Effect of AED-optimized Telephone-assisted CPR Instructions on No-flow Time and Chest Compression Fraction

Effect of AED-optimized Telephone-assisted CPR Instructions on No-flow Time and Chest Compression Fraction in a Single-rescuer Cardiac Arrest Scenario - a Randomized-controlled Simulation Study

Out-of-hospital cardiac arrest (OHCA) remains a leading cause of mortality worldwide, with survival highly dependent on the immediate initiation of bystander cardiopulmonary resuscitation (CPR). Early recognition, prompt chest compressions, and rapid defibrillation are critical components of the chain of survival. Telephone-assisted CPR (T-CPR) provided by emergency dispatchers has been shown to significantly increase bystander intervention rates and improve outcomes. While the availability and use of automated external defibrillators (AEDs) further enhance survival, the optimal integration of AED use into dispatcher-guided, single-rescuer scenarios remains insufficiently studied.

This prospective, randomized, controlled simulation study aims to evaluate the effect of modified telephone cardiopulmonary resuscitation (T-CPR) instructions optimized for automated external defibrillator (AED) use on no-flow time and chest compression fraction (CCF) during single-rescuer resuscitation. Participants are randomized to receive either standard T-CPR instructions or enhanced instructions focusing on minimizing interruptions in chest compressions and reducing time to first compression during AED use.

Study Overview

• Status: Recruiting
• Conditions: Cardiac Arrest (CA)
• Intervention / Treatment: Behavioral: T-CPR; Behavioral: AED-optimized T-CPR

Detailed Description

Out-of-hospital cardiac arrest (OHCA) is a major public health problem associated with low survival rates despite advances in emergency care systems. Survival is critically dependent on early recognition, immediate initiation of high-quality chest compressions, and timely defibrillation. Bystander intervention plays a pivotal role in this process, and telephone-assisted cardiopulmonary resuscitation (T-CPR) has been demonstrated to substantially increase the likelihood of CPR initiation prior to the arrival of emergency medical services.

The increasing availability of automated external defibrillators (AEDs) in public spaces has further strengthened the chain of survival. Early defibrillation is a key determinant of favorable outcomes, particularly in shockable rhythms. However, the integration of AED use into dispatcher-assisted scenarios - especially when only a single rescuer is present - poses practical challenges. In such situations, the rescuer must balance multiple tasks, including chest compressions, AED retrieval, device preparation, and adherence to voice prompts, all of which may introduce interruptions in compressions and increase no-flow time.

While the benefits of T-CPR and AED use independently are well established, there is limited evidence on how dispatcher instructions can optimally coordinate these interventions in single-rescuer scenarios. In particular, it remains unclear whether modified, AED-optimized T-CPR instructions can reduce no-flow time and improve chest compression fraction (CCF) by minimizing unnecessary interruptions and optimizing task sequencing.

This prospective, randomized, controlled simulation study aims to evaluate the effect of modified telephone cardiopulmonary resuscitation (T-CPR) instructions optimized for automated external defibrillator (AED) use on no-flow time and chest compression fraction (CCF) during single-rescuer resuscitation. Participants are randomized to receive either standard T-CPR instructions or enhanced instructions focusing on minimizing interruptions in chest compressions and reducing time to first compression during AED use.

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Bálint Bánfai, Ph.D.; Phone Number: +3630501500; Email: balint.banfai@etk.pte.hu

Study Locations

• Hungary
  • Pécs, Hungary, 7621
    • Recruiting
    • University of Pecs
    • Contact: Bálint Bánfai, Ph.D.; Phone Number: +3672501500; Email: balint.banfai@etk.pte.hu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Adolescents and adults (≥16 years)
• Healthcare professionals or laypersons
• Voluntary participation

Exclusion Criteria:

• pregnant women
• people with cardio-pulmonary and musculoskeletal diseases or any other impairment that would risk harm for the volunteer while performing CPR
• physical and/or psychological disabilities
• technical issue during data collection

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Standard T-CPR; Participants perform dispatcher-assisted CPR based on the European Resuscitation Council (ERC) 2025 guidelines and the national standard DA-CPR protocol.	Behavioral: T-CPR; Participants receive structured telephone CPR instructions reflecting current national practice. AED retrieval is instructed early; however, no additional guidance is provided to optimize timing or minimize interruptions during AED use.
Active Comparator: AED-optimized T-CPR; Participants perform dispatcher-assisted CPR based on the European Resuscitation Council (ERC) 2025 guidelines and a modified national DA-CPR protocol.	Behavioral: AED-optimized T-CPR; Participants receive standard T-CPR instructions supplemented with specific guidance aimed at: minimizing interruptions in chest compressions,; reducing time to first chest compression,; optimizing AED use workflow. Key elements include: immediate activation of the AED upon retrieval,; initiation of chest compressions even if AED voice prompts have not yet reached relevant steps,; continuation of compressions during AED preparation and charging (when appropriate),; minimization of pauses before and after shock delivery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
No-flow time	Time without chest compressions measured from entry into the simulation (collapse recognition) until termination of the scenario (giving the third shock).	During procedure.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to first chest compression	The time (in seconds) until the first chest compression (measured from entering the scenario).	During procedure.
Time to first shock	The time to the first shock by the AED (in seconds, from the time of entering the scenario).	During procedure
Chest compression fraction	Proportion of time during which chest compressions are performed (until giving the third shock), calculated from the first chest compression until scenario termination.	During procedure.
Peri-shock pause	The time without chest compression (in seconds) before and after giving the shock.	During procedure

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Attitude about T-CPR instructions	Subjective feelings after performing cardiopulmonary resuscitation based on a short survey using Likert-scale based queries (1-4 points, lower numbers indicate worse, higher score indicates better opinion).	Immediately after the CPR procedure (within 15 minutes)

Collaborators and Investigators

• Sponsor: University of Pecs

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): July 31, 2026
• Study Completion (Estimated): August 31, 2026

Study Registration Dates

• First Submitted: April 2, 2026
• First Submitted That Met QC Criteria: April 2, 2026
• First Posted (Actual): April 9, 2026

Study Record Updates

• Last Update Posted (Actual): April 14, 2026
• Last Update Submitted That Met QC Criteria: April 8, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: cardiac arrest; automated external defibrillator; dispatcher-assisted cardiopulmonary resuscitation; no-flow time; chest compression fraction
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Heart Diseases; Heart Arrest
• Other Study ID Numbers: DA-CPR and AED

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No