Incomplete chest wall decompression: a clinical evaluation of CPR performance by EMS personnel and assessment of alternative manual chest compression–decompression techniques

Is It Feasible to Perform Infant CPR during Transfer on a Stretcher until Cannulation for Extracorporeal CPR? A Randomization Simulation Study

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) improves infant survival outcomes after cardiac arrest. If not feasible at the place of arrest, victims must be transported to a suitable room to perform ECMO while effective, sustained resuscitation maneuvers are performed. The objective of this simulation study was to compare the quality of resuscitation maneuvers on an infant manikin during simulated transfer on a stretcher (stretcher test) within a hospital versus standard stationary resuscitation maneuvers (control test).

METHODS

A total of 26 nursing students participated in a randomized crossover study. In pairs, the rescuers performed two 2 min tests, consisting of five rescue breaths followed by cycles of 15 compressions and two breaths. The analysis focused on CPR variables (chest compression and ventilation), CPR quality, the rate of perceived exertion and the distance covered.

RESULTS

No differences were observed in the chest compression quality variable (82 ± 10% versus 84 ± 11%, p = 0.15). However, significantly worse values were observed in the test for ventilation quality on the stretcher (18 ± 14%) compared to the control test (28 ± 21%), with a value of p = 0.030. Therefore, the overall CPR quality was worse in the stretcher test (50 ± 9%) than in the control test (56 ± 13%) (p = 0.025).

CONCLUSIONS

Infant CPR performed by nursing students while walking alongside a moving stretcher is possible. However, in this model, the global CPR quality is less due to the low ventilation quality.

Evaluation of compressor fatigue at 150 compressions per minute during cardiopulmonary resuscitation using a large dog manikin

OBJECTIVE

To determine whether CPR providers can perform chest compressions (CC) appropriately at a rate of 150 compressions per minute during a 2-minute cycle and to identify the presence of rescuer fatigue.

DESIGN

High fidelity simulator study.

SETTING

University veterinary teaching hospital.

SUBJECTS

Sixty subjects, 30 women and 30 men.

INTERVENTIONS

Subjects performed CC at 150 compressions per minute on a dog manikin for 2 minutes. Real-time depth of compressions, compression release, and compression rate were measured using a CPR training device. Demographic data from the subjects were analyzed alongside data obtained from the monitoring device.

MEASUREMENTS AND MAIN RESULTS

Only 38.3% of participants were able to perform CC with appropriate depth and release at 150 compressions per minute during a 2-minute cycle. There was a decay in the quality of CC between the first and the second minute. The number of compressions and percentage of compressions with correct release were similar among various genders, ages, and professions. In contrast, the percentage of compressions with correct depth was significantly higher among individuals with higher body mass index (correlation coefficient [r] = 0.293; P = 0.023) and higher biceps brachii muscle circumference during muscle contraction (r = 0.423; P = 0.001).

CONCLUSIONS

This study suggests that increasing the compression rate to 150 compressions per minute in large dogs using the thoracic pump technique might not be viable because most participants were not able to sustain enough appropriate CC. Rescuer fatigue affects compression depth at this rate, leading to a decay in CPR quality.

Design and Evaluation of CPR Emergency Equipment for Non-Professionals

Sudden cardiac death is a sudden and highly fatal condition. Implementing high-quality emergency cardiopulmonary resuscitation (CPR) early on is an effective rescue method for this disease. However, the rescue steps of CPR are complicated and difficult to remember, and the quantitative indicators are difficult to control, which leads to a poor quality of CPR emergency actions outside the hospital setting. Therefore, we have developed CPR emergency equipment with a multisensory feedback function, aiming to guide rescuers in performing CPR through visual, auditory, and tactile interaction. This equipment consists of three components: first aid clothing, an audio-visual integrated terminal, and a vital sign detector. These three components are based on a micro-power WiFi-Mesh network, enabling the long-term wireless transmission of the multisensor data. To evaluate the impact of the multisensory feedback CPR emergency equipment on nonprofessionals, we conducted a controlled experiment involving 32 nonmedical subjects. Each subject was assigned to either the experimental group, which used the equipment, or the control group, which did not. The main evaluation criteria were the chest compression (CC) depth, the CC rate, the precise depth of the CC ratio (5-6 cm), and the precise rate of the CC ratio -(100-120 times/min). The results indicated that the average CC depth in the experimental group was 51.5 ± 1.3 mm, which was significantly better than that of the control group (50.2 ± 2.2 mm, p = 0.012). Moreover, the average CC rate in the experimental group (110.1 ± 6.2 times/min) was significantly higher than that of the control group (100.4 ± 6.6 times/min) (p < 0.001). Compared to the control group (66.37%), the experimental group showed a higher proportion of precise CC depth (82.11%), which is closer to the standard CPR rate of 100%. In addition, the CC ratio of the precise rate was 93.75% in the experimental group, which was significantly better than that of 56.52% in the control group (p = 0.024). Following the experiment, the revised System Availability Scale (SUS) was utilized to evaluate the equipment's usability. The average total SUS score was 78.594, indicating that the equipment's acceptability range was evaluated as 'acceptable', and the overall adjective rating was 'good'. In conclusion, the multisensory feedback CPR emergency equipment significantly enhances the CC performance (CC depth, CC rate, the precise depth of CC ratio, the precise rate of CC ratio) of nonprofessionals during CPR, and the majority of participants perceive the equipment as being easy to use.

Resuscitation Quality Improvement® (RQI®) HeartCode® Complete Program Improves Chest Compression Rate in Real World Out-of Hospital Cardiac Arrest Patients

BACKGROUND

The Resuscitation Quality Improvement® (RQI®) HeartCode© Complete program is designed to enhance cardiopulmonary resuscitation (CPR) training by using real-time feedback manikins. Our objective was to assess the quality of CPR, such as chest compression rate, depth, and fraction, performed on out-of-hospital cardiac arrest (OHCA) patients among paramedics trained with the RQI program vs. paramedics who were not.

METHODS AND RESULTS

Adult OHCA cases from 2021 were analyzed; 353 OHCA cases were classified into one of three groups: 1) 0 RQI®-trained paramedics, 2) 1 RQI®-trained paramedic, and 3) 2-3 RQI®-trained paramedics. We reported the median of the average compression rate, depth, and fraction, as well as percent of compressions that were between 100 to 120/minute and percent of compressions that were 2.0 to 2.4 inches deep. Kruskal-Wallis Tests were used to assess differences in these metrics across the three groups of paramedics. Of 353 cases, the median of the average compression rate/minute among crews with 0, 1, and 2-3 RQI®-trained paramedics was 130, 125, and 125, respectively (p=0.0032). Median percent of compressions between 100 to 120 compressions/minute was 10.3%, 19.7%, and 20.1% among crews with 0, 1, and 2-3 RQI®-trained paramedics, respectively (p=0.0010). Median of the average compression depth was 1.7 inches across all three groups (p=0.4881). Median compression fraction was 86.4%, 84.6%, and 85.5% among crews with 0, 1, and 2-3 RQI-trained paramedics, respectively (p=0.6371).

