Effect of topography and weather on call to automatic electrical defibrillator attach time by drone for out-of-hospital cardiac arrest: a virtual flight simulation study

Abstract Background Delivery of automatic electrical defibrillator (AED) by unmanned aerial vehicle like drones was suggested to improve early defibrillation for out-of-hospital cardiac arrest. We developed a drone-AED flight virtual simulator using 3-dimensional topographic and meteorological information. The goal of this study is to assess the effect of topography and weather on call to AED attach time in drone-AED program. Methods We included patients from 2013 to 2016 in Seoul, South Korea, registered in the Korean out-of-hospital cardiac arrest registry. We developed a drone-AED flight simulation using topographic information of Seoul for Euclidean flight pathway and topographic flight pathway including vertical flight to overcome high-rise structures. We used 4 drone flight scenarios according to weather conditions or visibility: flight and control advanced drone, flight advanced drone, control advanced drone and basic drone. Primary outcome was emergency medical service call to AED attach time. Secondary outcome was success rate of call to AED attachment within 5 or 10 minutes, and pre-arrival rate of drone-AED before AED delivery by ground ambulance. Results 16,596 patients were included. Median flight time of drone-AED was 2.6 and 1.0 minute for topographic flight simulation and Euclidean pathway. Call to AED attach time in topographic pathway was 7.0 minutes in flight and control advanced drone and 8.0 minutes in basic drone. The time in Euclidean pathway was 6.5 minutes in flight and control advanced drone and 7.0 minutes in basic drone. Pre-arrival rate of drone-AED in Euclidean pathway was 38.0% and 16.3% for flight and control advanced drone and basic drone. whereas, pre-arrival rate in the topographic pathway was 27.0% and 11.7%, respectively. Conclusions Drone-AED took longer call to AED attach time in basic drone than flight and control advanced drone. Pre-arrival rate of flight and control advanced drone was decreased in topographic flight pathway compared to Euclidean pathway. Trial registration This study used cases retrospectively registered in the Korean out-of-hospital cardiac arrest registry.