Does the quality of chest compressions deteriorate when the chest compression rate is above 120/min?

A Cluster-Randomized Control Study Comparing a New Cue "Two Compressions per Second" with "100-120 Compressions per Minute" in Training of Bystander Cardiopulmonary Resuscitation

BACKGROUND

Chest compression at a rate of 100-120 compressions per minute (cpm) during cardiopulmonary resuscitation (CPR) is associated with the highest survival rates. Performing compressions at a faster rate may exhaust the rescuers.

OBJECTIVES

To compare a new cue of 'two compressions per second' to the traditional cue of '100-120 compressions per minute' on compression rate in CPR training.

METHODS

In this cluster-randomized study, students from two senior high schools were assigned into two groups. For the experimental group, the cue for the compression rate was 'two compressions per second'. For the control group, the cue was '100-120 cpm'. Except the different cues, all participants underwent the same standardized CPR training program. Verbal compression rate-related feedback was not obtained during practice. Quality indicators of chest compressions were recorded by a sensorized manikin. The primary outcome measure was mean compression rate at course conclusion. The secondary outcome measures were individual compression quality indicators at course conclusion and 3 months after training.

RESULTS

We included 164 participants (85 participants, experimental group; 79 participants, control group). Both groups had similar characteristics. The experimental group had a significantly lower mean compression rate at course conclusion (144.3 ± 16.17 vs. 152.7 ± 18.38 cpm, p = 0.003) and at 3 months after training (p = 0.09). The two groups had similar mean percentage of adequate compression rate (≥ 100 cpm), mean compression depth, and mean percentage of complete recoil at course conclusion and 3 months after training.

CONCLUSION

The new cue of 'two compressions per second' resulted in participants having a lower compression rate, although it still exceeded 120 cpm.

Effects of metronome use on cardiopulmonary resuscitation quality

OBJECTIVE:

Whether the use of metronome affects the quality of cardiopulmonary resuscitation (CPR) remains unclear. In this study, we investigated the effect of metronome use on CPR quality.

METHODS:

This was a prospective, simulation-based CPR manikin study. There were two phases: without and with metronome use. Chest compression was performed for 2 min, and three CPR quality criteria including chest compression depth, recoil, and rate were recorded with TrueCPR Feedback Device in both phases.

RESULTS:

In all, 102 resident physicians were included. The achievement of optimal chest compression depth and complete recoil was better with metronome use than without (83% and 77% vs. 78% and 39%, P ≤ 0.001, respectively). Optimal chest compression rate was also reached with metronome use because the range of the compression rate was closer to the normal limits than those without metronome use (110 [interquartile range (IQR) 109–113] vs. 120 [IQR 109–129], P ≤ 0.001). Of all the participants, 70.6% stated that metronome use had a positive effect on their performance during the CPR application and 66.7% stated that they wished to use the metronome in their daily practice.

CONCLUSION:

Using a metronome during simulation-based CPR improved the compression depth and recoil by fixing chest compression rate. We suggested that metronome should be used in CPR trainings of health-care professionals.

The effect of chest compression frequency on the quality of resuscitation by lifeguards. A prospective randomized crossover multicenter simulation trial

BACKGROUND

The ability to perform high-quality cardiopulmonary resuscitation is one of the basic skills for lifeguards. The aim of the study was to assess the influence of chest compression frequency on the quality of the parameters of chest compressions performed by lifeguards.

METHODS

This prospective observational, randomized, crossover simulation study was performed with 40 lifeguards working in Warsaw, Wroclaw, and Poznan, Poland. The subjects then participated in a target study, in which they were asked to perform 2-min cycles of metronome-guided chest compressions at different rates: 80, 90, 100, 110, 120, 130, 140, and 150 compressions per minute (CPM).

RESULTS

The study involved 40 lifeguards. Optimal chest compression score calculated by manikin software was achieved for 110-120 CPM. Chest compression depth achieved 53 (interquartile range [IQR] 52-54) mm, 56 (IQR 54-57) mm, 52.5 (IQR 50-54) mm, 53 (IQR 52-53) mm, 50 (IQR 49-51) mm, 47 (IQR 44-51) mm, 41 (IQR 40-42) mm, 38 (IQR 38-43) mm for 80, 90, 100, 110, 120, 130, 140 and 150 CPM, respectively. The percentage of chest compressions with the correct depth was lower for rates exceeding 120 CPM.

