Mechanical devices for chest compression: to use or not to use?

Comparison of manual chest compression versus mechanical chest compression for out-of-hospital cardiac arrest: A systematic review and meta-analysis

BACKGROUND

Out-of-hospital cardiac arrest is a life-threatening condition that requires immediate intervention to increase the prospect of survival. There are various ways to achieve cardiopulmonary resuscitation in such patients, either through manual chest compression or mechanical chest compression. Thus, we performed a systematic review and meta-analysis to investigate the differences between these interventions.

METHODS

PubMed, Cochrane Library, and Scopus were explored from inception to May 2023. Additionally, the bibliographies of relevant studies were searched. The Cochrane Risk of Bias Tool for Randomized Controlled Trials, Newcastle-Ottawa Scale, and the Risk of Bias in Non-Randomized Studies-I tools were utilized to perform quality and risk of bias assessments.

RESULTS

There were 24 studies included within this quantitative synthesis, featuring a total of 111,681 cardiac arrest patients. Overall, no statistically significant differences were observed between the return of spontaneous circulation, survival to hospital discharge, short-term survival, and long-term survival. However, manual chest compression was associated with a significantly superior favorability of neurological outcomes (OR: 1.41; 95% CI: 1.07, 1.84; P = .01).

CONCLUSION

Although there were no major differences between the strategies, the poorer post-resuscitation neurological outcomes observed in mechanical chest compression indicate the need for further innovation and advancements within the current array of mechanical devices. However, future high-quality studies are necessary in order to arrive at a valid conclusion.

The effects of cardiopulmonary resuscitation (CPR) performed out-of-hospital and in-hospital with manual or automatic device methods and laboratory parameters on survival of patients with cardiac arrest

OBJECTIVE

Determining the predictive factors for cardiac arrest may be helpful in the management of in-hospital cardiac arrest (IHCA) and out-of-hospital cardiac arrest (OHCA) and in estimating the outcome. Therefore, in the present study, we aimed to investigate the effect of demographic data, cardiopulmonary resuscitation (CPR) initiating setting, compression method, and laboratory parameters on survival from cardiac arrest.

METHODS

A total of 414 patients who met the inclusion criteria were included in the study. Patients were grouped into those who underwent out-of-hospital CPR and those who underwent CPR in the hospital and patients who received automatic compression and those who did not receive. In addition to pH, lactate and bicarbonate in arterial blood gas, CK-MB, troponin, urea, creatinine, calcium, potassium, and glucose were measured.

RESULTS

The mean age of patients was 70.36±15.68 years, and 170 (41.1%) were female. Although the success rate of CPR in the OHCA group (22.2%) was lower than in the patients in the IHCA group (30.9%), the difference was not statistically significant. There was no difference between the two groups in the comparison of mechanical compression devices and manual compression. In the logistic regression analysis, high pH and low lactate values were found to be independent predictors of survival.

CONCLUSION

The results of this study revealed no significant difference between IHCA and OHCA CPR applications and between manual and mechanical compressions in terms of survival in patients with cardiac arrest. In addition, higher pH levels and lower lactate levels measured during CPR were independent predictors of survival.

Development of an automatic device performing chest compression and external defibrillation: An animal-based pilot study

BACKGROUND

Automatic chest compression devices (ACCDs) can promote high-quality cardiopulmonary resuscitation (CPR) and are widely used worldwide. Early application of automated external defibrillators (AEDs) along with high-quality CPR is crucial for favorable outcomes in patients with cardiac arrest. Here, we developed an automated CPR (A-CPR) apparatus that combines ACCD and AED and evaluated its performance in a pilot animal-based study.

METHODS

Eleven pigs (n = 5, A-CPR group; n = 6, ACCD CPR and AED [conventional CPR (C-CPR)] group) were enrolled in this study. After 2 min observation without any treatment following ventricular fibrillation induction, CPR with a 30:2 compression/ventilation ratio was performed for 6 min, mimicking basic life support (BLS). A-CPR or C-CPR was applied immediately after BLS, and resuscitation including chest compression and defibrillation, was performed following a voice prompt from the A-CPR device or AED. Hemodynamic parameters, including aortic pressure, right atrial pressure, coronary perfusion pressure, carotid blood flow, and end-tidal carbon dioxide, were monitored during resuscitation. Time variables, including time to start rhythm analysis, time to charge, time to defibrillate, and time to subsequent chest compression, were also measured.

RESULTS

There were no differences in baseline characteristics, except for arterial carbon dioxide pressure (39 in A-CPR vs. 33 in C-CPR, p = 0.034), between the two groups. There were no differences in hemodynamic parameters between the groups. However, time to charge (28.9 ± 5.6 s, A-CPR group; 47.2 ± 12.4 s, C-CPR group), time to defibrillate (29.1 ± 7.2 s, A-CPR group; 50.5 ± 12.3 s, C-CPR group), and time to subsequent chest compression (32.4 ± 6.3 s, A-CPR group; 56.3 ± 10.7 s, C-CPR group) were shorter in the A-CPR group than in the C-CPR group (p = 0.015, 0.034 and 0.02 respectively).

