Duration of well-controlled core temperature correlates with neurological outcome in patients with post-cardiac arrest syndrome

PurposeDetailed procedures for optimal therapeutic hypothermia (TH) have yet to be established. We examined how duration of well-controlled core temperature within the first 24 hours after cardiac arrests (CA) correlated with neurological outcomes of successfully resuscitated out-of-hospital CA (OHCA) patients.MethodsOHCA patients who survived over 24 hours and treated with TH were included. Core temperature was measured every hour. Physicians intended to maintain temperature at 33°C ± 1°C for 24 hours. Cerebral performance categories (CPC) of patients at 6 months were recorded and patients were retrospectively divided into favorable (CPC1,2) and poor (CPC3-5) neurological outcome groups. Total time while the core temperature reached to 33°C ± 1°C within the first 24 hours after CA was measured and this duration was defined that of well-controlled temperature. receiver-operating characteristic analysis was performed on duration of well-controlled temperature to select the optimal cutoff value. Neurological outcome predictors were investigated by logistic regression analysis.ResultsFifty-six patients were included. Optimal cutoff value of duration of well-controlled temperature was 18 hours. Ratio of male sex, witnessed by emergency medical service (EMS) personnel, first electrocardiogram as shockable, and duration of well-controlled core temperature ≥18 h of favorable neurological outcome group (n = 21) were significantly larger than that of poor neurological outcome group (n = 35). Logistic regression analysis identified “witnessed by EMS”, “performed bystander CPR,” and “the duration ≥18 h” as independent predictors of favorable neurological outcome.ConclusionTH maintained at target temperature of 33°C ± 1°C over 18 hours independently correlated with favorable neurological outcome. Therefore, stable core temperature control may improve neurological outcome of successfully resuscitated OHCA.