Drones for Automated External Defibrillator Delivery: Where Do We Stand?

AED delivery at night - Can drones do the Job? A feasibility study of unmanned aerial systems to transport automated external defibrillators during night-time

BACKGROUND

In their recent guidelines the European Resuscitation Council have recommended the use of Unmanned Aerial systems (UAS) to overcome the notorious shortage of AED. Exploiting the full potential of airborne AED delivery would mandate 24 h UAS operability. However, current systems have not been evaluated for nighttime use. The primary goal of our study was to evaluate the feasibility of night-time AED delivery by UAS. The secondary goal was to obtain and compare operational and safety data of night versus day missions.

METHODS

We scheduled two (one day, one night) flights each to ten different locations to assess the feasibility of AED delivery by UAS during night-time. We also compared operational data (mission timings) and safety data (incidence of critical events) of night versus day missions.

RESULTS

All missions were completed without safety incident. The flights were performed automatically without pilot interventions, apart from manually choosing the landing site and correcting the descent. Flight distances ranged from 910 m to 6.960 m, corresponding mission times from alert to AED release between 3:48 min and 11:20 min. Night missions (T¯_m:night = 7:26 ± 2:29 min) did not take longer than day missions (T¯_m:day = 7:59 ± 2:27 min). Despite slightly inferior visibility of the target site, night landings (T¯_land:night = 64 ± 15 sec) were on average marginally quicker than day landings (T¯_land:day = 69 ± 11sec).

CONCLUSIONS

Our results demonstrate the feasibility of UAS supported AED delivery during nighttime. Operational and safety data indicate no major differences between day- and night-time use. Future research should focus on integration of drone technology into the chain of survival.

Drones delivering automated external defibrillators: A new strategy to improve the prognosis of out-of-hospital cardiac arrest

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) is a serious threat to human life and health, characterized by high morbidity and mortality. However, given the limitations of the current emergency medical system (EMS), it is difficult to immediately treat patients who experience OHCA. It is well known that rapid defibrillation after cardiac arrest is essential for improving the survival rate of OHCA, yet automated external defibrillators (AED) are difficult to obtain in a timely manner.

OBJECTIVE

This review illustrates the feasibility and advantages of AED delivery by drones by surveying current studies on drones, explains that drones are a new strategy in OHCA, and finally proposes novel strategies to address existing problems with drone systems.

RESULTS

The continuous development of drone technology has been beneficial for patients who experience OHCA, as drones have demonstrated powerful capabilities to provide rapid delivery of AED. Drones have great advantages over traditional EMS, and the delivery of AED by drones for patients with OHCA is a new strategy. However, the application of this new strategy in real life still has many challenges.

CONCLUSION

Drones are promising and innovative tools. Many studies have demonstrated that AED delivery by drones is feasible and cost-effective; however, as a new strategy to improve the survival rate of OHCA patients, there remain problems to be solved. In the future, more in-depth investigations need to be conducted.

A review on initiatives for the management of daily medical emergencies prior to the arrival of emergency medical services

Emergency services worldwide face increasing cost pressure that potentially limits their existing resources. In many countries, emergency services also face the issues of staff shortage-creating extra challenges and constraints, especially during crisis times such as the COVID-19 pandemic-as well as long distances to sparsely populated areas resulting in longer response times. To overcome these issues and potentially reduce consequences of daily (medical) emergencies, several countries, such as Sweden, Germany, and the Netherlands, have started initiatives using new types of human resources as well as equipment, which have not been part of the existing emergency systems before. These resources are employed in response to medical emergency cases if they can arrive earlier than emergency medical services (EMS). A good number of studies have investigated the use of these new types of resources in EMS systems, from medical, technical, and logistical perspectives as their study domains. Several review papers in the literature exist that focus on one or several of these new types of resources. However, to the best of our knowledge, no review paper that comprehensively considers all new types of resources in emergency medical response systems exists. We try to fill this gap by presenting a broad literature review of the studies focused on the different new types of resources, which are used prior to the arrival of EMS. Our objective is to present an application-based and methodological overview of these papers, to provide insights to this important field and to bring it to the attention of researchers as well as emergency managers and administrators.

Automated external defibrillators delivered by drones to patients with suspected out-of-hospital cardiac arrest

AIMS 

Early defibrillation is critical for the chance of survival in out-of-hospital cardiac arrest (OHCA). Drones, used to deliver automated external defibrillators (AEDs), may shorten time to defibrillation, but this has never been evaluated in real-life emergencies. The aim of this study was to investigate the feasibility of AED delivery by drones in real-life cases of OHCA.

METHODS AND RESULTS 

In this prospective clinical trial, three AED-equipped drones were placed within controlled airspace in Sweden, covering approximately 80 000 inhabitants (125 km2). Drones were integrated in the emergency medical services for automated deployment in beyond-visual-line-of-sight flights: (i) test flights from 1 June to 30 September 2020 and (ii) consecutive real-life suspected OHCAs. Primary outcome was the proportion of successful AED deliveries when drones were dispatched in cases of suspected OHCA. Among secondary outcomes was the proportion of cases where AED drones arrived prior to ambulance and time benefit vs. ambulance. Totally, 14 cases were eligible for dispatch during the study period in which AED drones took off in 12 alerts to suspected OHCA, with a median distance to location of 3.1 km [interquartile range (IQR) 2.8-3.4). AED delivery was feasible within 9 m (IQR 7.5-10.5) from the location and successful in 11 alerts (92%). AED drones arrived prior to ambulances in 64%, with a median time benefit of 01:52 min (IQR 01:35-04:54) when drone arrived first. In an additional 61 test flights, the AED delivery success rate was 90% (55/61).

