Post–Cardiac Arrest Cooling — Colder Is Not Better

Current guidelines recommend therapeutic hypothermia as a cornerstone of management for patients who remain unconscious after cardiac arrest, as it has been demonstrated to reduce mortality and improve neurologic function. However, the optimal target temperature (typically between 32°C and 35°C) has been unclear. Researchers randomized 950 patients in 36 European and Australian intensive care units to target temperatures of either 33°C or 36°C, to determine which might be more effective.

Of 939 patients included in the primary intention-to-treat analysis, 460 had died by the end of the trial (mean follow-up, 256 days). All-cause mortality was similar in the 33°C and 36°C groups (50% and 48%), as was the composite secondary outcome of death or poor neurologic function at 180 days (54% and 52%, respectively). Rates of serious adverse events also were similar in the two groups (93% and 90%).