Predictive Accuracy of Biomarkers for Survival Among Cardiac Arrest Patients With Hypothermia: A Prospective Observational Cohort Study in Japan

Abstract

Background:There is little information onthe predictive accuracy of commonly used predictors, such as lactate,pH or serum potassium for the survival among out-of-hospital cardiac arrest (OHCA) patients with hypothermia. This studyaimed to identify the predictive accuracy of these biomarkers forsurvival among OHCA patients with hypothermia.Methods: In this retrospective study, we analyzed the data from a multicenter, prospective nationwide registry among OHCA patients transported to emergency departments in Japan (the JAAM-OHCA Registry). We included all adult (≥18 years) OHCA patients with hypothermia (≤32.0°C)who were registeredfrom June 2014 to December 2017and whose blood test results on hospital arrival were recorded. We calculated the predictive accuracy of pH and lactate for 1-month survival.Results: Of the 34,754 patients in the JAAM-OHCA database, we included 754 patients from 66 hospitals. The 1-monthsurvival was 5.8% (44/754). The areas under the curve of the predictors were as follows: pH 0.829[0.767–0.877] and lactate 0.843[0.793–0.882]. On setting the cutoff points of 6.9 in pH, and 120 mg/dL (13.3 mmol/L) in lactate, the predictors had a high sensitivity (lactate: 0.91, and pH 0.91) and a low LR- (lactate: 0.14 and pH 0.13), which are suitable to rule-out 1-month survival.Conclusion: Among adult OHCA patients with hypothermia, pH 6.9 and lactate 120 mg/dLcan predictivelyrule out 1-month survival.