Hypothermia does not improve outcome from traumatic brain injury.

Therapeutic hypothermia is a potentially dangerous treatment with a very narrow therapeutic index. It is of proven benefit in certain conditions, including post ventricular fibrillation cardiac arrest and intermediate severity neonatal asphyxia. It is of no benefit and may cause harm in other contexts, such as elective neurovascular surgery. In traumatic brain injury there has been much provocative early evidence. While it is clear that hypothermia decreases intracranial pressure, a major phase III trial demonstrated no improvement in neurological outcomes with hypothermia, in an unselected group of patient with severe head injury. More focused phase III trials are underway but until the results are known this treatment should not be offered to patients outside the context of a clinical trial.