Incomplete chest wall decompression: a clinical evaluation of CPR performance by trained laypersons and an assessment of alternative manual chest compression-decompression techniques

Active decompression during automated head-up cardiopulmonary resuscitation

BACKGROUND

The combination of active compression-decompression cardiopulmonary resuscitation (ACD-CPR) with an impedance threshold device (ITD) and controlled head-up positioning (AHUP-CPR) is associated with improved outcomes compared with conventional CPR (C-CPR). This study focused on the role of active decompression (AD) during AHUP-CPR.

METHODS

Farm pigs (n = 10, ∼40 kg) were anesthetized, intubated and ventilated. Physiological parameters and right ventricular pressure-volume loops were recorded continuously. Ventricular fibrillation was induced and left untreated for 10 mins, followed by automated C-CPR (2 min), ACD + ITD CPR in the flat position (2 min), and then AHUP-CPR with 3 cm of lift above the neutral chest position. After 15 min of CPR, AD was discontinued and then restarted incrementally to 4 cm. Data were analyzed with a linear mixed-effects model, using random intercepts for individual pigs.

RESULTS

Upon cessation of AD during AHUP-CPR, decompression right atrial pressure (+59%) increased (p < 0.01), whereas multiple hemodynamic parameters positively associated with perfusion, including coronary (-25%) and cerebral perfusion pressures (-11%), end-tidal CO2 (-13%), stroke volume and cardiac output (-26%), decreased immediately and significantly with p < 0.05. Restoration of AD reduced right atrial pressure and increased positive perfusion parameters in an incremental manner. Only with ≥ 3 cm of AD were all hemodynamic parameters restored to ≥ 90% of pre-AD discontinuation levels.

CONCLUSION

Full chest wall lift, achieved with ≥ 3 cm of AD, was needed to maintain and optimize hemodynamics during AHUP-CPR in pigs. These findings should be considered when optimizing care with this new approach.

Trained Lifeguards Performing Pediatric Cardiopulmonary Resuscitation While Running: A Pilot Simulation Study

The aim of this study was to compare the quality of standard infant CPR with CPR in motion (i.e., walking and running) via performing maneuvers and evacuating the infant from a beach. Thirteen trained lifeguards participated in a randomized crossover study. Each rescuer individually performed three tests of 2 min each. Five rescue breaths and cycles of 30 chest compressions followed by two breaths were performed. Mouth-to-mouth-and-nose ventilation was carried out, and chest compressions were performed using the two-fingers technique. The manikin was carried on the rescuer's forearm with the head in the distal position. The analysis variables included compression, ventilation, and CPR quality variables, as well as physiological and effort parameters. Significantly lower compression quality values were obtained in running CPR versus standard CPR (53% ± 14% versus 63% ± 15%; p = 0.045). No significant differences were observed in ventilation or CPR quality. In conclusion, lifeguards in good physical condition can perform simulated infant CPR of a similar quality to that of CPR carried out on a victim who is lying down in a fixed position.

Implementation and Evaluation of Resuscitation Training for Childcare Workers

BACKGROUND AND OBJECTIVE

Children spend a large amount of time in daycare centers or schools. Therefore, it makes sense to train caregivers well in first-aid measures in children. The aim of this study is to evaluate whether a multimodal resuscitation training for childcare workers can teach adherence to resuscitation guidelines in a sustainable way.

MATERIALS AND METHODS

Caregivers at a daycare center who had previously completed a first-aid course received a newly developed multimodal resuscitation training in small groups of 7-8 participants by 3 AHA certified PALS instructors and providers. The 4-h focused retraining consisted of a theoretical component, expert modeling, resuscitation exercises on pediatric manikins (Laerdal Resusci Baby QCPR), and simulated emergency scenarios. Adherence to resuscitation guidelines was compared before retraining, immediately after training, and after 6 months. This included evaluation of chest compressions per round, chest compression rate, compression depth, full chest recoil, no-flow time, and success of rescue breaths. For better comparability and interpretation of the results, the parameters were evaluated both separately and summarized in a resuscitation score reflecting the overall adherence to the guidelines.

RESULTS

A total of 101 simulated cardiopulmonary resuscitations were evaluated in 39 participants. In comparison to pre-retraining, chest compressions per round (15.0 [10.0-29.0] vs. 30.0 [30.0-30.0], p < 0.001), chest compression rate (100.0 [75.0-120.0] vs. 112.5 [105-120.0], p < 0.001), correct compression depth (6.7% [0.0-100.0] vs. 100.0% [100.0-100.0], p < 0.001), no-flow time (7.0 s. [5.0-9.0] vs. 4.0 s. [3.0-5.0], p < 0.001), success of rescue breaths (0.0% [0.0-0.0] vs. 100.0% [100.0-100.0], p < 0.001), and resuscitation score were significantly improved immediately after training (3.9 [3.2-4.9] vs. 6.3 [5.6-6.7], p < 0.001). At follow-up, there was no significant change in chest compression rate and success of rescue breaths. Chest compressions per round (30.0 [15.0-30.0], p < 0.001), no-flow time (5.0 s. [4.0-8.0], p < 0.001), compression depths (100.0% [96.7-100.0], p < 0.001), and resuscitation score worsened again after 6 months (5.7 [4.7-6.4], p = 0.03). However, the results were still significantly better compared to pre-retraining.

