An innovative Hearing AED alarm system shortens delivery time of automated external defibrillator – A randomized controlled simulation study

Background

Early defibrillation with an automated external defibrillator (AED) is a key element in the out-of-hospital cardiac arrest (OHCA) chain. However, a public automatic defibrillator (PAD) is often not easily accessible during emergency situations. Here, we have developed an AED-based alarm system together with a smartphone Hearing AED application (APP) that would activate registered public access AED within 300 m radius from the location of an OHCA event. It also alerts nearby related personnel to bring in the AED to the OHCA location for emergency assistance. The aim of this study is to determine if this novel Hearing AED alarm system shortens the AED delivery time.

Methods

This was a randomized controlled simulation study. Participants were randomly assigned to one of the 3 groups: (a) bystander group, (b) APP responder group, and (c) AED alarm responder in equal ratios. The bystanders were stationed at the OHCA scene, and must access a nearby AED by the instruction of the dispatcher of emergency medical services. APP responders were stationed within 300 m of the cardiac arrest scene, and were activated by the Hearing AED APP. The AED alarm responders were brought to AED location, and were activated by the AED-based alarm device mounted on an AED case. We measured the time taken to find and bring the nearby AED to the OHCA scene. The primary outcome was the total delivery time in each group. The secondary outcomes were times needed: (a) from the starting point to AED place, (b) from AED place to the OHCA scene, and (c) the operation time.

Results

We enrolled 90 participants in this study. The total AED delivery times were significantly different across the 3 groups. The shortest time was in the AED alarm responder group, compared with the other two groups. The median time from the starting point to AED was statistically shorter in the bystander group than in the APP responder group (116.0 sec, IQR 80.0–135.0 vs 159.0 sec, IQR 98.5–200.5, p = 0.029). In the analysis with the general linear model, we found statistically shorter total AED delivery time in the AED alarm responder group (β = -122.4, p = 0.004). In contrast, the APP responder group was associated with a markedly longer total AED delivery time (β = 104.6, P=0.016).

Conclusion

In this simulation study, the Hearing AED system contributed to shortening the AED delivery time. Further studies are needed to determine its validation in the real world situation in the future.