Chest compression rate: where is the sweet spot?

Optimal Combination of Compression Rate and Depth During Cardiopulmonary Resuscitation for Functionally Favorable Survival

Importance

Previous studies of basic cardiopulmonary resuscitation (CPR) indicate that both chest compression rate (CCR) and chest compression depth (CCD) each are associated with survival probability after out-of-hospital cardiac arrest. However, an optimal CCR-CCD combination has yet to be identified, particularly with respect to age, sex, presenting cardiac rhythm, and CPR adjunct use.

Objectives

To identify an ideal CCR-CCD combination associated with the highest probability of functionally favorable survival and to assess whether this combination varies with respect to age, sex, presenting cardiac rhythm, or CPR adjunct use.

Design, Setting, and Participants

This cohort study used data collected between June 2007 and November 2009 from a National Institutes of Health (NIH) clinical trials network registry of out-of-hospital and in-hospital emergency care provided by 9-1-1 system agencies participating in the network across the United States and Canada (n = 150). The study sample included 3643 patients who had out-of-hospital cardiac arrest and for whom CCR and CCD had been simultaneously recorded during an NIH clinical trial of a CPR adjunct. Subgroup analyses included evaluations according to age, sex, presenting cardiac rhythm, and application of a CPR adjunct. Data analysis was performed from September to November 2018.

Interventions

Standard out-of-hospital cardiac arrest interventions compliant with the concurrent American Heart Association guidelines as well as use of the CPR adjunct device in half of the patients.

Main Outcomes and Measures

The optimal combination of CCR-CCD associated with functionally favorable survival (modified Rankin scale ≤3) overall and by age, sex, presenting cardiac rhythm, and CPR adjunct use.

Results

Of 3643 patients, 2346 (64.4%) were men; the mean (SD) age was 67.5 (15.7) years. The identified optimal CCR-CCD for all patients was 107 compressions per minute and a depth of 4.7 cm. When CPR was performed within 20% of this value, survival probability was significantly higher (6.0% vs 4.3% outside that range; odds ratio, 1.44; 95% CI, 1.07-1.94; P = .02). The optimal CCR-CCD combination remained similar regardless of age, sex, presenting cardiac rhythm, or CPR adjunct use. The identified optimal CCR-CCD was associated with significantly higher probabilities of survival when the CPR device was used compared with standard CPR (odds ratio, 1.90; 95% CI, 1.06-3.38; P = .03), and the device's effectiveness was dependent on being near the target CCR-CCD combination.

Conclusions and Relevance

The findings suggest that the combination of 107 compressions per minute and a depth of 4.7 cm is associated with significantly improved outcomes for out-of-hospital cardiac arrest. The results merit further investigation and prospective validation.

Evaluation of the Quality of Manual, Compression-Only Cardiopulmonary Resuscitation in a Moving Ski Patrol Toboggan

Introduction: Cardiopulmonary resuscitation (CPR) quality may be impacted by location and setting of an out of hospital cardiac arrest. This study compared the quality of CPR performed on a moving ski patrol toboggan versus stationary CPR, both performed outdoors in winter. Materials and Methods: Compression-only CPR was performed on a manikin attached to a backboard secured into a toboggan. A CPR device was used to measure compression rate, depth and recoil, and elapsed time. A convenience sample of 30 patrollers, in weather-appropriate clothing, participated in this nonrandomized, crossover study. Each first performed 5 continuous sets of 30 compressions of stationary CPR straddling the manikin while kneeling. After 15 minutes rest, participants performed CPR while moving down the designated ski run (fixed length, vertical drop, and slope angles). Each ski run was video captured with a GoPro camera. Quality was defined as compliance with 2015 International Liaison Committee on Resuscitation (ILCOR) guidelines for CPR. Results: Overall, stationary and moving chest compressions complied with ILCOR guidelines, but there was a statistically significant degradation of CPR quality while moving and over time. Fewer compressions met ILCOR guidelines in comparison to stationary CPR compressions: (1) stationary mean depth 87% compliant, moving mean depth 35% compliant, 95% confidence interval: 39-65 (p < 0.001); (2) stationary mean rate 90% while moving mean rate 64% compliant; and (3) stationary recoil 74%, while moving recoil 77% compliant. Noncompliant compressions were typically too shallow, and noncompliance for rate was typically too fast. There were no pauses over 10 seconds once compressions were started. Conclusions: Despite CPR quality being reduced while moving, there were sufficient compliant compressions to support the use of CPR in this setting. Maintaining regular CPR training in a working environment and optimal body position in relation to the patient may be keys to performing high quality CPR on a moving toboggan.

