LO36: Out-of-hospital cardiac arrest in British Columbia: Ten years of increasing survival

Abstract

Introduction: Survival for victims of out-of-hospital cardiac arrest (OHCA) is typically between 8 and 12%. We sought to report the trends in survival in British Columbia (BC) over a 10-year period. Methods: The BC Resuscitation Outcomes Consortium prospectively collected detailed prehospital and hospital data on consecutive non-traumatic OHCAs from 2006 to 2016 within BC’s four metropolitan areas. We included EMS-treated adult patients without DNR orders. To describe baseline characteristics we organized patient characteristics in three time periods: 2006-09, 2010-13, and 2014-16 (first and last periods reported below). The primary and secondary endpoints were survival at hospital discharge and return of spontaneous circulation (ROSC). We tested the significance of year-by-year trends in baseline characteristics, and performed multivariable Poisson regression, using calendar year as an independent variable, to calculate risk-adjusted rates for survival. Results: Between January 1, 2006 and March 31, 2016 there were a total of 26 433 non-traumatic OHCAs, with 15 145 included in this study. There were significant decreases in the proportion with initial shockable cardiac rhythms (28% to 23%) and bystander witnessed arrests (42% to 39%), however significant increases in the proportion with bystander CPR (40% to 49%) and ALS treatment (86% to 97%), and the median chest compression fraction (0.81 to 0.87). There was a significant increase in the median time until termination of resuscitation in those who did not achieve ROSC (27 to 32 minutes), and a significant decrease in the proportion of patients who were transported in absence of ROSC (17% to 6.5%). There was a significant improvement in achieving ROSC (44% to 48%; adjusted rate ratio per year 1.02, 95% CI 1.01 to 1.02) and survival at hospital discharge (10% to 14%; adjusted rate ratio per year 1.05, 95% CI 1.04 to 1.06). Both subgroups of initial shockable (adjusted rate ratio per year 1.04, 95% CI 1.03 to 1.05) and non-shockable (adjusted rate ratio per year 1.08, 95% CI 1.06 to 1.12) cardiac rhythms demonstrated survival improvement. Conclusion: Despite a significant decrease in those with initial shockable rhythms, out-of-hospital cardiac arrest survival in BC’s metropolitan regions increased by approximately 40% over a 10-year period. During this time there were system changes and quality of care improvements as provided by bystanders and professionals.