Impact of physical fitness and biometric data on the quality of external chest compression: a randomised, crossover trial

Effect of the Brief Instructional Video Intervention on the Quality of Cardiopulmonary Resuscitation

Background: Chest compressions are the basis of cardiopulmonary resuscitation (CPR), and high-quality chest compressions can improve survival rate in patients with out-of-hospital cardiac arrest. Although many efforts have been made to improve the quality of CPR in inexperienced adults, the results are still not high, especially during emergencies. The primary purpose of this study is to investigate whether a brief instructional chest compression-only CPR video could improve chest compression quality in inexperienced adults. Methods: One hundred adults with no CPR experience (age: 20.28 ± 2.28 years; women: 50, men: 50) participated in this study. Participants completed body composition and handgrip strength measurements, and performed two CPR quality tests on the Laerdal^® Little Anne QCPR Manikin, namely without video-CPR (WV-CPR) and video-CPR (V-CPR). The WV-CPR quality test was performed first. After 2 minutes of continuous chest compression, the participants rested for 10 seconds and repeated 3 cycles (phase 1, phase 2, and phase 3). After resting for more than 72 hours, V-CPR quality test was conducted. During the V-CPR with video intervention, the participants also continued to compress the chest for 2 minutes, and then rested for 10 seconds, repeating 3 cycles. Results: In phase 1, compared with WV-CPR, the V-CPR has a significant increase (p < 0.001) in chest compression fraction (CCF) (56.31 ± 33.22% vs. 41.82 ± 32.30%) and percent of correct compression rate (PCCR) (96.17 ± 8.45% vs. 26.31 ± 37.55%). In addition, the V-CPR has significantly lower (p < 0.001) chest compression rate (CCR) (110.85 ± 2.40 cpm vs. 128.86 ± 24.52 cpm) and rating of perceived exertion (RPE) (11.89 ± 2.25 vs. 12.87 ± 2.25). For phases 2 through 3, V-CPR and WV-CPR achieved significant differences in CCF, CCD, CCR, PCCR, and RPE (p < 0.01). There were significant differences (p < 0.05) in CCF, CCD, chest compression rebound rate, and RPE among the different administration stages of both WV-CPR and V-CPR. Conclusions: The results of this study revealed that a brief instructional chest compression-only CPR video could improve chest compression quality for inexperienced adults by reducing fatigue and CCR, and increasing CCF and PCCR.

The Impact of Compression Rates on the Quality of Cardiopulmonary Resuscitation: A Cross Over Randomized Control Study in Manikin

Background

High-quality cardiopulmonary resuscitation (HQ-CPR) focuses on improving heart and brain blood perfusion. The evaluation of HQ-CPR included depth, frequency, rate of chest compressions, and the occurrence of chest recoil between two chest compressions. Staff performing CPR may not be performing HQ-CPR since it is influenced by individual stamina, physical strength, and lack of target marker. We aimed to study the impact of 100 times per minute rate vs. 120 times per minute CPR rate on the depth and percentage of depth-on-target done by trained staff on a manikin.

Methods

This was a cross-over randomized control study. The subjects were anesthesiology and intensive care residents in a tertiary teaching hospital in Indonesia, all certified to perform advanced life support. The subject was asked to perform both CPR of 100 and 120 times per minute after a period of one-day rest. The standardized adult manikin was used, and the depth of CPR was measured using a pad-sensor attached to the manikin, and the results were transferred to recording software. Analysis was done using the chi-square analysis, and p < 0.05 was considered statistically significant.

Results

A total of 35 subjects were included. The results showed that the average compression depth at 100 times/minute was more statistically superficial than the 120 times/minute treatment (5.210 ± 0.319 vs. 5.430 ± 0.283, p = 0.007). In contrast, the compression depth-on-target percentage was significantly higher at a speed of 100 times per minute (37.130 ± 10.233 vs. 18.730 ± 7.224, p = 0.0001).

Conclusion

One hundred times per minute CPR resulted in a statistically significant lower compression depth, although not clinically significant, with a statistically significant higher percentage of compression depth-on-target than 120 times per minute CPR.