CONCLUSIONS

A-CPR can provide effective chest compressions and defibrillation, thereby shortening the time required for defibrillation.

Prehospital transport and termination of resuscitation of cardiac arrest patients: A review of prehospital care protocols in the United States

Background

The objective was to describe emergency medical services (EMS) protocol variability in transport expectations for out-of-hospital cardiac arrest (OHCA) patients and the involvement of online medical control for on-scene termination of resuscitation in the United States. Whether other aspects of OHCA care were mentioned, including the definition of a "pediatric" patient, and use of end-tidal carbon dioxide monitoring, mechanical chest compression devices (MCCDs), and extracorporeal membrane oxygenation (ECMO), were also described.

Methods and Results

Review of EMS protocols publicly accessible from https://www.emsprotocols.org and through searches on the internet when protocols were unavailable on the website from June 2021 to January 2022. Frequencies and proportions were used to describe outcomes. Of 104 protocols reviewed, 51.9% state to initiate transport after return of spontaneous circulation (ROSC), 26.0% do not specify when to initiate transport, and 6.7% state to transport after ≥20 minutes of on-scene cardiopulmonary resuscitation for adults. For pediatric patients, 38.5% of protocols do not specify when to initiate transport, 32.7% state to transport after ROSC, and 10.6% state to transport as soon as possible. Most protocols (42.3%) did not specify the age that defines "pediatric" in cardiac arrest. More than half (51.9%) of the protocols require online medical control for termination of resuscitation. Most protocols mention the use of end-tidal carbon dioxide monitoring (81.7%), 50.0% mention the use of MCCDs, and 4.8% mention ECMO for cardiac arrest.

Conclusions

In the United States, EMS protocols for initiation of transport and termination of resuscitation for OHCA patients are highly variable.

Cardiopulmonary Resuscitation During Simulated Pediatric Interhospital Transport: Lessons Learned From Implementation of an Institutional Curriculum

INTRODUCTION

Little is known about cardiopulmonary resuscitation (CPR) quality during pediatric interhospital transport; hence, our aim was to investigate its feasibility.

METHODS

After implementing an institutional education curriculum on pediatric resuscitation during ambulance transport, we conducted a 4-year prospective observational study involving simulation events. Simulated scenarios were (1) interhospital transport of a child retrieved in cardiac arrest (Sim1) and (2) unanticipated cardiac arrest of a child during transport (Sim2). Cardiopulmonary resuscitation data were collected via Zoll RSeries defibrillators. Performance was evaluated using age-appropriate American Heart Association (AHA) Guidelines. Video recordings were reviewed for qualitative thematic analysis.

RESULTS

Twenty-six simulations were included: 16 Sim1 [mannequins: Laerdal SimMan 3G (n = 13); Gaumard 5-year-old HAL (n = 3)] and 10 Sim2 [Gaumard 1-year-old HAL (n = 8); Laerdal SimBaby (n = 2)]. Median (IQR) CPR duration was 18 minutes 23 seconds (14-22 minutes), chest compression rate was 112 per minute (106-118), and fraction (CCF) was 1 (0.9-1). Five hundred eight 60-second resuscitation epochs were evaluated (Sim1: 356; Sim2: 152); 73% were AHA compliant for rate and 87.8% for CCF. Twenty-four minutes (4.7%) had pauses more than 10 seconds. One hundred fifty seven Sim1 epochs (44.1%) met criteria for excellent CPR (AHA-compliant for rate, depth, and CCF). Rates of excellent CPR were higher for learner groups with increased simulation and transport experience (59.1% vs. 35.3%, P < 0.001). Thematic analysis identified performance-enhancing strategies, stemming from anticipating challenges, planning solutions, and ensuring team's shared mental model.

CONCLUSIONS

High-quality CPR may be achievable during pediatric interhospital transport. Certain transport-specific strategies may enhance resuscitation quality. Learners' performance improved with simulation and transport experience, highlighting ongoing education's role.

Back Plate Marking of a Mechanical Chest Compression Device to Reduce the Duration of Chest Compression Interruptions

Objective

Methods

Results

Conclusion

Retrospective Comparison of Prehospital Sustained Return of Spontaneous Circulation (ROSC) Rates Within a Single Basic Life Support Jurisdiction Using Manual vs Lund University Cardiac Assist System (LUCAS-2) Mechanical Cardiopulmonary Resuscitation

Objective

Several studies have examined the impact of mechanical cardiopulmonary resuscitation (CPR) devices among multi-jurisdictional emergency medical services (EMS) systems; however, the variability across such systems can inject bias and confounding variables. We focused our investigation on the effect of introducing the Lund University Cardiac Assist System 2 (LUCAS-2) into a single basic life support (BLS) fire department first response jurisdiction served by a single private advanced life support (ALS) agency, hypothesizing that the implementation of the device would increase prehospital return of spontaneous circulation (ROSC) rates as compared with manual CPR. 

