initiated within 8 hours after injury and continued for 24 hours does not improve the neurologic outcome and may increase mortality. (Current Controlled Trials number, ISRCTN77393684 [controlled-trials.com].).