Abstract 421: Automated External Defibrillator Implementation Gaps in Three Non-Urban U.S. Communities

Abstract

Introduction: Automated external defibrillators (AEDs) represent a crucial component of bystander response to out-of-hospital cardiac arrest (OHCA), yet epidemiologic evidence suggests that AEDs are deployed by laypersons in less than 5% of OHCA events in the US. The reasons for low utilization remain poorly characterized, especially in rural/suburban environments. We hypothesized that in these non-urban environments, layperson AED use is mostly in commercial or public locations despite most arrests occuring in private residences. Methods: We conducted an analysis of EMS-treated atraumatic OHCA events from 3 non-urban US regions (Cumberland County, PA; Jackson, TN; Forsyth County, GA), abstracted from EMS patient care reports. Data included Utstein reporting elements, arrest location type, and response intervals as calculated by dispatch and EMS arrival times. We excluded events in skilled nursing facilities and prisons. CPR and AED delivery by laypersons was measured. Results: Between 12/8/17-12/31/21, we identified 1542 adult OHCA patients with median age 66.5 y (IQR 22.5), 37% female, 18% had initial shockable rhythms, and 75% occurred in private residences. Return of spontaneous circulation was obtained in 19% of cases. Bystander CPR was performed in 23% and AEDs were deployed by laypersons in 3%. Laypersons applied AEDs in 12% of OHCA in commercial locations, 6% of OHCA in public, and 3% of OHCA in private residences. EMS response times were 4% less than 4 min, 48% 4-9 min, and 48% >9 min; prevalence of AED use was indistinguishable between time intervals of EMS response. 16% OHCA victims still had initial shockable rhythms even among the >9 min EMS response cases; of these, 1% received AED use from laypersons. Conclusion: In three non-urban US regions, most arrests occurred in private residences while AED use was much more likely in public or commercial locales, suggesting an important gap in AED deployment. Even in cases with prolonged response times, many patients had shockable rhythms, suggesting an important opportunity for earlier AED deployment. Future work will test whether placement of AEDs in residential areas using trained volunteer responders in these same communities will improve OHCA response and survival outcomes.