Methods

A retrospective observational analysis of adult non-traumatic prehospital cardiac arrest ALS agency records was conducted. Descriptive statistics were computed, and logistic regression was used to assess the impact of CPR method, response time, age, gender, CPR initiator, witnessed status, automated external defibrillator (AED) initiator, and presence of an initial shockable rhythm on ROSC rates. A Chi-square analysis was used to compare ROSC rates among compression modalities both before and after the implementation of LUCAS-2 on July 1, 2011. 

Results

From an initial dataset of 857 cardiac arrest records, only 264 (74 pre-LUCAS period, 190 LUCAS-2 period) met inclusion criteria for the primary objective. The ROSC rates were 29.7% (22/74) and 29.5% (56/190), respectively, for manual-only and LUCAS-assisted CPR (p=0.9673). Logistic regression revealed a significant association between ROSC and two of the independent variables: arrest witnessed (OR 3.104; 95% CI 1.896-5.081; p<0.0001) and initial rhythm shockable (OR 2.785; 95% CI 1.492-5.199; p<0.0013). 

Conclusions

Analyses support the null hypothesis that there is no difference in prehospital ROSC rates among adult non-traumatic cardiac arrest patients when comparing mechanical-assisted and manual-only CPR. These results are consistent with other larger multi-jurisdictional mechanical CPR studies. Systems with limited personnel might consider augmenting their resuscitations with a mechanical CPR device, although cost and system design should be factored into the decision. Secondary analysis of independent variables suggests that prehospital cardiac arrest patients with a witnessed arrest or an initial rhythm that is shockable have a higher likelihood of attaining ROSC. The power of our primary objective was limited by the sample size. Additionally, we were not able to adequately assess the quality of CPR among the two comparison groups with a lack of consistent end-tidal carbon dioxide (EtCO2) data.  

Nonskeletal injuries related to cardiopulmonary resuscitation: An autopsy study

The current standard technique for cardiopulmonary resuscitation (CPR), initially described in the early 1960s, has quickly become the expected response for all persons found without a pulse or respiration. Despite the potentially lifesaving properties of external cardiac massage, the mainstay of resuscitation, it consists of repeated blunt force trauma to the chest, which can lead to extensive traumatic skeletal and nonskeletal injuries. Numerous autopsy-based studies have documented the incidence and patterns of rib and sternal fractures associated with attempted CPR, but there is relatively little data on the incidence and severity of nonskeletal CPR-related injuries. We reviewed reports from 1878 autopsies performed between September 2017 and December 2019 (inclusive), for documentation of CPR-related injuries. Among these cases, there were 93 cases with resuscitation-related nonskeletal injuries. The most common type of injury identified were visceral contusions, documented in 57.0% of cases. These contusions predominantly involved the heart, lungs, neck soft tissue, and surrounding structures. Resuscitation-related lacerations were seen in 17.2% of the cases, most predominantly involving the pericardium, heart, and liver. Statistical analysis of the data demonstrated that lacerations were more likely to be seen in females and with associated sternal fractures. Additionally, hemothoraces were present in 34.4% of cases and hemopericardium was seen in 8.6% of cases. This study provides additional documentation of the range, severity, and incidence of various types of resuscitation-related visceral injuries to better assist autopsy pathologists in distinguishing these injuries from other antecedent traumatic injuries.

The role of automated compression devices in out-of- and in- hospital cardiac arrest. Can we spare rescuers’ hands?

Research regarding the use of mechanical compressions in the setting of a cardiac arrest, either outside of or inside the hospital environment has produced mixed results. The debate whether they can replace manual compressions still remains. The aim of this review is to present current literature contemplating the application of mechanical compressions in both settings, data comparing them to manual compressions as well as current guidelines regarding their implementation in everyday clinical use. Currently, their implementation in the resuscitation protocol seems to benefit the victims of an in-hospital cardiac arrest rather than the victims that sustain a cardiac arrest outside of the hospital.

Transportation during and after cardiac arrest: who, when, how and where?

PURPOSE OF REVIEW

Out-of-hospital cardiac arrest (OHCA) is the most devastating and time-critical medical emergency. Survival after OHCA requires an integrated system of care, of which transport by emergency medical services is an integral component. The transport system serves to commence and ensure uninterrupted high-quality resuscitation in suitable patients who would benefit, terminate resuscitation in those that do not, provide critical interventions, as well as convey patients to the next appropriate venue of care. We review recent evidence surrounding contemporary issues in the transport of OHCA, relating to who, where, when and how to transport these patients.

RECENT FINDINGS

We examine the clinical and systems-related evidence behind issues including: contemporary approaches to field termination of resuscitation in patients in whom continued resuscitation and transport to hospital would be medically futile, OHCA patients and organ donation, on-scene versus intra-transport resuscitation, significance of response time, intra-transport interventions (mechanical chest compression, targeted temperature management, ECMO-facilitated cardiopulmonary resuscitation), OHCA in high-rise locations and cardiac arrest centers. We highlight gaps in current knowledge and areas of active research.

SUMMARY

There remains limited evidence to guide some decisions in transporting the OHCA patient. Evidence is urgently needed to elucidate the roles of cardiac arrest centers and ECPR in OHCA.