CONCLUSION 

In this pilot study, we have shown that AEDs can be carried by drones to real-life cases of OHCA with a successful AED delivery rate of 92%. There was a time benefit as compared to emergency medical services in cases where the drone arrived first. However, further improvements are needed to increase dispatch rate and time benefits.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Identifier: NCT04415398.

National coverage of out-of-hospital cardiac arrests using automated external defibrillator-equipped drones - A geographical information system analysis

BACKGROUND

Early defibrillation is essential for increasing the chance of survival in out-of-hospital-cardiac-arrest (OHCA). Automated external defibrillator (AED)-equipped drones have a substantial potential to shorten times to defibrillation in OHCA patients. However, optimal locations for drone deployment are unknown. Our aims were to find areas of high incidence of OHCA on a national level for placement of AED-drones, and to quantify the number of drones needed to reach 50, 80, 90 and 100% of the target population within eight minutes.

METHODS

This is a retrospective observational study of OHCAs reported to the Swedish Registry for Cardiopulmonary Resuscitation between 2010-2018. Spatial analyses of optimal drone placement were performed using geographical information system (GIS)-analyses covering high-incidence areas (>100 OHCAs in 2010-2018) and response times.

RESULTS

39,246 OHCAs were included. To reach all OHCAs in high-incidence areas with AEDs delivered by drone or ambulance within eight minutes, 61 drone systems would be needed, resulting in overall OHCA coverage of 58.2%, and median timesaving of 05:01 (min:sec) [IQR 03:22-06:19]. To reach 50% of the historically reported OHCAs in <8 min, 21 drone systems would be needed; for 80%, 366; for 90%, 784, and for 100%, 2408.

CONCLUSIONS

At a national level, GIS-analyses can identify high incidence areas of OHCA and serve as tools to quantify the need of AED-equipped drones. Use of only a small number of drone systems can increase national coverage of OHCA substantially. Prospective real-life studies are needed to evaluate theoretically optimized suggestions for drone placement.

Development of unmanned aerial vehicle (UAV) networks delivering early defibrillation for out-of-hospital cardiac arrests (OHCA) in areas lacking timely access to emergency medical services (EMS) in Germany: a comparative economic study

OBJECTIVES

This study wants to assess the cost-effectiveness of unmanned aerial vehicles (UAV) equipped with automated external defibrillators (AED) in out-of-hospital cardiac arrests (OHCA). Especially in rural areas with longer response times of emergency medical services (EMS) early lay defibrillation could lead to a significant higher survival in OHCA.

PARTICIPANTS

3296 emergency medical stations in Germany.

SETTING

Rural areas in Germany.

PRIMARY AND SECONDARY OUTCOME MEASURES

Three UAV networks providing 80%, 90% or 100% coverage for rural areas lacking timely access to EMS (ie, time-to-defibrillation: >10 min) were developed using a location allocation analysis. For each UAV network, primary outcome was the cost-effectiveness using the incremental cost-effectiveness ratio (ICER) calculated by the ratio of financial costs to additional life years gained compared with current EMS.

RESULTS

Current EMS with 3926 emergency stations was able to gain 1224 life years on annual average in the study area. The UAV network providing 100% coverage consisted of 1933 UAV with average annual costs of €43.5 million and 1845 additional life years gained on annual average (ICER: €23 568). The UAV network providing 90% coverage consisted of 1074 UAV with average annual costs of €24.2 million and 1661 additional life years gained on annual average (ICER: €14 548). The UAV network providing 80% coverage consisted of 798 UAV with average annual costs of €18.0 million and 1477 additional life years gained on annual average (ICER: €12 158).

CONCLUSION

These results reveal the relevant life-saving potential of all modelled UAV networks. Furthermore, all analysed UAV networks could be deemed cost-effective. However, real-life applications are needed to validate the findings.

Delay to initiation of out-of-hospital cardiac arrest EMS treatments

BACKGROUND

Time to initial treatment is important in any response to out-of-hospital cardiac arrest (OHCA). The purpose of this paper was to quantify the time delay for providing initial EMS treatments supplemented by comparison with those of other EMS systems conducting clinical trials.

METHODS

Data were collected between 1/1/16-2/15/19. Dispatched, EMS-worked, adult OHCA cases occurring before EMS arrival were included and compared with published treatment time data. Response time and time-to-treatment intervals were profiled in both groups. Time intervals were calculated by subtracting the following timepoints from 9-1-1 call receipt: ambulance in route; at curb; patient contact; first defibrillation; first epinephrine; and first antiarrhythmic.

RESULTS

342 subjects met study inclusion/exclusion. Mean time intervals (min [95%CI]) from 9-1-1 call receipt to the following EMS endpoints were: dispatch 0.1 [0.05-0.2]; at curb 5.0 [4.5, 5.5]; at patient 6.7 [6.1, 7.2];, first defibrillation initially shockable 11.7 [10.1, 13.3]; first epinephrine (initially shockable 15.0 [12.8, 17.2], initially non-shockable 14.8 [13.5, 15.9]), first antiarrhythmic 25.1 [22.0, 28.2]. These findings were similar to data in 5 published clinical trials involving 12,954 subjects.

CONCLUSIONS

Delay to EMS treatments are common and may affect clinical outcomes. Neither Utstein out-of-hospital guidelines [1] nor U.S. Cardiac Arrest Registry to Enhance Survival (CARES) databases require capture of these elements. EMS is often not providing treatments quickly enough to optimize clinical outcomes. Further regulatory change/research are needed to determine whether OHCA outcome can be improved by novel changes such as enhancing bystander effectiveness through drone-delivered drugs/devices & real-time dispatcher direction on their use.