Development and Validation of a Novel Ultra-Compact and Cost-Effective Device for Basic Hands-On CPR Training: A Randomized, Sham-Controlled, Blinded Trial

To examine the performance of a novel low-cost, ultra-compact, and attractive auditory feedback device for training laypeople in external chest compressions (ECCs), we conducted a quasi-experimental cross-sectional study from September to November 2021 at the Faculty of Nursing of Albacete, University of Castille-La Mancha, Spain. The ECC sequence was performed in the laboratory with the new device for basic hands-on CPR training. Results: One hundred college students were included in this study. The compression rate/min with the new device was 97.6, and the adequate %ECC was 52.4. According to the status of body mass index (BMI) and muscle strength of the upper limbs in the bivariate analysis, it was observed that the new device discriminated between those who performed correct ECCs according to their BMI and muscle strength and those who did not, which led to significantly influenced results in terms of the percentage of ECCs with correct depth. Conclusions: The new ultra-compact auditory feedback device "Salvando a Llanetes^®" demonstrated utility for teaching and learning ECCs in basic CPR. We can affirm that the analyzed device is an adequate, safe and economical method for teaching "CPR Hands-Only™" to the general population.

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.

The Relationship between Selected Body Composition Components and Cardiopulmonary Resuscitation Parameters in Nurses: An Observational Simulation Study

The provision of cardiopulmonary resuscitation (CPR) may be related to the physical parameters of the medical personnel, including fat mass (FM) and fat-free mass (FFM) components. In this study, we aimed to assess the relationship between selected body composition components and chest compression and ventilation parameters provided by medical staff. An observational simulation study was undertaken between December 2017 and January 2019 at the Center for Innovative Research in Medical and Natural Sciences of Rzeszów. In all participants (505 nurses, 37.71 y ± 12.16), the body weight and height were measured and the body mass index (BMI) was calculated. The body composition indicators were obtained using a bioelectrical impedance device, AKERN BIA 101. Afterwards, all participants performed CPR sequences (30 chest compressions and rescue for 2 breaths) for 2 min on a Laerdal Resusci Anne simulator placed on an examination couch with a self-inflating bag and a face mask. Our observations proved that high values of the anthropometric, nutritional and body composition parameters of the medical staff demonstrated a positive significant correlation with the depth and rate chest parameters and were inversely related to the chest adequate recoil. No statistically significant differences were found between the FM or FFM components and ventilation parameters. This study showed that nutritional status and body composition components may be important factors affecting the quality of CPR.

Commencing one-handed chest compressions while activating emergency medical system using a handheld mobile device in lone-rescuer basic life support: a randomised cross-over simulation study

INTRODUCTION

In conventional basic life support (c-BLS), a lone rescuer is recommended to start chest compressions (CCs) after activating the emergency medical system. To initiate earlier CCs in lone-rescuer BLS, we designed a modified BLS (m-BLS) sequence in which the lone rescuer commences one-handed CCs while calling for help using a handheld cellular phone with the other free hand. This study aimed to compare the quality of BLS between c-BLS and m-BLS.

METHODS

This was a simulation study performed with a randomised cross-over controlled trial design. A total of 108 university students were finally enrolled. After training for both c-BLS and m-BLS, participants performed a 3-minute c-BLS or m-BLS on a manikin with a SkillReporter at random cross-over order. The paired mean difference with SE between c-BLS and m-BLS was assessed using paired t-test.

RESULTS

The m-BLS had reduced lag time before the initiation of CCs (with a mean estimated paired difference (SE) of -35.0 (90.4) s) (p<0.001). For CC, a significant increase in compression fraction and a higher number of CCs with correct depth were observed in m-BLS (with a mean estimated paired difference (SE) of 16.2% (0.6) and 26.9% (3.3), respectively) (all p<0.001). However, no significant paired difference was observed in the hand position, compression rate and interruption time. For ventilation, the mean tidal volumes did not differ. However, the number of breaths with correct tidal volume was higher in m-BLS than in c-BLS.

CONCLUSION

In simulated lone-rescuer BLS, the m-BLS could deliver significantly earlier CCs than the c-BLS while maintaining high-quality cardiopulmonary resuscitation.

Evaluation of the effect of shift cycle time on chest compression quality during cardiopulmonary resuscitation

Objective

Considering the potential role of shift cycle time on chest compression quality during cardiopulmonary resuscitation (CPR) and the available contradictory results in this regard, the present study aimed at evaluating the effect of 1-min versus 2-min shift cycle time on the quality of CPR.

Materials and Methods

In this randomized crossover study, 80 rescuers performed CPR on a manikin in two scenarios with a rotation of 1 and 2-min cycles. The quality of CPR was evaluated and compared based on the information obtained regarding the chest compression depth, recoil, and rate of chest compression. In addition, rescuer fatigue was recorded in 1-min versus 2-min shift cycles.

