Early Initiation of Therapeutic Hypothermia after Sudden Out-of-Hospital Cardiac Arrest

Lee, Dong Hoon; Lee, Byung Kook; Chun, Byeong Jo; Heo, Tag; Min, Yong Il; Ryu, Hyun Ho

Abstract

PURPOSE
Therapeutic hypothermia (TH) improves the probability of survival and neurologic recovery after resuscitation from out-of-hospital cardiac arrest (OHCA). However, the best time to initiate TH after the return of spontaneous circulation (ROSC) remains unknown.
METHODS
The aim of this study was to evaluate the correlation between TH initiation time after ROSC and the resulting neurological outcome. Methods: A retrospective analysis was performed on 122 OHCA patients enrolled between January 2008 and December 2011. Therapeutic hypothermia (32~34degrees C) was induced immediately after ROSC. The primary measure of outcome was neurological function at hospital discharge, as determined by a cerebral performance category (CPC) scale.
RESULTS
Out of the 122 patients, 34 patients (27.9%) had a good neurological outcome at hospital discharge. The initiation time following ROSC was shorter, although not statistically significant, in patients with good neurological outcomes compared to those with poor outcomes. Based on subgroup analysis, only the shockable rhythm group showed a significant difference, in the time after ROSC to TH initiation, between good and poor neurological outcome groups. Receiver operator characteristic analysis suggested that an initiation time of 250 min after ROSC was most predictive of CPC 1-2 outcomes compared to other time points. Furthermore, the 250 min initiation time after ROSC correlated with neurological outcome in patients with OHCA undergoing TH treatment.
CONCLUSION
Compared to late initiation, early initiation (within 250 min) with TH had neurologic benefits for patients with OHCA.