Relationship between chest compression depth and novice rescuer body weight during cardiopulmonary resuscitation

Temporal analysis of continuous chest compression rate and depth performed by firefighters during out of hospital cardiac arrest

BACKGROUND

Quality of chest compressions (CC) during cardiopulmonary resuscitation (CPR) often do not meet guideline recommendations for rate and depth. This may be due to the fatiguing nature of physically compressing a patient's chest, meaning that CPR quality reduces over time.

OBJECTIVE

This analysis investigates the effect of CPR duration on the performance of continuous CCs delivered by firefighters equipped with CPR feedback devices.

METHODS

Data were collected from a first responder group which used CPR feedback and automatic external defibrillator devices when attending out-of-hospital cardiac arrest events. Depth and rate of CC were analysed for 134 patients. Mean CC depth and rate were calculated every 5 s during two-minute episodes of CPR. Regression models were created to evaluate the relationship between applied CC depth and rate as a function of time.

RESULTS

Mean (SD) CC depth during the investigation was 48 (9) mm. An inverse relationship was observed between CC depth and CPR duration, where CC depth decreased by 3.39 mm, over two-minutes of CPR (p < 0.001). Mean (SD) CC rate was 112.06 (5.87) compressions per minute. No significant relationship was observed between CC rate and CPR duration (p = 0.077). Mean depth was within guideline range for 33.58% of patient events, while guideline rate was observed in 92.54% of cases.

CONCLUSIONS

A reduction in CC depth was observed during two-minutes of continuous CCs while CC rate was not affected. One third of patients received a mean CC depth within guideline range (50 to 60 mm).

Association of Training in Basic Life Support with the Evolution of Cardiopulmonary Resuscitation Performed by Firefighters

Introduction

This study aimed to compare the results of professional technical and anthropometric anamnesis data with the transmission of external chest compressions performed by military firefighters at different execution times.

Objective

The objective was to evaluate the performance and perceived effort of the sequence of external chest compressions performed in two minutes, as well as the evolution of the technique over time.

Materials and Methods

This was a descriptive, correlational study involving adult firefighters who were members of a specific firefighter group, comprising a population of 105 individuals with a voluntary sample of 44 participants. The study used a Bayesian statistical approach to provide probabilistic expressions.

Results

The participants had an average work experience of 17 years, an average age of 38.6 years, an average weight of 81.48 kilograms, an average height of 176 centimeters, and an average of 2.5 qualifications. The results indicated that the firefighters performed external chest compressions with excellent technique and a moderate level of perceived effort in a two-minute evaluation. The evaluation of the evolution of the technique over time showed that the participants were able to maintain high-quality compressions for an average of 6 minutes, with a maximum of 20 uninterrupted minutes.

Conclusion

The study underscores the critical role of professional firefighters in performing and maintaining high-quality external chest compressions, which has the potential to reduce morbidity and mortality in cases of cardiorespiratory arrest.

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.

Chest compressions become deeper when pushing with forward lean: A simulation study

Aim

Chest compression depth (CCD) in cardiopulmonary resuscitation is important. However, lightweight rescuers have difficulty achieving an appropriate depth. Chest compression force (CCFORCE) can be increased by placing the arms at 100° to the patient's frontal plane. In a simulation manikin study, we compared the CCD at 90° and 100° among lightweight Asian females and hypothesized that the CCD would be greater when the arms were placed at 100°.

Methods

We included 35 lightweight female students from Shimane University who performed compressions 30 times each at 90° and 100°. The CCFORCE and CCD and the residual force on the chest wall during decompression for each chest compression were compared using CPRmeter-2.

Results

Of the 35 participants, 3 were excluded because their angles deviated from the prescribed angle. Thirty-two participants were categorized according to CCD at 90°: ≤40 mm (group 1), 41-49 mm (group 2), and ≥ 50 mm (group 3). The overall mean CCD increased from 90° to 100° (44.3 ± 8.2 mm vs. 48.1 ± 7.2 mm; p < 0.05). The mean CCD changes between 90° and 100° were 34.4 ± 4.7 mm vs. 42.9 ± 4.8 mm (p < 0.05) in group 1, 44.9 ± 2.5 mm vs. 47.0 ± 4.2 mm (p = 0.17) in group 2, and 53.0 ± 2.7 mm vs. 55.4 ± 5.6 mm (p < 0.05) in group 3. The residual force was greater when the chest compression angle was 100°.

