Predictive model of return of spontaneous circulation among patients with out-of-hospital cardiac arrest in Thailand: The WATCH-CPR Score.

BACKGROUND:Out-of-hospital cardiac arrest is an emergency that requires immediate management to save lives. However, some predictive scores for the immediate outcomes of patients with out-of-hospital cardiac arrest are difficult to use in clinical practice. AIMS:This study aimed to identify predictors of sustained return of spontaneous circulation and to develop a predictive score. METHODS:This prospective observational study evaluated sustained return of spontaneous circulation among out-of-hospital cardiac arrest patients in a Thai emergency department between July 2014 and March 2018. The baseline characteristics and prehospital and hospital findings were analysed. RESULTS:Of 347 patients, 126 (36.3%) had sustained return of spontaneous circulation and 20 (5.8%) were discharged. Witnessed arrest (odds ratio = 2.9, 95% confidence interval 1.3-6.2), time from arrest to chest compression <15 min (odds ratio = 3.0, 95% confidence interval 1.3-7.0) and chest compression duration <30 min (odds ratio = 15.6, 95% confidence interval 8.7-28.0) predicted sustained return of spontaneous circulation; these were developed into the WATCH-CPR (Witnessed Arrest, Time from arrest to CHest compression-CPR duration) score. A score of ≥2 was optimal for predicting sustained return of spontaneous circulation, which provided an area under the receiver operating characteristic of 0.775 (95% confidence interval 0.724-0.825) and a sensitivity of 72.2% (95% confidence interval 63.4-79.6%) and specificity of 76.0% (95% confidence interval 69.8-81.4%). CONCLUSIONS:The factors including witnessed arrest, time from arrest to chest compression and chest compression duration were developed as the WATCH-CPR score for predicting sustained return of spontaneous circulation among patients with out-of-hospital cardiac arrest.