CONCLUSION

Our multimodal cardiopulmonary resuscitation training program for caregivers is effective to increase the resuscitation performance immediately after training. Although the effect diminishes after 6 months, adherence to resuscitation guidelines was significantly better than before retraining.

Enhancing cardiac arrest survival with extracorporeal cardiopulmonary resuscitation: insights into the process of death

Extracorporeal cardiopulmonary resuscitation (ECPR) is an emerging method of cardiopulmonary resuscitation to improve outcomes from cardiac arrest. This approach targets patients with out-of-hospital cardiac arrest previously unresponsive and refractory to standard treatment, combining approximately 1 h of standard CPR followed by venoarterial extracorporeal membrane oxygenation (VA-ECMO) and coronary artery revascularization. Despite its relatively new emergence for the treatment of cardiac arrest, the approach is grounded in a vast body of preclinical and clinical data that demonstrate significantly improved survival and neurological outcomes despite unprecedented, prolonged periods of CPR. In this review, we detail the principles behind VA-ECMO-facilitated resuscitation, contemporary clinical approaches with outcomes, and address the emerging new understanding of the process of death and capability for neurological recovery.

Can a Glove-Coach Technology Significantly Increase the Efficacy of Cardiopulmonary Resuscitation on Non-healthcare Professionals? A Controlled Trial

Introduction: Cardiovascular accidents are the world's leading cause of death. A good quality cardiopulmonary resuscitation (CPR) can reduce cardiac arrest-associated mortality. This study aims to test the coaching system of a wearable glove, providing instructions during out-of-hospital CPR. Materials and Methods: We performed a single-blind, controlled trial to test non-healthcare professionals during a simulated CPR performed on an electronic mannequin. The no-glove group was the control. The primary outcome was to compare the accuracy of depth and frequency of two simulated CPR sessions. Secondary outcomes were to compare the decay of CPR performance and the percentage of the duration of accurate CPR. Results: About 130 volunteers were allocated to 1:1 ratio in both groups; mean age was 36 ± 15 years (min-max 21-64) and 62 (48%) were men; 600 chest compressions were performed, and 571 chest compressions were analyzed. The mean frequency in the glove group was 117.67 vs. 103.02 rpm in the control group (p < 0.001). The appropriate rate cycle was 92.4% in the glove group vs. 71% in the control group, with a difference of 21.4% (p < 0.001). Mean compression depth in the glove group was 52.11 vs. 55.17 mm in the control group (p < 0.001). A mean reduction of compression depth over time of 5.3 mm/min was observed in the control group vs. 0.83 mm/min of reduction in the glove group. Conclusion: Visual and acoustic feedbacks provided through the utilization of the glove's coaching system were useful for non-healthcare professionals' CPR performance.

Leg-heel chest compression as an alternative for medical professionals in times of COVID-19

OBJECTIVE

To evaluate leg-heel chest compression without previous training as an alternative for medical professionals and its effects on distance to potential aerosol spread during chest compression.

METHODS

20 medical professionals performed standard manual chest compression followed by leg-heel chest compression after a brief instruction on a manikin. We compared percentage of correct chest compression position, percentage of full chest recoil, percentage of correct compression depth, average compression depth, percentage of correct compression rate and average compression rate between both methods. In a second approach, potential aerosol spread during chest compression was visualized.

RESULTS

Our data indicate no credible difference between manual and leg-heel compression. The distance to potential aerosol spread could have been increased by leg-heel method.

CONCLUSION

Under special circumstances like COVID-19-pandemic, leg-heel chest compression may be an effective alternative without previous training compared to manual chest compression while markedly increasing the distance to the patient.

Prognostic benefits of prior amiodarone or β-blocker use before the onset of ventricular arrhythmia with hemodynamic collapse

Although antiarrhythmic drugs have long been used for the suppression of various types of arrhythmias, their prior use before the onset of ventricular arrhythmia with hemodynamic collapse and the effect on prognosis is not well known. Data from 1004 consecutive patients with cardiovascular shock in the Japanese Circulation Society's Shock Registry were analyzed. Eighty-four cases of ventricular arrhythmia-induced shock and ROSC (return of spontaneous circulation) were divided into the prior amiodarone or β-blockers use group (Aβ group, n = 27) and the non-amiodarone and non-β-blockers use group (non-Aβ group; n = 57) based on treatment before the onset of those arrhythmias. Clinical outcomes related to hemodynamic collapse such as OHCA (out-of-hospital cardiovascular arrest) was less in the Aβ group [Aβ group, 11/26 (42%) vs. non-Aβ group, 41/56 (73%); p = 0.007]. Similarly, syncope was less common in the Aβ group than in the non-Aβ group [Aβ group 4/27 (15%) vs. non-Aβ group 27/57 (47%); p = 0.004]. Furthermore, prior amiodarone or β-blockers use before the onset of ventricular arrhythmias was strongly associated with both survival at discharge (odds ratio 3.19; 95% confidence interval 1.06-9.67; p = 0.040) and neurological outcomes at discharge (odds ratio 3.96; 95% confidence interval 1.32-11.85; p = 0.014) based on multivariate logistic regression analysis. Prior amiodarone or β-blockers use before the onset of malignant ventricular arrhythmia and maintaining appropriate blood concentrations in advance is associated with a good survival rate and better neurological outcomes after recovery from ventricular arrhythmia with hemodynamic collapse.