Results

In the 1-min group, the number of chest compressions per minute, complete recoil, and good rate with the mean of 114.89 ± 3.62, 54.34 ± 3.86, and 76.06 ± 8.00 were significantly higher than those of the 2-min group with the mean of 113.78 ± 4.94, 53.49 ± 5.27, and 73.98 ± 7.87 (P < 0.05), respectively. In addition, the quality of CPR provided by males was significantly higher than females in both groups. The score of rescuer fatigue was higher in the 2-min group as compared with the 1-min group (P < 0.001).

Conclusion

According to the results of the present study, the difference in the quality of CPR in terms of the number of chest compressions, complete recoil, and good rate was higher in the 1-min group as compared with the 2-min group. In addition, the quality of CPR in terms of chest compression depth and number in both 1-and 2-min rotation cycles was higher for male rescuers than females. Furthermore, rescuer fatigue was higher in the 2-min group as compared with the 1-min group. The mentioned finding may be a factor in reducing, albeit slightly, the quality of CPR in the group with a longer time.

Deliberate practice in resuscitation training using a feedback device, and the effects of the physical characteristics of the rescuer on the acquisition and retention of cardiopulmonary resuscitation skills: Randomized clinical trial

BACKGROUND

Cardiopulmonary resuscitation (CPR) skills decline rapidly and rescuers' physical characteristics could impact on their performance. Our aim was to analyse the effects of deliberate practice using a feedback device (FD) on the CPR performance of nursing students prior to, immediately after, and three months after training, considering their physical characteristics.

METHOD

Sixty nursing students participated in this randomized clinical trial (control group n = 28; training group n = 32). Their physical characteristics (weight, height, forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC)% index, handgrip strength, and CPR position strength) were measured before starting the trial. The training group followed a CPR training programme based on deliberate practice, providing feedback on their performance using an FD. All participants were evaluated during two-minute CPR compression/ventilation cycles.

RESULTS

The training group showed an improved ability to perform chest compressions (F_{(2, 115.2)} = 13.3; p < .001; ω²_p = 0.17) and ventilations (F_{(2, 115.3)} = 102.1; p < .001; ω²_p = 0.63), improving their overall quality of CPR (F_{(2, 115.2)} = 40.1; p < .001; ω²_p = 0.40). The physical characteristics of the participants did not affect CPR performance in any study phase.

CONCLUSIONS

A structured training programme based on deliberate practice using an FD had a positive effect on the acquisition of CPR skills by participants, while their physical characteristics had no impact on performance.

How Does Rescuer Fitness Affect the Quality of Prolonged Cardiopulmonary Resuscitation?

Objective: High quality cardiopulmonary resuscitation (CPR) is crucial for patients experiencing cardiac arrest. CPR quality declines within the first few minutes of CPR performance. Being more fit is associated with higher CPR quality, yet the fitness parameters needed remain uncertain. It is also unknown how CPR quality is affected during a protocol of realistic CPR when rescuers switch compressors every two minutes, as recommended by the American Heart Association (AHA), and extended duration, as might be encountered with an out-of-hospital cardiac arrest. The purpose of the present study is to determine the extent to which different measures of physical fitness predict high quality CPR performance when rescuers follow current CPR guidelines. Methods: Subjects underwent a fitness assessment evaluating lower back muscular endurance, abdominal muscular endurance, upper body muscular strength, and upper body anaerobic power. At least 48 hours later, subjects returned to the laboratory for CPR testing. CPR quality was determined by compression rate (>100/minute), compression depth (>2 inches, or 50 mm), and adequate (full) chest recoil between compressions, based on American Heart Association guidelines. A CPR Quality Score, designed to represent cardiac output, was calculated as the product of compression rate and depth. Results: Thirty-three of 42 subjects were able to achieve a CPR Quality Score greater than 5000, the minimum needed to meet AHA recommendations. Higher anaerobic power and bench press scores were predictive of both high CPR Quality Scores (R²=0.47) and compression depth (R²=0.47). Sex (female) was predictive of better chest compression recoil percentages (R²=0.15). Conclusion: Most rescuers can maintain high quality CPR if given two minute breaks between cycles. Rescuers with high anaerobic fitness and muscular strength may be able to provide higher quality CPR.

