Dispatcher-assisted AED use in single-rescuer cardiac arrest: study protocol for a randomized simulation study...

Although automated external defibrillators (AEDs) improve outcomes in shockable rhythms, their use introduces interruptions in chest compressions. In single-rescuer scenarios, AED retrieval and application may further increase no-flow time. The effect of dispatcher instruction strategy on these interruptions remains unclear. This study aims to evaluate whether AED-optimized dispatcher-assisted CPR (DACPR) instructions reduce no-flow time compared with standard instructions in a simulated single-rescuer OHCA setting.

This prospective, randomized, controlled, parallel-group simulation trial will include adult laypersons and healthcare professionals. Participants will be allocated in a 1:1 ratio to either standard or AED-optimized DACPR instruction groups. All scenarios will be conducted in a controlled simulation environment with standardized AED accessibility (≤1 min retrieval distance) to isolate the effect of dispatcher communication on CPR performance. The primary outcome will be total no-flow time. Secondary outcomes include chest compression fraction, time to first compression, time to first shock, peri-shock pauses, and CPR quality metrics.

This study investigates dispatcher instruction as a modifiable determinant of CPR interruption during AED use in single-rescuer scenarios. Findings will provide mechanistic insight into how communication strategies influence CPR quality under controlled conditions and may inform refinement of DACPR protocols.

The study protocol was approved by the Institutional Ethics Committee of the University of Pécs (PTE/87175-1/2025). Written informed consent will be obtained. Results will be disseminated via peer-reviewed publication and scientific conferences.

ClinicalTrials.gov: NCT07520877, prospectively registered on 8 April 2026.