Muscles used for chest compression under static and transportation conditions

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.

"Elbow-Lock" Chest Compression Method in the Setting of Single Rescuer Pediatric Cardiopulmonary Resuscitation: A Crossover Simulation Study

BACKGROUND

We designed a new 1-handed chest compression method, the "elbow-lock" chest compression (ELCC), for a single rescuer in pediatric cardiopulmonary resuscitation (CPR). Then, we compared the effectiveness between the ELCC and standard chest compression (SCC) method.

METHODS

This prospective, randomized controlled, crossover simulation trial studied 34 emergency medical professionals, including physicians, nurses, and EMTs. We compare the quality of chest compression and fatigue point time between the ELCC and the SCC.

RESULTS

Participants who performed the ELCC method maintained a proper depth of compression compared with SCC method (50.0 ± 0.3 mm vs 40.5 ± 0.4 mm, P < 0.001). However, the 2 methods did not differ in terms of compression velocity since neither reached the standard velocity (96.7 ± 7.1/minutes vs 91.7 ± 7.0/minutes, P < 0.016). With respect to the overall score, ELCC was more effective than the SCC (91.6 ± 3.7% vs 85.3 ± 8.8%, P = 0.002). In addition, the fatigue point time was slower in the ELCC group than the SCC group (7.3 ± 0.3/minutes vs 6.1 ± 0.4/minutes, P < 0.001).

CONCLUSIONS

The single rescuer ELCC method is an effective alternative to the SCC method for pediatric CPR because the ELCC method can prevent elbow flexion.Trial registration: Our research is simulation manikin study. So we do not need to "trial registration".

The feasibility of emergency medical technicians performing intermittent high-quality cardiopulmonary resuscitation

Background: Whether intermittent chest compressions have an effect on the quality of CPR is worthy of discussion. The purpose of this study was to investigate differences in the chest compression quality of emergency medical technicians (EMTs) performing cardiopulmonary resuscitation (CPR) with different rest intervals. Methods: Seventy male firefighters with EMT licenses participated in this study. Participants completed body composition measurements and three CPR quality tests, as follows: (1) CPR-uninterrupted for 10 minutes; (2) after 2 days of rest, CPR 10s-intermittent (CPR-10s), for 2 minutes each time and 5 cycles; (3) after another 2 days of rest, CPR 20s-intermittent (CPR-20s), for 2 minutes each time and 5 cycles. Results: Body composition results showed that body mass (BM), body mass index (BMI), upper limb muscle mass (ULMM), core muscle mass (CMM), and upper limb-core muscle mass (UL+CMM) were positively correlated with chest compression depth (CCD) (p < 0.05). Analysis of the three different modes of CPR quality analysis indicated significant differences in the chest compression fraction (CCF, F = 6.801, p = 0.001), chest compression rebound rate (CCRR, F = 3.919, p = 0.021), and ratings of perceived exertion (RPE, F = 23.815, p < 0.001). Among the different performance cycles of CPR-10s, significant differences were found in CCF, CCD, CCR (chest compression rate), and RPE (p < 0.05). On the other hand, among the different performance cycles of CPR-20s, significant differences were found in CCD, CCR, and RPE (p < 0.05). Moreover, the CCF, CCD, and RPE scores of the two tests reached significant differences in specific phases (p < 0.05). Conclusions: This study confirmed that the upper limb muscle mass or the weight of the upper body of EMTs is positively correlated with the quality of CPR. In addition, intermittent chest compressions with safe interruption intervals can reduce fatigue caused by long-term chest compressions and maintain better chest compression quality.

What muscles need to be trained for high-quality chest compression?

BACKGROUND

This study is aimed to identify the muscles that need to be trained for high-quality cardiopulmonary resuscitation by evaluating the muscles that are fatigued during chest compression in both kneeling and standing positions.

METHODS

In this randomized crossover trial, 37 participants performed continuous chest compressions on a manikin for 5min, alternating between kneeling and standing positions. The median frequency values of 16 muscles were determined from surface electromyography recordings.

RESULTS

The median frequency values of the arm muscles (flexor carpi radialis, extensor carpi radialis, biceps brachii, triceps brachii) in both positions were significantly lower during the last 30s than during the first 30s, demonstrating muscle fatigue over time. The cervical erector spinae in the kneeling position and the external oblique abdominis in the standing position were also fatigued over time. In the deltoideus, quadriceps femoris, and biceps femoris muscles, the difference in median frequency between the last 30s and the first 30s was significantly different between the two positions, and muscles were more fatigued in the standing position than in the kneeling position.

