Aims  Early defibrillation is critical for the chance of survival in out-of-hospital cardiac arrest (OHCA). Drones, used to deliver automated external defibrillators (AEDs), may shorten time to defibrillation, but this has never been evaluated in real-life emergencies. The aim of this study was to investigate the feasibility of AED delivery by drones in real-life cases of OHCA. Methods and results  In this prospective clinical trial, three AED-equipped drones were placed within controlled airspace in Sweden, covering approximately 80 000 inhabitants (125 km2). Drones were integrated in the emergency medical services for automated deployment in beyond-visual-line-of-sight flights: (i) test flights from 1 June to 30 September 2020 and (ii) consecutive real-life suspected OHCAs. Primary outcome was the proportion of successful AED deliveries when drones were dispatched in cases of suspected OHCA. Among secondary outcomes was the proportion of cases where AED drones arrived prior to ambulance and time benefit vs. ambulance. Totally, 14 cases were eligible for dispatch during the study period in which AED drones took off in 12 alerts to suspected OHCA, with a median distance to location of 3.1 km [interquartile range (IQR) 2.8–3.4). AED delivery was feasible within 9 m (IQR 7.5–10.5) from the location and successful in 11 alerts (92%). AED drones arrived prior to ambulances in 64%, with a median time benefit of 01:52 min (IQR 01:35–04:54) when drone arrived first. In an additional 61 test flights, the AED delivery success rate was 90% (55/61). Conclusion  In this pilot study, we have shown that AEDs can be carried by drones to real-life cases of OHCA with a successful AED delivery rate of 92%. There was a time benefit as compared to emergency medical services in cases where the drone arrived first. However, further improvements are needed to increase dispatch rate and time benefits. Trial registration number ClinicalTrials.gov Identifier: NCT04415398.

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Background: Early defibrillation is essential for increasing the chance of survival in out-of-hospital-cardiac-arrest (OHCA). Automated external defibrillator (AED)-equipped drones have a substantial potential to shorten times to defibrillation in OHCA patients. However, optimal locations for drone deployment are unknown. Our aims were to find areas of high incidence of OHCA on a national level for placement of AED-drones, and to quantify the number of drones needed to reach 50, 80, 90 and 100% of the target population within eight minutes.Methods: This is a retrospective observational study of OHCAs reported to the Swedish Registry for Cardiopulmonary Resuscitation between 2010 À2018. Spatial analyses of optimal drone placement were performed using geographical information system (GIS)-analyses covering high-incidence areas (>100 OHCAs in 2010À2018) and response times.Results: 39,246 OHCAs were included. To reach all OHCAs in high-incidence areas with AEDs delivered by drone or ambulance within eight minutes, 61 drone systems would be needed, resulting in overall OHCA coverage of 58.2%, and median timesaving of 05:01 (min:sec) [IQR 03:22À06:19]. To reach 50% of the historically reported OHCAs in <8 min, 21 drone systems would be needed; for 80%, 366; for 90%, 784, and for 100%, 2408.Conclusions: At a national level, GIS-analyses can identify high incidence areas of OHCA and serve as tools to quantify the need of AED-equipped drones. Use of only a small number of drone systems can increase national coverage of OHCA substantially. Prospective real-life studies are needed to evaluate theoretically optimized suggestions for drone placement.

Background Early defibrillation is critical for the chance of survival in in out-of-hospital cardiac arrest (OHCA). Drones, used to deliver automated external defibrillators (AEDs), may shorten time to defibrillation, but this has never been evaluated in real-life emergencies. Purpose The aim of this study was to investigate the feasibility of AED-delivery by drones in real-life cases of OHCA. Methods In this prospective clinical trial, three AED-equipped drones were placed within controlled airspace in Sweden, covering approximately 80,000 inhabitants (125km2). Drones were integrated in the emergency medical services for automated deployment in beyond-visual-line-of-sight flights in; a) consecutive real-life suspected OHCAs b) test-flights from 06–01–20 to 09–30–20. Primary outcome was the proportion of successful AED-deliveries when drones were dispatched in cases of suspected OHCA. Among secondary outcomes were the proportion of cases where AED-drones arrived prior to ambulance and time benefit vs. ambulance. Results Totally 14 cases were eligible for dispatch during the study period in which AED-drones took off in 12 alerts to suspected OHCA; with a median distance to location 3,1 km (IQR:2,8–3,4). AED-delivery was feasible within 9 meters (IQR:7,5–10,5) from the location and successful in 11 alerts, 92%. AED-drones arrived prior to ambulances in 64%, with a median time benefit of 01:52 minutes (IQR:01:35–04:54). In an additional 61 test-flights the AED-delivery success rate was 90% (55/61). Conclusion In this pilot study, we have shown that AED-delivery by drones in real-life cases of OHCA is feasible with a substantial time benefit and a successful delivery rate of 92%. Further technological improvements are needed to increase dispatch rate and time gains. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Swedish heart-lung foundation