A survey of cardiopulmonary resuscitation in COVID-19 patients

Background and Aims:

The novel coronavirus 2 (SARS-CoV-2) pandemic has placed severe resource constraints on hospitals. High mortality rates of the COVID-19 have overwhelmed the resuscitation services. The constant fear of virus infection during cardiopulmonary resuscitation (CPR) has placed severe restrictions on the resuscitation services. Reports of poor outcomes after CPR further dampened the spirits of CPR providers. Hence we surveyed CPR practices for COVID -19 patients across hospitals in India by health care providers.

Material and Methods:

An online survey using Google Forms was initiated to collect data on performance of CPR in diagnosed cases of COVID-19 after in-hospital cardiac arrest. The survey's web-link was publicized using social media, and participation sought of all personnel involved in CPR delivery in COVID-19 patients. The responses received were analyzed. The main outcome measured were determination of the percentage of COVID-19 patients discharged home who were administered CPR.

Results:

There were 248 responses from different parts of India. At the time of cardiac arrest, 194 victims had diffuse lung infiltrates, 22 had mild lung disease, while 32 had no documented lung lesion. Twenty-five victims had evidence of pulmonary embolism, 39 had cardiac involvement, and 3 had brain involvement. Return of spontaneous circulation (ROSC) was achieved in 59.27% of cases but ROSC sustained in only 22.59%. 7.25% of patients, who received CPR, could be discharged home.

Conclusion:

The survey has shown reasonable survival rates after CPR administration in COVID-19 patients suffering from IHCA. We should not ignore the need to maximize live outcomes after CPR, even in COVID-19 patients.

Interaction Effect Between Prehospital Mechanical Chest Compression Device Use and Post-Cardiac Arrest Care on Clinical Outcomes After Out-Of-Hospital Cardiac Arrest

BACKGROUND

Prehospital application of a mechanical chest compression device (MCD) and post-cardiac arrest (PCA) care including coronary reperfusion therapy (CRT) or targeted temperature management (TTM) could affect the clinical outcome in out-of-hospital cardiac arrest (OHCA).

OBJECTIVES

This study aimed to assess whether the effect of PCA care including CRT or TTM differs according to prehospital MCD use in patients with OHCA.

METHODS

Adult OHCA cases with a presumed cardiac etiology and with survival to admission from 2016 to 2017 were enrolled from the Korean nationwide OHCA registry. The main exposures were CRT and TTM during PCA care. The primary outcome was good neurologic recovery defined by a cerebral performance category score of 1 or 2 at hospital discharge. We conducted interaction analyses between MCD use and PCA care including CRT or TTM.

RESULTS

Four thousand three hundred sixty-six OHCA cases were enrolled and 7.9% underwent MCD application. TTM and CRT were performed in 11.2% and 17.9% of the study population. In the interaction analysis, the adjusted odds ratios of TTM and CRT for good neurologic recovery were 2.41 (1.90-3.06) and 3.40 (2.79-4.14) in patients without MCD use and 1.89 (0.97-3.68), and 1.54 (0.79-3.01) in patients with MCD use.

CONCLUSIONS

The effect of PCA care on neurologic outcomes was different according to MCD use in OHCA. The association of good neurologic outcome and PCA care was not observed in the prehospital MCD use group compared with that in the MCD nonuse group.

Manual cardiopulmonary resuscitation versus mechanical cardiopulmonary resuscitation: Which one is more effective during ambulance transport?

OBJECTIVES:

Although studies in the field of emergency medical services (EMS) generally compare survival and hospital discharge rates, there are not many studies measuring the quality of cardiopulmonary resuscitation (CPR). In this study, we aimed to compare the mechanical chest compression device and paramedics in terms of CPR quality.

METHODS:

This is an experimental trial. This study was performed by the EMS of Ankara city (capital of Turkey). Twenty (ten males and ten females) paramedics participated in the study. We used LUCAS™ 2 as a mechanical chest compression device in the study. Paramedics applied chest compression in twenty rounds, whereas mechanical chest compression device applied chest compression in another set of twenty rounds. The depth, rate, and hands-off time of chest compression were measured by means of the model's recording system.

RESULTS:

The median chest compression rate was 120.1 compressions per minute (interquartile range [IQR]: 25%–75% = 117.9–133.5) for the paramedics, whereas it was 102.3 compressions per minute for the mechanical chest compression device (IQR: 25%–75% = 102.1–102.7) (P < 0.001). The median chest compression depth was 38.9 mm (IQR: 25%–75% = 32.9–45.5) for the paramedics, whereas it was 52.7 mm for the mechanical chest compression device (IQR: 25%–75% = 51.8–55.0) (P < 0.001). The median hands-off time during CPR was 6.9% (IQR: 25–75 = 5.0%–10.1%) for the paramedics and 9% for the mechanical chest compression device (IQR: 25%–75% = 8.2%–12.5%) (P = 0.09).

CONCLUSION:

During patient transport, according to the chest compression performed by the health-care professionals, it was found that those performed by the mechanical chest compression device were more suitable than that performed by the guides in terms of both speed and duration.

