The Case for Drone-assisted Emergency Response to Cardiac Arrest: An Optimized Statewide Deployment Approach

BACKGROUND Despite evidence linking rapid defibrillation to out-of-hospital cardiac arrest (OHCA) survival, bystander use of automatic external defibrillators (AEDs) remains low, due in part to AED placement and accessibility. AED-equipped drones may improve time-to-defibrillation, yet the benefits and costs are unknown.METHODS We designed drone deployment networks for the state of North Carolina using mathematical optimization models to select drone stations from existing infrastructure by specifying the number of stations and the targeted AED arrival time. Expected outcomes were evaluated over the drone's lifespan (4 years). We estimated the following parameters: proportion of OHCAs within a targeted AED delivery time, bystander utilization of AEDs, survival/neurological status, and incremental cost per quality-adjusted life year (QALY).RESULTS Statewide, 16,503 adults aged 18 or older were expected to experience OHCA with an attempted resuscitation over 4 years. Compared to no drone network, all proposed drone networks were expected to improve survival outcomes. For example, assuming 46% of OHCAs have bystanders willing to use an AED, a 500-drone network decreased the median time of defibrillator arrival from 7.7 to 2.7 minutes compared to no drone network. Expected survival rates doubled (24.5% versus 12.3%), resulting in an additional 30,267 QALYs ($858/incremental QALY). If just 4.5% of OHCAs had willing bystanders, 13.8% of victims would have survived. Sensitivity analysis demonstrated that an AED drone network remained cost-effective over a wide range of assumptions.CONCLUSIONS With proper integration into existing systems, large-scale networks for drone AED delivery have the potential to substantially improve OHCA survival rates while remaining cost-effective. Public health researchers should consider advocating for feasibility studies and policy development surrounding drones

Vital exhaustion and sudden cardiac death in the Atherosclerosis Risk in Communities Study

Objective Vital exhaustion (VE), a construct defined as lack of energy, increased fatigue and irritability, and feelings of demoralisation, has been associated with cardiovascular events. We sought to examine the relation between VE and sudden cardiac death (SCD) in the Atherosclerosis Risk in Communities (ARIC) Study. Methods The ARIC Study is a predominately biracial cohort of men and women, aged 45-64 at baseline, initiated in 1987 through random sampling in four US communities. VE was measured using the Maastricht questionnaire between 1990 and 1992 among 13 923 individuals. Cox proportional hazards models were used to examine the hazard of out-of-hospital SCD across tertiles of VE scores. Results Through 2012, 457 SCD cases, defined as a sudden pulseless condition presumed due to a ventricular tachyarrhythmia in a previously stable individual, were identified in ARIC by physician record review. Adjusting for age, sex and race/centre, participants in the highest VE tertile had an increased risk of SCD (HR 1.48, 95% CI 1.17 to 1.87), but these findings did not remain significant after adjustment for established cardiovascular disease risk factors (HR 0.94, 95% CI 0.73 to 1.20). Conclusions Among participants of the ARIC study, VE was not associated with an increased risk for SCD after adjustment for cardiovascular risk factors

Drone Delivery of an Automated External Defibrillator

To the Editor: Every year, an estimated 350,000 persons in the United States have an out-ofhospital cardiac arrest; only approximately 10% survive.1 The probability of survival doubles when a bystander administers cardiopulmonary resuscitation (CPR) and uses an automated external defibrillator (AED) before emergency medical services (EMS) arrive, but bystander AED use occurs in less than 2% of cardiac arrests in the United States.2 Survival is most likely when CPR and defibrillation are delivered within 5 minutes after the start of a cardiac arrest3; however, the median arrival time of EMS in the United States is 8 minutes and in remote areas can extend to 30 minutes

Delivery of Automated External Defibrillators via Drones in Simulated Cardiac Arrest: Users' Experiences and the Human-Drone Interaction

Background: Survival after out-of-hospital cardiac arrest (OHCA) in the United States is approximately 10%. Automatic external defibrillators (AEDs) are effective when applied early, yet public access AEDs are used in <2% of OHCAs. AEDs are often challenging for bystanders to locate and are rarely available in homes, where 70% of OHCAs occur. Drones have the potential to deliver AEDs to bystanders efficiently; however, little is known about the human-drone interface in AED delivery. Objectives: To describe user experiences with AED-equipped drones in a feasibility study of simulated OHCA in a community setting. Methods: We simulated an OHCA in a series of trials with age-group/sex-matched participant pairs, with one participant randomized to search for a public access AED and the other to call a mock 9-1-1 telephone number that initiated the dispatch of an AED-equipped drone. We investigated user experience of 17 of the 35 drone recipient participants via semi-structured qualitative interviews and analyzed audio-recordings for key aspects of user experience. Results: Drone recipient participants reported largely positive experiences, highlighting that this delivery method enabled them to stay with the victim and continue cardiopulmonary resuscitation. Concerns were few but included drone arrival timing and direction as well as bystander safety. Participants provided suggestions for improvements in the AED-equipped drone design and delivery procedures. Conclusion: Participants reported positive experiences interacting with an AED-equipped drone for a simulated OHCA in a community setting. Early findings suggest a role for drone-delivered AEDs to improve bystander AED use and improve outcomes for OHCA victims