Drones could deliver defibrillators faster than ambulances

Researchers at Karolinska Institutet in Sweden have been testing whether drones carrying defibrillators could get to heart attack patients quicker than ambulances.

In more than half of cases in the experiment in western Sweden, the drones beat the ambulance by an average of three minutes, and the drone-delivered automated external defibrillator (AED) was used in more than half of the cases. 

"The use of an AED is the single most important factor in saving lives," says Andreas Claesson, Associate Professor at the Center for Cardiac Arrest Research at the Department of Clinical Research and Education, Södersjukhuset, Karolinska Institutet.

"We have been deploying drones equipped with AED since the summer of 2020 and show in this follow-up study that drones can arrive at the scene before an ambulance by several minutes. This lead time has meant that the AED could be used by people at the scene in several cases." 

Using an AED can drastically improve the prospects for people who suffer a cardiac arrest, and although there are now thousands in the community, they are not available in people's homes, which is where most cardiac arrests occur. 

Karolinska Institutet has been working with the drone operator Everdrone since 2020 to send out a drone at the same time as an ambulance is alerted, covering an area of approximately 200,000 people in Western Sweden. They began with a pilot study and have just published the results of a follow-up. 

“This more comprehensive and follow-up study now shows in a larger material that the methodology works throughout the year, summer and winter, in daylight and darkness. Drones can be alerted, arrive, deliver AED, and people on site have time to use the AED before the ambulance arrives," says Sofia Schierbeck, PhD student at the same department and first author of the study.   

During the study, drones delivered an AED 55 times to cases of suspected cardiac arrest, and in 37 of those cases it arrived before the ambulance, with an average gap of 3 minutes and 18 seconds. Eighteen of those cases were actual cardiac arrests, and the AED was used six times—saving at least one life. 

“Our study now shows once and for all that it is possible to deliver AED with drones and that this can be done several minutes before the arrival of the ambulance in connection with acute cardiac arrest," says Claesson. “This time saving meant that the healthcare emergency centre could instruct the person who called the ambulance to retrieve and use the AED in several cases before the ambulance arrived."