Introduction

Out-of-hospital cardiac arrest (OHCA) poses a tough medical challenge with poor survival rates. Factors that may enable survival include resuscitation measures initiated by a bystander, early use of an automated external defibrillator (AED), and further performance of advanced life support. The latter will arrive on scene with an inevitable time-delay due to logistics challenges and potential AED unavailability, especially in rural areas. Here, drones might deliver an AED in order to increase the probability of survival.

Methods

Nineteen medical laypersons who were hiking in a mountainous region (Bodental, Carinthia, Austria) were confronted with a person suffering from OHCA within a field test scenario without detailed information. The scenario included a mock-call to the emergency response center responsible for the Austrian State Carinthia that dispatched a semi-autonomously flying drone towards the caller’s GPS coordinates. During the emergency call, participants should perform cardiopulmonary resuscitation (CPR) measures and were informed that a drone delivers a training-AED. Various timepoints (time to (tt) emergency call, tt start CPR, tt drone start, tt first shock, hands-off times) as well as CPR quality were subject of analysis.

Results

Only 37 % of the participants reported to know the algorithms for basic life support. On average, the cardiac arrest was realized after 62 ± 72 seconds. Almost half of the laypersons called the emergency number before identifying the cardiac arrest. All laypersons started chest compressions, 73 % compressed the chest more than 45 millimeters, 50 % reached a compression frequency of more than 100 per minute, 72 % performed the chest compressions more than 80 % of the time at the correct position, and 67 % managed to perform sufficient mouth-to-mouth ventilation. All participants were advised via mobile phone by an emergency call taker or in case of a loss of the telephone connection through a paramedic on stage. The drone equipped with an AED was activated in mean after 6:30 ± 1:21 minutes and dropped an AED after 10:33 ± 1:52 minutes. Hands-off times to place the defibrillation electrodes were 2:11 ± 0:39 minutes. The first shock was delivered in mean after 14:15 ± 2:08 minutes. All laypersons used the AED correctly and continued basic life support until the end of the scenario. We observed no safety issues and in a post-trial interview, all laypersons stated to not have felt at risk by the appearance of the drone.

Conclusion

CPR quality performed by medical laypersons is suboptimal and emphasises the need for regular trainings. The delivery and usage of an AED via a semi-autonomously flying drone in a remote region is feasible and safe. The drone delivery of an AED in mountainous regions can lead to early application of shocks.