A trade-off relationship between chest compression depth and chest wall recoil during cardiopulmonary resuscitation

The relationship between upper extremity functional performance and anthropometric features and the quality criteria of cardiopulmonary resuscitation

Objectives: This study aims to examine the effect of upper extremity performance using the Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST) on cardiopulmonary resuscitation (CPR) quality criteria according to the European Resuscitation Council (ERC) Guidelines for Resuscitation 2015, including chest compression rate, depth, and recoil.

Patients and methods: This simulation-based study included 105 paramedic students (43 males, 62 females; median age: 19 years; range, 18 to 20 years) attending a two-year paramedic program between February 2018 and April 2018. The CKCUEST was used to determine upper extremity performance scores, including the touch number, normalized, and power score of the paramedic students. A TrueCPR® feedback device was used to measure CPR quality criteria throughout the study. The characteristics of the providers, such as height, weight, body mass index (BMI), and fat-free mass were also analyzed.

Results: Adequate compression depth had a positive correlation with body fat-free mass (r=0.397, p<0.001), power score (r=0.326, p=0.001), height (r=0.326, p=0.001), weight (r=0.314, p=0.001), and BMI (r=0.204, p=0.037). Full chest recoil had a negative correlation with the power score (r=-0.249, p=0.010) and height (r=-0.219, p=0.025). None of the variables were significantly different between the groups with and without the correct compression rate. In the receiver operating characteristic curve analysis for power score and correct compression depth as 100%, the area under the curve was 0.845 (p<0.001).

Conclusion: The power score combination of upper extremity functionality and the rescuer’s weight is the main factor affecting chest compression depth. However, this score is negatively correlated with full chest recoil.

Effects of vertical compression during pediatric cardiopulmonary resuscitation using the one-handed chest compression technique

OBJECTIVE

The posture of the rescuer while performing the one-handed chest compression (OHCC) has not yet been evaluated. This study aimed to investigate the effect of vertical compression during pediatric cardiopulmonary resuscitation (CPR) using the OHCC technique.

METHODS

This was a prospective randomized crossover simulation trial. A total of 42 medical doctors conducted a 2-min single-rescuer CPR using the conventional OHCC (Test 1) or vertical OHCC (Test 2) technique on a pediatric manikin. The chest compression and ventilation parameters were measured in real time during the experiments using sensors embedded in the manikin. In addition, the compression force of each technique was measured using a force plate.

RESULTS

The average and adequate chest compression depth (CCD) were significantly higher in Test 2 than in Test 1 (average depth: 54.0 mm (interquartile range [IQR]: 48.5-56.0) in Test 2 vs. 49.0 mm (IQR: 40.0-54.0) in Test 1, P < 0.001; adequate depth: 99.0% (IQR: 36.3-100.0) in Test 2 vs. 52.0% (IQR: 0.0-98.0) in Test 1, P < 0.001). The average force of compression was also significantly higher in vertical OHCC than that in conventional OHCC (25.7 kg ± 4.4 in vertical OHCC vs. 24.5 kg ± 4.2 in conventional OHCC, P < 0.001). The ventilation parameters were not significantly different between Tests 1 and 2.

CONCLUSIONS

The vertical OHCC could provide a deeper and more adequate CCD compared with the conventional OHCC, and the advantages of the vertical OHCC originate from the superiority of the compression force.

Advantage and Limitation of Using a Visual Feedback Device during Cardiopulmonary Resuscitation Training

INTRODUCTION

Recent cardiopulmonary resuscitation (CPR) guidelines recommend the use of CPR prompt/feedback devices during CPR training because it can improve the quality of CPR.

PROBLEM

Chest compression depth and full chest recoil show a trade-off relationship. Therefore, achievement of both targets (adequate chest compression depth and full chest recoil) simultaneously is a difficult task for CPR instructors. This study hypothesized that introducing a visual feedback device to the CPR training could improve the chest compression depth and ratio of full chest recoil simultaneously.

METHODS

The study investigated the effects of introducing a visual feedback device during CPR training by comparing the results of skill tests before and after introducing a visual feedback device. The results of skill tests from 2016 through 2018 were retrospectively reviewed. The strategy of emphasizing chest compression depth was implemented during the CPR training in 2017, and a visual feedback device was introduced in 2018. The interval between the CPR training and skill tests was seven days. Feedback was not provided during the skill tests.

RESULTS

In total, 159 students completed skill tests. Although the chest compression depth increased significantly from 50 mm (42-54) to 60 mm (59-61) after emphasizing chest compression depth (P < .001), the ratio of full chest recoil decreased simultaneously from 100% (100-100) to 81% (39-98; P < .001). The ratio of full chest recoil increased significantly from 81% (39-98) to 95% (77-100) after introducing a visual feedback device (P = .018). However, the students who did not achieve 80% of the ratio of full chest recoil remained significantly higher than in 2016 (1% in 2016, 49% in 2017, and 27% in 2018; P < .001).

CONCLUSIONS

Although introducing a visual feedback device during CPR training resulted in increasing the ratio of full chest recoil while maintaining the adequacy of chest compression depth, 27% of the students still did not achieve 80% of the ratio of full chest recoil. Another educational strategy should be considered to increase the qualities of CPR more completely.