Influence of Physical Activity of the Rescuer on Chest Compression Duration and its Effects on Hemodynamics and Fatigue Levels of the Rescuer: A Simulation-based Study

Background

Cardiopulmonary resuscitation (CPR) is a lifesaving skill performed during the cardiac arrest. Various factors of rescuer affect CPR quality, and rescuers physical fitness is one among the important factors needs to be explored for improved CPR quality. This study aimed to assess the physical activity (PA) levels of the health care providers (HCPs) who were trained in basic life support (BLS) and its relationship on chest compression duration, hemodynamic parameters, and fatigue levels of the rescuers.

Materials and methods

A single-center, cross-sectional study was conducted on 48 HCPs who were trained in BLS within one year. Eligible participants were contacted by email, and the responders’ level of PA was determined using the global physical activity questionnaire (GPAQ). The participants were recruited for chest compression-only cardiac arrest scenarios. Each subject performed continuous chest compression on the manikin until they perceived maximum fatigue. Heart rate (HR), blood pressure (BP), oxygen saturation (SpO₂), and fatigue level were assessed at baseline, immediately after and following two minutes of cessation of chest compressions. The total duration of chest compression was also documented.

Results

Most participants (24, 50%) reported high levels of PA while 22 (45.83%) and 2 (4.17%) reported moderate and low intensity of PA, respectively. The mean age of the 35 participants was 26.08 ± 4.60 years. The mean duration of chest compressions was 193.25 seconds with higher times reported for those with high PA when compared to those with moderate PA (p = 0.017). Similar findings were also observed for fatigue.

Conclusion

Rescuers who reported high PA had lower levels of fatigue and could perform longer duration of chest compressions.

How to cite this article

Nayak VR, Babu A, Unnikrishnan R, Babu AS, Krishna HM. Influence of Physical Activity of the Rescuer on Chest Compression Duration and its Effects on Hemodynamics and Fatigue Levels of the Rescuer: a Simulation-based Study. Indian J Crit Care Med 2020;24(6):409–413.

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.

Mechanical adjuncts for cardiocerebral resuscitation

Introduction: Cardiac arrest remains a worldwide health problem with very poor outcome. In the absence of bystander resuscitation, survival rates decrease by 10% per minute of arrest and global ischemia. Even the best manual chest compressions, however, can only produce a fraction of normal cardiac output and blood flow to vital organs. Physiological principles and current evidence for the use of mechanical devices to increase survival and quality of life after cardiac arrest are highlighted in this review article. Areas covered: Mechanical adjuncts such as the Active Compression Decompression device, automated chest compressors and the use of a negative pressure valve (Impedance Threshold Device) can synergistically aid in improving quality of CPR and increasing cardiac output and vital organ perfusion. Expert opinion: The current conclusions that the use of mechanical adjunct devices in a preclinical setting is not recommended or neutral at best, need to be reevaluated, especially with regard to new advanced and promising treatments that require prolonged high-quality CPR during the transport to a hospital to improve the outcome of patients.

Analyzing the Effectiveness of Different Forms of Cardiopulmonary Resuscitation

BACKGROUND

In order to simulate a heartbeat in a cardiac arrest patient, cardiopulmonary resuscitation (CPR) requires that chest compressions be delivered with a force of at least 560 N at a rate >100 compressions/min. Many new learners initially use CPR forms that may not meet these parameters sufficiently. We examined three forms of CPR: the form recommended by the American Heart Association (AHA) and two forms that are common among new learners but that are considered incorrect, using a CPR manikin placed on a force plate. Four trained CPR users tested the different methods.

DISCUSSION

AHA-recommended CPR is the most effective, delivering a force of 737.2 ± 5.3 N at a rate of 103.2 ± 1.2 compressions/min. Compressions using a bent arms method delivered compressions with a force of 511.8 ± 4.1 N at a rate of 112.8 ± 3.0 compressions/min. Compressions using a different hand position from that recommended by the AHA delivered compressions with a force of 433.3 ± 3.2 N at a rate of 115.2 ± 1.2 compressions/min.

CONCLUSIONS

AHA-recommended CPR more effectively compresses a patient's heart than the bent-arms method or the alternate hand-position method, and, of the three methods, only the AHA-recommended form can reliably simulate a patient's heartbeat.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Effectiveness of hands-on cardiopulmonary resuscitation practice with self-debriefing for healthcare providers: A simulation-based controlled trial

Introduction:

The psychomotor skill of cardiopulmonary resuscitation emphasized the importance of high-quality chest compression. This investigation examined the effect of self-debriefing and the different materials of debriefing during hands-on cardiopulmonary resuscitation practice for healthcare providers.