Caregiver Characteristics Associated With Quality of Cardiac Compressions on an Adult Mannequin With Real-Time Visual Feedback: A Simulation-Based Multicenter Study

INTRODUCTION

Chest compression (CC) quality directly impacts cardiac arrest outcomes. Provider body type can influence the quality of cardiopulmonary resuscitation (CPR); however, the magnitude of this impact while using visual feedback is not well described. The aim of the study was to determine the association between provider anthropometric variables on fatigue and CC adherence to 2015 American Heart Association CPR while receiving visual feedback.

METHODS

This was a planned secondary analysis of healthcare professionals from multiple hospitals performing continuous CC for 2 minutes on an adult CPR mannequin with dynamic visual feedback. Main outcome measures include compression data (depth, rate, and lean) evaluated in 30-second epochs to explore performance fatigue. Multivariable models examined the relationship of provider anthropometrics to CC quality. Binomial mixed effects models were used to characterize fatigue by examining performance for 4 epochs.

RESULTS

Three hundred seventy-seven 2-minute CC episodes were analyzed. Extreme (low and high) BMI and weight are associated with poorer CC. Larger size (height, weight, and BMI) is associated with better depth but worse lean compliance. Performance fatigued for all providers for 2 minutes, but shorter, lighter weight, female participants had the greatest decline. On multivariable analysis, rate compliance did not deteriorate regardless of provider anthropometrics.

CONCLUSIONS

Anthropometrics impact provider CC quality. Despite visual feedback, variable effects are seen on compression depth, rate, recoil, and fatigue depending on the provider sex, weight, and BMI. The 2-minute interval for changing chest compressors should be reconsidered based on individual provider characteristics and risk of fatigue's impact on high-quality CPR.

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.

Impact of Infant Positioning on Cardiopulmonary Resuscitation Performance During Simulated Pediatric Cardiac Arrest: A Randomized Crossover Study

OBJECTIVES

The primary objective was to determine the impact of infant positioning on cardiopulmonary resuscitation performance during simulated pediatric cardiac arrest.

DESIGN

A single-center, prospective, randomized, unblinded manikin study.

SETTING

Medical university-affiliated simulation facility.

SUBJECTS

Fifty-two first-line professional rescuers (n = 52).

INTERVENTIONS

Performance of cardiopulmonary resuscitation was determined using an infant manikin model in three different positions (on a table [T], on the provider's forearm with the manikin's head close to the provider's elbow [P], and on the provider's forearm with the manikin's head close to the provider's palm [D]). For the measurement of important cardiopulmonary resuscitation performance variables, a commercially available infant simulator was modified. In a randomized sequence, healthcare professionals performed single-rescuer cardiopulmonary resuscitation for 3 minutes in each position. Performances of chest compression (primary outcome), ventilation, and hands-off time were analyzed using a multilevel regression model.

MEASUREMENTS AND MAIN RESULTS

Mean (± SD) compression depth significantly differed between table and the other two manikin positions (31 ± 2 [T], 29 ± 3 [P], and 29 ± 3 mm [D]; overall p < 0.001; repeated measures design adjusted difference: T vs P, -2 mm [95% CI, -2 to -1 mm]; T vs D, -1 mm [95% CI, -2 to -1 mm]). Secondary outcome variables showed no significant differences.

CONCLUSIONS

Compressions were significantly deeper in the table group compared to positions on the forearm during cardiopulmonary resuscitation, yet the differences were small and perhaps not clinically important.

Randomised simulation trial found an association between rescuers' height and weight and chest compression quality during paediatric resuscitation

AIM

Our aim was to examine the relationship between rescuers' anthropometric data and chest compression quality during paediatric resuscitation training.

METHODS

This study focused on 224 medical students (53% women) who performed 2 minutes of paediatric resuscitation at the Medical University of Vienna, Austria: 116 on a baby manikin and 108 on an adolescent manikin. Skill Reporter software measured chest compression quality by recording compression depth, frequency, hand position and complete recoil. The participants' height, weight and body mass index (BMI) were recorded.

RESULTS

Participants with a lower BMI achieved higher total chest compression scores on both the baby and adolescent manikins than participants with a higher BMI. The latter were more likely to exceed the correct compression depth and not achieve complete chest recoil in the adolescent manikin. When it came to the baby manikin, the female participants achieved better chest recoil and the males achieved a higher number of compressions at the correct rate. Males also achieved better chest recoil with the adolescent manikins. Being tall only correlated with incomplete recoil in the adolescent manikin.

CONCLUSION

The results indicate that anthropometric variables were associated with chest compression quality in paediatric patients and should be considered by future education programmes.

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.

