Out-of-Hospital Cardiac Arrest: Public-Access Defibrillation and System Approaches to Minimize Avoidable Delay.

Area of Science:

• Emergency Medicine
• Cardiology
• Public Health

Background:

• Out-of-hospital cardiac arrest (OHCA) is a major cause of sudden death globally.
• Survival rates for EMS-treated OHCA are low (<10%) and highly time-dependent.
• Delays in CPR and defibrillation significantly reduce survival and neurological recovery.

Purpose of the Study:

• To review evidence and strategies for reducing time-to-CPR and time-to-shock.
• To focus on public-access defibrillation (PAD) using automated external defibrillators (AEDs) to mitigate delays.
• To compare different PAD delivery models and discuss emerging technologies.

Main Methods:

• Narrative review synthesizing randomized trials and large registry studies.
• Comparison of various PAD delivery models (EMS-based, first-responder, community systems).
• Review of emerging strategies like citizen-responder networks and drone delivery.

Main Results:

• AED use before EMS arrival significantly improves survival in shockable rhythms.
• Real-world PAD effectiveness is limited by accessibility, placement, and public awareness.
• Community-integrated models like 'Progetto Vita' show promise in minimizing delays.

Conclusions:

• Reducing time-to-CPR and time-to-shock through PAD is critical for OHCA survival.
• System integration, alert performance, and AED accessibility are key to patient benefit.
• Future priorities include national registries and scalable solutions for home cardiac arrests.