Methods:

This was a randomized controlled trial of a cardiopulmonary resuscitation training program involving emergency medical technicians in northern Taiwan. Participants were blinded to the study purpose and were allocated randomly using the black envelope method. All participants completed a 2-min pre-test of hands-only cardiopulmonary resuscitation using a manikin. Those who were allocated to the control group received self-debriefing with knowledge of pre-test result. Those who were allocated to the experimental group received self-debriefing with an additional biomechanical information of performance of chest compression. A post-test was performed 30 min after the pre-test.

Results:

A total of 88 participants were enrolled with 44 in each group. There was significant difference of cardiopulmonary resuscitation quality after self-debriefing among all participants (pre- vs post-test adequate rate, 54.7% vs 67.5%, p = 0.028; adequate depth, 41.2% vs 69.5%, p < 0.001; full recoil, 35.9% vs 54.5%, p = 0.001). The analysis of effects of self-debriefing with additional knowledge of performance revealed no significant difference in any of the measurements (improvement in adequate rate, 11.3% vs 14.2%, p = 0.767; adequate depth, 29.6% vs 27.0%, p = 0.784; full recoil, 23.0% vs 14.1%, p = 0.275).

Conclusion:

Self-debriefing improved hands-only cardiopulmonary resuscitation quality whether or not biomechanical information of performance of chest compression was given.

Can the British Heart Foundation PocketCPR application improve the performance of chest compressions during bystander resuscitation: A randomised crossover manikin study

This study aims to determine whether the British Heart Foundation PocketCPR training application can improve the depth and rate of chest compression and therefore be confidently recommended for bystander use. A total of 118 candidates were recruited into a randomised crossover manikin trial. Each candidate performed cardiopulmonary resuscitation for 2 min without instruction or performed chest compressions using the PocketCPR application. Candidates then performed a further 2 min of cardiopulmonary resuscitation within the opposite arm. The number of chest compressions performed improved when PocketCPR was used compared to chest compressions when it was not (44.28% vs 40.57%, p < 0.001). The number of chest compressions performed to the required depth was higher in the PocketCPR group (90.86 vs 66.26). The British Heart Foundation PocketCPR application improved the percentage of chest compressions that were performed to the required depth. Despite this, more work is required in order to develop a feedback device that can improve bystander cardiopulmonary resuscitation without creating delay.

Are the current guideline recommendations for neonatal cardiopulmonary resuscitation safe and effective?

A recently published review of approaches to optimize chest compressions in the resuscitation of asphyxiated newborns discussed the current recommendations and explored potential determinants of effective neonatal cardiopulmonary resuscitation (CPR). However, not all potential determinants of effective neonatal CPR were explored. Chest compression shallower than the current guideline recommendation of approximately 33% of the anterior-posterior (AP) chest diameter may be safer and more effective. From a physiological standpoint, high-velocity brief duration shallower compression may be more effective than current recommendations. The application of a 1- or 2-finger method of high-impulse CPR, which would depend on the size of the subject, may be more effective than using a 2-thumb (TT) encircling hands method of CPR. Adrenaline should not be used in the treatment of asphyxiated neonates and when necessary titrated vasopressin should be used.

Impact of the 2010 resuscitation guidelines training on layperson chest compressions

BACKGROUND

Survival from cardiac arrest is sensitive to the quality of delivered CPR. In 2010, updated international resuscitation guidelines emphasized deeper chest compressions and faster rates, yet it is unknown whether training laypersons using updated guidelines resulted in changed CPR performance. We hypothesized that laypersons taught CPR using the 2010 guidelines performed deeper and faster compressions than those taught using the 2005 materials.

METHODS

This work represents a secondary analysis of a study conducted at eight hospitals where family members of hospitalized cardiac patients were trained in CPR. An initial cohort was trained using the 2005 guidelines, and a subsequent cohort was trained using the 2010 guideline materials. Post training, CPR skills were quantified using a recording manikin.

RESULTS

Between May 2009 to August 2013, 338 subjects completed the assessment. Among the subjects, 176 received 2005 training and 162 underwent 2010 training. The mean compression rate in the 2005 cohort was 87 (95%CI 83-90) per minute, and in the 2010 cohort was 86 (95%CI 83-90) per minute (P=ns), while the mean compression depth was 34 (95%CI 32-35) mm in the 2005 cohort and 46 (95%CI 44-47) mm in the 2010 cohort (P<0.01).

CONCLUSIONS

Training with the 2010 CPR guidelines resulted in a statistically significant increase in trainees' compression depth but there was no change in compression rate. Nevertheless, the majority of CPR performed by trainees in both cohorts was below the guideline recommendation, highlighting an important gap between training goals and trainee performance.

Rescuer factors predict high-quality CPR--a manikin-based study of health care providers

BACKGROUND

In the provision of high-quality cardiopulmonary resuscitation (CPR) by health care providers, factors associated with high-quality CPR should be explored.

