HeroTech8’s drone used in the UK study. Credit: HeroTech8
In some emergency medical situations, early bystander treatment is the key to saving a life. For example, a patient who goes into cardiac arrest is up to three times as likely to survive if a bystander initiates CPR immediately, including the use of an automated external defibrillators (AEDs) is warranted. The same can be said for a patient experiencing a drug overdose—one or more doses of naloxone can immediately reverse an overdose. In this situation, the sooner the naloxone is delivered, the better the chances of survival.
But not everyone is carrying a naloxone kit in their pocket, and they certainly aren’t walking around with a portable AED. That’s why we rely so heavily on first responders. Unfortunately, first responding units are vulnerable to a myriad of problems, including traffic, staffing, other emergencies, etc.
Now, two new studies are proposing an alternative delivery system in emergency medication situations: drones. The study out of North Carolina used simulations to assess the feasibility of drones delivering an AED to a bystander in a cardiac arrest situation, while the second study in the UK used real-world data and modeling to see if drones could deliver naloxone faster than ambulances.
Treating a cardiac arrest in 5 minutes
According to the American Heart Association, more than 350,000 cardiac arrests occur outside of the hospital each year, with a survival rate of only about 10%. While an AED can triple the patient’s chances of survival, timely access to an AED is still a major barrier, especially in rural areas.
For the study, researchers developed a simulation model that evaluated how quickly an AED could be delivered to the scene of a cardiac arrest in 19 counties in North Carolina between January 2013 and December 2019. The data included nearly 9,000 cardiac arrests—more than 5,700 that occurred in urban areas and around 3,200 that occurred in rural areas.
The model hypothesized that all local first responders, including EMS, firefighters and police officers, would carry an AED, and then optimized a network of AED-carrying drones. The simulation model compared the response time until an AED arrived on scene between this hypothetical intervention and the historical first responder/EMS response in each area.
Using the drones, the researchers found that a 5-minute response time for AED arrival would improve from 24% to 77% for urban areas, and 10% to 23% for rural areas.
Additionally, the estimated average response times were projected to be reduced by 42% to 4 minutes in urban areas, and by 24% to 7 minutes in rural areas. The historical median response time for first responders is 6.9 minutes in urban areas and 9.4 minutes in rural areas. Overall, all counties showed significant improvement in response time for urban and rural populations.
First signs of an overdose
Meanwhile, researchers in England used real-world data of fatal opioid overdoses to show that naloxone-delivering drones reach patients in 7 minutes or less in 78% of cases—compared with 14% reached by ambulances in that timeframe.
For the study, published in Addiction, King’s College London reserachers examined opioid overdose cases with bystanders likely present that occurred in the Teesside (UK) area over a five-year period from 2015 to 2019. Cases with bystanders present were selected as someone would need to call for and administer the delivered naloxone. Additionally, the Teesside area was selected as it comprises a range of urban, semi-urban and rural areas.
In analysis of real-world data and experimentation with C1 class drone models, the researchers found that drones arrive in 7 minutes in 78% of overdose cases (45 out of the examined 58 cases). In those same cases, ambulances were estimated to arrive in 7 minutes in 14% of the time, as long as traffic was “best case scenario.” In high-volume traffic conditions, ambulances were estimated to arrive in 7 minutes in only 7% of the overdose cases. In all examined cases, the drone would have arrived before the ambulance.
In 13 cases, bad weather—namely low temperatures and high winds—prohibited drones from taking flight. However, the researchers say technological advances can address this challenge. For example, an insulated cargo cradle could keep the naloxone at a stable temperate, despite the outside temperature. The team also found that prevailing wind speed and direction could be negated by enhanced C1 drone speed. With these improvements, the study estimates that drones would reach opioid overdose patients in 7 minutes in 98% (57 of 58) of cases.