Physiological demands of quality cardiopulmonary resuscitation performed at simulated 3250 meters high

AIM

To analyse the effect of oxygen fraction reduction (O2 14%, equivalent to 3250 m) on Q-CPR and rescuers' physiological demands.

METHODOLOGY

A quasi-experimental study was carried out in a sample of 9 Q-CPR proficient health care professionals. Participants, in teams of 2 people, performed 10 min CPR on a Laerdal ResusciAnne mannequin (30:2 compression/ventilation ratio and alternating roles between rescuers every 2 min) in two simulated settings: T21-CPR at sea level (FiO2 of 21%) and T14 - CPR at 3250 m altitude (FiO2 of 14%). Effort self-perception was rated from 0 (no effort) to 10 (maximum demand) points.

RESULTS

Quality of chest compressions was good and similar in both conditions (T21 vs T14). However, the percentage of ventilations with adequate tidal volume was lower in altitude than at sea level conditions (35.9 ± 25.2% vs. 54.7 ± 23.2%, p = 0.035). The subjective perception of effort was significantly higher at simulated altitude (5 ± 2) than at sea level (3 ± 2) (p = 0.038). Maximum heart rate during the tests was similar in both conditions; however, mean oxygen saturation was significantly lower in altitude conditions (90.5 ± 2.5% vs. 99.3 ± 0.5%, p < 0.001).

CONCLUSION

Although performing CPR under simulated hypoxic altitude conditions significantly increases the physiological demands and subjective feeling of tiredness compared to sea level CPR, trained rescuers are able to deliver good Q-CPR in such conditions, at least in the first 10 min of resuscitation.

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.

Electrophysiology of Muscle Fatigue in Cardiopulmonary Resuscitation on Manikin Model

Cardiopulmonary resuscitation requires the provider to adopt positions that could be dangerous for his or her spine, specifically affecting the muscles and ligaments in the lumbar zone and the scapular spinal muscles. Increased fatigue caused by muscular activity during the resuscitation could produce a loss of quality and efficacy, resulting in compromising resuscitation. The aim of this study was to evaluate the maximum time a rescuer can perform uninterrupted chest compressions correctly without muscle fatigue. This pilot study was performed at Universidad Complutense de Madrid (Spain) with the population recruited following CONSORT 2010 guidelines. From the 25 volunteers, a total of 14 students were excluded because of kyphoscoliosis (4), lumbar muscle pain (1), anti-inflammatory treatment (3), or not reaching 80% of effective chest compressions during the test (6). Muscle activity at the high spinal and lumbar (L5) muscles was assessed using electromyography while students performed continuous chest compressions on a ResusciAnne manikin. The data from force exerted were analyzed according to side and muscle groups using Student's t test for paired samples. The influence of time, muscle group, and side was analyzed by multivariate analyses ( p ≤ .05). At 2 minutes, high spinal muscle activity (right: 50.82 ± 9.95; left: 57.27 ± 20.85 μV/ms) reached the highest values. Activity decreased at 5 and 15 minutes. At 2 minutes, L5 activity (right: 45.82 ± 9.09; left: 48.91 ± 10.02 μV/ms) reached the highest values. After 5 minutes and at 15 minutes, activity decreased. Fatigue occurred bilaterally and time was the most important factor. Fatigue began at 2 minutes. Rescuers exert muscular countervailing forces in order to maintain effective compressions. This imbalance of forces could determine the onset of poor posture, musculoskeletal pain, and long-term injuries in the rescuer.

CPR feedback/prompt device improves the quality of hands-only CPR performed in manikin by laypersons following the 2015 AHA guidelines

PURPOSE

We investigated the effects of a cardiopulmonary resuscitation (CPR) feedback/prompt device on the quality of chest compression (CC) during hands-only CPR following the 2015 AHA guidelines.

METHODS

A total of 124 laypersons were randomly assigned into three groups. The first (n=42) followed the 2010 guidelines, the second (n=42) followed the 2015 guidelines with no feedback/prompt device, the third (n=40) followed the 2015 guidelines with a feedback/prompt device (2015F). Participants underwent manual CPR training and took a written basic life support examination, then required to perform 2min of hands-only CPR monitored by a CPR feedback/prompt device. The quality of CPR was quantified as the percentage of correct CCs (mean CC depth and rate, complete recoil and chest compression fraction (CCF)) per 20s, as recorded by the CPR feedback/prompt device.

