The impact of resuscitation guideline terminology on quality of dispatcher-assisted cardiopulmonary resuscitation: A randomised controlled manikin study

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.

Comparisons of the vertical one-handed chest compressions according to the rescuer's handedness

OBJECTIVE

The vertical one-handed chest compression (OHCC) technique has demonstrated superior compression power and chest compression depth (CCD) compared to conventional OHCC. This study aimed to determine if a rescuer's handedness influences the CCD during the vertical OHCC.

METHODS

This prospective randomized crossover simulation trial included 59 medical doctors. Each performed a 2-min single-rescuer cardiopulmonary resuscitation (CPR) on a pediatric manikin using the vertical OHCC, once with the dominant hand (Test 1) and once with the non-dominant hand (Test 2). CPR parameters were recorded in real-time via sensors in the manikin, and the compression force exerted by each hand was measured using a force plate.

RESULTS

The mean and adequate CCD did not differ significantly between Test 1 and 2 (mean depth: 52 mm (interquartile range [IQR]: 49-57) in Test 1 vs. 52 mm (IQR: 49-57) in Test 2, P = 0.625; adequate depth: 97% (IQR: 37-100) in Test 1 vs. 92% (IQR: 51-99) in Test 2, P = 0.619). The mean compression force was significantly greater in the dominant hand compared to the non-dominant hand (23.1 kg ± 4.9 in dominant hand vs. 21.7 kg ± 4.1 in non-dominant hand, P < 0.001). Other parameters showed no significant differences between Tests 1 and 2.

CONCLUSIONS

While vertical OHCC with a dominant hand generated greater force, the rescuer's handedness did not affect the CCD during the vertical OHCC.

Effects of cardiopulmonary resuscitation instructions on the outcomes of out-of-hospital cardiac arrest: An analysis of the JAAM-OHCA registry

Aim

To determine whether dispatcher-provided cardiopulmonary resuscitation (CPR) instructions improve the outcomes of out-of-hospital cardiac arrest (OHCA).

Methods

Cases registered in the Japanese Association for Acute Medicine Out-of-Hospital Cardiac Arrest (JAAM-OHCA) Registry between June 2014 and December 2019 were included. Cases in which the dispatcher provided CPR instructions to the bystander were included in the "Instructions" group", and cases without CPR instructions were included in the "No Instructions" group. The primary outcome was the proportion of patients with a favorable neurological outcome, defined as a Glasgow-Pittsburgh cerebral performance category scale of 1 to 2 at 1 month after OHCA.

Results

Overall, 51,199 patients with OHCA were registered in the JAAM-OHCA Registry during the study period. Of these, 33,745 were eligible for the study, with 16,509 in the Instructions group and 17,236 in the No Instructions group. The proportion of patients with a favorable neurological outcome at 1 month after OHCA was inferior in the Instructions group than in the No Instructions group (2.3% versus 3.0%, p < 0.001). After adjustment for patient background characteristics, no association was found between CPR instructions provided by a dispatcher and favorable neurological outcomes at 1 month after OHCA (adjusted odds ratio, 1.000; 95% confidence interval, 0.869-1.151, p = 0.996).

Conclusion

The present study found no clear clinical benefit of dispatcher-provided CPR instructions on the neurological outcomes of cases with OHCA.

Relief Alternatives during Resuscitation: Instructions to Teach Bystanders. A Randomized Control Trial

To analyze the quality of resuscitation (CPR) performed by individuals without training after receiving a set of instructions (structured and unstructured/intuitive) from an expert in a simulated context, the specific objective was to design a simple and structured CPR learning method on-site. An experimental study was designed, consisting of two random groups with a post-intervention measurement in which the experimental group (EG) received standardized instructions, and the control group (CG) received intuitive or non-standardized instructions, in a public area simulated scenario. Statistically significant differences were found (p < 0.0001) between the EG and the CG for variables: time needed to give orders, pauses between chest compressions and ventilations, depth, overall score, chest compression score, and chest recoil. The average depth of the EG was 51.1 mm (SD 7.94) and 42.2 mm (SD 12.04) for the CG. The chest recoil median was 86.32% (IQR 62.36, 98.87) for the EG, and 58.3% (IQR 27.46, 84.33) in the CG. The use of a sequence of simple, short and specific orders, together with observation-based learning makes possible the execution of chest compression maneuvers that are very similar to those performed by rescuers, and allows the teaching of the basic notions of ventilation. The structured order method was shown to be an on-site learning opportunity when faced with the need to maintain high-quality CPR in the presence of an expert resuscitator until the arrival of emergency services.

Sustaining improvement of dispatcher-assisted cardiopulmonary resuscitation for out-of-hospital cardiac arrest patients in Japan: An observational study

Objectives

We aimed to estimate the relationship between the promotion of bystander cardiopulmonary resuscitation (CPR) with dispatcher-assistance over time and good cerebral function after out-of-hospital cardiac arrests (OHCAs).

Methods

This was a retrospective observational study, using a nationwide OHCA database in Japan. The eligible 267,193 witnessed cardiogenic OHCA patients between 2005 and 2016 were analysed. Multivariable logistic regression models were performed to estimate the effect of dispatcher-assisted bystander CPR per year. In addition, we calculated the number of patients with good cerebral function, which was attributed to dispatcher-assisted bystander CPR.