CONCLUSIONS

Understanding patterns of muscle fatigue and training of these muscles would assist healthcare providers in performing high-quality chest compressions. ClinicalTrials.gov number: NCT02088879.

Effect of chest compression with kneeling on the bed in clinical situations

Aim

Cardiopulmonary resuscitation is vital for survival after cardiac arrest, and chest compressions are an important aspect of this. When performing chest compression in a hospital setting, the rescuer often has to kneel on the bed to overcome inconvenient differences in height between the rescuer and the bed. However, as yet no study has evaluated the quality of chest compressions in this position. The aim of this study was to examine the impact on the quality of chest compressions while kneeling on the bed.

Methods

Fifteen female students performed 2‐min chest compressions on a manikin placed on the floor and a bed. Measurement parameters included compression depth, heart rate, integrated electromyogram, and a visual analog scale. The parameters were measured every 30 s and were statistically compared between the conditions.

Results

Compression depth at 30, 60, 90, and 120 s differed significantly between the conditions. Heart rate values at 150 and 210 s of recovery significantly differed between the conditions. Integrated electromyogram values for the trapezius, rectus femoris, and biceps femoris differed between the floor and bed conditions during 2‐min chest compressions, whereas the external oblique muscle significantly differed at 60 and 120 s. Visual analog scales for fatigue, effectiveness, and stability significantly differed between the conditions.

Conclusion

Kneeling on the bed does not enable grounding of the toe, causing the upper body to be unstable and limiting generation of the power required for chest compression. Our results suggest that rotation every minute is necessary to maintain effective cardiopulmonary resuscitation while kneeling on the bed.

The Effect of Operator Position on the Quality of Chest Compressions Delivered in a Simulated Ambulance

BACKGROUND

Ambulances are where patient care is often initiated or maintained, but this setting poses safety risks for paramedics. Paramedics have found that in order to optimize patient care, they must compromise their own safety by standing unsecured in a moving ambulance.

HYPOTHESIS/PROBLEM

This study sought to compare the quality of chest compressions in the two positions they can be delivered within an ambulance.

METHODS

A randomized, counterbalanced study was carried out with 24 paramedic students. Simulated chest compressions were performed in a stationary ambulance on a cardiopulmonary resuscitation (CPR) manikin for two minutes from either: (A) an unsecured standing position, or (B) a seated secured position. Participants' attitudes toward the effectiveness of the two positions were evaluated.

RESULTS

The mean total number of chest compressions was not significantly different standing unsecured (220; SD = 12) as compared to seated and secured (224; SD = 21). There was no significant difference in mean compression rate standing unsecured (110 compressions per minute; SD = 6) as compared to seated and secured (113 compressions per minute; SD = 10). Chest compressions performed in the unsecured standing position yielded a significantly greater mean depth (52 mm; SD = 6) than did seated secured (26 mm; SD = 7; P < .001). Additionally, the standing unsecured position produced a significantly higher percentage (83%; SD = 21) for the number of correct compressions, as compared to the seated secured position (8%; SD = 17; P < .001). Participants also believed that chest compressions delivered when standing were more effective than those delivered when seated.

CONCLUSIONS

The quality of chest compressions delivered from a seated and secured position is inferior to those delivered from an unsecured standing position. There is a need to consider how training, technologies, and ambulance design can impact the quality of chest compressions.

Comparison of chest compression quality in walking versus straddling cardiopulmonary resuscitation during stretcher transportation: A prospective randomised crossover study using manikins

The optimal strategy to ensure chest compression quality for patients being transported on a stretcher has not been established yet. We hypothesised that straddling cardiopulmonary resuscitation may improve chest compression quality in patients being transported on stretchers. We conducted a prospective randomised crossover study using manikins to investigate whether straddling cardiopulmonary resuscitation improves chest compression quality (depth, recoil, rate, correct hand position) performed on patients during stretcher transportation compared to walking cardiopulmonary resuscitation. Walking and straddling cardiopulmonary resuscitation were performed for 2 minutes each. The mean chest compression depth (mm) for 2 minutes was significantly greater in the straddling cardiopulmonary resuscitation group than in the walking cardiopulmonary resuscitation group (median, 51.3 [interquartile range, 46.7–55.5] versus 40.9 [34.6–50.1], P = 0.003). An adequate depth of chest compressions could not be achieved when walking cardiopulmonary resuscitation was performed by female participants, but the depth of chest compressions was within the acceptable range when female participants performed straddling cardiopulmonary resuscitation. On the other hand, the degree of deterioration was relatively small in male participants, even when they performed walking cardiopulmonary resuscitation. In patients with cardiac arrest being transported on a stretcher, straddling cardiopulmonary resuscitation improved the depth of chest compressions compared to walking cardiopulmonary resuscitation. Female rescuers, in particular, may consider using straddling cardiopulmonary resuscitation.