CONCLUSIONS

RQI® training was associated with statistically significant improvement in chest compression rate, but not improved chest compression depth or fraction in OHCA.

Effect of real-time feedback device compared to use or non-use of a checklist performance aid on post-training performance and retention of infant cardiopulmonary resuscitation: A randomized simulation-based trial

INTRODUCTION

This study aims to determine the best method for achieving optimal performance of pediatric cardiopulmonary resuscitation (CPR) during simulation-based training, whether with or without a performance aid.

METHODS

In this randomized controlled study, 46 participants performed simulated CPR in pairs on a Resusci Baby QCPR™ mannequin, repeated after four weeks. All participants performed the first simulation without performance aids. For the second simulation, they were randomly assigned to one of three groups with stratification based on status: throughout CPR, Group A (n = 16) was the control group and did not use a performance aid; Group B (n = 16) used the CPR checklist; Group C (n = 14) used real-time visualization of their CPR activity on a feedback device. Overall performance was assessed using the QCPR™.

RESULTS

All groups demonstrated improved performance on the second simulation (p < 0.01). Use of the feedback device resulted in better CPR performance than use of the CPR checklist (p = 0.02) or no performance aid (p = 0.04). Additionally, participants thought that the QCPR™ could effectively improve their technical competences.

CONCLUSIONS

Performance aid based on continuous feedback is helpful in the learning process. The use of the QCPR™, a real-time feedback device, improved the quality of resuscitation during infant CPR simulation-based training.

The high impulse, palm lift technique for chest compression: Prospective, experimental, pilot study

BACKGROUND

The classic technique of high quality chest compression (HQCC) during cardiopulmonary resuscitation (CPR) is based on the International Liaison Committee on Resuscitation (ILCOR) guidelines which specify that the rescuer's hands should maintain constant contact with the chest surface but should not lean upon it, in order to provide full chest recoil. Since end-tidal CO2 (EtCO2) values have been shown to be a reliable indicator of CPR quality, we examined a method where classic HQCC was modified by a high impulse and palm lifting (HIPL) technique which merged rapid forceful compression with disconnection of the rescuer's palm from the patient's sternum during the recoil phase. The object of the study was to detect any differences in HIPL EtCO2 values in comparison with those from classic HQCC.

METHODS

We report a prospective pilot study in which we compared EtCO2 readings achieved during 2 min of classic HQCC technique with readings after implementing 2 min of the HIPL technique during out-of-hospital CPR, provided by medical emergency response teams for cases of cardiac arrest.

RESULTS

EtCO2 values obtained from16 cases who received HQCC followed by HIPL compressions showed a significant difference (p = 0.037) between the two techniques. Mean ± SD EtCO2 values after 2 min of each technique were: HQCC: 18 ± 9 mmHg; HIPL: 27 ± 11 mmHg; followed by a further 2 min of HQCC: 19 ± 11 mmHg. Linear regression showed that the differences in EtCO2 were associated with non - significant changes in ventilation rate (p = 0.493) and chest compression rate (p = 0.889).

CONCLUSIONS

The results obtained suggest that modifying HQCC with the HIPL technique led to a significant increase in EtCO2 values in comparison with classic HQCC, indicating an improvement in circulation during CPR. We think that these encouraging early results warrant a larger multi - centre study of HIPL.

Association between prehospital prognostic factors and out-of-hospital cardiac arrest: Effect of rural-urban disparities

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) is associated with a poor prognosis and a highly variable survival rate. Few studies have focused on outcomes in rural and urban groups while also evaluating underlying diseases and prehospital factors for OHCAs.

OBJECTIVE

To investigate the relationship between the patient's underlying disease and outcomes of OHCAs in urban areas versus those in rural areas.

METHODS

We reviewed the emergency medical service (EMS) database for information on OHCA patients treated between January 2015 and December 2019, and collected data on pre-hospital factors, underlying diseases, and outcomes of OHCAs. Univariate and multivariate logistic regression analyses were used to evaluate the prognostic factors for OHCA.

RESULTS

Data from 4225 OHCAs were analysed. EMS response time was shorter and the rate of attendance by EMS paramedics was higher in urban areas (p < 0.001 for both). Urban area was a prognostic factor for >24-h survival (odds ratio [OR] = 1.437, 95% confidence interval [CI]: 1.179-1.761). Age (OR = 0.986, 95% CI: 0.979-0.993). EMS response time (OR = 0.854, 95% CI: 0.811-0.898), cardiac arrest location (OR = 2.187, 95% CI: 1.707-2.795), attendance by paramedics (OR = 1.867, 95% CI: 1.483-2.347), and prehospital defibrillation (OR = 2.771, 95% CI: 2.154-3.556) were independent risk factors for survival to hospital discharge, although the influence of an urban area was not significant (OR = 1.211, 95% CI: 0.918-1.584).

CONCLUSIONS

Compared with rural areas, OHCA in urban areas are associated with a higher 24-h survival rate. Shorter EMS response time and a higher probability of being attended by paramedics were noted in urban areas. Although shorter EMS response time, younger age, public location, defibrillation by an automated external defibrillator, and attendance by Emergency Medical Technician-paramedics were associated with a higher rate of survival to hospital discharge, urban area was not an independent prognostic factor for survival to hospital discharge in OHCA patients.

Optimal Combination of Compression Rate and Depth During Cardiopulmonary Resuscitation for Functionally Favorable Survival

Importance

Previous studies of basic cardiopulmonary resuscitation (CPR) indicate that both chest compression rate (CCR) and chest compression depth (CCD) each are associated with survival probability after out-of-hospital cardiac arrest. However, an optimal CCR-CCD combination has yet to be identified, particularly with respect to age, sex, presenting cardiac rhythm, and CPR adjunct use.

Objectives

To identify an ideal CCR-CCD combination associated with the highest probability of functionally favorable survival and to assess whether this combination varies with respect to age, sex, presenting cardiac rhythm, or CPR adjunct use.

Design, Setting, and Participants

This cohort study used data collected between June 2007 and November 2009 from a National Institutes of Health (NIH) clinical trials network registry of out-of-hospital and in-hospital emergency care provided by 9-1-1 system agencies participating in the network across the United States and Canada (n = 150). The study sample included 3643 patients who had out-of-hospital cardiac arrest and for whom CCR and CCD had been simultaneously recorded during an NIH clinical trial of a CPR adjunct. Subgroup analyses included evaluations according to age, sex, presenting cardiac rhythm, and application of a CPR adjunct. Data analysis was performed from September to November 2018.

