Abstract 243: Drone-delivery Of Automated External Defibrillators Before Ambulance Arrival In Suspected Out-of-hospital Cardiac Arrest

Introduction: Early defibrillation is essential for increasing survival in out-of-hospital-cardiac-arrest (OHCA). Previous studies on AED-delivery using drones have shown that the method is feasible and has potential to shorten time to defibrillation. However, it is still unclear if drones can deliver AEDs before ambulance arrival with clinically relevant time benefits in real-life suspected OHCA. Our aim was to investigate if drones, used as a complement to standard care, can deliver AEDs before ambulance arrival in real-life suspected OHCA in Sweden. Method: Five AED-equipped drones were placed in separate sectors within two controlled airspaces around Gothenburg, Sweden. In cases of suspected OHCA during a study period of 11 months, a drone was dispatched by the dispatch center. A drone operator deployed and remotely surveilled the autonomously responding drone (beyond visual line of sight), which on arrival winched down an AED. The dispatchers then instructed the callers to retrieve the AED. The drone range one-way was 6 kilometers and the drone had a velocity of approximately 60 km/h. Alerts to no-fly zones and alerts in rain and wind > 8 m/s were excluded. Time to AED delivery was compared to standard of care ambulance delay in each case. Results: A total of 223 suspected OHCA were observed in the study areas. In 72 (32%) cases a drone took off, out of these an AED was delivered in 58 (81%) cases. In 56 cases, arrival times for both drone and ambulance were available. The AED-delivery occurred prior to ambulance arrival in 36 of these cases (64%) with a median time benefit of 3 min and 14 sec. Totally 6 patients (11%) had an AED attached, amongst them two were defibrillated and one patient survived 30 days. The main reasons for non-flights were weather conditions (16%), cancelled by dispatch center (17%) and service offline (13%). Conclusion: The use of AED-equipped drones has potential to enable AED delivery prior to ambulance arrival in many cases of suspected OHCA and the time benefit seen in this study indicates potential to facilitate defibrillation before ambulance arrival. However, more improvements and studies are needed to further increase time benefits and the proportion of cases where an AED is attached and used before ambulance arrival.