Cooper DJ, et al. - Researchers investigated the efficacy of early prophylactic hypothermia in improving long-term neurologic outcomes in patients with severe traumatic brain injury. Outcomes of this randomized clinical trial including 511 adults revealed that early prophylactic hypothermia vs normothermic management led to no statistically significant difference in terms of favorable neurologic outcomes at 6 months.

Methods

• Researchers recruited 511 patients both out-of-hospital and in emergency departments following severe traumatic brain injury in this multicenter randomized trial, named the Prophylactic Hypothermia Trial to Lessen Traumatic Brain Injury–Randomized Clinical Trial (POLAR-RCT), conducted in 6 countries.
• They enrolled the first patient on December 5, 2010, and the last on November 10, 2017; the final follow-up was performed on May 15, 2018.
• The prophylactic hypothermia group comprised 266 patients and normothermic management was done in 245.
• The early induction of hypothermia (33°C-35°C) for at least 72 hours and up to 7 days was targeted in prophylactic hypothermia if intracranial pressures were elevated, followed by gradual rewarming.
• When required, they used surface-cooling wraps for targeting 37°C in Normothermia.
• They managed the temperature in both groups for 7 days; at the discretion of the treating physician, all other care was determined.
• Favorable neurologic outcomes or independent living (Glasgow Outcome Scale–Extended score, 5-8 [scale range, 1-8]) obtained by blinded assessors 6 months after injury were assessed as the primary outcome.

Results

• Researchers randomized 511 patients; among these, 500 provided ongoing consent (mean age, 34.5 years [SD, 13.4]; 402 men [80.2%]) and 466 completed the primary outcome evaluation.
• After injury, hypothermia was initiated rapidly (median, 1.8 hours [IQR, 1.0-2.7 hours]) and rewarming occurred slowly (median, 22.5 hours [IQR, 16-27 hours]).
• Favorable outcomes (Glasgow Outcome Scale–Extended score, 5-8) at 6 months occurred in 117 patients (48.8%) and 111 (49.1%), in the hypothermia group and the normothermia group, respectively (risk difference, 0.4% [95% CI, –9.4% to 8.7%]; relative risk with hypothermia, 0.99 [95% CI, 0.82-1.19]; P=.94).
• The hypothermia and normothermia groups displayed pneumonia at the rates of 55.0% vs 51.3%, respectively, and increased intracranial bleeding at the rates of 18.1% vs 15.4%, respectively.