Interventions

Standard out-of-hospital cardiac arrest interventions compliant with the concurrent American Heart Association guidelines as well as use of the CPR adjunct device in half of the patients.

Main Outcomes and Measures

The optimal combination of CCR-CCD associated with functionally favorable survival (modified Rankin scale ≤3) overall and by age, sex, presenting cardiac rhythm, and CPR adjunct use.

Results

Of 3643 patients, 2346 (64.4%) were men; the mean (SD) age was 67.5 (15.7) years. The identified optimal CCR-CCD for all patients was 107 compressions per minute and a depth of 4.7 cm. When CPR was performed within 20% of this value, survival probability was significantly higher (6.0% vs 4.3% outside that range; odds ratio, 1.44; 95% CI, 1.07-1.94; P = .02). The optimal CCR-CCD combination remained similar regardless of age, sex, presenting cardiac rhythm, or CPR adjunct use. The identified optimal CCR-CCD was associated with significantly higher probabilities of survival when the CPR device was used compared with standard CPR (odds ratio, 1.90; 95% CI, 1.06-3.38; P = .03), and the device's effectiveness was dependent on being near the target CCR-CCD combination.

Conclusions and Relevance

The findings suggest that the combination of 107 compressions per minute and a depth of 4.7 cm is associated with significantly improved outcomes for out-of-hospital cardiac arrest. The results merit further investigation and prospective validation.

Comparison of Chest Compression Quality between Transfer Sheet and Stretcher Use for Transporting out-of-Hospital Cardiac Arrest Patients in a High-Rise Building - A Randomized and Open-Label Cross-over Design

OBJECTIVES

Stretchers are commonly used for transporting cardiac arrest patients, but their use may be limited in confined spaces, like elevators. Use of transfer sheet as an alternative has not been explored. We aimed to compare manual chest compression quality between these two methods. Methods: In this prospective, open-label, randomized cross-over manikin study, the subjects included emergency medical technicians who were assigned to 12 three-person crews. Scenarios included transport of a cardiac arrest in a high-rise building and elevator using transfer sheet (TS) and stretchers adjusted to 45° (S45) and 90° (S90). Chest compression quality was measured using a recording manikin and that before (on-scene phase) and after (transport phase) the manikin moved via transfer sheet or stretcher were compared. Results: The final analysis included 72 simulation runs. Chest compression quality did not differ among the groups in the on-scene phase. In the transport phase, the transfer sheet group provided greater mean compression depth (54.4 ± 4.2 vs 39.6 ± 7.2 mm, p < 0.01 and 54.4 ± 4.2 vs 40.6 ± 8.3 mm, p < 0.01, respectively) than stretchers of S45 and S90, and higher percentage of deep-enough compression (TS: 51.0 [23.8-74.8]% vs S45: 19.5 [5.8-29.5]%, p < 0.01) than the S45 group. Transfer sheet use showed a trend of lower percentages of full recoil (TS: 40.0 [12.8-64.5]% vs S45: 70.5 [47.0-79.8]% vs S90: 52.5 [25.3-76.0]%, p = 0.09). Chest compression fraction, compressions with correct hand position, and mean compression rates did not differ between groups in the transport phase. The TS group showed shorter time intervals of simulation start-to-first-compression (TS: 13.9 [12.4-15.1] sec vs S90: 15.9 [13.3-16.4] sec, p = 0.04) and total run time (TS: 145.7 [135.1-151.4] sec vs S90: 160.0 [151.9-175.4] sec, p < 0.01) than the S90 group. Conclusion: In this simulation, using transfer sheet outperform using stretcher for transporting cardiac arrest patients from high-rise buildings. Rescuers need to be aware of full chest recoil.

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

INTRODUCTION

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

PROBLEM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The changes in cardiopulmonary resuscitation guidelines: from 2000 to the present

This review aims to determine the changes made in the cardiopulmonary resuscitation (CPR) guidelines from 2000 to the present. The study was mainly undertaken by using International Guidelines from American Heart Association. The main change of CPR was chest compression skill. The guidelines have improved high-quality CPR through the change of chest compression skill. The latest adult CPR guidelines are as follows: (a) push chest quickly (100-120/min), (b) compress appropriately (5-6 cm), (c) relax chest fully (complete chest recoil), (d) avoid interruption of compression, and (e) avoid hyperventilation. The understanding of the latest CPR skills will be helpful in improving survival rate from sudden cardiac death.

Real-Time Cardiopulmonary Resuscitation Feedback and Targeted Training Improve Chest Compression Performance in a Cohort of International Healthcare Providers

BACKGROUND

Optimal cardiopulmonary resuscitation (CPR) performance is the foundation of successful cardiac arrest resuscitation. However, health care providers perform inadequate compressions. Better training techniques and real-time CPR feedback may improve compression performance.

OBJECTIVE

We sought to evaluate the impact of a targeted training program combined with real-time defibrillator CPR feedback on chest compression performance in an international cohort of health care providers.

METHODS

Physicians, nurses, respiratory therapists, and technicians from 6 hospitals in 5 countries (Taiwan, Singapore, China, Bahrain, and Kuwait) participated in a standardized resuscitation workshop. Chest compression was measured before and after didactics and activation of CPR feedback. Compressions were performed for 1 min on standard CPR manikins placed on a hospital bed and backboard and measured using ZOLL R Series defibrillators. The percentage of compressions meeting target values for depth and rate were compared before and after the workshop and activation of real-time CPR feedback. No depth maximum was defined to allow for mattress compression.

RESULTS

Chest compressions were more likely to meet targets for depth (71-95%, odds ratio [OR] 8.61 [95% confidence interval {CI} 4.42-16.77], p < 0.001), rate (41-81%, OR 6.4 [95% CI 4.2-9.8], p < 0.001), and both depth and rate (5-42%, OR 2.4 [95% CI 6.7-22.9], p < 0.001) after the workshop and activation of real-time CPR feedback.

CONCLUSIONS

A targeted training intervention combined with real-time CPR feedback improved chest compression performance among health care providers from various countries.

Chest compression release velocity factors during out-of-hospital cardiac resuscitation

BACKGROUND

Higher chest compression release velocity (CCRV) has been associated with better outcomes after out-of-hospital cardiac arrest (OHCA), and patient factors have been associated with variations in chest wall compliance and compressibility. We evaluated whether patient sex, age, weight, and time in resuscitation were associated with CCRV during pre-hospital resuscitation from OHCA.