Conclusion

CCD can be increased for lightweight rescuers when using a forward leaning position of 100° to the frontal plane of the patient. Further research is required to obtain more realistic situations.

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.

Sports safety matting diminishes cardiopulmonary resuscitation quality and increases rescuer perceived exertion

OBJECTIVES

Compliant surfaces beneath a casualty diminish the quality of cardiopulmonary resuscitation (CPR) in clinical environments. To examine this issue in a sporting environment, we assessed chest compression quality and rescuer exertion upon compliant sports safety matting.

METHODS

Twenty-seven advanced life support providers volunteered (13 male/14 female; mass = 79.0 ± 12.5 kg; stature = 1.77 ± 0.09 m). Participants performed 5 × 2 min, randomized bouts of continuous chest compressions on a mannequin, upon five surfaces: solid floor; low-compliance matting; low-compliance matting with a backboard; high-compliance matting; high-compliance matting with a backboard. Measures included chest compression depth and rate, percentage of adequate compressions, and rescuer heart rate and perceived exertion.

RESULTS

Chest compression depth and rate were significantly lower upon high-compliance matting relative to other surfaces (p<0.05). The percentage of adequate compressions (depth ≥50 mm) was lowest upon high-compliance matting (40 ± 39%) versus low-compliance matting (60 ± 36%) and low-compliance matting with a backboard (59 ± 39%). Perceived exertion was significantly greater upon high-compliance matting versus floor, low-compliance matting, and low-compliance matting with a backboard (p<0.05).

CONCLUSION

Providers of CPR should be alerted to the detrimental effects of compliant safety matting in a sporting environment and prepare to alter the targeted compression depth and rescuer rotation intervals accordingly.

Basic life support skills can be improved among certified basic life support instructors

Background

A correct visual skill demonstration is important when learning cardiopulmonary resuscitation (CPR) and the use of an automated external defibrillator (AED). Basic life support (BLS) instructors are expected to master and demonstrate CPR/AED skills correctly. The aim of this study was to evaluate certified BLS instructors’ competencies in demonstrating CPR and the use of an AED.

Methods

Certified BLS instructors demonstrated CPR and the use of an AED on a resuscitation manikin. Skills were evaluated using data collected from the manikin and video recordings and compared to resuscitation guidelines. Further, instructors completed questionnaires on resuscitation guidelines and rating of their own CPR/AED skills.

Results

Overall, we analyzed data from 125 instructors. Of all chest compressions, only 22% were within guideline recommendations regarding depth. Instructors performed chest compressions with excessive depth (mean depth 64 mm (7.3)) and a mean rate of 115 min⁻¹ (10.8). Only 25% of instructors placed the left AED electrode correctly (median distance 7.6 cm (5.0;10.5)), while the right AED electrode usually was placed correctly (median distance 2.9 cm (1.5;4.0), 85% placed correctly). Nearly half of the instructors failed to state correct answers regarding how to diagnose a cardiac arrest and where to place the AED electrodes. Despite their performance, instructors rated their BLS skills as good.

Conclusion

Certified BLS instructors’ have poor CPR/AED skills and several important knowledge gaps on CPR/AED guidelines in contrast to instructors’ self-reported skills. This highlights a need for improving BLS instructor education, including continuous faculty development to ensure optimal learning conditions for BLS course participants.

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.

Long-term benefits of chest compression-only cardiopulmonary resuscitation training using real-time visual feedback manikins: a randomized simulation study

Objective

Cardiopulmonary resuscitation (CPR) education with a feedback device is known to result in better CPR skills compared to one without the feedback device. However, its long-term benefits have not been established. The purpose of this study was to evaluate the long-term CPR skill retention after training using real-time visual manikins in comparison to that of non-feedback manikins.

Methods

We recruited 120 general university students who were randomly divided into the real-time feedback group (RTFG) and the non-feedback group. Of them, 95 (RTFG, 48; non-feedback group, 47) attended basic life support and automated external defibrillation training for 1 hour. For comparison of retention of CPR skills, the two groups were evaluated based on 2-minute chest compression performed immediately after training and at 3, 6, and 9 months. The CPR parameters between the two groups were also compared using a generalized linear model.

Results

At immediately after training, the performance of RTFG was better in terms of average chest compression depth (51.9±1.1 vs. 45.5±1.1, p<0.001) and a higher percentage of adequate chest compression depth (51.0±4.1 vs. 26.9±4.2, p<0.001). This significant difference was maintained until 6 months after training, but there was no difference at 9 months after training. However, there was no significant difference in the chest compression rate and the correct hand position at any time point.

