Drone-delivered automated external defibrillators for out-of-hospital cardiac arrest: A simulation-based feasibility study

Abstract

Background Cardiopulmonary resuscitation (CPR) and defibrillation markedly increases survival following out-of-hospital cardiac arrest (OHCA). Members of the public can perform both before the ambulance service arrives. However, bystanders use a public-access Automated External Defibrillator (AED) in around 5% of cases. Using Unmanned Aerial Vehicles (‘drones’) to deliver AEDs may overcome many of the barriers preventing public-access AED use. The study team investigated how quickly and easily bystanders performing CPR could use drone-delivered AEDs. Methods The study team developed an AED-capable drone between May and November 2020 and conducted 18 OHCA simulations in July and September 2021. A single participant found a simulated patient inside a building and made a 999-call to a Welsh Ambulance Services NHS Trust call-handler. Once cardiac arrest was confirmed during the 999-call a nearby drone launched, reached hovering altitude and delivered the AED immediately outside the building. The participant retrieved the AED when instructed to do so, attached it to the patient and delivered a single shock. The primary outcome was hands-off CPR time. Secondary outcomes included ease of AED retrieval, by using a questionnaire adapted from the System Usability Scale and exploring participant behaviours via post-simulation interviews and reviews of audio and video recordings of the simulation. Results Hands-off CPR time was (median) 109 s (interquartile range 87–130 s). Participants spent 19 s (16–22 s) away from the patient's side when retrieving the AED. Participants found it easy to use the AED but often sought the call-handler's reassurance that it was appropriate to retrieve it. Conclusion Participants found it easy to retrieve and use an AED delivered by drone in simulated OHCAs. Hands-off CPR time was potentially clinically relevant in this lone bystander simulation, but there was only a small increase in hands-off time caused by retrieval of the drone-delivered AED.