Transesophageal echocardiography in patients with cardiac arrest: from high-quality chest compression to effective resuscitation

BACKGROUND

Survival after cardiac arrest depends on prompt and effective cardiopulmonary resuscitation (CPR). Transesophageal echocardiography (TEE) can be applied to evaluate the effectiveness of chest compression-decompression maneuvers in the setting of cardiac arrest undergoing CPR. The efficacy of chest compression can be continuously assessed by TEE that can improve the effectiveness of CPR guiding the rescuer to optimize or correct chest compression and decompression by directly examining the movements of the cardiac walls and valve leaflets.

PURPOSE

The review describes how to perform TEE in the emergency setting of cardiopulmonary arrest, its advantages, and limitations, and ultimately propose an echo-guided approach to CPR.

Mechanical versus manual chest compressions in the treatment of in-hospital cardiac arrest patients in a non-shockable rhythm: A multi-centre feasibility randomised controlled trial (COMPRESS-RCT)

BACKGROUND

Mechanical chest compression devices deliver high-quality chest compressions. Early data suggests that mechanical devices may be superior to manual chest compressions in adults following an in-hospital cardiac arrest patients. To determine the feasibility of undertaking an effectiveness trial in this population, we undertook a feasibility randomised controlled trial.

METHODS

We undertook a multi-centre parallel group feasibility randomised controlled trial (COMPRESS-RCT). Adult in-hospital cardiac arrest patients that were in a non-shockable rhythm were randomised in a 3:1 ratio to receive mechanical CPR (Jolfe AB/Stryker, Lund, Sweden) or ongoing manual CPR. Recruitment was led by the clinical cardiac arrest team. The primary study outcome was the proportion of eligible participants randomised in the study during site operational recruitment hours. Patients were enrolled under a model of deferred consent. We report data using descriptive statistics, point estimates and 95% confidence intervals.

RESULTS

Over a two-year period, we recruited 127 patients across five UK hospitals. We recruited 55.2% (95% CI 48.5%-61.8%) of eligible study participants in site operational recruitment hours. Most participants were male (n = 76, 59.8%) with a mean age of 72 (95% CI: 69.9-74.9) years. Median arrest duration was 18 (IQR 13-29) minutes. In patients randomised to mech-CPR, median time from CPR start to device deployment was 11 (IQR 7-15) minutes. ROSC was achieved in 27.6% (n = 35) participants and 4.7% (n = 6) were alive at 30-days.

CONCLUSION

COMPRESS-RCT identified important factors that preclude progression to an effectiveness trial of mechanical CPR in the hospital setting in the UK. Findings will inform the design of future in-hospital intra-arrest intervention trials. ISRCTN38139840, date of registration 9th January 2017.

Mechanical Chest Compression Device for Out-Of-Hospital Cardiac Arrest: A Nationwide Observational Study

BACKGROUND

There are few studies on the use of a mechanical chest compression (meCC) device during transport in patients with out-of-hospital cardiac arrest (OHCA).

OBJECTIVE

The aim of our study was to compare the performance of an meCC device with that of manual chest compression during transport after OHCA.

METHODS

This study used data from the national cardiac arrest registry of patients with OHCA of presumed cardiac etiology. The primary exposure was the use of an meCC device by an Emergency Medical Services provider while transporting a patient to the emergency department. The primary endpoint was good cerebral performance category at discharge. We compared survival and neurologic outcomes between an meCC device group and a manual chest compression group. We also performed an interaction analysis to assess changes in study outcomes of meCC device use by the initial electrocardiogram (ECG) and transport time interval (TTI).

RESULTS

Among 30,021 adult patients after OHCA with presumed cardiac etiology, an meCC device was used in 2357 (7.6%). After adjustment for possible confounders, there were no significant differences with respect to good neurologic recovery in the outcomes of patients who were treated with an meCC device and those who received manual chest compression (adjusted odds ratio [AOR] 0.66; 95% confidence interval [CI] 0.43-1.02) and survival to discharge (AOR 0.83; 95% CI 0.64-1.06). In the interaction model, the AOR of the meCC device study outcome did not interact with the initial ECG and TTI.

CONCLUSIONS

The meCC device did not show better study outcomes than manual compression.

Kinetics of manual and automated mechanical chest compressions

AIM

Early onset of adequate chest compression is mandatory for cardiopulmonary resuscitation (CPR) following cardiac arrest. Transmission of forces from chest strain to the heart may be variable between manual and mechanical chest compressions. Furthermore, automated mechanical chest devices can deliver an active decompression, thus improving the venous return to the heart. This pilot study investigated the kinetics of cardiac deformation during these two CPR methods.

METHODS

Transesophageal echocardiographic analysis of the right ventricular wall behind the sternum during CPR was assessed during manual and mechanical chest compression in adult patients admitted to the emergency department for out-of-hospital cardiac arrest.