METHODS

Observational study of prospectively collected OHCA quality improvement data in two suburban EMS agencies in Arizona between 10/1/2008 and 12/31/2016. Subject-level mean CCRV during the first 10 min of compressions was correlated with categorical variables by the Wilcoxon rank-sum test and with continuous variables by the Spearman's rank correlation coefficient. Generalized estimating equation and linear mixed-effect models were used to study the trend of CCRV over time.

RESULTS

During the study period, 2535 adult OHCA cases were treated. After exclusion criteria, 1140 cases remained for analysis. Median duration of recorded compressions was 8.70 min during the first 10 min of CPR. An overall decline in CCRV was observed even after adjusting for compression depth. The subject-level mean CCRV was higher for minutes 0-5 than for minutes 5-10 (mean 347.9 mm/s vs. 339.0 mm/s, 95% CI of the difference -12.4 to -5.4, p < 0.0001). Males exhibited a greater mean CCRV compared to females [344.4 mm/s (IQR 307.3-384.6) vs. 331.5 mm/s (IQR 285.3-385.5), p = 0.013]. Mean CCRV was negatively correlated with age and positively correlated with patient weight.

CONCLUSION

CCRV declines significantly over the course of resuscitation. Patient characteristics including male sex, younger age, and increased weight were associated with a higher CCRV.

The impact of real-time chest compression feedback increases with application of the 2015 guidelines

BACKGROUND

Cardiac arrest survival depends upon chest compression quality. Real-time audiovisual feedback may improve compression guideline adherence, particularly with the more specific 2015 guidelines.

METHODS

Subjects included healthcare providers from multiple U.S. hospitals. Compression rate and depth were recorded using standard manikins and real-time audiovisual feedback defibrillators (ZOLL R Series). Subjects were enrolled before (n = 756) and after (n = 995) release of the 2015 guidelines, which define narrower compression targets. Subjects performed 2 min of continuous compressions before and after activation of feedback. The percentage of compressions meeting appropriate rate/depth targets was determined before and after release of the 2015 guidelines.

RESULTS

An increase in compression guideline adherence was observed with use of feedback before [68.7% to 96.3%, p < .001] and after [16.6% to 94.1%, p < .001] release of the 2015 guidelines. The proportion of subjects requiring feedback to achieve adherence was higher for the 2015 guidelines [28.6% vs. 78.5%, OR 9.12, 95% CI 7.33-11.35, p < .001].

CONCLUSIONS

The use of real-time audiovisual feedback increases adherence to chest compression guidelines, particularly with application of the narrower 2015 guidelines targets for compression depth and rate.

Effect of real-time visual feedback device 'Quality Cardiopulmonary Resuscitation (QCPR) Classroom' with a metronome sound on layperson CPR training in Japan: a cluster randomized control trial

OBJECTIVES

'Quality Cardiopulmonary Resuscitation (QCPR) Classroom' was recently introduced to provide higher-quality Cardiopulmonary Resuscitation (CPR) training. This study aimed to examine whether novel QCPR Classroom training can lead to higher chest-compression quality than standard CPR training.

DESIGN

A cluster randomised controlled trial was conducted to compare standard CPR training (control) and QCPR Classroom (intervention).

SETTING

Layperson CPR training in Japan.

PARTICIPANTS

Six hundred forty-two people aged over 15 years were recruited from among CPR trainees.

INTERVENTIONS

CPR performance data were registered without feedback on instrumented Little Anne prototypes for 1 min pretraining and post-training. A large classroom was used in which QCPR Classroom participants could see their CPR performance on a big screen at the front; the control group only received instructor's subjective feedback.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcomes were compression depth (mm), rate (compressions per minute (cpm)), percentage of adequate depth (%) and recoil (%). Survey scores were a secondary outcome. The survey included participants' confidence regarding CPR parameters and ease of understanding instructor feedback.

RESULTS

In total, 259 and 238 people in the control and QCPR Classroom groups, respectively, were eligible for analysis. After training, the mean compression depth and rate were 56.1±9.8 mm and 119.2±7.3 cpm in the control group and 59.5±7.9 mm and 116.8±5.5 cpm in the QCPR Classroom group. The QCPR Classroom group showed significantly more adequate depth than the control group (p=0.001). There were 39.0% (95% CI 33.8 to 44.2; p<0.0001) and 20.0% improvements (95% CI 15.4 to 24.7; P<0.0001) in the QCPR Classroom and control groups, respectively. The difference in adequate recoil between pretraining and post-training was 2.7% (95% CI -1.7 to 7.1; pre 64.2±36.5% vs post 66.9%±34.6%; p=0.23) and 22.6% in the control and QCPR Classroom groups (95% CI 17.8 to 27.3; pre 64.8±37.5% vs post 87.4%±22.9%; p<0.0001), respectively.

CONCLUSIONS

QCPR Classroom helped students achieve high-quality CPR training, especially for proper compression depth and full recoil. For good educational achievement, a novel QCPR Classroom with a metronome sound is recommended.

A meta-analysis of the resuscitative effects of mechanical and manual chest compression in out-of-hospital cardiac arrest patients

Objectives

To evaluate the resuscitative effects of mechanical and manual chest compression in patients with out-of-hospital cardiac arrest (OHCA).

Methods

All randomized controlled and cohort studies comparing the effects of mechanical compression and manual compression on cardiopulmonary resuscitation in OHCA patients were retrieved from the Cochrane Library, PubMed, EMBASE, and Ovid databases from the date of their establishment to January 14, 2019. The included outcomes were as follows: the return of spontaneous circulation (ROSC) rate, the rate of survival to hospital admission, the rate of survival to hospital discharge, and neurological function. After evaluating the quality of the studies and summarizing the results, RevMan5.3 software was used for the meta-analysis.

Results

In total, 15 studies (9 randomized controlled trials and 6 cohort studies) were included. The results of the meta-analysis showed that there were no significant differences in the resuscitative effects of mechanical and manual chest compression in terms of the ROSC rate, the rate of survival to hospital admission and survival to hospital discharge, and neurological function in OHCA patients (ROSC: RCT: OR = 1.12, 95% CI (0.90, 1.39), P = 0.31; cohort study: OR = 1.08, 95% CI (0.85, 1.36), P = 0.54; survival to hospital admission: RCT: OR = 0.95, 95% CI (0.75, 1.20), P = 0.64; cohort study: OR = 0.98 95% CI (0.79, 1.20), P = 0.82; survival to hospital discharge: RCT: OR = 0.87, 95% CI (0.68, 1.10), P = 0.24; cohort study: OR = 0.78, 95% CI (0.53, 1.16), P = 0.22; Cerebral Performance Category (CPC) score: RCT: OR = 0.88, 95% CI (0.64, 1.20), P = 0.41; cohort study: OR = 0.68, 95% CI (0.34, 1.37), P = 0.28). When the mechanical compression group was divided into Lucas and Autopulse subgroups, the Lucas subgroup showed no difference from the manual compression group in ROSC, survival to admission, survival to discharge, and CPC scores; the Autopulse subgroup showed no difference from the manual compression subgroup in ROSC, survival to discharge, and CPC scores.

