Are drone-delivered AEDs the future of out-of-hospital cardiac arrest survival?

February 21, 2020
By Vivian Nguyen

According to 2018 statistics from the American Heart Association (AHA), the incidence of out-of-hospital cardiac events (OHCA) assessed by emergency medical services (EMS) personnel is only 141 people per 100,000 population.
Nationwide, between 180,000 and 400,000 deaths caused by cardiovascular disease overall are sudden, unpredictable cardiac deaths — many of which occur outside of the hospital and potentially are not assessed by EMS personnel at all.

Further research published in the journal Circulation confirmed automatic external defibrillators (AEDs) significantly improve survival after cardiac arrest episodes. For over 50 years, research has shown return of spontaneous circulation (ROSC) is not likely achieved via a defibrillator if the shock was delivered more than three minutes after pulseless, shockable rhythm onset. However, many organizations, including the AHA, have adopted the eight-minute standard, which is the target time from the dispatcher receiving the emergency call to arrival of a defibrillator on scene. Researchers tested this eight-minute standard and discovered that a mere reduction of one minute can save an additional 23 lives per year, and a reduction of two minutes save up to 51 more lives per year. So why set the bar at eight minutes?

Traditionally, patients who need emergency defibrillation have two methods of obtaining a shock via AED: 1) a bystander who finds and accesses a static AED in a public location or 2) provided by EMS who arrive on scene. Time required for AED arrival is heavily impacted by AED accessibility and EMS coverage, especially in rural, less accessible regions, compared to urban areas.

Research examining AED accessibility and its effects on AED coverage over 17 years found that 61.8 percent of all cardiac arrests occurred in public locations. However, AED coverage in public locations decreased significantly by 53.4 percent outside of normal business hours such as evenings and weekends. Rural areas have even more difficulty accessing timely lifesaving treatment, due to far distances from a dispatch center in conjunction with decreased volume of public AEDs overall.

Drones are already being used worldwide after major natural disasters, including the Haiti earthquake in 2010, hurricane Sandy in 2012, and the Nepal earthquake in 2015, delivering small aid packages across terrain that was unsafe via land travel. Since then, the uses of drones to assist in efficient, cost-effective delivery of healthcare have been countless. Previous studies have already proved that drones are a safe and feasible alternative for providing delivery of blood products, vaccines, and testing kits, especially to communities with poor road systems, disease endemic areas, or that have limited healthcare provider availability. Theoretically, if drones can deliver AEDs faster than traditional EMS response times to provide timely shocks, then OHCA mortality could decrease significantly. Are drones the future’s answer to saving lives?

Upon further research, three studies were found to have conducted the most extensive analysis on how influential AED drones could be in increasing survival rates. One study conducted in Sweden found that AED-equipped drones were predicted to arrive before EMS responders 93 percent of the time in rural OHCA cases; which saved an average of 19 minutes in travel time. Another study in Salt Lake City, Utah found using pre-existing EMS infrastructure in addition to establishment of new drone launch sites provided 90.3 percent coverage of the intended area within a 1-minute time frame. Finally, a study in Toronto assessed a region-specific network, which revealed that AED-equipped drones arrived before emergency responders in 94.6 percent of cases for the three-minute response reduction goal.

All of these studies theoretically concluded that a drone network equipped with AEDs has great potential to speed up arrival time to an OHCA. This preliminary research illustrates that drones can help save cardiac arrest patients in not only rural settings, but also in high building locations, mountainous areas, or other settings lacking rapid AED access.

Drones can provide 24/7 AED availability to both public and private locations and provide life-saving support to the bystander and the OHCA victim. Drones can be equipped with video, voice, and speaker capabilities the dispatcher can use to help guide the bystander through pre-hospital care including high-quality CPR before EMS arrival. The dispatcher can also assess situational safety for both the patient and bystander simultaneously to prevent further adverse events for all parties.

Because the studies used mathematical models to simulate drone deliveries, they did not account for possible adverse weather conditions, operational error, or technical malfunctions of the AED devices, which are all very realistic limitations to drone deliveries of any kind. Studies that control for the aforementioned factors should be performed in the future to properly assess the efficacy of drone-delivered AEDs on OHCA mortality rate specifically.

The likelihood of a layperson to use an AED is yet another challenge to face. Though AEDs provide clear instructions, many people are either unfamiliar with an AED and its functions or are uncomfortable utilizing it when needed. However, delivery of AEDs to bystanders gives them a chance at administering a shock to a cardiac arrest patient as opposed to not having AED access at all.

Further research also shows that bystanders’ experiences with retrieving AEDs via drones felt safe and overall provided a sense of helpfulness and relief. Integrating a drone network into society’s daily life may increase comfort and public acceptance overall in order to successfully deliver AEDs via drone. Overall, AED-equipped drones would add another link that must be worked seamlessly into the chain of survival.

Agencies such as the Federal Aviation Administration (FAA) and other governmental entities would require policy and guideline changes specifically addressing medical drones and flight restrictions. Security of patient information in compliance with HIPAA would need to be carefully considered as well. Production and maintenance costs of adding drones into the chain of command in addition to existing EMS infrastructure is another avenue that should be explored.

Beginning in 2017, the Unmanned Aircraft System (UAS) Integrative Pilot Program (IPP) in partnership with the U.S. Department of Transportation (USDOT) and the FAA have made significant advancements toward safe drone integration at both local and national levels. The City of Reno, Nevada was chosen as an IPP Lead Participant site and chose Flirtey as their partner, a Reno-based drone delivery company established in 2013 as the first drone delivery service in the world. The project focuses on drones to deliver AEDs to decrease OHCA mortality.

These partners have been granted ability to fly drones beyond a pilot’s visual line of sight, conduct night operations, and fly over people, all of which were significant barriers previously to integration of drone networks. This program will integrate established EMS infrastructure that will provide opportunity for an AED-equipped drone to be dispatched at the same time EMS responders are deployed. The project is set to officially launch in 2020.

Vivian Nguyen
About the author: Vivian Nguyen, PA-C was born and raised in Albuquerque, NM. She received her Bachelor of Science in Exercise Science from the University of New Mexico. She recently graduated with her Master of Physician Assistant Studies from Pacific University in Hillsboro, OR where she completed her capstone project researching drone-delivered AEDs and their possible impacts on survival rates. She currently practices as a certified physician assistant in Emergency Medicine in western Colorado.