RESULTS

9 patients had manual and 11 mechanical chest compression. Mechanical chest compression was characterized by greater right ventricular lateral wall displacement [with a median (IQR) of 3.7 (3.12-4.27) vs. 2.53 (2.27-2.6) cm, p < 0.0001], and lower rising time [123 (102-169) vs. 187 (164-215) ms, p = 0.002], relaxing time [109 (102-127) vs. 211 (133-252) ms, p = 0.0003], compression rate [100.6 (99.6-102.2) vs. 131.9 (125.4-151.4) bpm, p < 0.0001], with compression-decompression time ratio of [1.04 (0.86-1.1) vs. 0.86 (0.78-0.96), p = 0.046].

CONCLUSION

Mechanical compared to manual chest compression delivered a more rapid compression and decompression of the cardiac structures at an adequate rate, with broader inward-outward movement of the ventricular walls suggesting greater emptying and filling of the ventricles. Transesophageal echocardiography may be a useful tool to assess the adequacy of chest compression without CPR interruption.

Randomised controlled trial of simulation-based education for mechanical cardiopulmonary resuscitation training

INTRODUCTION

Mechanical cardiopulmonary resuscitation (M-CPR) is increasingly used in the management of cardiac arrest. There are no previously reported randomised studies investigating M-CPR training. This study of newly trained M-CPR providers hypothesised that a brief simulation-based intervention after 4 months would improve M-CPR performance at 6 months.

METHODS

This study used a simulated 'in situ' cardiac arrest model. The M-CPR device used was a proprietary Lund University Cardiac Assist System 3 machine (Physio Control, Redmond, Washington, USA). Standardised baseline training was provided to all participants. Following training, baseline performance was assessed. The primary outcome measure was the time taken to initiate M-CPR and the secondary outcome was performance against a checklist of errors. Participants were then randomised to intervention group (simulation training) or control group (routine clinical use of M-CPR). After 6 months the outcome measures were reassessed. Comparative statistical tests used an intention-to-treat analysis.

RESULTS

112 participants were enrolled. The intervention group (n=60) and control group (n=52) had similar demographic characteristics. At the 6-month assessment, median time to M-CPR initiation was 27.0 s (IQR 22.0-31.0) in the intervention group and 31.0 s (IQR 25.6-46.0) in the control group (p=0.003). The intervention group demonstrated fewer errors compared with controls at 6 months (p<0.001) CONCLUSION: In this randomised study of approaches to M-CPR training, providers receiving additional simulation-based training had higher retention levels of M-CPR skills. Therefore, when resuscitation skills are newly learnt, provision follow-up training should be an important consideration.

Association between left ventricular outflow tract opening and successful resuscitation after cardiac arrest

BACKGROUND

Survival after cardiac arrest depends on adequate cardiopulmonary resuscitation (CPR). Manual or mechanical external chest compression may be ineffective to restore circulation: structures subjected to external chest compression may differ in forces transfer to intrathoracic structures due to anatomic characteristics and physiological changes. This clinical study aims to assess the association of trans-oesophageal findings during CPR and successful resuscitation.

METHODS

Retrospective cohort study. Trans-oesophageal assessment of right ventricular fractional area change, right ventricular outflow tract fractional shortening, left ventricular volumes, ejection fraction, and aortic diameters were performed in refractory out-of-hospital cardiac arrest patients admitted to emergency department for extracorporeal CPR.

RESULTS

19 patients were analyzed. 15 of 19 patients (79%) received venous-arterial extracorporeal membrane oxygenation support. Resuscitation was successful with return of spontaneous circulation or electromechanical activity in 7 patients (group-SUXX) and failed in 12 patients (group-FAIL). 6 patients (32%) were alive at 24 h from the cardiac arrest, one patient (5%) survived to hospital discharge. Left ventricular outflow tract (LVOT) was open during CPR in all patients in group-SUXX and in 1 patient in group-FAIL (p 0.0002). None of the patients with closed LVOT had successful resuscitation. Patients in group-SUXX had a higher ejection fraction (p 0.03), ascending aortic diameter (p 0.04), and survival rate than those in group-FAIL (p 0.015). In a multiple variable Cox's proportional model LVOT opening was the only variable associated with successful resuscitation.

CONCLUSIONS

Trans-oesophageal echocardiography can be useful in the emergency setting of cardiopulmonary arrest for discriminating between successful and failing resuscitation.

Mechanical versus manual chest compressions in the treatment of in-hospital cardiac arrest patients in a non-shockable rhythm: a randomised controlled feasibility trial (COMPRESS-RCT)

BACKGROUND

Mechanical chest compression devices consistently deliver high-quality chest compressions. Small very low-quality studies suggest mechanical devices may be effective as an alternative to manual chest compressions in the treatment of adult in-hospital cardiac arrest patients. The aim of this feasibility trial is to assess the feasibility of conducting an effectiveness trial in this patient population.