The Impact of Backboard Placement on Chest Compression Quality: A Mannequin Study

Introduction:

High-quality chest compressions (CCs) are associated with high survival rates and good neurological outcomes in cardiac arrest patients. The 2015 American Heart Association (AHA; Dallas, Texas USA) Guidelines for Resuscitation defined and recommended high-quality CCs during cardiopulmonary resuscitation (CPR). However, CPR providers struggle to achieve high-quality CCs. There is a debate about the use of backboards during CPR in literature. Some studies suggest backboards improve CC quality, whereas others suggest that backboards can cause delays. This is the first study to evaluate all three components of high-quality CCs: compression depth, recoil depth, and rate, at the same time with a high number of subjects. This study evaluated the impact of backboards on CC quality during CPR. The primary outcome was the difference in successful CC rates between two groups.

Methods:

This was a randomized, controlled, single-blinded study using a high-fidelity mannequin. The successful CC rates, means CC depths, recoil depths, and rates achieved by 6th-grade undergraduate medical students during two minutes of CPR were compared between two randomized groups: an experimental group (backboard present) and a control group (no backboard).

Results:

Fifty-one of all 101 subjects (50.5%) were female, and the mean age was 23.9 (SD = 1.01) years. The number and the proportion of successful CCs were significantly higher in the experimental group (34; 66.7%) when compared to the control group (19; 38.0%; P = .0041). The difference in mean values of CC depth, recoil depth, and CC rate was significantly higher in the experiment group.

Conclusion:

The results suggest that using a backboard during CPR improves the quality of CCs in accordance with the 2015 AHA Guidelines.

Sanri E, Karacabey S. The impact of backboard placement on chest compression quality: a mannequin study. Prehosp Disaster Med. 2019;34(2):182–187

Can the British Heart Foundation PocketCPR application improve the performance of chest compressions during bystander resuscitation: A randomised crossover manikin study

This study aims to determine whether the British Heart Foundation PocketCPR training application can improve the depth and rate of chest compression and therefore be confidently recommended for bystander use. A total of 118 candidates were recruited into a randomised crossover manikin trial. Each candidate performed cardiopulmonary resuscitation for 2 min without instruction or performed chest compressions using the PocketCPR application. Candidates then performed a further 2 min of cardiopulmonary resuscitation within the opposite arm. The number of chest compressions performed improved when PocketCPR was used compared to chest compressions when it was not (44.28% vs 40.57%, p < 0.001). The number of chest compressions performed to the required depth was higher in the PocketCPR group (90.86 vs 66.26). The British Heart Foundation PocketCPR application improved the percentage of chest compressions that were performed to the required depth. Despite this, more work is required in order to develop a feedback device that can improve bystander cardiopulmonary resuscitation without creating delay.

Effect of the Cardio First Angel™ device on CPR indices: a randomized controlled clinical trial

Background

A number of cardiopulmonary resuscitation (CPR) adjunct devices have been developed to improve the consistency and quality of manual chest compressions. We investigated whether a CPR feedback device would improve CPR quality and consistency, as well as patient survival.

Methods

We conducted a randomized controlled study of patients undergoing CPR for cardiac arrest in the mixed medical-surgical intensive care units of four academic teaching hospitals. Patients were randomized to receive either standard manual CPR or CPR using the Cardio First Angel™ CPR feedback device. Recorded variables included guideline adherence, CPR quality, return of spontaneous circulation (ROSC) rates, and CPR-associated morbidity.

Results

A total of 229 subjects were randomized; 149 were excluded; and 80 were included. Patient demographics were similar. Adherence to published CPR guidelines and CPR quality was significantly improved in the intervention group (p < 0.0001), as were ROSC rates (72 % vs. 35 %; p = 0.001). A significant decrease was observed in rib fractures (57 % vs. 85 %; p = 0.02), but not sternum fractures (5 % vs. 17 %; p = 0.15).

