Hypothermia in the management of traumatic brain injury - A systematic review and meta-analysis

Objective. Brain injury remains the leading cause of death in cases of trauma in North America and Europe. This article critically appraised and summarised all published and peer-reviewed, randomised, controlled trials of the use of hypothermia in traumatic brain injury. Design. To be included, a study had to be a published, randomised, controlled trial of the use of hypothermia in the management of traumatic brain injury. Pooling of data and meta-analysis of results occurred. Setting. Conducted at a tertiary level Canadian teaching hospital. Patients and participants. Patients were combined from eight randomised, controlled trials to generate a population of 748 severely head-injured patients. Measurements and results. Eight studies provided data on the efficacy of hypothermia in the management of traumatic brain injury. The pooled odds ratio of mortality in the hypothermic group was 0.81 (95%CI =0.59-1.13, p=0.22). The OR of a poor neurological outcome (GOS 1,2 or 3) was 0.75 (95% CI=0.56-1.01, p=0.06). The odds ratio for pneumonia in the normothermic group was 0.42 (95%CI =0.25-0.70, p=0.001). Conclusions. Although meta-analysis suggests that iatrogenic hypothermia may confer a marginal benefit in neurological outcome, there does not appear to be clear evidence of lower mortality rates in unselected traumatic brain injury patients. Prolonged hypothermia may confer a benefit, particularly in patients with elevated intracranial pressure refractory to conventional manipulations. Conclusions regarding the use of hypothermia are controversial and not strongly supported by the available evidence.