Dispatcher/Telecommunicator-Assisted CPR

Optimization of Dispatcher-Assisted Recognition of Out-of-Hospital Cardiac Arrest

Last Full Review: ILCOR 2023

Bystanders to cardiac arrest in the out-of-hospital setting typically call 9-1-1 to report the event. Dispatchers and telecommunicators are trained to recognize cardiac arrest from the caller’s description and to assist the bystander, as necessary, in the delivery of cardiopulmonary resuscitation (CPR). A 2020 International Liaison Committee on Resuscitation (ILCOR) systematic review and Consensus on Science with Treatment Recommendations (Olasveengen et al. 2020, S41) on emergency medical dispatcher diagnosis of out-of-hospital cardiac arrest (OHCA) recommended that dispatch centers look for ways to optimize the sensitivity of that diagnosis (i.e., to minimize false negatives and increase the accurate identification of cardiac arrest). Specific, potential interventions to improve recognition of cardiac arrest by dispatchers and telecommunicators have not been previously reviewed by ILCOR.

 

Evidence Summary

A 2023 scoping review (Dainty et al. 2024, 100715; Malta Hansen et al. 2024; Greif et al. 2024) by ILCOR sought to identify factors and interventions that improve dispatcher-assisted recognition of cardiac arrest, defined as the initiation of cardiac arrest-specific actions, such as instructions to perform CPR. Of the 60 articles included, most were primarily retrospective observational studies that assessed the proportion of OHCAs recognized by dispatchers and associated factors therein. There were no randomized controlled trials (RCTs) comparing different strategies to improve dispatcher-assisted recognition of OHCA, and only a single study reported on dispatcher-assisted recognition of pediatric cardiac arrests.

Studies included in the scoping review were grouped first by themes of factors related to dispatcher-assisted recognition of cardiac arrest, and then by interventions to improve dispatcher-assisted recognition of cardiac arrest.

Categories included:

• Communication between the caller and dispatcher (e.g., caller’s emotional state, proximity to the patient, language barriers, use of trigger words)
• Symptoms and patient characteristics (e.g., agonal breathing, seizures, patient demographics)
• New technology to improve dispatcher recognition of OHCA (e.g., closed-circuit television, machine learning, smart devices to detect agonal breathing)
• Quality improvement or implementation of new protocols to improve dispatcher recognition of cardiac arrest (e.g., Medical Priority Dispatch System [MPDS], criterion-based dispatch, breathing)

 

The scoping review noted that the most pertinent challenge to dispatcher-assisted recognition of OHCA appears to be determining whether the patient is breathing normally. While different strategies for assessment of breathing were studied, such as having the caller place their hand on the patient’s stomach, none were shown to have better results than a two-question strategy (“Is the patient conscious?” and “Is the patient breathing normally?”), and no RCTs compared alternative strategies. The review concluded that there is insufficient evidence to pursue a systematic review at this time (Malta Hansen et al. 2024; Greif et al. 2024).

Insights and Implications

Current Red Cross guidelines support the use of standardized and evidence-based protocols for recognition of cardiac arrest. Improving the ability to recognize OHCA creates the potential for earlier delivery of CPR. Many knowledge and research gaps were identified with this scoping review. Different protocols and strategies need to be compared with each other in randomized trials, and factors to improve recognition of OHCA by dispatchers need to be evaluated for their sensitivity, specificity and positive predictive values. Additional studies are also needed to help optimize recognition of pediatric OHCA, and research is needed to identify ways to improve layperson identification of normal breathing.

 

Optimization of Dispatcher-Assisted CPR Instructions

Last Full Review: ILCOR 2024

Emergency (9-1-1) telecommunicators provide cardiopulmonary resuscitation (CPR) instructions, when needed, to callers reporting a cardiac arrest. Are there specific strategies that can improve or optimize dispatcher-assisted instructions for CPR?

 

Evidence Summary

A 2018 International Liaison Committee on Resuscitation (ILCOR) systematic review and Consensus on Science with Treatment Recommendations (Olasveengen et al. 2018) led to strong recommendations that emergency medical dispatch centers have systems in place to enable call handlers to provide CPR instructions for adult patients in cardiac arrest, and that emergency medical call takers provide CPR instructions, when required, for adult patients in cardiac arrest.

A new scoping review (Dainty et al. 2024; Greif et al. 2024) by ILCOR sought to identify interventions used in addition to standard instructions to increase the effectiveness of dispatcher-assisted CPR. The review included 31 studies of various designs but identified only one study that focused on dispatcher-assisted pediatric cardiac arrest.