METHODS

COMPRESS-RCT is a multi-centre parallel group feasibility randomised controlled trial, designed to assess the feasibility of undertaking an effectiveness to compare the effect of mechanical chest compressions with manual chest compressions on 30-day survival following in-hospital cardiac arrest. Over approximately two years, 330 adult patients who sustain an in-hospital cardiac arrest and are in a non-shockable rhythm will be randomised in a 3:1 ratio to receive ongoing treatment with a mechanical chest compression device (LUCAS 2/3, Jolife AB/Stryker, Lund, Sweden) or continued manual chest compressions. It is intended that recruitment will occur on a 24/7 basis by the clinical cardiac arrest team. The primary study outcome is the proportion of eligible participants randomised in the study during site operational recruitment hours. Participants will be enrolled using a model of deferred consent, with consent for follow-up sought from patients or their consultee in those that survive the cardiac arrest event. The trial will have an embedded qualitative study, in which we will conduct semi-structured interviews with hospital staff to explore facilitators and barriers to study recruitment.

DISCUSSION

The findings of COMPRESS-RCT will provide important information about the deliverability of an effectiveness trial to evaluate the effect on 30-day mortality of routine use of mechanical chest compression devices in adult in-hospital cardiac arrest patients.

TRIAL REGISTRATION

ISRCTN38139840 , date of registration 9th January 2017.

Out-of-hospital cardiac arrest: prehospital management

Sudden out-of-hospital cardiac arrest is the most time-critical medical emergency. In the second paper of this Series on out-of-hospital cardiac arrest, we considered important issues in the prehospital management of cardiac arrest. Successful resuscitation relies on a strong chain of survival with the community, dispatch centre, ambulance, and hospital working together. Early cardiopulmonary resuscitation and defibrillation has the greatest impact on survival. If the community response does not restart the heart, resuscitation is continued by emergency medical services' staff. However, the best approaches for airway management and the effectiveness of currently used drug treatments are uncertain. Prognostic factors and rules for termination of resuscitation could guide the duration of a resuscitation attempt and decision to transport to hospital. If return of spontaneous circulation is achieved, the focus of treatment shifts to stabilisation, restoration of normal physiological parameters, and transportation to hospital for ongoing care.

The dead and the dying - a difficult part of EMS transport: A Swiss cross-sectional study

Objective

Most deaths occur in the pre-hospital setting, whereas mortality in the emergency department (ED) is low (<1%). However, our clinical impression is that some patients are being transported to hospital in devastating conditions with no likelihood of survival, but demanding extensive hospital resources. The decision on whether to transport a dying person to hospital or not is a difficult task for emergency medical services (EMS) personnel. As there is little epidemiological data about these patients, this paper aims to describe this special population.

Methods

Retrospective cross-sectional study on adult patients transported by ground ambulance to the ED of a Swiss university hospital, who died during their stay in the ED between January 2008 and December 2012. Data was collected on the basis of ambulance report forms and discharge summaries of the ED.

Results

One hundred and sixty-one patients were analysed. Most deaths were due to cardiovascular diseases (43%). Only 9% of patients died of trauma. The median age was 70 years (IQR 56–81 years) and 70% (n = 112) were men. Trauma patients were significantly younger (median age 55 years, p<0.001). The overall mortality rate was 0.9% for all patients transported by EMS to the ED. About one third of all patients received cardiopulmonary resuscitation (CPR) from bystanders (n = 53). The most common electrocardiogram (ECG) findings were asystole (n = 57) and pulseless electrical activity (n = 91). Fifty percent (n = 64) of the resuscitated patients were defibrillated. Three quarters (n = 115, 72%) of all patients were intubated on site. The mechanical chest compression device Lucas™2 was mainly used in cases of cardiovascular or uncertain cause of death and did not reduce the operating time on site.

Conclusion

The low ED mortality rate of 0.9% shows that only a few dying patients are transported to hospital. However, transport to hospital has to be carefully evaluated, especially for elderly patients with asystole or PEA due to medical conditions. The low CPR rate from bystanders demonstrates that public CPR training should be promoted further. The use of Lucas™2 did not reduce the operating time on site. For further investigations, comparison with survivors would be needed.

Training approaches for the deployment of a mechanical chest compression device: a randomised controlled manikin study

OBJECTIVES

To evaluate the effect of training strategy on team deployment of a mechanical chest compression device.

DESIGN

Randomised controlled manikin trial.

SETTING

Large teaching hospital in the UK.

PARTICIPANTS

Twenty teams, each comprising three clinicians. Participating individuals were health professionals with intermediate or advanced resuscitation training.

INTERVENTIONS

Teams were randomised in a 1:1 ratio to receive either standard mechanical chest compression device training or pit-crew device training. Training interventions lasted up to 1 h. Performance was measured immediately after training in a standardised simulated cardiac arrest scenario in which teams were required to deploy a mechanical chest compression device.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome was chest compression flow fraction in the minute preceding the first mechanical chest compression. Secondary outcomes included cardiopulmonary resuscitation quality and mechanical device deployment metrics, and non-technical skill performance. Outcomes were assessed using video recordings of the test scenario.

RESULTS

In relation to the primary outcome of chest compression flow fraction in the minute preceding the first mechanical chest compression, we found that pit-crew training was not superior to standard training (0.76 (95% CI 0.73 to 0.79) vs 0.77 (95% CI 0.73 to 0.82), mean difference -0.01 (95% CI -0.06 to 0.03), P=0.572). There was also no difference between groups in performance in relation to any secondary outcome.