CONCLUSIONS

The rate of 100-120 CPM, as recommended by international guidelines, is the optimal chest compression rate for cardiopulmonary resuscitation performed by lifeguards. A rate above 120 CPM was associated with a dramatic decrease in chest compression depth and overall chest compression quality. The role of full chest recoil should be emphasized in basic life support training.

Does the use of cardiopulmonary resuscitation feedback devices improve the quality of chest compressions performed by doctors? A prospective, randomized, cross-over simulation study

BACKGROUND

The aim of the study was to compare the quality of chest compressions (CCs) carried out with and without the use of the TrueCPR device during simulated cardiopulmonary resuscitations conducted by trainee doctors.

METHODS

The study was a prospective, randomized, cross-over simulation study. The study involved 65 trainee doctors who were tasked with performing a 2-min cycle of uninterrupted CCs under conditions of a simulated cardiopulmonary resuscitation of adults. CC were carried out in two scenarios: with and without TrueCPR chest compression support. Participants did not have experience in the use of CCs prior to this study.

RESULTS

The depth of compressions in regard to CC techniques were varied by 45 mm (IQR 43-48) for manual CC and 53 mm (IQR 51-55) for the TrueCPR device (p < 0.001). The incidence of CCs with and without TrueCPR was: 112 (IQR 103-113) vs. 129 (IQR 122-135) compressions (p = 0.002). The degree of complete chest relaxation with the TrueCPR device was 95% (IQR 76-99) and without the device, 33% (IQR 29-38) (p < 0.001).

CONCLUSIONS

In the simulation study performed, the use of the TrueCPR device resulted in a significant improvement in the quality of CCs in relation to frequency and depth of CCs and correctness of chest relaxation.

Effectiveness of 100 Beats per Minute Music on Cardiopulmonary Resuscitation Compression Rate Education: A Manikin Study

Introduction

Recent cardiopulmonary resuscitation (CPR) guidelines emphasize the importance of high-quality chest compression. The aim of this study is to determine the effect of education using music on the chest compression rate.

Methods

This randomised, open-labeled study enrolled 81 medical students. They were randomly divided into three groups. After they were educated in CPR according to the American Heart Association 2010 guidelines, they performed 100 chest compressions using a mannequin capable of collecting each compression depth and speed. After that, the control group received a verbal feedback about their own results. The metronome group was also notified of their own results, and listened to the metronome sound at 100 beats per minute (bpm). The music group listened to the music (about 100 bpm). Twenty-four hours after their CPR education, chest compressions were performed again with the method identical to the first evaluation. The results were compared using multivariate analysis of variances.

Result

Compression rate (bpm): There was a significant difference between the control (mean, 110.4; 95% CI: 104.4, 116.5) and metronome group (mean, 98.5; 95% CI: 91.6, 105.4) after education (p=0.01). There was a significant difference between control and music group (mean, 98.2; 95% CI: 94.6, 101.8) after education (p<0.001) There were no differences between the music and metronome group before or after education (p=0.50, p=0.94). However, the variance of music group was significantly less than the metronome group (p=0.01). Compression depth (inches): there was no difference between the groups according to the CPR education method. (Control: 1.8±0.3; Metronome group: 1.6±0.2; Music group: 1.7±0.3 p=0.09)

Conclusion

Both education method of using music and metronome are more effective than conventional method. However the effect of using music may be better than using metronome.

Optimal chest compression rate in cardiopulmonary resuscitation: a prospective, randomized crossover study using a manikin model

OBJECTIVES

When performing cardiopulmonary resuscitation (CPR), the 2010 American Heart Association guidelines recommend a chest compression rate of at least 100 min, whereas the 2010 European Resuscitation Council guidelines recommend a rate of between 100 and 120 min. The aim of this study was to examine the rate of chest compression that fulfilled various quality indicators, thereby determining the optimal rate of compression.

METHODS

Thirty-two trainee emergency medical technicians and six paramedics were enrolled in this study. All participants had been trained in basic life support. Each participant performed 2 min of continuous compressions on a skill reporter manikin, while listening to a metronome sound at rates of 100, 120, 140, and 160 beats/min, in a random order. Mean compression depth, incomplete chest recoil, and the proportion of correctly performed chest compressions during the 2 min were measured and recorded.

RESULTS

The rate of incomplete chest recoil was lower at compression rates of 100 and 120 min compared with that at 160 min (P=0.001). The numbers of compressions that fulfilled the criteria for high-quality CPR at a rate of 120 min were significantly higher than those at 100 min (P=0.016).