RESULTS

Significantly higher correct ratios of CC, CC depth, and rate were achieved in the 2010 group in each minute vs the 2015 group. The greater mean CC depth and rate were observed in the 2015F group vs the 2015 group. The correct ratio of CC was significantly higher in the 2015F group vs the 2015 group. CCF was also significantly higher in the 2015F group vs the 2015 group in the last 20s of CPR.

CONCLUSIONS

It is difficult for a large percentage of laypersons to achieve the targets of CC depth and rate following the 2015 AHA guidelines. CPR feedback/prompt devices significantly improve the quality of hands-only CPR performance by laypersons following the standards of the 2015 AHA guidelines.

A Study of the Factors Related to Cardiopulmonary Resuscitation Physical Fatigue and the Quality of Resuscitation

Effective chest compression is an important factor playing a key role in the cardiac arrest patient survival. An understanding of the factors causing an early physical fatigue can help to improve the quality of CPR operations in hospitals. Therefore, this study aimed to assess the factors relevant to the onset time of physical fatigue and resuscitation quality during cardiopulmonary resuscitation (CPR) provision by Iranian nurses.

The present cross-sectional study was performed on 194 subjects selected based on a stratified random sampling procedure from different hospital wards. The participants were required to perform CPR operations on a manikin. As they were performing CPR, the time and the quality of compressions were measured by a chronometer and visual analogue fatigue scale, respectively. The rescuers themselves reported the onset time of physical fatigue.

Statistical analyses run on the collected data revealed that the majority of participants experienced extreme physical fatigue after a two-minute CPR operation. Moreover, about 71.2% of the participants managed to provide compressions over five centimeters deep. Finally, the physical fatigue experienced by the participants was meaningfully correlated with the body weight, sex, university degree, and work place of the participants (p < 0.05). Since the findings of the present study showed that various factors including the sex, weight, height, university degree, and the work place of the rescuer were significantly correlated with the onset time of physical fatigue experienced during CPR operation, it is recommended that male nurses with greater height and weight be employed in the rescue teams in ICU wards. Moreover, it seems mandatory for the nurses currently working in such teams in hospitals to improve their physical fitness through doing aerobics on a regular basis so that they may experience less fatigue during their CPR operations in future.

Quality of Basic Life Support - A Comparison between Medical Students and Paramedics

INTRODUCTION

Poor survival rates after cardiac arrest can partly be explained by poor basic life support skills in medical professionals.

AIM

This study aimed to assess quality of basic life support in medical students and paramedics.

MATERIALS AND METHODS

We conducted a prospective observational study with 100 early medical students (group A), 100 late medical students (group B) and 100 paramedics (group C), performing a 20-minute basic life support simulation in teams of two. Average frequency and absolute number of chest compressions per minute (mean (±SD)), chest decompression (millimetres of compression remaining, mean (±SD)), hands-off-time (seconds/minute, mean (±SD)), frequency of switching positions between ventilation and chest compression (per 20 minutes) and rate of sufficient compressions (depth ≥50mm) were assessed as quality parameters of CPR.

RESULTS

In groups A, B and C the rates of sufficiently deep chest compressions were 56%, 42% and 52%, respectively, without significant differences. Male gender and real-life CPR experience were significantly associated with deeper chest compression. Frequency and number of chest compressions were within recommended goals in at least 96% of all groups. Remaining chest compressions were 6 mm (±2), 6 mm (±2) and 5 mm (±2) with a significant difference between group A and C (p=0.017). Hands-off times were 6s/min (±1), 5s/min (±1) and 4s/min (±1), which was significantly different across all three groups.

CONCLUSION

Overall, paramedics tended to show better quality of CPR compared to medical students. Though, chest compression depth as an important quality characteristic of CPR was insufficient in almost 50% of participants, even in well trained paramedics. Therefore, we suggest that an effort should be made to find better ways to educate health care professionals in BLS.

Impact of a feedback device on chest compression quality during extended manikin CPR: a randomized crossover study

PURPOSES

Chest compressions require physical effort leading to increased fatigue and rapid degradation in the quality of cardiopulmonary resuscitation overtime. Despite harmful effect of interrupting chest compressions, current guidelines recommend that rescuers switch every 2 minutes. The impact on the quality of chest compressions during extended cardiopulmonary resuscitation has yet to be assessed.

BASIC PROCEDURES

We conducted randomized crossover study on manikin (ResusciAnne; Laerdal). After randomization, 60 professional emergency rescuers performed 2 × 10 minutes of continuous chest compressions with and without a feedback device (CPRmeter). Efficient compression rate (primary outcome) was defined as the frequency target reached along with depth and leaning at the same time (recorded continuously).

