Surviving out-of-hospital cardiac arrest: The important role of bystander interventions

Background: Substantial variations exist in relation to the characteristics and outcomes of out-of-hospital cardiac arrest (OHCA). As such, an understanding of region-specific factors is essential for informing strategies to improve OHCA survival. Methods: Analysis of a large state-wide OHCA database of the Queensland Ambulance Service, Australia. Adult patients, attended by paramedics between January 2000 and December 2018 for OHCA of medical origin, where the arrest was not witnessed by paramedics, and resuscitation was attempted, were included. Factors associated with survival were investigated. The number needed to treat (NNT) for bystander interventions was estimated. Results: Across a total of 23,510 patients, event survival, survival to discharge and 30-day survival was 22.6%, 11.9% and 11.5%, respectively. The corresponding figures for the Utstein patient group (initial shockable rhythm, bystander-witnessed) were 38.9%, 27.2% and 26.3%, respectively. Bystander cardiopulmonary resuscitation (CPR) and defibrillation substantially improved the likelihood of survival. The NNT for bystander CPR was 41, 63 and 64 for event survival, survival to discharge, and 30-day survival, respectively. The NNT for bystander defibrillation for these survival outcomes was 10, 14 and 14, respectively. Conclusions: Bystander interventions are critical for OHCA survival. Effort should be invested in strategies to improve the uptake of these interventions. (C) 2019 College of Emergency Nursing Australasia. Published by Elsevier Ltd. All rights reserved.