Abstract 154: Guideline Removal of Atropine and Survival After Adult In-Hospital Cardiac Arrest With Non-Shockable Rhythms

Abstract

Introduction: Atropine was removed from the 2010 American Heart Association’s Advanced Cardiac Life Support guidelines as routine management of non-shockable cardiac arrest, although the evidence to support or refute the use of atropine is lacking. In a previous study, atropine usage was shown to subsequently decline markedly. Whether removing atropine from the guidelines has affected survival remains unknown. Methods: Using the Get With The Guidelines®-Resuscitation registry, we included adult patients with an index in-hospital cardiac arrest between 2006-2015. Non-shockable and shockable cardiac arrest patients with high vs. low propensity score to receive atropine were separated into two cohorts. An interrupted time-series analysis was used to compare survival before (pre-exposure) and after (post-exposure) introduction of the 2010 guidelines. A difference-in-difference approach was used to compare the interrupted time-series results between the non-shockable and shockable cohorts to account for guideline changes unrelated to atropine. Results: We included 21,822 non-shockable and 4,268 shockable cardiac arrests. Patient characteristics were similar between the pre-exposure and post-exposure period. Atropine was used for 9,170 (86%) non-shockable and 733 (34%) shockable cardiac arrests in the pre-exposure period and 3,903 (35%) non-shockable and 339 (16%) shockable cardiac arrests in the post-exposure period. The change over time in survival from the pre-exposure to the post-exposure period was not significantly different for the non-shockable compared to the shockable cohort (mean difference: 2.0% [95%CI: -0.7, 4.6] per year, p = 0.15, Figure). The immediate change in survival after introducing the guidelines was also not different between the cohorts (mean difference: 3.9% [95%CI: -2.2, 10], p = 0.21, Figure). Conclusions: The removal of atropine from the 2010 guidelines was not associated with a change in survival in our analysis.