MAIN FINDINGS

The 10-minute mean efficient compression rate was significantly better in the feedback group: 42% vs 21% (P< .001). There was no significant difference between the first (43%) and the tenth minute (36%; P= .068) with feedback. Conversely, a significant difference was evident from the second minute without feedback (35% initially vs 27%; P< .001). The efficient compression rate difference with and without feedback was significant every minute, from the second minute onwards. CPRmeter feedback significantly improved chest compression depth from the first minute, leaning from the second minute and rate from the third minute.

PRINCIPAL CONCLUSIONS

A real-time feedback device delivers longer effective, steadier chest compressions over time. An extrapolation of these results from simulation may allow rescuer switches to be carried out beyond the currently recommended 2 minutes when a feedback device is used.

Degree of exercise intensity during continuous chest compression in upper-body-trained individuals

Background

Although chest-compression-only cardiopulmonary resuscitation (CCO-CPR) is recommended for lay bystanders, fatigue is easily produced during CCO-CPR. If CCO-CPR can be performed at a lower intensity of exercise, higher resistance to fatigue is expected. Since chest compression is considered to be a submaximal upper body exercise in a steady rhythm and since the unit of load for chest compression is expressed as work rate, we investigated the possibility that peak work rate of the upper body determines the level of exercise intensity during CCO-CPR.

Methods

Twelve sedentary individuals (group Se), 11 rugby players (group R), and 11 swimmers (group Sw) performed 10-min CCO-CPR, and heart rate (HR) and rating of perceived exertion (RPE) were measured as indices of exercise intensity. Multiple linear regression analysis was carried out to assess potential relationships of upper body weight, peak lumbar extension force, peak work rate, and peak oxygen uptake recorded during arm-crank exercise with HR and RPE during CCO-CPR.

Results

Values of peak work rate during arm-crank exercise (Peak WR_-AC) in group Se, group R, and group Sw were 108 ± 12, 139 ± 27, and 146 ± 24 watts, respectively. Values of the latter two groups were significantly higher than the value of group Se (group R, P < 0.01; group Sw, P < 0.001). HR during CCO-CPR increased with time, reaching 127.8 ± 17.6, 114.8 ± 16.5, and 118.1 ± 14.2 bpm at the 10th minute in group Se, group R, and group Sw, respectively. On the other hand, RPE during CCO-CPR increased with time, reaching 16.4 ± 1.4, 15.4 ± 1.7, and 13.9 ± 2.2 at the 10th minute in group Se, group R, and group Sw, respectively. Multiple linear regression analysis showed that only peak WR_-AC affects both HR and RPE at the 10th minute of CCO-CPR (HR, r = −0.458; P < 0.01; RPE, r = −0.384, P < 0.05).

Conclusions

The degree of exercise intensity during CCO-CPR is lower in individuals who have a higher peak work rate of the upper body.

Predicted VO2max and effectiveness of external chest compression by Chinese nurses

OBJECTIVES

The aims of this study were to assess the influence of sex and body position on external chest compression (ECC) to a manikin by Chinese nurses and to determine the relationship between rescuer's predicted VO2max and ECC depth.

PARTICIPANTS AND METHODS

A total of 40 nurses performed ECC on a manikin for 5 min in the standing (S) and bed-mount kneeling (K) position, then completed a Chester step-test, in 3 separate days. The rate and depth of compressions and oxygen consumption during ECC were measured.

RESULTS

Mean compression rate recorded was above 100/min in both positions throughout ECC. Mean compression depth for male participants was more than 38 mm for 5 min in the K-position but only 3 min in the S-position. Female participants achieved this compression depth for less than 90 s in the K-position but not at all in the S-position.

CONCLUSION

Irrespective of sex, the K-position appears to facilitate effective ECC. The relationship between aerobic fitness of female nurses and their ability to perform effective cardiopulmonary resuscitation warrants further investigation.

