Precision timing in public-access defibrillation: a study of time-stamped data recorded by automatic external...

Early defibrillation by a bystander using an automated external defibrillator (AED) is essential to improve outcomes from out-of-hospital cardiac arrest. Railway stations have been considered ideal locations for public access defibrillation (PAD). This study aims to analyze second-by-second time-stamped data recorded by AEDs deployed at Japanese railway stations to better understand how AEDs are actually operated in the real world.

A retrospective observational study was conducted using internal data from 1066 AEDs deployed at railway stations. Data were collected from March 2019 to August 2023. Time-stamped variables were evaluated as follows: power-on, start and completion of rhythm analysis, shock delivery or internal discharge, and power-off. AED operating times were categorized into four time periods and frequency of use was descriptively summarized.

The AEDs were activated 384 times during 53 months; shockable rhythms were identified in 111 out of 384 cases (29.4 %) and shocks were delivered in 109 out of 384 cases (28.9 %). Internal discharges occurred in only two cases (1.8 %). The median time from power-on to rhythm analysis was 53 s, and the median interval from completion of charge to shock delivery was 5 s. The number of uses varied by location, with some devices used up to 10 times and others not used at all.

Second-by-second AED log data in real world can provide valuable insight into the actual implementation of PAD programs. Railway stations are high-impact locations for AED deployment, and such data can provide a practical benchmark for assessing and improving AED accessibility.