Conclusion

There were no significant differences in resuscitative effects between mechanical and manual chest compression in OHCA patients. To ensure the quality of CPR, we suggest that manual chest compression be applied in the early stage of CPR for OHCA patients, while mechanical compression can be used as part of advanced life support in the late stage.

Supportive technology in the resuscitation of out-of-hospital cardiac arrest patients

PURPOSE OF REVIEW

To discuss the increasing value of technological tools to assess and augment the quality of cardiopulmonary resuscitation (CPR) and, in turn, improve chances of surviving out-of-hospital cardiac arrest (OHCA).

RECENT FINDINGS

After decades of disappointing survival rates, various emergency medical services systems worldwide are now seeing a steady rise in OHCA survival rates guided by newly identified 'sweet spots' for chest compression rate and chest compression depth, aided by monitoring for unnecessary pauses in chest compressions as well as methods to better ensure full-chest recoil after compressions. Quality-assurance programs facilitated by new technologies that monitor chest compression rate, chest compression depth, and/or frequent pauses have been shown to improve the quality of CPR. Further aided by other technologies that enhance flow or better identify the best location for hand placement, the future outlook for better survival is even more promising, particularly with the potential use of another technology - extracorporeal membrane oxygenation for OHCA.

SUMMARY

After 5 decades of focus on manual chest compressions for CPR, new technologies for monitoring, guiding, and enhancing CPR performance may enhance outcomes from OHCA significantly in the coming years.

Ventilation rate in adults with a tracheal tube during cardiopulmonary resuscitation: A systematic review

AIM

The optimal ventilation rate during cardiopulmonary resuscitation (CPR) with a tracheal tube is unknown. We evaluated whether in adults with cardiac arrest and a secure airway (tracheal tube), a ventilation rate of 10min^-1, compared to any other rate during CPR, improves outcomes.

METHODS

A systematic review up to 14 July 2016. We included both adult human and animal studies. A GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach was used to evaluate the quality of evidence for each outcome.

RESULTS

We identified one human observational study with 67 patients and ten animal studies (234 pigs and 30 dogs). All studies carried a high risk of bias. All studies evaluated for return of spontaneous circulation (ROSC). Studies showed no improvement in ROSC with a ventilation rate of 10 min-1 compared to any other rate. The evidence for longer-term outcomes such as survival to discharge and survival with favourable neurological outcome was very limited.

CONCLUSION

A ventilation rate recommendation of 10 min-1 during adult CPR with a tracheal tube and no pauses for chest compression is a very weak recommendation based on very low quality evidence.

Effect of an interactive cardiopulmonary resuscitation assist device with an automated external defibrillator synchronised with a ventilator on the CPR performance of emergency medical service staff: a randomised simulation study

Background

The present study evaluates whether the quality of advanced cardiac life support (ALS) is improved with an interactive prototype assist device. This device consists of an automated external defibrillator linked to a ventilator and provides synchronised visual and acoustic instructions for guidance through the ALS algorithm and assistance for face-mask ventilations.

Methods

We compared the cardiopulmonary resuscitation (CPR) quality of emergency medical system (EMS) staff members using the study device or standard equipment in a mannequin simulation study with a prospective, controlled, randomised cross-over study design. Main outcome was the effect of the study device compared to the standard equipment and the effect of the number of prior ALS trainings of the EMS staff on the CPR quality. Data were analysed using analyses of covariance (ANCOVA) and binary logistic regression, accounting for the study design.

Results

In 106 simulations of 56 two-person rescuer teams, the mean hands-off time was 24.5% with study equipment and 23.5% with standard equipment (Difference 1.0% (95% CI: −0.4 to 2.5%); p = 0.156). With both types of equipment, the hands-off time decreased with an increasing cumulative number of previous CPR trainings (p = 0.042). The study equipment reduced the mean time until administration of adrenaline (epinephrine) by 23 s (p = 0.003) and that of amiodarone by 17 s (p = 0.016). It also increased the mean number of changes in the person doing chest compressions (0.6 per simulation; p < 0.001) and decreased the mean number of chest compressions (2.8 per minute; p = 0.022) and the mean number of ventilations (1.8 per minute; p < 0.001). The chance of administering amiodarone at the appropriate time was higher, with an odds ratio of 4.15, with the use of the study equipment CPR.com compared to the standard equipment (p = 0.004). With an increasing number of prior CPR trainings, the time intervals in the ALS algorithm until the defibrillations decreased with standard equipment but increased with the study device.

Conclusions

EMS staff with limited training in CPR profit from guidance through the ALS algorithm by the study device. However, the study device somehow reduced the ALS quality of well-trained rescuers and thus can only be recommended for ALS provider with limited experience.

Correlation of Impedance Threshold Device use during cardiopulmonary resuscitation with post-cardiac arrest Acute Kidney Injury

PURPOSE

To assess whether use of Impedance Threshold Device (ITD) during cardiopulmonary resuscitation (CPR) reduces the degree of post-cardiac arrest Acute Kidney Injury (AKI), as a result of improved hemodynamics, in a porcine model of ventricular fibrillation (VF) cardiac arrest.

METHODS

After 8 min of untreated cardiac arrest, the animals were resuscitated either with active compression-decompression (ACD) CPR plus a sham ITD (control group, n=8) or with ACD-CPR plus an active ITD (ITD group, n=8). Adrenaline was administered every 4 min and electrical defibrillation was attempted every 2 min until return of spontaneous circulation (ROSC) or asystole. After ROSC the animals were monitored for 6 h under general anesthesia and then returned to their cages for a 48 h observation, before euthanasia. Two novel biomarkers, Neutrophil Gelatinase-Associated Lipocalin (NGAL) in plasma and Interleukin-18 (IL-18) in urine, were measured at 2 h, 4 h, 6 h, 24 h and 48 h post-ROSC, in order to assess the degree of AKI.

RESULTS

ROSC was observed in 7 (87.5%) animals treated with the sham valve and 8 (100%) animals treated with the active valve (P=NS). However, more than twice as many animals survived at 48 h in the ITD group (n=8, 100%) compared to the control group (n=3, 37.5%). Urine IL-18 and plasma NGAL levels were augmented post-ROSC in both groups, but they were significantly higher in the control group compared with the ITD group, at all measured time points.

