Interventions to optimize dispatcher-assisted CPR instructions: A scoping review

Aim: To review and summarize existing literature and knowledge gaps regarding interventions that have been tested to optimize dispatcher-assisted CPR (DA-CPR) instruction protocols for out-of-hospital cardiac arrest (OHCA). Methods: This scoping review was undertaken by an International Liaison Committee on Resuscitation (ILCOR) Basic Life Support scoping review team and guided by the ILCOR methodological framework and the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR). Studies were eligible for inclusion if they were published in peer-reviewed journals and evaluated interventions used to improve DA-CPR. The search was carried out in MEDLINE, EMBASE, Education Resources Information Center (ERIC), PsycINFO, the Cochrane Library, Evidence Based Medicine (EBM) Reviews, and the Campbell Library from 2000 to December 18, 2023. Results: After full text review, 31 studies were included in the final review. The interventions reviewed were use of video at the scene (n = 9), changes in terminology about compressions (n = 6), implementation of novel DA-CPR protocols (n = 4), advanced dispatcher training (n = 3), centralization of the dispatch center (n = 2), use of metronome or varied metronome rates (n = 2), change in CPR sequence and compression ratio (n = 1), animated audio-visual recording (n = 1), pre-recorded instructions vs. conversational live instructions (n = 1), inclusion of “undress patient” instructions (n = 1), and specific verbal encouragement (n = 1). Studies ranged in methodology from registry studies to randomized clinical trials with the majority being observational studies of simulated EMS calls for OHCA. Outcomes were highly variable but included rates of bystander CPR, confidence & willingness to perform CPR, time to initiation of bystander CPR, bystander CPR quality (including CPR metrics: chest compression depth and rate; chest compression fraction; full chest recoil, ventilation rate, overall CPR competency), rates of automated external defibrillator (AED) use, return of spontaneous circulation (ROSC) and survival. Overall, all interventions seem to be associated with potential improvement in bystander CPR and CPR metrics. Conclusion: There appears to be trends towards improvement on key outcomes however more research is needed. This scoping review highlights the lack of high-quality clinical research on any of the tested interventions to improve DA-CPR. There is insufficient evidence to explore the effectiveness of any of these interventions via systematic review.