Drones could help reduce the time it takes to deliver a defibrillator to people experiencing cardiac arrests outside of hospital, according to new research.
In the UK alone, there are more than 30,000 out-of-hospital cardiac arrests each year where emergency medical services attempt resuscitation, according to the British Heart Foundation. However, fewer than one in 10 people survive such an event, and some survivors are left with neurological problems.
One critical factor affecting survival is how quickly victims receive treatment — every minute without CPR and defibrillation reduces the chance of survival by 10%.
Study Analyzes Cardiac Arrest Data
To explore the issue, the team analyzed the number and location of 28,349 out-of-hospital cardiac arrests that occurred between 2011 and 2024 in administrative areas within the Greater Paris area, excluding central Paris. They cross-referenced these events with the location of fixed automated external defibrillators (AEDs).
The researchers found that accessibility of the 1,893 AEDs varied considerably across the area. “Only 30% of all [out-of-hospital cardiac arrest] cases occurred within the target 500-metre network distance of the nearest recorded fixed AED,” said Dr Hillary Minka, an emergency physician at the Lariboisière hospital in Paris and first author of the work.
The team found that an extra 910 fixed AEDs would be needed for 84.5% of recorded cardiac arrest cases to be within 500 metres of an AED, while 1,712 extra fixed AEDs would be needed for 100% coverage.
Drones Reduce Need for Fixed Devices
However, by using drones operating within a radius of 3,900 metres, coverage could be increased with fewer devices. “As drone bases were introduced, the number of additional fixed AEDs required fell substantially,” said Minka, noting that with 100 drone bases and 26 additional fixed AEDs, more than 97% of cardiac arrest cases would be located either within 500 metres of a fixed AED or within approximately 4km (2.5 miles) of a drone base. Using 200 drone bases and just four extra AEDs meant more than 99% of cases would have been covered.
The researchers also examined the proportion of cardiac arrest cases deemed close enough to an existing fixed AED that the device could be retrieved in a round trip within five minutes. The results revealed only 30-40% of cases had access to current fixed AEDs within this time period using the ground transportation network.
Heidet added that this figure was optimistic. “In France, only 8% of out-of-hospital cardiac arrest patients benefit from the application of a public AED before the arrival of the [emergency services],” he said, noting one factor is that a large proportion of AEDs are inaccessible, for example because they are housed in enclosed private spaces that are not open at all times.
By contrast, Minka noted that in a scenario involving 200 drone bases, 871 existing fixed AED sites and four additional fixed AED sites, drone delivery reached virtually all of the cardiac arrest cases covered by the model within five minutes.
Real-World Implementation
The team’s models were based on drones being housed at sites ranging from current AED locations to fire stations and mobile intensive care units, and did not look at real-world deployment of such technology. Heidet noted it is not the first time drones have been considered for AED delivery; the approach is already being used in parts of Sweden and has saved lives.
In real-world systems, Heidet added, drones are operated by trained drone pilots. “Once an emergency call is received and an [out-of-hospital cardiac arrest] is identified at the dispatch centre, the drone is activated by EMS dispatchers. It then takes off and follows an automated flight path, while the final approach and subsequent AED delivery are handled by the drone pilot. The entire process is conducted under the supervision of the emergency medical service,” he said. Once delivered, the AED can be used by members of the public at the scene.
Heidet added that the cost of drones needed to be integrated into the evaluation of such technology, noting there may be a balance between the ideal model and the feasible economic model. The study, which has not yet been peer-reviewed, is to be presented at the European Emergency Medicine Congress in Paris on Saturday.