CONCLUSION

Use of ITD during ACD-CPR improved hemodynamic parameters, increased 48 h survival and decreased the degree of post-cardiac arrest AKI in the resuscitated animals.

Mechanical chest compression devices are associated with poor neurological survival in a statewide registry: A propensity score analysis

OBJECTIVE

To compare functional survival (discharge cerebral performance category 1 or 2) among victims of out-of-hospital cardiac arrest (OHCA) who had resuscitations performed using mechanical chest compression (mech-CC) devices vs. those using manual chest compressions (man-CC).

METHODS

Observational cohort of 2600 cases of OHCA from a statewide, prospectively-collected cardiac arrest registry (Utah Cardiac Arrest Registry to Enhance Survival). Comparison of functional survival among those receiving mech-CC vs man-CC was performed using a mixed-effects Poisson model with inverse probability weighted propensity scores to control for selection bias.

RESULTS

Overall, mech-CC was utilized in 405/2600 (16%) of the total arrests in Utah during this period. 371/405 (92%) were of the load-distributing band type (AutoPulse(®)) and 22/405 (5%) were mechanical piston devices (LUCAS™), while 12/405 (3%) employed other devices. The relative risk (RR) for functional survival comparing mech-CC to man-CC after propensity score adjustment was 0.41 (95% CI 0.24-0.70, p=0.001).

CONCLUSIONS

Mechanical chest compression device use was associated with lower rates of functional survival in this propensity score analysis, controlling for Utstein variables and early return of spontaneous circulation.

Short structured feedback training is equivalent to a mechanical feedback device in two-rescuer BLS: a randomised simulation study

BACKGROUND

Resuscitation guidelines encourage the use of cardiopulmonary resuscitation (CPR) feedback devices implying better outcomes after sudden cardiac arrest. Whether effective continuous feedback could also be given verbally by a second rescuer ("human feedback") has not been investigated yet. We, therefore, compared the effect of human feedback to a CPR feedback device.

METHODS

In an open, prospective, randomised, controlled trial, we compared CPR performance of three groups of medical students in a two-rescuer scenario. Group "sCPR" was taught standard BLS without continuous feedback, serving as control. Group "mfCPR" was taught BLS with mechanical audio-visual feedback (HeartStart MRx with Q-CPR-Technology™). Group "hfCPR" was taught standard BLS with human feedback. Afterwards, 326 medical students performed two-rescuer BLS on a manikin for 8 min. CPR quality parameters, such as "effective compression ratio" (ECR: compressions with correct hand position, depth and complete decompression multiplied by flow-time fraction), and other compression, ventilation and time-related parameters were assessed for all groups.

RESULTS

ECR was comparable between the hfCPR and the mfCPR group (0.33 vs. 0.35, p = 0.435). The hfCPR group needed less time until starting chest compressions (2 vs. 8 s, p < 0.001) and showed fewer incorrect decompressions (26 vs. 33 %, p = 0.044). On the other hand, absolute hands-off time was higher in the hfCPR group (67 vs. 60 s, p = 0.021).

CONCLUSIONS

The quality of CPR with human feedback or by using a mechanical audio-visual feedback device was similar. Further studies should investigate whether extended human feedback training could further increase CPR quality at comparable costs for training.

A review of approaches to optimise chest compressions in the resuscitation of asphyxiated newborns

OBJECTIVE

Provision of chest compressions (CCs) and/or medications in the delivery room is associated with poor outcomes. Based on the physiology of perinatal asphyxia, we aimed to provide an overview of current recommendations and explore potential determinants of effective neonatal cardiopulmonary resuscitation (CPR): balancing ventilations and CC, CC rate, depth, full chest recoil, CC technique and adrenaline.

DESIGN

A search in the databases MEDLINE (Ovid) and EMBASE until 10 April 2015.

SETTING

Delivery room.

PATIENTS

Asphyxiated newborn infants.

INTERVENTIONS

CCs.

MAIN OUTCOME MEASURES

Haemodynamics, recovery and survival.

RESULTS

Current evidence is derived from mathematical models, manikin and animal studies, and small case series. No randomised clinical trials examining neonatal CC have been performed. There is no evidence to refute a CC to ventilation (C:V) ratio of 3:1. Raising the intrathoracic pressure, for example, by superimposing a sustained inflation on uninterrupted CC, and a CC rate >120/min may be beneficial. The optimal neonatal CC depth is unknown, but factors influencing depth and consistency include the C:V ratio. Incomplete chest wall recoil can cause less negative intrathoracic pressure between CC and reduced CPR effectiveness. CC should be performed with the two-thumb method over the lower third of the sternum. The optimal dose, route and timing of adrenaline administration remain to be determined.

CONCLUSIONS

Successful CPR requires the delivery of high-quality CC, encompassing optimal (A) C:V ratio (B) rate, (C) depth, (D) chest recoil between CC, (E) technique and (F) adrenaline dosage. More animal studies with high translational value and randomised clinical trials are needed.

[Randomised study of the relationship between the use of CPRmeter® device and the quality of chest compressions in a simulated cardiopulmonary resuscitation]

OBJECTIVE

To determine whether the use of CPRmeter(®) during the resuscitation manoeuvres, is related to a higher quality of external cardiac massage, as recommended by the International Liaison Committee on Resuscitation (ILCOR). To compare the quality obtained without the use or this, and whether there are differences related to anthropometric, demographic, professional and/or occupational factors.

METHOD

Experimental, open trial performed with life support simulators in a stratified random sample of 88 health workers randomly distributed between groups A (without indications of the device) and B (with them). The homogeneity of their confounding variables was compared, as well as the compressions depth and compressions rate, the proportion of completed release, and distribution of the quality massage variable (according to criteria ILCOR) between the groups. The qualitative variables were analysed with the chi-square test, and quantitative variables with the Student t-test or Mann-Whitney U-test and the association between the variable quality massage variable, and use of the device with the odds ratio.

RESULTS

Group A: mean depth 42.1mm (standard deviation 10.1), mean rate 121.3/min (21.6), percentage of complete release 71.2% (36.9). Group B: 51.2mm (5.9) 111.9/min (6.4), 92.9% (10.1) respectively. Odds ratio for quality massage regarding the use of the device was 5.170 (95% CI; 2.060-12.977).

CONCLUSIONS

The use of CPRmeter(®) device in simulated resuscitations is related to a higher quality of cardiac massage, improving the approach to the ILCOR recommendations, regardless of the characteristics of the participants. They were 83.8% more likely to achieve a quality massage using the device than without it.

