Abstract 197: What Limits the Use of AEDs by Bystanders?

Introduction: In Japan, the number of automated external defibrillators (AEDs) placed in public areas has climbed up to the estimated 530,000. We reported previously that a half of out-of-hospital cardiac arrests occurred within 100 m from a public AED in urban areas. However, shocks for defibrillation were given to less than 15% of those patients. The objectives of this study was to identify the limiting factors against the use of AEDs by bystanders. Methods: A prospective survey on out-of-hospital cardiac arrest was conducted in the city of Osaka (Dec 2016 through Mar 2017) and the city of Nagoya (Dec 2016 through Nov 2017) searching for patient demographics and AED settings including; absence/presence of a public AED on the scene, attachment of AED pads, delivery of shocks before the time of EMS arrival. Results: Of 558 cases of cardiac arrest registered during the survey period, an AED had already been delivered at the patient side by the time of EMS arrival in 92 case (16.5%). Of those, pads had been attached in 89 cased (96.7%). Shocks had been advised in 35 cases (39.3%) and to all but one of those cases at least 1 shock had been given by the bystanders. There were no statistically significant differences between the groups of cases with and without AEDs at the patient side regarding the patient age (65 years [IQR: 48-74] vs 63 years [IQR49-75], p=0.84), gender (p=0.68) and the time from call to EMS arrival (7 min [IQR: 6-9] vs 7 min [IQR: 6-9], p=0.74). Cases occurring indoors had more chances of AEDs being delivered on the patient side than cases occurring outdoors (24.0% vs 7.8%, p Conclusions: Our study indicates that once an AED is delivered at the patient side, pads are successfully attached and shocks are given if indicated in almost all cases. This suggests that finding and delivering an AED onto the patient side are the limiting factors against the use of AEDs by bystanders. In order to popularize the use of AEDs by bystanders, informing people with AED placement and clear direction to the AED location seem to be the key steps.