Early prophylactic hypothermia in people who have a brain injury should no longer be used because it does not improve neurologic outcomes at six months, an Australian led randomised study concludes.

Lead researcher Jamie Cooper,  director of the Australian and New Zealand Intensive Care Research Centre at Monash University, Melbourne, and colleagues noted that prophylactic hypothermia had long been thought to improve neurological outcomes in patients, but evidence had been conflicting.

In their current study published in JAMA, conducted across five centres, 511 patients with traumatic brain injury were randomised to either hypothermia treatment (a bolus of 4°C saline and surface cooling wraps targeting a core temperature of 33°C-35°C for three to seven days) as soon as possible after injury or to no hypothermia treatment.

Results showed that favourable outcomes at six months, as measured by the Glasgow Outcome Scale (Extended), occurred in 117 patients (48.8%) in the hypothermia group and in 111 (49.1%) in the normothermia group (risk difference 0.4% (95% confidence interval –9.4% to +8.7%); relative risk with hypothermia 0.99 (0.82 to 1.19); P=0.94). Pneumonia was more common in patients treated with hypothermia (55.0%) than in those not given this treatment (51.3%), as was intracranial bleeding (18.1% vs 15.4%).

“Among patients with severe traumatic brain injury, early prophylactic hypothermia compared with normothermia did not improve neurologic outcomes at 6 months. These findings do not support the use of early prophylactic hypothermia for patients with severe traumatic brain injury,” the study authors concluded.