Delivering an automated external defibrillator (AED) by drone is feasible and often faster than having bystanders to out-of-hospital cardiac arrest (OHCA) search nearby buildings for an AED, according to a pilot study conducted on the campus of University of North Carolina at Chapel Hill.
“We see this as a first step to integrating drone technology in existing EMS systems to improve access to timely defibrillation,” Wayne Rosamond, PhD, from the Global School of Public Health at UNC-Chapel Hill, told theheart.org | Medscape Cardiology.
The study was published in the September 17 issue of the New England Journal of Medicine.
Each year, about 350,000 people in the United States suffer an OHCA, and only about 10% survive. Survival is most likely when CPR and defibrillation are administered within 5 minutes of the onset of the cardiac arrest. However, the median arrival time of EMS is the 8 minutes in most of the country, but in remote areas, that can extend to 30 minutes.
In their study, Rosamond and colleagues used GPS technology to deliver AEDs by drone 35 times to five different locations on the UNC campus, selected to present different environmental obstacles to drone navigation and to bystanders who had to retrieve the AED.
Participants were UNC students, staff, and faculty. In each test, an OHCA was simulated with the use of a life-size mannequin and two “bystanders” present at the scene. One would call a mock 911 operator, a research assistant on the other side of campus, who would initiate the drone’s autonomous flight. At the same time, the other person went in search of an AED.
“We wanted to test whether you can actually get a drone to fly on its own and find the right place to land safely, and to see how long it takes relative the current situation, where a bystander to a heart attack might try to find an AED somewhere in the environment. We wanted to see which one got there first.”
“The drone landed safely, every time, within 10 feet of the person, and it usually beat a person trying to find an AED,” Rosamond said.
“In fact, oftentimes the person had a lot of difficulty finding an AED, didn’t know where to go. Sometimes they would go to a building and the door would be locked. They were actually quite frustrated with trying to find it,” he noted.
For the five locations, the median time from drone launch to drone arrival with the defibrillator ranged from about 2 to 2.5 minutes. In contrast, it took the bystander up to 4 minutes to retrieve an AED, depending on the zone.
With the drone, the time from cardiac arrest to AED delivery was between 4 and 5 minutes. With the bystander search, time to AED delivery was between 4 and 8 minutes.
There was one outlier zone that did better than the drone. “We selected this zone because we knew it would be a challenge for the drone to win,” Rosamond said. “This zone was right in front of the Student Union, next to the bookstore and the library, and there are seven or eight AEDs within 50 feet, so the person won that time,” he said.
All the participants reported that they would be willing to access an AED drone-delivery system in a true OHCA.
Drones are already being used to transport vital medicines — including vaccines, blood products, and insulin — to remote areas of the world and during disasters.
Support for the study was provided by from the National Center for Advancing Translational Sciences (NCATS), part of the National Institutes of Health. Rosamond has received grants from NCATS.
N Engl J Med. 2020;383:1186-1188. Abstract