METHODS

This is a post hoc analysis using data from a manikin-based survey of CPR quality among volunteer emergency medical technicians (EMTs) from 2 county fire departments in northern Taiwan.

RESULTS

Among the 95 enrolled EMTs, 36 (37.9%) performed high-quality CPR on a manikin. The baseline characteristics that differed significantly between groups were board-certified EMT levels (P = .010), body mass index (BMI, P = .029), average exercise frequency (P = .001), and average exercise duration (P = .005). Average total exercise time per week, which uses frequency times exercise duration, was independently associated with high-quality CPR performance after adjusting for variables via logistic regression analysis (odds ratio, 1.004; P = .044). An index was developed (BMI × ExeTime) based on the product of BMI and average total exercise time per week. A comparison of the area under curve for the different indices showed that BMI × ExeTime was a significant predictor of high-quality CPR, with an area under curve of 0.718 (95% confidence interval, 0.613-0.824; P < .001; Fig. 2) and a cutoff value of 4136.7 kg·min/m(2) (sensitivity, 0.722; specificity, 0.678).

CONCLUSIONS

This study identified factors associated with the performance by health care providers of high-quality CPR, including BMI and exercise habits. To optimize CPR quality, a program of exercise frequency and duration adjusted according to individual's BMI should be considered in such populations.

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.

Changes to DA-CPR instructions: can we reduce time to first compression and improve quality of bystander CPR?

INTRODUCTION

Dispatcher-assisted CPR (DA-CPR) can increase rates of bystander CPR, survival, and quality of life following cardiac arrest. Dispatcher protocols designed to improve rapid recognition of arrest and coach CPR may increase survival by (1) reducing preventable time delays to start of chest compressions and (2) improving the quality of bystander CPR.

METHODS

We conducted a randomized controlled trial comparing a simplified DA CPR script to a conventional DA CPR script in a manikin cardiac arrest simulation with lay participants. The primary outcomes measured were the time interval from call receipt to the first chest compression and the core metrics of chest compression (depth, rate, release, and compression fraction). CPR was measured using a recording manikin for the first 3 min of participant CPR.

RESULTS

Of the 75 participants, 39 were randomized to the simplified instructions and 36 were randomized to the conventional instructions. The interval from call receipt to first compression was 99 s using the simplified script and 124 s using the conventional script for a difference of 24s (p<0.01). Although hand position was judged to be correct more often in the conventional instruction group (88% versus 63%, p<0.01), compression depth was an average 7 mm deeper among those receiving the simplified CPR script (32 mm versus 25 mm, p<0.05). No statistically significant differences were detected between the two instruction groups for compression rate, complete release, number of hands-off periods, or compression fraction.

DISCUSSION

Simplified DA-CPR instructions to lay callers in simulated cardiac arrest settings resulted in significant reductions in time to first compression and improvements in compression depth. These results suggest an important opportunity to improve DA CPR instructions to reduce delays and improve CPR quality.

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.

Sternal wall pressure comparable to leaning during CPR impacts intrathoracic pressure and haemodynamics in anaesthetized children during cardiac catheterization

AIM

Force due to leaning during cardiopulmonary resuscitation (CPR) negatively affects haemodynamics and intrathoracic airway pressures (ITP) in animal models and adults, but has not been studied in children. We sought to characterize the effects of sternal force (SF) comparable to leaning force on haemodynamics and ITP in anaesthetized children.

METHODS

Children (6 months to 8yrs) presenting for routine haemodynamic cardiac catheterization with anaesthesia and mechanical ventilation >6 months after cardiac transplant were studied. Haemodynamics and ITP were measured before and during incremental increases in SF of 10% and 20% body weight.

RESULTS

20 subjects (5.4±1.7yrs of age and 18.3±3.3kg) were studied. Mean right atrial pressure (6.5±2.6 at baseline vs. 7.7±2.6 at 10% SF vs. 8.6±2.7mmHg at 20% SF), mean pulmonary capillary wedge pressure (10.2±2.9 at baseline vs. 11±3.3 at 10% SF vs. 11.8±3.4mmHg at 20% SF) and ITP (16.3±3.2 at baseline vs. 17.9±3.9 at 10% SF vs. 19.5±4cm H2O) all increased significantly with incremental SF (p<0.001 for all). Aortic systolic pressure (85±10mmHg at baseline vs. 83±10mmHg at 10% SF vs. 82±10mmHg at 20% SF, p=0.014) and coronary perfusion pressure (42±7mmHg at baseline vs. 39±7mmHg at 10% SF vs. 38±7mmHg at 20% SF, p<0.001) both decreased significantly with incremental SF.

CONCLUSIONS

In asymptomatic, anaesthetized children after cardiac transplantation, sternal forces comparable to leaning previously reported to occur during CPR elevate ITP and right atrial pressure and decrease coronary perfusion pressure. These haemodynamic effects may be clinically important during CPR and warrant further study.

