Effects of positive dispatcher encouragement on the maintenance of bystander cardiopulmonary resuscitation quality

Background : Implementation of dispatcher-assisted cardiopulmonary resuscitation (DACPR) has increased the likelihood of bystander CPR upon cardiac arrest. However, the quality of CPR has been found to be very low. In this study, we aimed to compare CPR quality between the current DACPR practices and the interventional instruction of adding verbal encouragement from the dispatcher. Methods : In this randomized controlled trial, we recruited adult (age >= 18) laypersons who were non-health care providers and had never received any previous verified CPR training. They were randomly selected to perform DACPR using metronome sounds (mDACPR) as per the standard protocol, or DACPR with metronome sounds along with human encouragement (mheDACPR). The ratio of accurate compression rate, depth, and complete release for each CPR phase was examined. Results: Sixty nine records (34, mDACPR; 35, mheDACPR) were taken. The median proportion of accurate chest compression rate was initially 29.5% with mDACPR, and significantly increased to 71% after 2 minutes of CPR administration (P = .046). However, the median ratio of accurate chest compression depth was 61.5% in the first phase, and significantly decreased to 0% in the last phase (P < .001). In contrast, for the mheDACPR group, a high accurate compression rate was maintained throughout the 2 minutes of CPR administration (91%, 100%, 100%, 100%). Conclusion : To maintain the quality of CPR administered by bystanders, continuous feedback and repeated human encouragement should be provided during DACPR. Active dispatcher intervention reduces the time required to reach an appropriate CPR rate and allows for the maintenance of accurate compression rates.