Evaluating the Quality of Cardiopulmonary Resuscitation in the Emergency Department by Real-Time Video Recording System

Objectives

To compare cardiopulmonary resuscitation (CPR) quality between manual CPR and miniaturized chest compressor (MCC) CPR. To improve CPR quality through evaluating the quality of our clinical work of resuscitation by real-time video recording system.

Methods

The study was a retrospective observational study of adult patients who experienced CPR at the emergency department of Shanghai Tenth People’s Hospital from March 2013 to August 2014. All the performance of CPR were checked back by the record of “digital real-time video recording system”. Average chest compression rate, actual chest compression rate, the percentage of hands-off period, time lag from patient arrival to chest compression, time lag from patient arrival to manual ventilation, time lag from patient arrival to first IV establish were compared. Causes of chest compression hands-off time were also studied.

Results

112 cases of resuscitation attempts were obtained. Average chest compression rate was over 100 compression per minute (cpm) in the majority of cases. However, indicators such as percentage of hands-off periods, time lag from patient arrival to the first manual ventilation and time lag from patient arrival to the first IV establish seemed to be worse in the manual CPR group compared to MCC CPR group. The saving of operators change time seemed to counteract the time spent on MCC equipment. Indicators such as percentage of hands-off periods, time lag between patient arrival to the first chest compression, time lag between patient arrival to the first manual ventilation and time lag from patient arrival to the first IV establish may influence the survival.

Conclusion

Our CPR quality remained to be improved. MCC may have a potentially positive role in CPR.

Evaluation of Zoll Medical's ResQCPR System for cardiopulmonary resuscitation

Cardiac arrest remains a leading cause of death, currently affecting more than 250,000 Americans annually. As recommended by the American Heart Association, the current standard of care for patients with an out-of-hospital cardiac arrest (OHCA) includes manual cardiopulmonary resuscitation (S-CPR). Survival with favorable neurological function for all patients following OHCA and treated with S-CPR averages <6%. The ResQCPR System is intended to provide greater circulation to the heart and brain compared with S-CPR, thereby increasing the likelihood of survival. A recent Phase III, multicenter randomized study demonstrated a 50% increase in survival to hospital discharge with favorable neurologic function in subjects with an OHCA of presumed cardiac etiology treated with the ResQCPR System compared with conventional CPR. The ResQCPR System has been recently approved by the FDA as a CPR adjunct to improve the likelihood of survival in adult patients with non-traumatic cardiac arrest.

Chest compression release velocity: Association with survival and favorable neurologic outcome after out-of-hospital cardiac arrest

PURPOSE

We evaluated the association between chest compression release velocity (CCRV) and outcomes after out-of-hospital cardiac arrest (OHCA).

MATERIALS AND METHODS

CPR quality was measured using a defibrillator with accelerometer-based technology (E Series, ZOLL Medical) during OHCA resuscitations by 2 EMS agencies in Arizona between 10/2008 and 06/2013. All non-EMS-witnessed adult (≥ 18 years) arrests of presumed cardiac etiology were included. The association between mean CCRV (assessed as an appropriate measure of central tendency) and both survival to hospital discharge and neurologic outcome (Cerebral Performance Category score = 1 or 2) was analyzed using multivariable logistic regression to control for known and potential confounders and multiple imputation to account for missing data.

RESULTS

981 OHCAs (median age 68 years, 65% male, 11% survival to discharge) were analyzed with 232 (24%) missing CPR quality data. All-rhythms survival varied significantly with CCRV [fast (≥ 400 mm/s) = 18/79 (23%); moderate (300-399.9 mm/s) = 50/416 (12%); slow (<300 mm/s) 17/255 (7%); p < 0.001], as did favorable neurologic outcome [fast = 14/79 (18%); moderate = 43/415 (10%); slow = 11/255 (4%); p < 0.001]. Fast CCRV was associated with increased survival compared to slow [adjusted odds ratio (aOR) 4.17 (95% CI: 1.61, 10.82) and moderate CCRV [aOR 3.08 (1.39, 6.83)]. Fast CCRV was also associated with improved favorable neurologic outcome compared to slow [4.51 (1.57, 12.98)]. There was a 5.2% increase in the adjusted odds of survival for each 10mm/s increase in CCRV [aOR 1.052 (1.001, 1.105)].

CONCLUSION

CCRV was independently associated with improved survival and favorable neurologic outcome at hospital discharge after adult OHCA.

Optimal chest compression technique for paediatric cardiac arrest victims

BACKGROUND

The aim of this study was to assess the quality of chest compressions performed by inexperienced rescuers using three different techniques: two-hand, right one-hand, and left one-hand.

METHODS

We performed a prospective, randomised, crossover study in a simulated 6-year-old paediatric manikin model. Each participant performed 2-minute continuous chest compressions, using three different techniques. Chest compression quality data, including compression rate, compression depth, and residual leaning was recorded by a Q-CPR™ compression sensor connected to HeartStart MRx (Philips Healthcare, Andover, MA, USA). To examine trends in chest compression performance over time, each 2-minute period was divided into six consecutive 20-second epochs.

RESULTS

The 36 participants completed 108 two-minute trials, consisting of a total of 25,030 compressions. The mean compression rates [95% confidence interval] were as follows: two-hand, 116.8 [111.7-121.9]; left one-hand, 115.0 [109.9-120.1]; and right one-hand, 115.5 [110.4-120.6] (p = 0.565). The mean compression depth for two-hand was 38.7 mm (37.1-40.2), which was higher than for left one-hand (36.3 mm [34.8-37.9]) or right one-hand (35.4 mm [33.9-37.0]) (p < 0.001). Chest compression depth declined over time, regardless of the technique (p < 0.001). The pattern of compression depth change over time was similar for all techniques (p > 0.999). The residual leaning rate was higher with two-hand (40.7 [27.9-53.5]) than that for left one-hand (29.2 [16.4-42.0]) or right one-hand (25.8 [13.0-38.6]) (p = 0.021).

CONCLUSIONS

For paediatric cardiopulmonary resuscitation by inexperienced rescuers, the two-hand technique has the advantage of producing deeper compressions than the one-hand technique, but it is accompanied by more frequent residual leaning. For the one-hand techniques, the right and left hand produced chest compressions of similar quality.

Should unobstructed gasping be facilitated and confirmed before administering adrenaline, otherwise, give titrated vasopressin?