Updates in the American Heart Association guidelines for cardiopulmonary resuscitation and potential applications to veterinary patients

OBJECTIVE

To review the updates in the American Heart Association (AHA) guidelines for cardiopulmonary resuscitation (CPR) and identify potential applications to veterinary patients.

ETIOLOGY

Cardiopulmonary arrest is common in veterinary emergency and critical care, and consensus guidelines are lacking. Human resuscitation guidelines are continually evolving as new clinical and experimental studies support updated recommendations. Synthesis of human, experimental animal model, and veterinary literature support the potential for updates and advancement in veterinary CPR practices.

THERAPY

This review serves to highlight updates in the AHA guidelines for CPR and evaluate their application to small animal veterinary patients. Interventions identified will be evaluated for trans-species potential, raise questions regarding best resuscitation recommendations, and offer opportunities for further research to continue to advance veterinary CPR.

PROGNOSIS

The prognosis for any patient undergoing cardiopulmonary arrest remains guarded.

Novel adhesive glove device (AGD) for active compression-decompression (ACD) CPR results in improved carotid blood flow and coronary perfusion pressure in piglet model of cardiac arrest

OBJECTIVE

ACD-CPR improves coronary and cerebral perfusion. We developed an adhesive glove device (AGD) and hypothesized that ACD-CPR using an AGD provides better chest decompression resulting in improved carotid blood flow as compared to standard (S)-CPR.

DESIGN

Prospective, randomized and controlled animal study.

METHODS

Sixteen anesthetized and ventilated piglets were randomized after 3 min of untreated VF to receive either S-CPR or AGD-ACD-CPR by a PALS certified single rescuer with compressions of 100 min(-1) and C:V ratio of 30:2. AGD consisted of a modified leather glove exposing the fingers and thumb. A wide Velcro patch was sewn to the palmer aspect of the glove and the counter Velcro patch was adhered to the pig's chest wall. Carotid blood flow was measured using ultrasound. Data (mean±SD) was analyzed using one way ANOVA and unpaired t-test; p-value ≤ 0.05 was considered statistically significant.

RESULTS

Right atrial pressure (mmHg) during the decompression phase was lower during AGD-ACD-CPR (-3.32±2.0) when compared to S-CPR (0.86±1.8, p=0.0007). Mean carotid blood flow was 53.2±27.1 (% of baseline blood flow in ml/min) in AGD vs. 19.1±12.5% in S-CPR, p=0.006. Coronary perfusion pressure (CPP, mmHg) was 29.9±5.8 in AGD vs. 22.7±6.9 in S-CPR, p=0.04. There was no significant difference in time to ROSC and number of epinephrine doses.

CONCLUSION

Active chest decompression during CPR using this simple and inexpensive adhesive glove device resulted in significantly better carotid blood flow during the first 2 min of CPR.

A counterbalanced cross-over study of the effects of visual, auditory and no feedback on performance measures in a simulated cardiopulmonary resuscitation

BACKGROUND

Previous research has demonstrated that trained rescuers have difficulties achieving and maintaining the correct depth and rate of chest compressions during both in and out of hospital cardiopulmonary resuscitation (CPR). Feedback on rate and depth mitigate decline in performance quality but not completely with the residual performance decline attributed to rescuer fatigue. The purpose of this study was to examine the effects of feedback (none, auditory only and visual only) on the quality of CPR and rescuer fatigue.

METHODS

Fifteen female volunteers performed 10 minutes of 30:2 CPR in each of three feedback conditions: none, auditory only, and visual only. Visual feedback was displayed continuously in graphic form. Auditory feedback was error correcting and provided by a voice assisted CPR manikin. CPR quality measures were collected using SkillReporter® software. Blood lactate (mmol/dl) and perceived exertion served as indices of fatigue. One-way and two way repeated measures analyses of variance were used with alpha set a priori at 0.05.

RESULTS

Visual feedback yielded a greater percentage of correct compressions (78.1 ± 8.2%) than did auditory (65.4 ± 7.6%) or no feedback (44.5 ± 8.1%). Compression rate with auditory feedback (87.9 ± 0.5 compressions per minute) was less than it was with both visual and no feedback (p < 0.05). CPR performed with no feedback (39.2 ± 0.5 mm) yielded a shallower average depth of compression and a lower percentage (55 ± 8.9%) of compressions within the accepted 38-50 mm range than did auditory or visual feedback (p < 0.05). The duty cycle for auditory feedback (39.4 ± 1.6%) was less than it was with no feedback (p < 0.05). Auditory feedback produced lower lactate concentrations than did visual feedback (p < 0.05) but there were no differences in perceived exertion.

CONCLUSIONS

In this study feedback mitigated the negative effects of fatigue on CPR performance and visual feedback yielded better CPR performance than did no feedback or auditory feedback. The perfect confounding of sensory modality and periodicity of feedback (visual feedback provided continuously and auditory feedback provided to correct error) leaves unanswered the question of optimal form and timing of feedback.

Adequacy of chest compressions performed by medical housestaff

BACKGROUND

Chest compressions (CCs) are a critical part of cardiopulmonary resuscitation. We studied the presence and duration of adequate CCs performed by medical housestaff, and correlated our findings with gender and body mass index.

