Hypothermia Isn't Better Than Normothermia After Cardiac Arrest

Hypothermic temperature control after out-of-hospital cardiac arrest had been recommended routinely for several decades, after two small studies suggested superior neurological outcomes in hypothermic patients. Since then, two much larger studies — the Targeted Temperature Management trials (TTM 1&2; NEJM JW Emerg Med Jan 2014 and N Engl J Med 2013; 369:2197; NEJM JW Gen Med Aug 1 2021 and N Engl J Med 2021; 384:2283) have shown that cooling out-of-hospital post–cardiac arrest patients to 33°C is not better than maintaining temperature at 36°C to 37.7°C (normothermia).

Researchers performed a meta-analysis, combining the 2800 patients in the TTM1 and TTM2 trials, to identify any subgroups (e.g., specific presenting cardiac rhythms, older age…