Drones could dramatically improve survival rates for out-of-hospital cardiac arrests

Every minute matters when someone's heart stops beating outside a hospital. In the United Kingdom alone, more than 30,000 people suffer out-of-hospital cardiac arrests each year, and emergency services attempt resuscitation in most of these cases. Yet the survival rate remains grim: fewer than one in ten make it. Among those who do survive, some face lasting neurological damage. The difference between life and death often comes down to a single factor—how fast a defibrillator reaches the patient. Each minute without CPR and defibrillation cuts survival chances by 10 percent.

Researchers in France have begun exploring whether drones could close this gap. A team led by Matthieu Heidet, a professor of emergency medicine at Henri-Mondor university hospital in Créteil, analyzed nearly 28,350 out-of-hospital cardiac arrests that occurred between 2011 and 2024 across the Greater Paris area, excluding central Paris itself. They cross-referenced each incident with the locations of 1,893 fixed automated external defibrillators already in place. What they found was stark: only 30 percent of cardiac arrests happened within 500 metres of the nearest defibrillator. To achieve 84.5 percent coverage using only ground-based devices, the region would need to install an additional 910 fixed defibrillators. Full coverage would require 1,712 more.

Drones offered a different calculus. The researchers modeled what would happen if defibrillators could be delivered by unmanned aircraft operating within a 3,900-metre radius. The numbers shifted dramatically. With 100 drone bases and just 26 additional fixed defibrillators, more than 97 percent of cardiac arrest cases would fall within either 500 metres of a fixed device or roughly 4 kilometres of a drone base. Increase the drone bases to 200 and reduce additional fixed devices to four, and coverage exceeded 99 percent.

Dr Hillary Minka, an emergency physician at Lariboisière hospital in Paris and lead author of the study, examined another critical measure: how many cardiac arrests could be reached within five minutes using existing infrastructure. The answer was sobering. Only 30 to 40 percent of cases had access to a fixed defibrillator within that window using ground transportation. Heidet noted this figure was optimistic anyway. In France, he said, only 8 percent of out-of-hospital cardiac arrest patients actually receive a public defibrillator before emergency services arrive, partly because many devices sit locked inside private buildings that are not accessible around the clock.

When Minka modeled a scenario with 200 drone bases, 871 existing fixed defibrillator sites, and four additional fixed devices, drone delivery reached virtually all cardiac arrest cases within five minutes. The drones would be stationed at locations ranging from current defibrillator sites to fire stations and mobile intensive care units. Once an emergency dispatcher identifies a cardiac arrest, the drone is activated and follows an automated flight path. A trained pilot handles the final approach and delivery. Once on the ground, the defibrillator can be used by anyone present at the scene.

This is not theoretical. Sweden has already deployed drone-based defibrillator systems in real-world conditions, and they have saved lives. Heidet acknowledged that cost remains a significant consideration—the economic feasibility of such a system must be weighed against its potential to save lives. The study, which has not yet undergone peer review, will be presented at the European Emergency Medicine Congress in Paris this weekend. What remains to be seen is whether other regions will adopt the model and whether the investment in drone infrastructure can be justified against the alternative: continuing to watch three out of every four out-of-hospital cardiac arrest patients die.