METHODS

Fifty-eight first-postgraduate-year medical housestaff performed CCs on a computerized patient simulator equipped with a calibrated CC measurement device. Following initial testing, subjects were trained to perform adequate CCs. Subjects were retested 2 weeks later. Presence and duration of adequate CCs were measured during a 120-second endurance test.

RESULTS

Before training, 14/28 (50%) of the male housestaff performed adequate CCs and 0/30 (0%) of the female housestaff performed adequate CCs. After training, 25/28 (89%) of the male housestaff and 16/30 (53%) of the female housestaff performed adequate CCs. Body mass index and height were not related to adequacy of CCs. After training, 7/28 (25%) of the male subjects and 1/30 (3%) of the female subjects were able to maintain adequate CCs for 120 seconds.

CONCLUSIONS

Training housestaff on a patient simulator is an effective means of improving the adequacy of CCs. Despite training, a significant number of women were unable to perform adequate CCs compared with men; body mass index and height were not determining factors. Very few housestaff were able to sustain 120 seconds of adequate CCs, despite training.

Protective athletic equipment slows initiation of CPR in simulated cardiac arrest

OBJECTIVE

Standard protective athletic equipment used in collision sports such as American football poses a unique challenge to rescuers because they block access to both the airway and chest. The main objective of this investigation was to determine the effect of athletic equipment on the initiation of CPR. The feasibility of performing compressions over the chest protector as a potential time-saving step was also evaluated.

METHODS

Thirty-four certified athletic trainers performed CPR on a manikin wearing protective equipment during a simulated episode of cardiac arrest. For one trial the protective equipment was removed or unfastened prior to initiating CPR, and for another, chest compressions were initiated over the protective equipment. The following were recorded for comparison purposes: time until first breath and first compression; percentage of compressions delivered to the recommended depth; compression rate; accuracy of hand placement; percentage of compressions without full chest recoil.

RESULTS

Although chest compressions began sooner when compressions were delivered over the chest protector, this improvement was not statistically significant. A more notable positive outcome resulting from keeping the chest protector on was an increase in the number of compressions that were delivered to the recommended depth. Unfortunately, one of the significant negative outcomes of performing chest compression over the chest pad was the increased percentage of compressions that did not obtain full chest recoil.

CONCLUSIONS

Although removal of the chest protector delays the initiation of chest compressions, keeping the chest protector on during CPR does not appear to be a feasible option.

Advances in cardiopulmonary resuscitation

This article focuses on important advances in the science of cardiopulmonary resuscitation in the last decade that have led to a significant improvement in understanding the complex physiology of cardiac arrest and critical interventions for the initial management of cardiac arrest and postresuscitation treatment. Special emphasis is given to the basic simple ways to improve circulation, vital organ perfusion pressures, and the grave prognosis of sudden cardiac death.

Manual versus mechanical cardiopulmonary resuscitation. An experimental study in pigs

BACKGROUND

Optimal manual closed chest compressions are difficult to give. A mechanical compression/decompression device, named LUCAS, is programmed to give compression according to the latest international guidelines (2005) for cardiopulmonary resuscitation (CPR). The aim of the present study was to compare manual CPR with LUCAS-CPR.

METHODS

30 kg pigs were anesthetized and intubated. After a base-line period and five minutes of ventricular fibrillation, manual CPR (n = 8) or LUCAS-CPR (n = 8) was started and run for 20 minutes. Professional paramedics gave manual chest compression's alternating in 2-minute periods. Ventilation, one breath for each 10 compressions, was given to all animals. Defibrillation and, if needed, adrenaline were given to obtain a return of spontaneous circulation (ROSC).

RESULTS

The mean coronary perfusion pressure was significantly (p < 0.01) higher in the mechanical group, around 20 mmHg, compared to around 5 mmHg in the manual group. In the manual group 54 rib fractures occurred compared to 33 in the LUCAS group (p < 0.01). In the manual group one severe liver injury and one pressure pneumothorax were also seen. All 8 pigs in the mechanical group achieved ROSC, as compared with 3 pigs in the manual group.

CONCLUSIONS

LUCAS-CPR gave significantly higher coronary perfusion pressure and significantly fewer rib fractures than manual CPR in this porcine model.

Implementing the 2005 American Heart Association Guidelines improves outcomes after out-of-hospital cardiac arrest

OBJECTIVE

The purpose of the study was to determine whether applying highly recommended changes in the 2005 American Heart Association (AHA) Guidelines would improve outcomes after out-of-hospital cardiac arrest.

BACKGROUND

In 2005, AHA recommended multiple ways to improve circulation during cardiopulmonary resuscitation (CPR).

METHODS

Conglomerate quality assurance data were analyzed during prospective implementation of the 2005 AHA Guidelines in five emergency medical services (EMS) systems. All EMS personnel were trained in the key new aspects of the 2005 AHA Guidelines, including use of an impedance threshold device. The primary outcome was survival to hospital discharge. Secondary outcomes were return of spontaneous circulation (ROSC), survival by initial cardiac arrest rhythm, and the cerebral performance category (CPC) score at hospital discharge.

