Cooper DJ, et al. - In this randomized clinical trial involving 511 adults, researchers determined the efficacy of early prophylactic hypothermia compared to the normothermic management of patients following severe traumatic brain injury. According to the findings obtained, early prophylactic hypothermia did not improve neurological outcomes in patients with severe traumatic brain injury in 6 months compared to normothermia. This investigation did not support the use of early prophylactic hypothermia for patients with severe traumatic brain injury.

Methods

• In 6 countries, 511 candidates both out-of-hospital and in Emergency Departments after severe traumatic brain injury were recruited for a randomized trial namely The Prophylactic Hypothermia Trial to Lessen Traumatic Brain Injury–Randomized Clinical Trial (POLAR-RCT).
• The first patient was enlisted on December 5, 2010, and the last on November 10, 2017.
• May 15, 2018 was the final date of follow-up.
• They randomized 266 patients to the prophylactic hypothermia group and 245 to normothermic management.
• For at least 72 hours and up to 7 days, prophylactic hypothermia was targeted as early induction of hypothermia (33°C-35°C) in case intracranial pressures were elevated, followed by gradual rewarming.
• Normothermia was targeted at 37°C, using surface-cooling wraps when needed.
• In both groups, temperature was managed for 7 days.
• All other care was at the circumspection of the treating physician.
• 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 was the primary outcome.

Results

• Five hundred were provided ongoing consent (mean age, 34.5 years [SD, 13.4]; 402 men [80.2%]) and 466 completed the primary outcome evaluation among 511 randomized patients.
• 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 results (Glasgow Outcome Scale–Extended score, 5-8) at 6 months obtained in 117 subjects (48.8%) in the hypothermia group and 111 (49.1%) in the normothermia group (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 rates of pneumonia in the hypothermia and normothermia groups were 55.0% vs 51.3%, respectively, and rates of increased intracranial bleeding were 18.1% vs 15.4%, respectively.