Conclusion

CPR training with a real-time visual feedback manikin improved skill acquisition in chest compression depth, but only until 6 months after the training. It could be a more effective educational method for basic life support training in laypersons.

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.

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).

Acquisition of Knowledge and Practical Skills after a Brief Course of BLS-AED in First-Year Students in Nursing and Physiotherapy at a Spanish University

Out-of-hospital cardiorespiratory arrest is one of the leading causes of death in the Western world. Early assistance with quality Cardiopulmonary Resuscitation (CPR) and the use of a defibrillator may increase the percentage of survival after this process. The objective of this study was to evaluate the effect of CPR training and the management of an Automatic External Defibrillator (AED). A descriptive, cross-sectional, observational study was carried out among students in the first year of a Nursing and Physiotherapy degree of the University of León. To achieve this goal, a theoretical-practical educational intervention of four hours’ duration which included training on CPR, AED and Basic Life Support (BLS) was carried out. A total of 112 students were included. The results showed an increase in theoretical knowledge on BLS as well as on CPR and AED, and practical skills in CPR and AED management. A theoretical exposition of fifteen minutes and the practical training of CPR wasenough for the students to acquire the necessary theoretical knowledge, although the participants failed to reach quality criteria in CPR. Only 35.6% of students reached the right depth in compressions. Also, ventilation was not performed properly. Based on the results, we cannot determine that the percentage of overall quality of CPR was appropriate, since 57.6% was obtained in this respect and experts establish a value higher than 70% for quality CPR. There was a clear relationship between sex, weight, height and body max index (BMI), and quality CPR performance, being determinant variables to achieve quality parameters. Currently, Basic Life Support training in most universities is based on training methods similar to those used in the action described. The results obtained suggest implementing other training methods that favour the acquisition of quality CPR skills.

The assessment of the kinematics of the rescuer in continuous chest compression during a 10-min simulation of cardiopulmonary resuscitation

BACKGROUND

In pursuit of improvement in cardiopulmonary resuscitation (CPR), new technologies for the measurement and assessment of CPR quality are implemented. In our study, we assessed the kinematics of the rescuer during continuous chest compression (CCC-CPR). The proper performance of the procedure is a survival predictor for patients with cardiac arrest (CA). The purpose of the study was a prospective assessment of the kinematics of the rescuer's body with consideration given to the depth and rate of chest compression (CC) as the indicator of properly performed CC maneuver by professional and non-professional rescuers during a simulation of a 10-min CCC using a manikin.

METHODS

Forty participants were enrolled in the study. CCC-CPR was performed in accordance with the 2015 AHA guidelines on a manikin positioned on the floor. Kinematic data on the movement were obtained from the measuring system (X-sens MVN Biomech) transmitting information from 17 inertial sensors. Measurement data were imported to the author's program RKO-Kinemat written in the Matlab and C # environments. Two groups of results were distinguished: Group I-results of CC with the depth of ≥ 40 mm and Group 2-CC results with the depth of < 40 mm.

RESULTS

The multiple regression model demonstrated that the path length, left knee flexion angle, and left elbow flexion angle were the essential elements of the rescuer's kinematics that facilitated achieving and maintaining the normal depth of CC.

CONCLUSIONS

We believe that raising the rescuer's hips by moving the center of the rescuer's body over the point of sternal compression increases the value of the CC force vector, thereby increasing the depth of CC. In addition, we observed that, during an effective CC, the rescuer was unable to maintain arms straight and, in consequence, a slight elbow flexion was observed. It, however, did not influence the quality of the maneuver.

Morbid obesity impairs adequacy of thoracic compressions in a simulation-based model

Adequate cardiopulmonary resuscitation is an important predictor of survival, however, obesity provides a significant physical barrier to thoracic compressions. This study explores the effect of morbid obesity on compression adequacy. We performed a prospective randomised controlled crossover study, assessing the adequacy of thoracic compressions on a manikin modified to emulate a morbidly obese patient. Participants recruited from critical care departments were randomised to perform continuous compressions for two minutes on each manikin. Accelerometers were used to measure thoracic wall movement. The primary endpoint was a composite measure of compression adequacy (rate, depth and recoil). Secondary endpoints were the individual components of the composite outcome and measures of perceived effectiveness, fatigue, and pain. One hundred and one participants were recruited. There was a significant difference between the obese and control groups in the composite endpoint (4% versus 30%, <i>P</i> <0.001), as well as the individual components of adequacy (<i>P</i> <0.01 for all). Quartile data showed significant deterioration in adequacy of depth and recoil in both groups, and this occurred significantly earlier in the obese group (<i>P</i> ≤0.001). Participants' perception of effectiveness was significantly lower (<i>P</i> ≤0.001) in the obese group, and levels of fatigue (<i>P</i> ≤0.001) and pain (<i>P</i> ≤0.001) significantly higher. Morbid obesity impairs the adequacy of thoracic compressions for trained rescuers in a simulation-based model. Participants were not fully aware of how ineffective compressions were. There is evidence of earlier fatigue further reducing effectiveness. These findings have significant implications for the training of rescuers in a clinically relevant population and the planning of future research.