Studies included in the review evaluated 11 different types of interventions, including:

• Advanced dispatcher training
• Centralized dispatch center
• Use of a metronome or varied metronome rates
• Change in CPR sequence and compression ratio
• Animated audiovisual recording
• Prerecorded instructions versus conversational live instructions
• Use of novel dispatcher-assisted CPR protocols
• Changes in terminology and simplification of compression instruction language
• Inclusion of undress patient instructions
• Verbal encouragement
• Use of video at the scene

 

Most of these interventions had three or fewer published studies, and their effectiveness in improving dispatcher-assisted CPR is unclear. Studies on the simplification of compression instruction language or terminology suggest improved quality of CPR (Rodriguez et al. 2014, 119; Trethewey et al. 2019, 91; Mirza et al. 2008, 97; Leong et al. 2021, 647). Compared with audio emergency calls, findings from several studies suggested that the addition of video communication improved CPR performance and quality (Bolle et al. 2009, 116; Lee et al. 2011, 64; Lee et al. 2021, 15555; Yang et al. 2009, 490; Peters et al. 2022, e451; Linderoth et al. 2021, 101). A description of all studies included and the various interventions used can be found in the full online scoping review.

Insights and Implications

The Red Cross guidelines recommend that dispatchers provide instructions to perform compression-only CPR for suspected out-of-hospital cardiac arrest to those untrained in CPR or who are unable to recall CPR performance steps. Although this scoping review noted a lack of high-quality evidence and human studies to support a systematic review, it identified several interventions, in addition to standard instructions, for dispatcher-assisted CPR by dispatch instructors that deserve additional research and may lead to improved quality of CPR delivered by 9-1-1 callers. Additional studies are needed to include pediatric patients. No good practice statements were released with this scoping review and the Red Cross guidelines remain unchanged.

 

Optimization of Dispatcher-Assisted Public Access AED Retrieval and Use

Last Full Review: ILCOR 2024

Emergency 9-1-1 telecommunicators who are called due to a cardiac emergency ask callers if an automated external defibrillator (AED) is immediately available or if someone has been asked to retrieve one. In some emergency medical services (EMS) systems, 9-1-1 telecommunicators may assist the caller in locating the closest AED. Little is known about how this process occurs or could be optimized to improve the use of public access AEDs.

 

Evidence Summary

A 2024 scoping review (Smith et al. 2024; Greif et al. 2024) by the International Liaison Committee on Resuscitation (ILCOR) sought evidence for dispatcher-assisted AED retrieval and its use in adults and children with out-of-hospital cardiac arrest (OHCA) and with any reported outcomes. Limited evidence was identified, primarily from simulation studies, and no studies evaluated patient outcomes.

Observational studies performed in EMS systems using dispatcher-assisted AED retrieval reported low rates of AED retrieval, pad application and shocks delivered. One study reported a greater rate of bystander defibrillation with dispatcher instructions to retrieve an AED compared with cases in which no instructions were provided. The time to delivery of the first shock, as measured from the time of AED arrival, was reported in simulation studies to be longer when dispatcher assistance was provided compared with the time measured when no dispatcher assistance was provided (Bang et al. 2020, 4069749; Ecker et al. 2001, 968). Some studies, however, reported a shorter time to first shock when time to retrieve an AED was factored in (Neves Briard et al. 2019; Riyapan et al. 2016, 590).

Other studies included in the scoping review evaluated AED competence scores with dispatcher assistance, correct placement of AED pads with video instruction and use of prerecorded video instruction compared with real-time verbal instructions.

Although there was insufficient evidence from the scoping review to support a systematic review, several good practice statements were made by ILCOR (Smith et al. 2024; Greif et al. 2024) as follows:

• Emergency medical services implementing dispatcher-assisted public access AED systems should monitor and evaluate the effectiveness of their system.
• Once a cardiac arrest is recognized during the emergency call and CPR has been started, dispatchers should ask if there is an AED (or defibrillator) immediately available at the scene and ask the caller to update them when one arrives.
• If an AED is not immediately available and if there is more than one rescuer present, dispatchers should offer instructions to locate and retrieve an AED. Retrieval instructions should be supported, where resources allow, by up-to-date registries about public-access AED locations and accessibility.
• Once an AED is available, dispatchers should offer instructions on its use.

 

Insights and Implications

In many locations in the United States, 9-1-1 telecommunicators provide CPR instructions to callers reporting an unconscious or unresponsive person. Because bystander use of AEDs is associated with high-survival rates from OHCA, the logical step to expedite the chain of survival is to provide information on the location of nearby AEDs. Some existing medical dispatch protocols (JEMS 2020; PulsePoint 2020) use software that provides the geolocation of an AED from an AED registry (e.g., nationalAEDregistry.com), thus allowing 911 telecommunicators to inform callers of the exact location of AEDs while using existing medical dispatch protocols. Research is needed to determine their effectiveness, benefit or associated risks in overall community and EMS response to OHCA.

