Is hypothermia more neuroprotective than avoiding fever after cardiac arrest?

Abstract

Hypothermia was increasingly proposed as a neuroprotective therapy in the 1990s, culminating in the publication of two randomized trials in 2002, which showed beneficial effects of therapeutic hypothermia in comatose survivors of cardiac arrest.1,2 Therapeutic hypothermia was subsequently included in guidelines for the treatment of this patient group. However, doubt as to whether hypothermia provided benefit over targeted normothermia (i.e. preventing fever) was raised in 2013 when a large randomized trial showed no difference in survival or neurological function between cardiac arrest survivors cooled to 33 or 36°C.3 Recently the results from a large (1900 patients) randomized open-label trial, comparing patients cooled to 33°C or maintained normothermic (≤37.5°C), was published by Dankiewicz et al.4 in the New England Journal of Medicine. In agreement with the 2013 publication,3 no difference in disability or death was detected between the treatment groups after 6 months. The only significant difference in adverse events was arrhythmias; those resulting in haemodynamic compromise were more common in the hypothermia group than in the normothermia group (24% vs. 17%).4