Abstract 11985: The Role of Bystanders in Timely CPR and Related Outcomes After Out-of-Hospital Cardiac Arrest

Abstract

Objective: Without cardiopulmonary resuscitation (CPR), cardiac arrest survival declines 5-10% for every minutes. But, there is a limit to reduce the time from collapse to Emergency medical service (EMS) arrival. This study aimed to examine the association between the time interval from collapse to CPR by EMS providers and related outcomes in patients who received bystander CPR. Methods: A population-based observational study was conducted with out-of-hospital cardiac arrests (OHCA) of cardiac etiology who were witnessed by laypersons in Korea between 2012 and 2014. Exposure variable was the proportion of the time interval from collapse to CPR by EMS providers categorized into quartile groups: group 1 (time < 4 min), group 2 (4 ≤ time < 8), group 3 (8 ≤ time< 15), group 4 (15 ≤ time < 30). Primary endpoint was time interval from collapse to CPR by EMS providers and secondary endpoint were survival to discharge and survival with favorable neurological outcome (Cerebral Performance Category (CPC) 1-2). Multivariable logistic regression analysis was performed. The final model was performed to evaluate interactive effect between bystander CPR and the time interval from collapse to CPR by EMS providers. Results: A total of 15,354 OHCAs were analyzed. Bystander CPR was performed in 8,591 (55.95%). The survival to discharge rate was 10.6% (1632) and favorable neurological outcome was 6.5% (996). In an interaction model of bystander CPR patients, AORs (95% CIs) for survival to discharge rate were 0.89 (0.66-1.20) in group 2, 0.76 (0.57-1.02) in group 3, 0.52 (0.37-0.73) in group 4 compared with group 1. For favorable neurological outcome, AORs were 1.12 (0.77-1.62) in group 2, 0.90 (0.62-1.30) in group 3, 0.59 (0.38-0.91) in group 4. Conclusion: Despite of poor ambulance response time, patients who received bystander CPR would show favorable outcomes. Prompt delivered bystander CPR was strongly associated with increased survival. Keywords: Out-of-hospital cardiac arrest; Cardiopulmonary resuscitation; Emergency medical services