Conclusions

Use of the Cardio First Angel™ CPR feedback device improved adherence to published CPR guidelines and CPR quality, and it was associated with increased rates of ROSC. A decrease in rib but not sternum fractures was observed with device use. Further independent prospective validation is warranted to determine if these results are reproducible in other acute care settings.

Trial registration

ClinicalTrials.gov identifier: NCT02394977. Registered on 5 Mar 2015.

Competency in managing cardiac arrest: A scenario-based evaluation of dental students

OBJECTIVE

Advanced Cardiovascular Life Support (ACLS) in life-threatening situations is perceived as a basic skill for dental professionals. However, medical emergency training in dental schools is often not standardized. The dental students' knowledge transfer to an ACLS setting thus remains questionable. The aim of the study was to evaluate dental pre-doctorate students' practical competence in ACLS in a standardized manner to enable the curriculum to be adapted to meet their particular needs.

MATERIALS AND METHODS

Thirty dental students (age 25.47 ± 1.81; 16 male/14 female) in their last year of dental studies were randomly assigned to 15 teams. Students' ability to successfully manage ACLS was assessed by a scenario-based approach (training module: Laerdal® ALS Skillmaster). Competence was assessed by means of (a) an observation chart, (b) video analysis and (c) training module analysis (Laerdal HeartSim®4000; Version 1.4). The evaluation was conducted by a trained anesthesiologist with regard to the 2010 guidelines of the European Resuscitation Council (ERC).

RESULTS

Only five teams (33.3%) checked for all three vital functions (response, breathing and circulation). All teams initiated cardiopulmonary resuscitation (CPR). Only 54.12% of the compressions performed during CPR were sufficient. Four teams stopped the CPR after initiation. In total, 93% of the teams used the equipment for bag-valve-mask ventilation and 53.3% used the AED (Automated external defibrillator).

CONCLUSIONS

ACLS training on a regular basis is necessary and, consistent with a close link between dentistry and medicine, should be a standardized part of the medical emergency curriculum for dental students with a specific focus on the deficiencies revealed in this study.

The cardiocerebral resuscitation protocol for treatment of out-of-hospital primary cardiac arrest

Out-of-hospital cardiac arrest (OHCA) is a significant public health problem in most westernized industrialized nations. In spite of national and international guidelines for cardiopulmonary resuscitation and emergency cardiac care, the overall survival of patients with OHCA was essentially unchanged for 30 years--from 1978 to 2008 at 7.6%. Perhaps a better indicator of Emergency Medical System (EMS) effectiveness in treating patients with OHCA is to focus on the subgroup that has a reasonable chance of survival, e.g., patients found to be in ventricular fibrillation (VF). But even in this subgroup, the average survival rate was 17.7% in the United States, unchanged between 1980 and 2003, and 21% in Europe, unchanged between 1980 and 2004. Prior to 2003, the survival of patients with OHCA, in VF in Tucson, Arizona was less than 9% in spite of incorporating previous guideline recommendations. An alternative (non-guidelines) approach to the therapy of patients with OHCA and a shockable rhythm, called Cardiocerebral Resuscitation, based on our extensive physiologic laboratory studies, was introduced in Tucson in 2003, in rural Wisconsin in 2004, and in selected EMS areas in the metropolitan Phoenix area in 2005. Survival of patients with OHCA due to VF treated with Cardiocerebral Resuscitation in rural Wisconsin increased to 38% and in 60 EMS systems in Arizona to 39%. In 2004, we began a statewide program to advocate chest compression-only CPR for bystanders of witnessed primary OHCA. Over the next five years, we found that survival of patients with a shockable rhythm was 17.7% in those treated with standard bystander CPR (mouth-to-mouth ventilations plus chest compression) compared to 33.7% for those who received bystander chest-compression-only CPR. This article on Cardiocerebral Resuscitation, by invitation following a presentation at the 2011 Danish Society Emergency Medical Conference, summarizes the results of therapy of patients with primary OHCA treated with Cardiocerebral Resuscitation, with requested emphasis on the EMS protocol.