Improving Bystander Response: How Long Does It Take to Retrieve an AED From Varying Distances

Area of Science:

• Emergency Medicine
• Public Health
• Cardiology

Background:

• Out-of-hospital cardiac arrest (OHCA) survival rates are critically low (<10%).
• Early defibrillation is key for OHCA with a shockable rhythm.
• Mobile apps can locate victims and automated external defibrillators (AEDs), but lack guidance on responder actions.

Purpose of the Study:

• To determine AED retrieval times at various distances in a real-world setting.
• To compare AED retrieval times with emergency medical services (EMS) first response times.
• To inform best practices for bystander response during OHCA events.

Main Methods:

• Thirty participants completed four AED retrieval runs under simulated OHCA conditions.
• Runs were conducted outdoors on a busy street (all seasons) and indoors on a track.
• AED retrieval distances simulated were 200m (400m roundtrip), 400m (800m roundtrip), and 600m (1,200m roundtrip).

Main Results:

• Mean retrieval times: 4.05 min (200/400m), 6.62 min (400/800m), 8.62 min (600/1,200m).
• Indoor track runs were significantly faster (4.35 min for 400/800m) than real-life conditions (p < 0.001).
• Real-world retrieval times at distances >400m exceeded the median EMS first response time of 6.9 min.

Conclusions:

• Mobility barriers (traffic, weather, pedestrians) significantly impact AED retrieval times.
• Short AED retrieval distances (≤400m roundtrip) are essential for improving OHCA survival.
• Only retrieval distances of 400m or less allow for AED use before EMS arrival.