Abstract 284: Association of Neurological Outcome and Survival With Interventions by Bystander and Emergency Medical Service for Unwitnessed Out-of-Hospital Cardiac Arrest Patient; Results From the JCS-ReSS Study

Abstract

Introduction: Although studies have shown that bystander cardiopulmonary resuscitation (CPR) in witnessed out-of-hospital cardiac arrest (OHCA) is associated with better neurological prognosis, whether bystander and Emergency Medical Service (EMS) interventions are associated with prognosis in unwitnessed OHCA patients is not fully elucidated. We aimed to investigate the prognostic importance of bystander and EMS interventions among unwitnessed OHCA patients in Japan. Methods and Results: This study was a nation-wide population-based observational study of OHCA in Japan from 2011 to 2015 based on data from the All-Japan Utstein Registry. The outcome measures were neurological outcome and survival at 30-day. The neurologically favorable outcome was defined as Glasgow-Pittsburgh cerebral performance category score 1 or 2. First, to investigate the effectiveness of bystander interventions, we included 105,655 unwitnessed cardiogenic OHCA patients (aged 18-80 years). Of these, 1,614 (1.5%) showed neurologically favorable outcome and 3,273 (3.1%) survived at 30-day. Multivariate logistic regression analysis adjusting for age, sex, geographical region, year and EMS response time showed that bystander CPR was associated with neurologically favorable outcome (adjusted odds ratio [aOR] 1.49, 95% CI 1.35-1.65, P<0.001). Additionally, to investigate the effectiveness of EMS interventions for patients with non-shockable rhythm, we examined 43,342 patients who were performed public CPR and had the initial rhythm of pulseless electrical activity (PEA) or asystole. Of these, 101 (0.2%) showed neurologically favorable outcome and 453 (1.0%) were survival at 30-day. Advanced airway management by EMS was negatively associated with neurologically favorable outcome (aOR 0.55, 95% CI 0.37-0.81, P=0.003) and administration of epinephrine by EMS was associated with survival (aOR 2.35, 95% CI 1.89-2.92, P<0.001). Conclusions: Among unwitnessed OHCA patients, bystander CPR was associated with neurologically favorable prognosis. For unwitnessed OHCA patients with non-shockable rhythm, epinephrine administration was associated with survival, but advanced airway management was negatively associated with neurological outcome.