RESULTS

There were 1,605 patients in the intervention group and 1,641 patients in the control group. Demographics, the rate of bystander CPR, and time from the 911 call for help to arrival of EMS personnel were similar between groups. Survival to hospital discharge was 10.1% in the control group versus 13.1% in the intervention group (P = .007). For patients with a presenting rhythm of ventricular fibrillation/ventricular tachycardia, survival to discharge was 20% in controls versus 32.3% in the intervention group (P <.001). Survival to discharge with a CPC classification of 1 or 2 was 33.3% (10/30) in the control versus 59.6% (31/52) in the intervention group (P = .038).

CONCLUSIONS

Compared with controls, patients with out-of-hospital cardiac arrest treated with a renewed emphasis on improved circulation during CPR had significantly higher neurologically intact hospital discharge rates.

Improved out-of-hospital cardiac arrest survival after the sequential implementation of 2005 AHA guidelines for compressions, ventilations, and induced hypothermia: the Wake County experience

STUDY OBJECTIVE

We assess survival from out-of-hospital cardiac arrest after community-wide implementation of 2005 American Heart Association guidelines.

METHODS

This was an observational multiphase before-after cohort in an urban/suburban community (population 840,000) with existing advanced life support. Included were all adults treated for cardiac arrest by emergency responders. Excluded were patients younger than 16 years and trauma patients. Intervention phases in months were baseline 16; phase 1, new cardiopulmonary resuscitation 12; phase 2, impedance threshold device 6; and phase 3, full implementation including out-of-hospital-induced hypothermia 12. Primary outcome was survival to discharge. Other survival and neurologic outcomes were compared between study phases, and adjusted odds ratios with 95% confidence intervals (CIs) for survival by phase were determined by multivariate regression.

RESULTS

One thousand three hundred sixty-five cardiac arrest patients were eligible for inclusion: baseline n=425, phase 1 n=369, phase 2 n=161, phase 3 n=410. Across phases, patients had similar demographic, clinical, and emergency medical services characteristics. Overall and witnessed ventricular fibrillation and ventricular tachycardia survival improved throughout the study phases: respectively, baseline 4.2% and 13.8%, phase 1 7.3% and 23.9%, phase 2 8.1% and 34.6%, and phase 3 11.5% and 40.8%. The absolute increase for overall survival from baseline to full implementation was 7.3% (95% CI 3.7% to 10.9%); witnessed ventricular fibrillation/ventricular tachycardia survival was 27.0% (95% CI 13.6% to 40.4%), representing an additional 25 lives saved annually in this community.

CONCLUSION

In the context of a community-wide focus on resuscitation, the sequential implementation of 2005 American Heart Association guidelines for compressions, ventilations, and induced hypothermia significantly improved survival after cardiac arrest. Further study is required to clarify the relative contribution of each intervention to improved survival outcomes.

Dispatcher-assisted cardiopulmonary resuscitation: risks for patients not in cardiac arrest

BACKGROUND

Dispatcher-assisted cardiopulmonary resuscitation (CPR) instructions can increase bystander CPR and thereby increase the rate of survival from cardiac arrest. The risk of bystander CPR for patients not in arrest is uncertain and has implications for how assertive dispatch is in instructing CPR. We determined the frequency of dispatcher-assisted CPR for patients not in arrest and the frequency and severity of injury related to chest compressions.

METHODS AND RESULTS

The investigation was a prospective cohort study of adult patients not in cardiac arrest for whom dispatchers provided CPR instructions in King County, Washington, between June 1, 2004, and January 31, 2007. The study focused on those who received chest compressions. Information was collected through review of the audio and written dispatch report, written emergency medical services report, hospital record, and telephone survey. Of the 1700 patients for whom dispatcher CPR instructions were initiated, 55% (938 of 1700) were in arrest, 45% (762 of 1700) were not in arrest, and 18% (313 of 1700) were not in arrest and received bystander chest compressions. Of the 247 not in arrest who received chest compressions and had complete outcome ascertainment, 12% (29 of 247) experienced discomfort, and 2% (6 of 247) sustained injuries likely or possibly caused by bystander CPR. Only 2% (5 of 247) suffered a fracture, and no patients suffered visceral organ injury.

CONCLUSIONS

In this prospective study, the frequency of serious injury related to dispatcher-assisted bystander CPR among nonarrest patients was low. When coupled with the established benefits of bystander CPR among those with arrest, these results support an assertive program of dispatcher-assisted CPR.

Advances in Cardiopulmonary Resuscitation

This article focuses on important advances in the science of cardiopulmonary resuscitation (CPR) in the last decade that have led to a significant improvement in understanding the complex physiology of cardiac arrest and critical interventions for the initial management of cardiac arrest and postresuscitation treatment. Special emphasis is given to the basic simple ways to improve circulation, vital organ perfusion pressures, and the grave prognosis of sudden cardiac death.