Life-Saving Defibrillators: Delivered!

Annually, over 400,000 out of hospital cardiac arrests (OHCA) occur in the United States (US) with a survival rate of only 10%.¹ Reasons for high mortality include lack of access to care and medical equipment. Bystanders may not have the training to perform cardiopulmonary resuscitation (CPR) and the average emergency medical services (EMS) response time may vary depending on location, approximately 8 minutes.²  Automated external defibrillators (AEDs) can increase survival rate to 40% when available.³ For every minute without CPR and defibrillation, survival decreases by approximately 10%.³ So, what if there was a way to deliver AEDs to OHCAs?

At ESC Congress 2021, Dr. Sofia Schierbeck of Karolinska University Hospital in Stockholm, Sweden presented the first feasibility study evaluating AED delivery via drones for OHCAs, published in the European Heart Journal.⁴ The study involved three automated drone-systems with a primary outcome of successful AED deliveries when drones were dispatched. Among secondary outcomes was the proportion of cases where AED drones arrived prior to ambulance. During the study period, when dispatch centers indexed a suspected cardiac arrest during an emergency call, an automated alert was sent to the drone pilot who would then initiate pre-flight checks flight systems with route-planning software. The drones then flew, autonomously and out of sight, to the coordinates of the suspected OHCA, where the pilot manually approved drop point and initiated AED delivery.

Out of the 14 drones dispatched for OHCA, 11 were successfully delivered. The median distance to location was 3.1 km. AEDs arrived prior to EMS in 64% of cases, approximately two minutes earlier, conceivably improving survival rates.

The implications of this study are vast. First, medical equipment can be delivered via drone delivery systems. This is necessary in areas that are otherwise under-staffed by medical professionals or lack of access to equipment, especially in rural communities. Second, drones may be faster than EMS, decreasing the amount of time for initiation of defibrillation which can help decrease OHCA mortality.

While this study was conducted in Sweden, there are studies conducted in the US which evaluate the efficiency of AED drone delivery with similar results. However, more studies will be needed to determine: 1) feasibility of AED drone deliveries in the US in different environments and 2) economic or financial constraints vs. benefits AED drone deliveries sustain. In the right setting, AED drone deliveries may be the key to saving lives in record time.

References

1. Meaney PA, Bobrow BJ, Mancini ME, et al. Cardiopulmonary resuscitation quality: improving cardiac resuscitation outcomes both inside and outside the hospital: a consensus statement from the American Heart Association. Circulation. 2013;128(4):417-435.tion. 2013;128(4):417-435.
2. Nichol G, Thomas E, Callaway CW, et al. Regional variation in out-of-hospital cardiac arrest incidence and outcome. JAMA. 2008;300:1423-1431.
3. Link MS, Atkins DL, Passman RS, et al. 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care (Part 6). Circulation. 2010;122(suppl 3):S706 –S719.
4. Schierbeck S, Hollenberg J, Nord A, et al. Automated external defibrillators delivered by drones to patients with suspected out-of-hospital cardiac arrest, Euro Heart J. 2021;doi.org/10.1093/eurheartj/ehab498