Acute muscle fatigue and CPR quality assisted by visual feedback devices: A randomized-crossover simulation trial

Objective

To analyse the acute muscular fatigue (AMF) in triceps brachii and rectus abdominis during compression-only and standard cardiopulmonary resuscitation (CPR) performed by certified basic life support providers.

Methods

Twenty-six subjects were initially recruited and randomly allocated to two study groups according to the muscles analysed; eighteen finally met the inclusion criteria (nine in each group). Both groups carried out two CPR tests (compression-only and standard CPR) of 10 min divided into five 2-min intermittent periods. The ventilation method was freely chosen by each participant (mouth-to-mouth, pocket-mask or bag-valve-mask). CPR feedback was provided all the time. AMF was measured by tensiomyography at baseline and after each 2-min period of the CPR test, in triceps brachii or rectus abdominis according to the study group.

Results

Rectus abdominis’ contraction time increased significantly during the fifth CPR period (p = 0.020). Triceps brachii’s radial muscle belly displacement (p = 0.047) and contraction velocity (p = 0.018) were lower during compression-only CPR than during standard CPR. Participants who had trained previously with feedback devices achieved better CPR quality results in both protocols. Half of participants chose bag-valve-mask to perform ventilations but attained lower significant ventilation quality than the other subjects.

Conclusions

Compression-only CPR induces higher AMF than standard CPR. Significantly higher fatigue levels were found during the fifth CPR test period, regardless of the method. Adequate rescuer’s strength seems to be a requisite to take advantage of CPR quality feedback devices. Training should put more emphasis on the quality of ventilation during CPR.

Chest compression fraction in ambulance while transporting patients with out-of-hospital cardiac arrest to the hospital in rural Taiwan

INTRODUCTION

Maintaining the standard two-handed chest compression is difficult in high-speed ambulances in rural areas.

METHODS

A retrospective, video-based, observational study was conducted from June to September 2013 in Nantou, a rural county of central Taiwan, to evaluate the chest compression fraction in an ambulance carriage during the travel from the scene to the hospital. The chest compression fraction was calculated as the chest compression time period divided by the ambulance travelling time period; the one-handed and two-handed chest compression fractions were also calculated.

RESULTS

During the 4-month study period, a total of 102 videos that were recorded in an ambulance carriage were reviewed, including 97 cases of manual chest compressions. When there was only one emergency medical technician (EMT) in the carriage, the combined chest compression fraction was 50.6±20.7%; when there were two EMTs, the fraction was 58.3±16.0% and the fraction was 58.3±21.0% in a three-EMT scenario (p=0.221). Moreover, in the carriage, EMTs usually performed one-handed chest compressions.

CONCLUSIONS

The chest compression fraction was low for patients with out-of-hospital cardiac arrest in a moving ambulance, irrespective of the number of providers. Reasons for this observation, as well as the effectiveness of the one-handed chest compression require further evaluation.

Relationship between weight of rescuer and quality of chest compression during cardiopulmonary resuscitation

Background

According to the guidelines for cardiopulmonary resuscitation (CPR), the rotation time for chest compression should be about 2 min. The quality of chest compressions is related to the physical fitness of the rescuer, but this was not considered when determining rotation time. The present study aimed to clarify associations between body weight and the quality of chest compression and physical fatigue during CPR performed by 18 registered nurses (10 male and 8 female) assigned to light and heavy groups according to the average weight for each sex in Japan.

Methods

Five-minute chest compressions were then performed on a manikin that was placed on the floor. Measurement parameters were compression depth, heart rate, oxygen uptake, integrated electromyography signals, and rating of perceived exertion. Compression depth was evaluated according to the ratio (%) of adequate compressions (at least 5 cm deep).

Results

The ratio of adequate compressions decreased significantly over time in the light group. Values for heart rate, oxygen uptake, muscle activity defined as integrated electromyography signals, and rating of perceived exertion were significantly higher for the light group than for the heavy group.

Conclusion

Chest compression caused increased fatigue among the light group, which consequently resulted in a gradual fall in the quality of chest compression. These results suggested that individuals with a lower body weight should rotate at 1-min intervals to maintain high quality CPR and thus improve the survival rates and neurological outcomes of victims of cardiac arrest.