A recent commentary, "Resuscitation That's (Un)Shockable: Time to Get the Adrenaline Flowing", published in the New England Journal of Medicine Journal Watch called attention to a relatively recent study showing that a large and increasing percentage of patients with in-hospital cardiac arrests exhibit initial nonshockable rhythms (asystole or pulseless electrical activity [PEA]; 82% in 2009 vs 69% in 2000) and a most recent study that concluded that neurologically intact survival to hospital discharge after in-hospital cardiac arrest was significantly more likely after earlier epinephrine administration. It was found that delayed administration of epinephrine was associated significantly with lower chance for survival to hospital discharge, in stepwise fashion (12%, 10%, 8%, and 7% survival, respectively, for patients receiving their first epinephrine dose≤3, 4-6, 7-9, and >9 minutes after arrest). Although early use of epinephrine to manage patients with nonshockable rhythms lacks strong evidence to support efficacy, focus on time to epinephrine administration-in addition to high-quality chest compressions-might be the best early intervention. However, evidence may strongly support the recommendation that adrenaline needs to be used very early because without effective-depth cardiopulmonary resuscitation (CPR) with complete recoil, epinephrine may only be effective when gasping is present, which is a time-limited phenomenon. However, because very few rescuers can perform effective-depth chest compressions with complete recoil, gasping is critically necessary for adequate ventilation and generation of adequate coronary and cerebral perfusion. However, under acidemic conditions and high catecholamine levels and/or absence of gasping, vasopressin should be administered instead.

Adequate performance of cardiopulmonary resuscitation techniques during simulated cardiac arrest over and under protective equipment in football

OBJECTIVE

To investigate (1) cardiopulmonary resuscitation (CPR) adequacy during simulated cardiac arrest of equipped football players and (2) whether protective football equipment impedes CPR performance measures.

DESIGN

Exploratory crossover study performed on Laerdal SimMan 3 G interactive manikin simulator.

SETTING

Temple University/St Luke's University Health Network Regional Medical School Simulation Laboratory.

PARTICIPANTS

Thirty BCLS-certified ATCs and 6 ACLS-certified emergency department technicians.

INTERVENTIONS

Subjects were given standardized rescuer scenarios to perform three 2-minute sequences of compression-only CPR. Baseline CPR sequences were captured on each subject.

MAIN OUTCOME MEASURES

Experimental conditions included 2-minute sequences of CPR either over protective football shoulder pads or under unlaced pads. Subjects were instructed to adhere to 2010 American Heart Association guidelines (initiation of compressions alone at 100/min to 51 mm). Dependent variables included average compression depth, average compression rate, percentage of time chest wall recoiled, and percentage of hands-on contact during compressions.

RESULTS

Differences between subject groups were not found to be statistically significant, so groups were combined (n = 36) for analysis of CPR compression adequacy. Compression depth was deeper under shoulder pads than over (P = 0.02), with mean depths of 36.50 and 31.50 mm, respectively. No significant difference was found with compression rate or chest wall recoil.

CONCLUSIONS

Chest compression depth is significantly decreased when performed over shoulder pads, while there is no apparent effect on rate or chest wall recoil. Although the clinical outcomes from our observed 15% difference in compression depth are uncertain, chest compression under the pads significantly increases the depth of compressions and more closely approaches American Heart Association guidelines for chest compression depth in cardiac arrest.

Effects of uninterrupted chest compressions on the rescuer's physical condition

STUDY OBJECTIVE

Recent guidelines have emphasized the need for uninterrupted chest compressions. The purpose of this study was to evaluate the rescuer's tolerability of uninterrupted chest compressions.

METHODS

Twenty-five healthy subjects performed uninterrupted chest compressions for 7 minutes at a rate of 100 compressions per minute using a training manikin. The quality of chest compressions was assessed in terms of the total number and percentage of chest compressions, compression depth, recoil distance, and duty cycle. Correct chest compression was defined as a depth of 38 to 51 mm. Physiological and laboratory parameters were measured before and after the procedure. Fatigue was measured using a numerical rating scale. Data were compared before and after the procedure.

RESULTS

The participants were 10 emergency physicians and 15 medical students. The compression rate was nearly 100 compressions per minute. The number and percentage of correct compressions decreased gradually after 3 minutes. The compression depth decreased significantly after 2 minutes. The recoil distance and duty cycle were unchanged over 7 minutes. Systolic blood pressure, pulse rate, respiratory rate, numerical rating scale, serum lactate, adrenalin, and noradrenalin increased significantly after the procedure. Noradrenalin levels measured before the procedure were significantly and negatively correlated with the total number and percentage of correct compressions (r = -0.587, P = .004; r = -0.549, P = .008, respectively).

CONCLUSIONS

Performing uninterrupted chest compressions for 7 minutes is an arduous procedure. Higher noradrenalin levels before the procedure might be associated with incorrect chest compressions.

Miniaturized mechanical chest compressor improves calculated cerebral perfusion pressure without compromising intracranial pressure during cardiopulmonary resuscitation in a porcine model of cardiac arrest

OBJECTIVE

One of the major goals of cardiopulmonary resuscitation (CPR) is to provide adequate oxygen delivery to the brain for minimizing cerebral injury resulted from cardiac arrest. The optimal chest compression during CPR should effectively improve brain perfusion without compromising intracranial pressure (ICP). Our previous study has demonstrated that the miniaturized mechanical chest compressor improved hemodynamic efficacy and the success of CPR. In the present study, we investigated the effects of the miniaturized chest compressor (MCC) on calculated cerebral perfusion pressure (CerPP) and ICP.

METHODS

Ventricular fibrillation was electrically induced and untreated for 7min in 13 male domestic pigs weighing 39±3kg. The animals were randomized to receive mechanical chest compression with the MCC (n=7), or the Thumper device (n=6). CPR was performed for 5min before defibrillation attempt by a single 150J shock. At 2.5min of CPR, the epinephrine at a dose of 20μg/kg was administered. Additional epinephrine was administered at an interval of 3min thereafter. If resuscitation was not successful, CPR was resumed for an additional 2min prior to the next defibrillation until successful resuscitation or for a total of 15min. Post-resuscitated animals were observed for 2h.

RESULTS

Significantly greater intrathoracic positive and negative pressures during compression and decompression phases of CPR were observed with the MCC when compared with the Thumper device. The MCC produced significantly greater coronary perfusion pressure and end-tidal carbon dioxide. There were no statistically significant differences in systolic and mean ICP between the two groups; however, both of the measurements were slightly greater in the MCC treated animals. Interestingly, the diastolic ICP was significantly lower in the MCC group, which was closely related to the significantly lower negative intrathoracic pressure in the animals that received the MCC. Most important, systolic, diastolic and mean calculated CerPP were all significantly greater in the animals receiving the MCC.

CONCLUSIONS

In the present study, mechanical chest compression with the MCC significantly improved calculated CerPP but did not compromise ICP during CPR. It may provide a safe and effective chest compression during CPR. Protocol number: P1205.