Published in the European Heart Journal, the multi-partner study saw drones deploy defibrillators to several cardiac emergencies that took place in the cities of Gothenburg and Kungälv in the summer of 2020. During the four-month pilot, drones took off in response to 12 out of 53 alerts of suspected cardiac arrest, and successfully delivered an automated external defibrillator (AED) to the site in 11 of those cases. In seven instances, the drones arrived before the ambulance, with a median time benefit of 1 minute and 52 seconds.
“This is the first time in the world that a research group can report results from a study where drones flew defibrillators to location of real-life alerts of suspected cardiac arrest,” said lead researcher Andreas Claesson, an Associate Professor at Sweden’s Karolinska Institute.
Despite the success of the trial, none of the drone-delivered defibrillators were actually used on patients at the scene of the emergencies. The research team - which also included Sweden’s national emergency operator SOS Alarm, Region Västra Götaland and drone operator Everdrone AB - says future trials will require the drone dispatcher to interact with members of the public on the scene in order to give instructions on the use of the AED.
“Even if none of the AEDs were used this time, our study shows that it is possible to use drones to transport defibrillators in a safe way and with target precision during real-life emergencies,” said first-author Sofia Schierbeck, a PhD student at the Karolinska Institute’s Centre for Resuscitation Science. “A precondition for their future use is that the dispatcher takes initiative and instructs people on site to quickly collect and attach the AED in order to help the person with cardiac arrest.”
While the drones outpaced ambulances in just over half of the instances they were deployed, the researchers claim that further improvements to the system could increase dispatch rate and time benefits. For example, during the study, drones were prevented flying when it was dark, raining or in winds of eight meters per second or more, and were programmed to avoid flying over densely populated areas. With tweaks to these parameters, the capabilities could be boosted.
“Since this study was completed, we have identified several areas of improvement,” said Claesson.
“In April this year, we began a follow-up study with a more optimised system. In that study, we want to test if we can use the drones in more alerts and reduce the response time further and thereby increase the time benefit as compared to the ambulance. Every minute without treatment in the early stages reduces the chance of survival by around 10 percent, and that is why we believe this new method of delivery has the potential to save lives.”