CONCLUSION

The number of high-quality CPR compressions was the highest at a compression rate of 120 min, and increased incomplete recoil occurred with increasing compression rate. However, further studies are needed to confirm the results.

Effect of the rate of chest compression familiarised in previous training on the depth of chest compression during metronome-guided cardiopulmonary resuscitation: a randomised crossover trial

OBJECTIVES

To assess how the quality of metronome-guided cardiopulmonary resuscitation (CPR) was affected by the chest compression rate familiarised by training before the performance and to determine a possible mechanism for any effect shown.

DESIGN

Prospective crossover trial of a simulated, one-person, chest-compression-only CPR.

SETTING

Participants were recruited from a medical school and two paramedic schools of South Korea.

PARTICIPANTS

42 senior students of a medical school and two paramedic schools were enrolled but five dropped out due to physical restraints.

INTERVENTION

Senior medical and paramedic students performed 1 min of metronome-guided CPR with chest compressions only at a speed of 120 compressions/min after training for chest compression with three different rates (100, 120 and 140 compressions/min). Friedman's test was used to compare average compression depths based on the different rates used during training.

RESULTS

Average compression depths were significantly different according to the rate used in training (p<0.001). A post hoc analysis showed that average compression depths were significantly different between trials after training at a speed of 100 compressions/min and those at speeds of 120 and 140 compressions/min (both p<0.001).

CONCLUSIONS

The depth of chest compression during metronome-guided CPR is affected by the relative difference between the rate of metronome guidance and the chest compression rate practised in previous training.

Acceleration of MR parameter mapping using annihilating filter-based low rank hankel matrix (ALOHA)

PURPOSE

MR parameter mapping is one of clinically valuable MR imaging techniques. However, increased scan time makes it difficult for routine clinical use. This article aims at developing an accelerated MR parameter mapping technique using annihilating filter based low-rank Hankel matrix approach (ALOHA).

THEORY

When a dynamic sequence can be sparsified using spatial wavelet and temporal Fourier transform, this results in a rank-deficient Hankel structured matrix that is constructed using weighted k-t measurements. ALOHA then utilizes the low rank matrix completion algorithm combined with a multiscale pyramidal decomposition to estimate the missing k-space data.

METHODS

Spin-echo inversion recovery and multiecho spin echo pulse sequences for T₁ and T₂ mapping, respectively, were redesigned to perform undersampling along the phase encoding direction according to Gaussian distribution. The missing k-space is reconstructed using ALOHA. Then, the parameter maps were constructed using nonlinear regression.

RESULTS

Experimental results confirmed that ALOHA outperformed the existing compressed sensing algorithms. Compared with the existing methods, the reconstruction errors appeared scattered throughout the entire images rather than exhibiting systematic distortion along edges and the parameter maps.

CONCLUSION

Given that many diagnostic errors are caused by the systematic distortion of images, ALOHA may have a great potential for clinical applications. Magn Reson Med 76:1848-1864, 2016. © 2016 International Society for Magnetic Resonance in Medicine.

Rate at 120/min provides qualified chest compression during cardiopulmonary resuscitation

OBJECTIVES

The quality of cardiopulmonary resuscitation (CPR) is a very important prognostic factor for cardiac arrest. Chest compression is thought to be one of the most important aspects of high-quality CPR. Recent studies have prompted that there may be an interaction between chest compression rate and other factors related to the quality of chest compression. We aimed to investigate the effect of different compression rates on chest compression depth, recoil, and rescuers' fatigue point during CPR.

METHODS

Participants performed 2 minutes of chest compression-only CPR after the guiding sounds, at 3 rates (100, 120, and 140 compressions/min) in random sequence. A repeated-measures analysis of variance was used to compare the average chest compression depth and other factors related to the quality of chest compression among the groups.

RESULTS

As the chest compression rate increases through all the 3 rates, the fractions of chest compressions with complete release and the fractions of chest compressions with sufficient depth were deteriorated at the rate of 140 compressions/min (P < .05), although the average compression depth was above the recommended 2010 guideline depth of 5 cm(P > .05). Of note, the fatigue point at 140 compressions/min happened significantly (P < .05) sooner.

CONCLUSION

Our study supported the concern of some that there may be a risk of increasing recommended chest compression rate without providing an upper limit. An appropriate choice may be 120 compressions/min.