 

Video-Based Dispatcher-Assisted CPR

Last Full Review: ILCOR 2021
Last Update: 2022

Communication between dispatch centers and lay responders at the scene of a cardiac arrest are typically through an audio connection on a cell phone. The use of video-based dispatcher-assisted cardiopulmonary resuscitation (CPR) instructions is a promising means for improving CPR instruction delivery and technique.

 

Evidence Summary

A 2022 evidence update (Wyckoff et al. 2022, e483) to the 2021 International Liaison Committee on Resuscitation Consensus on Science with Treatment Recommendations (Wycoff et al. 2022, e645) on this topic identified two new studies (Lee et al. 2021, 15555; Linderoth et al. 2021, 35) The first observational study, conducted in a large metropolitan area in Korea and enrolling 2,109 adult out-of-hospital cardiac arrest patients with dispatch-assisted CPR, reported that video-instructed dispatcher-assisted CPR was significantly associated with neurologic recovery (aOR, 2.11; 95% CI, 1.48–3.01) and survival to hospital discharge (aOR, 1.81; 95% CI, 1.33–2.46) compared with audio-instructed dispatcher-assisted CPR in adult patients after adjusting for age, gender, underlying diseases and CPR location (Lee et al. 2021, 15555). The second study reported improved compression depth, hand position, compression rate and compression depth for bystanders with the use of live video-instructed dispatcher-assisted CPR instruction (Linderoth et al. 2021, 35).

Insights and Implications

Evidence reporting clinical outcomes from video-based dispatcher-assisted CPR is limited but supports the existing Red Cross guidelines. Further clinical research is needed to confirm potential benefits or to identify harm associated with video-based dispatcher-assisted CPR.

Dispatcher-Assisted Compression-Only CPR Versus Conventional CPR in Adults

Last Full Review: ILCOR 2025
Last Update: 2021

The 9-1-1 dispatchers/telecommunicators in the United States are generally trained to provide cardiopulmonary resuscitation (CPR) instructions to callers who are untrained in CPR or who are unable to recall CPR performance steps. The training and protocols, however, may vary state by state. In 2017 the International Liaison Committee on Resuscitation (ILCOR) performed a systematic review (Ashoor et al. 2017, 112) of dispatcher-assisted instructions to give chest compression-only CPR (CO-CPR) compared with instructions to give conventional compression-ventilation CPR (CV-CPR). Survival was not improved with dispatcher instructions for CO-CPR compared with instructions for standard CPR. This review has informed past Red Cross guidelines for dispatcher-assisted CPR.

 

Evidence Summary

The 2017 ILCOR systematic review on dispatcher CPR instructions was updated in 2024 (Cash et al. 2024; Bray et al. 2025, S34). Evidence from several additional randomized controlled trials and observational studies were added to the existing database (Riva et al. 2024, e010027; Goto et al. 2021, 408; Javaudin et al. 2021, 812; Kitamura et al. 2018, 29; Wnent et al. 2021, 101) comparing dispatcher-assisted CO-CPR with conventional (compression-ventilation) CPR in adults or all ages. Some of these studies were performed at a time when a compression-to-ventilation ratio of 15:2 was recommended; evidence from these studies was considered indirect. Studies included bystander CPR regardless of whether CPR was initiated before or after the time of the call. Despite significant heterogeneity between the studies, results from most studies suggested either a slight improvement or no difference in patient outcomes for dispatcher-assisted CO-CPR versus CV-CPR. Outcomes assessed included return of spontaneous circulation; survival to hospital admission, discharge, or 30 days; and survival with favorable neurological function. A strong recommendation was made by ILCOR that dispatchers provide CO-CPR instructions to callers for adults with suspected out-of-hospital cardiac arrest. Although the evidence supporting this strong recommendation was rated as low certainty, the ILCOR review team noted that bystander CPR more than doubles out-of-hospital cardiac arrest survival and using CO-CPR may increase the willingness of bystanders to provide CPR (Cash et al. 2024; Bray et al. 2025, S34).

Insights and Implications

The Red Cross guidelines continue to recommend that dispatchers provide instructions to perform CO-CPR for suspected out-of-hospital cardiac arrest to those untrained in CPR or who are unable to recall CPR performance steps. The Red Cross standard CPR instruction includes compressions with ventilation, with CO-CPR by those who are not trained or not willing to provide ventilation. Following the 2017 ILCOR systematic review, despite a lack of direct evidence, the Red Cross recommended, as a good practice statement, that dispatchers also provide standard CV-CPR instructional support, when needed, to those trained in CV-CPR who are unable to recall CPR performance steps. The ongoing TANGO2 trial (Riva et al. 2024, e010027) is investigating whether instructions to perform CO-CPR to bystanders with prior CPR-training is non-inferior to, or better than, standard CPR (CV-CPR) in witnessed out-of-hospital cardiac arrest. This trial is slated to be completed in 2028 and may trigger an updated review.