Basic cardiopulmonary life support (BCLS) for cardiopulmonary resuscitation by trained paramedics and medics outside the hospital

The cardiopulmonary resuscitation guideline of Basic Cardiopulmonary Life Support (BCLS) for management of adult victims with cardiopulmonary arrest outside the hospital provides an algorithmic stepwise approach for optimal outcome of the victims by trained medics and paramedics. This guideline has been developed considering the need to have a universally acceptable practice guideline for India and keeping in mind the infrastructural limitations of some areas of the country. This guideline is based on evidence elicited in the international and national literature. In the absence of data from Indian population, the excerpts have been taken from international data, discussed with Indian experts and thereafter modified to make them practically applicable across India. The optimal outcome for a victim with cardiopulmonary arrest would depend on core links of early recognition and activation; early high-quality cardiopulmonary resuscitation, early defibrillation and early transfer to medical facility. These links are elaborated in a stepwise manner in the BCLS algorithm. The BCLS also emphasise on quality check for various steps of resuscitation.

Kinect-based real-time audiovisual feedback device improves CPR quality of lower-body-weight rescuers

BACKGROUND

Chest compression (CC) quality is associated with rescuer posture and body weight. We designed a Kinect module-based real-time audiovisual feedback (AVF) device to investigate the relationship between rescuer posture, body weight, and CC quality.

METHODS

A total of 100 healthcare professionals were enrolled as participants in this randomized trial. A Kinect-based sensor system was used to monitor the depth and rate of CC and provide further real-time feedback. All participants were asked to perform continuous CC on a manikin with and without feedback for 2min individually in either a kneeling or standing position.

RESULTS

A kneeling posture can provide higher rate of CC than a standing posture can (111.4±22.6 per minute vs. 99.1±18.9per minute, p value=0.005). Real-time AVF feedback can provide a better compression depth, rate, and effective compression ratio (6.16±1.88cm vs. 5.54±1.89cm, p value=0.02; 103.2±21.0/min vs. 96.7±25.8/min, p value=0.03; 62.6±28.0% vs. 51.0±33.2%, p value=0.004). Regardless of the effect of real-time feedback, the CC depth correlated to the rescuers' body weight. Rescuers who weighed below 71kg benefited from the Kinect module-based real-time AVF device in terms of improved CC quality.

CONCLUSION

The Kinect-based AVF device can significantly improve CC quality in manikin training in rescuers with their body weight<71kg.

Complete chest recoil during laypersons' CPR: Is it a matter of weight?

INTRODUCTION

Chest compressions depth and complete chest recoil are both important for high-quality Cardio-Pulmonary Resuscitation (CPR). It has been demonstrated that anthropometric variables affect chest compression depth, but there are no data about they could influence chest recoil. The aim of this study was to verify whether physical attributes influences chest recoil in lay rescuers.

METHODS

We evaluated 1 minute of compression-only CPR performed by 333 laypersons immediately after a Basic Life Support and Automated External Defibrillation (BLS/AED) course. The primary endpoint was to verify whether anthropometric variables influence the achievement a complete chest recoil. Secondary endpoint was to verify the influence of anthropometric variables on chest compression depth.

RESULTS

We found a statistically significant association between weight and percentage of compressions with correct release (p≤0.001) and this association was found also for height, BMI and sex. People who are heavier, who are taller, who have a greater BMI and who are male are less likely to achieve a complete chest recoil. Regarding chest compressions depth, we confirm that the more a person weighs, the more likely the correct depth of chest compressions will be reached.

CONCLUSIONS

Anthropometric variables affect not only chest compression depth, but also complete chest recoil. CPR instructors should tailor their attention during training on different aspect of chest compression depending on the physical characteristics of the attendee.