Differences in Hands-off Time According to the Position of a Second Rescuer When Switching Compression in Pre-hospital Cardiopulmonary Resuscitation Provided by Two Bystanders: A Randomized, Controlled, Parallel Study

The change of compressing personnel will inevitably accompany hands off time when cardiopulmonary resuscitation (CPR) is performed by two or more rescuers. The present study assessed whether changing compression by a second rescuer located on the opposite side (OS) of the first rescuer can reduce hands-off time compared to CPR on the same side (SS) when CPR is performed by two rescuers. The scenario of this randomized, controlled, parallel simulation study was compression-only CPR by two laypersons in a pre-hospital situation. Considering sex ratio, 64 participants were matched up in 32 teams equally divided into two gender groups, i.e. , homogenous or heterogeneous. Each team was finally allocated to one of two study groups according to the position of changing compression (SS or OS). Every team performed chest compression for 8 min and 10 sec, with chest compression changed every 2 min. The primary endpoint was cumulative hands-off time. Cumulative hands-off time of the SS group was about 2 sec longer than the OS group, and was significant (6.6 ± 2.6 sec vs. 4.5 ± 1.5 sec, P = 0.005). The range of hands off time of the SS group was wider than for the OS group. The mean hands-off times of each rescuer turn significantly shortened with increasing number of turns (P = 0.005). A subgroup analysis in which cumulative hands-off time was divided into three subgroups in 5-sec intervals revealed that about 70% of the SS group was included in subgroups with delayed hands-off time ≥ 5 sec, with only 25% of the OS group included in these subgroups (P = 0.033). Changing compression at the OS of each rescuer reduced hands-off time compared to the SS in prehospital hands-only CPR provided by two bystanders.

Low compliance with the 2 minutes of uninterrupted chest compressions recommended in the 2010 International Resuscitation Guidelines

BACKGROUND

We aimed to analyze compliance with 2010 European guidelines' quality criteria for external chest compressions (ECC) during 2 minutes of uninterrupted cardiopulmonary resuscitation.

METHODS

Seventy-two healthy nurses and physicians trained in advanced cardiopulmonary resuscitation performed 2 uninterrupted minutes of ECC on a training manikin (Resusci Anne Advanced SkillTrainer; Laerdal Medical AS, Stavanger, Norway) that enabled us to measure the depth and rate of ECC. When professionals agreed to participate in the study, we recorded their age, body mass index (BMI), smoking habit, and their own subjective estimation of their physical fitness. To measure fatigue, we analyzed participants' heart rates, percentage of maximum tolerated heart rate (MHR), and subjective perception of their fatigue on a visual analog scale.

RESULTS

Nearly half (48.6%) the rescuers failed to achieve a minimum average ECC depth of 50 mm. Only 48.1% of ECCs fulfilled the 2010 guidelines' quality criteria; quality deteriorated mainly after the first minute. Poor ECC quality and deteriorating quality after the first minute were associated with BMI < 23 kg/m(2). Rescuers with BMI ≥ 23 kg/m(2) fulfilled the quality criteria throughout the 2 minutes, whereas those with BMI < 23 kg/m(2) fulfilled them for 80% of ECCs during the first minute, but for only 30% at the end of the 2 minutes.

CONCLUSIONS

Compliance with the 2010 guidelines' quality criteria is often poor, mainly due to lack of proper depth. The greater depth recommended in the 2010 guidelines with respect to previous guidelines requires greater force, so BMI < 23 kg/m(2) could hinder compliance. Limiting each rescuer's uninterrupted time doing ECC to 1 minute could help ensure compliance.

Influence of Rescuers' Gender and Body Mass Index on Cardiopulmonary Resuscitation according to the American Heart Association 2010 Resuscitation Guidelines

Background and Objectives. The quality of cardiopulmonary resuscitation (CPR) is an important factor in determining its overall outcome. This study aims to test the association between rescuers' gender, Body Mass Index (BMI), and the accuracy of chest compressions (CC) as well as ventilation, according to American Heart Association (AHA) 2010 resuscitation guidelines. Methods. The study included 72 participants of both genders. All the participants received CPR training according to AHA 2010 resuscitation guidelines. One week later, an assessment of their CPR was carried out. Moreover, the weight and height of the participants were measured in order to calculate their BMI. Results. Our analysis showed no significant association between gender and the CC depth (P = 0.53) as well as between gender and ventilation (P = 0.42). Females were significantly faster than males in CC (P = 0.000). Regarding BMI, participants with a BMI less than the mean BMI of the study sample tended to perform CC with the correct depth (P = 0.045) and to finish CC faster than those with a BMI more than the mean (P = 0.000). On the other hand, no significant association was found between BMI and ventilation (P = 0.187). Conclusion. CPR can be influenced by factors such as gender and BMI, as such the individual rescuer and CPR training programs should take these into account in order to maximize victims' outcome.

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.