Results

Dispatcher-assisted bystander CPR was performed to 84,076 (31.5%), those without dispatcher-assistance were 48,389 (18.1%), and non-bystander CPR were 134,728 (50.4%). The adjusted odds ratio (AOR) of dispatcher-assisted bystander CPR vs. non-bystander CPR was significantly related to good cerebral function, regardless of the year (AOR, 1.47, 1.62; 95%CI, 1.19-1.80, 1.42-1.85, 2005 and 2016, respectively). The association of dispatcher-assisted bystander CPR with good cerebral function tended to increase (AOR, 1.11, 2.97; 95%CI, 0.99-1.24, 2.69-3.28, 2006 and 2016, based on 2005, respectively). Estimating the number of patients with good cerebral function who attributed to dispatcher-assisted bystander CPR was a significant increase from 41 in 2005 to 580 in 2016 (p < .0001, r = 0.98). Furthermore, chest compression consistently contributed to higher number of patients with good cerebral function than that with a combination of chest compression and shock with public-access-defibrillation.

Conclusion

We found that the increased dispatcher-assisted bystander CPR rate was related to good cerebral function at 1-month post OHCA. Chest compression without public-access-defibrillation was most helpful to that number, explaining the effects of dispatcher-assistance and sustaining improvement.

Verbal Motivation vs. Digital Real-Time Feedback during Cardiopulmonary Resuscitation: Comparing Bystander CPR Quality in a Randomized and Controlled Manikin Study of Simulated Cardiac Arrest

OBJECTIVE

The use of smartphone applications increases bystander CPR quality as well as the use of telephone CPR protocols. The present prospective, randomized, controlled manikin trial analyses the effects of a smartphone application (PocketCPR©) on CPR quality in a bystander CPR scenario compared to a dispatcher-assisted telephone CPR with the additional use of a metronome and verbal motivation. Methods: 150 laypersons were included to perform 8-minute CPR on a manikin. Volunteers were randomly assigned to one of three groups: (1) dispatcher-assisted telephone CPR (telephone-group), (2) dispatcher-assisted telephone CPR combined with the smartphone-application (telephone + app-group) and (3) dispatcher-assisted telephone CPR with additional verbal motivation ("push harder, release completely," every 20 seconds, starting after 60 seconds) and a metronome with 100 min^-1 (telephone + motivation-group). Results: Median compression depth did not differ significantly between the study groups (p = 0.051). However, in the post hoc analysis median compression depth in the telephone + motivation-group was significantly elevated compared to the telephone + app-group (59 mm [IQR 47-67 mm] vs. 51 mm [IQR 46-57 mm]; p = 0.025). The median number of superficial compressions was significantly reduced in the telephone + motivation-group compared to the telephone + app-group (70 [IQR 3-362] vs. 349 [IQR 88-538]; p = 0.004), but not compared to the telephone-group (91 [IQR 4-449]; p = 0.707). In contrast to the other study groups, median compression depth of the telephone + motivation-group increased over time. Chest compressions with correct depth were found significantly more often in the telephone + app-group compared to the other study groups (p = 0.011). Median compression rate in the telephone + app-group was significantly elevated (108 min^-1 [IQR 96-119 min^-1]) compared to the telephone-group (78 min^-1 [IQR 56-106 min^-1]; p < 0.001) and the telephone + motivation-group (99 min^-1 [IQR 91-101 min^-1]; p < 0.001). Conclusions: The use of a smartphone application as well as verbal motivation by a dispatcher during telephone CPR leads to higher CPR quality levels compared to standard telephone CPR. Thereby, the use of the smartphone application mainly shows an increase in compression rate, while increased compression rate with simultaneously increased compression depth was only apparent in the telephone + motivation-group.

Differences in the performance of resuscitation according to the resuscitation guideline terminology during infant cardiopulmonary resuscitation: "Approximately 4 cm" versus "at least one-third the anterior-posterior diameter of the chest"

Aim

This study was conducted to investigate the effect of resuscitation guideline terminology on the performance of infant cardiopulmonary resuscitation (CPR).

Methods

A total of 40 intern or resident physicians conducted 2-min CPR with the two-finger technique (TFT) and two-thumb technique (TT) on a simulated infant cardiac arrest model with a 1-day interval. They were randomly assigned to Group A or B. The participants of Group A conducted CPR with the chest compression depth (CCD) target of “approximately 4 cm” and those of Group B conducted CPR with the CCD target of “at least one-third the anterior-posterior diameter of the chest”. Single rescuer CPR was performed with a 15:2 compression to ventilation ratio on the floor.

Results

In both chest compression techniques, the average CCD of Group B was significantly deeper than that of Group A (TFT: 41.0 [range, 39.3–42.0] mm vs. 36.5 [34.0–37.9] mm, P = 0.002; TT: 42.0 [42.0–43.0] mm vs. 37.0 [35.3–38.0] mm, P < 0.001). Adequacy of CCD also showed similar results (Group B vs. A; TFT: 99% [82–100%] vs. 29% [12–58%], P = 0.001; TT: 100% [100–100%] vs. 28% [8–53%], P < 0.001).

Conclusions

Using the CCD target of “at least one-third the anterior-posterior diameter of the chest” resulted in deep and adequate chest compressions during simulated infant CPR in contrast to the CCD target of “approximately 4 cm”. Therefore, changes in the terminology used in the guidelines should be considered to improve the quality of CPR.

Trial registration

Clinical Research Information Service; cris.nih.go.kr/cris/en (Registration number: KCT0003486).