CONCLUSIONS

Pit-crew training, compared with standard training, did not improve team deployment of a mechanical chest device in a simulated cardiac arrest scenario.

TRIAL REGISTRATION NUMBER

ISRCTN43049287; Pre-results.

Team Size and Stretching-Exercise Effects on Simulated Chest Compression Performance and Exertion

Introduction

Investigators conducted a prospective experimental study to evaluate the effect of team size and recovery exercises on individual providers’ compression quality and exertion. Investigators hypothesized that 1) larger teams would perform higher quality compressions with less exertion per provider when compared to smaller teams; and 2) brief stretching and breathing exercises during rest periods would sustain compressor performance and mitigate fatigue.

Methods

In Phase I, a volunteer cohort of pre-clinical medical students performed four minutes of continuous compressions on a Resusci-Anne manikin to gauge the spectrum of compressor performance in the subject population. Compression rate, depth, and chest recoil were measured. In Phase II, the highest-performing Phase I subjects were placed into 2-, 3-, and/or 4-compressor teams; 2-compressor teams were assigned either to control group (no recovery exercises) or intervention group (recovery exercises during rest). All Phase II teams participated in 20-minute simulations with compressor rotation every two minutes. Investigators recorded compression quality and real-time heart rate data, and calculated caloric expenditure from contact heart rate monitor measurements using validated physiologic formulas.

Results

Phase I subjects delivered compressions that were 24.9% (IQR1–3: [0.5%–74.1%]) correct with a median rate of 112.0 (IQR1–3: [103.5–124.9]) compressions per minute and depth of 47.2 (IQR1–3: [35.7–55.2]) mm. In their first rotations, all Phase II subjects delivered compressions of similar quality and correctness (p=0.09). Bivariate analyses of 2-, 3-, and 4-compressor teams’ subject compression characteristics by subsequent rotation did not identify significant differences within or across teams. On multivariate analyses, only subjects in 2-compressor teams exhibited significantly lower compression rates (control subjects; p<0.01), diminished chest release (intervention subjects; p=0.03), and greater exertion over successive rotations (both control [p≤0.03] and intervention [p≤0.02] subjects).

Conclusion

During simulated resuscitations, 2-compressor teams exhibited increased levels of exertion relative to 3- and 4-compressor teams for comparable compression delivery. Stretching and breathing exercises intended to assist with compressor recovery exhibited mixed effects on compression performance and subject exertion.

Extracorporeal Life Support and New Therapeutic Strategies for Cardiac Arrest Caused by Acute Myocardial Infarction - a Critical Approach for a Critical Condition

This review summarizes the most recent developments in providing advanced supportive measures for cardiopulmonary resuscitation, and the results obtained using these new therapies in patients with cardiac arrest caused by acute myocardial infarction (AMI). Also detailed are new approaches such as extracorporeal cardiopulmonary resuscitation (ECPR), intra-arrest percutaneous coronary intervention, or the regional models for systems of care aiming to reduce the critical times from cardiac arrest to initiation of ECPR and coronary revascularization.

CPR using the lifeline ARM mechanical chest compression device: a randomized, crossover, manikin trial

INTRODUCTION

European Resuscitation Council as well as American Heart Association guidelines for cardiopulmonary resuscitation (CPR) stress the importance of uninterrupted and effective chest compressions (CCs). Manual CPR decreases in quality of CCs over time because of fatigue which impacts outcome. We report the first study with the Lifeline ARM automated CC device for providing uninterrupted CCs.

METHODS

Seventy-eight paramedics participated in this randomized, crossover, manikin trial. We compared the fraction of effective CCs between manual CPR and automated CPR using the ARM.

RESULTS

Using the ARM during resuscitation resulted in a higher percentage of effective CCs (100/min [interquartile range, 99-100]) compared with manual CCs (43/min [interquartile range, 39-46]; P<.001). The number of effective CCs decreased less over time with the ARM (P<.001), more often reached the required depth of 5 cm (97% vs 63%, P<.001), and more often reached the recommended CC rate (P<.001). The median tidal volume was higher and hands-off time was lower when using the ARM.

CONCLUSION

Mechanical CCs in our study adhere more closely to current guidelines than manual CCs. The Lifeline ARM provides more effective CCs, more ventilation time and minute volume, less hands-off time, and less decrease in effective CCs over time compared with manual Basic Life Support and might therefore impact outcome.

Mechanical chest compression devices at in-hospital cardiac arrest: A systematic review and meta-analysis

AIM

To summarise the evidence in relation to the routine use of mechanical chest compression devices during resuscitation from in-hospital cardiac arrest.

METHODS

We conducted a systematic review of studies which compared the effect of the use of a mechanical chest compression device with manual chest compressions in adults that sustained an in-hospital cardiac arrest. Critical outcomes were survival with good neurological outcome, survival at hospital discharge or 30-days, and short-term survival (ROSC/1-h survival). Important outcomes included physiological outcomes. We synthesised results in a random-effects meta-analysis or narrative synthesis, as appropriate. Evidence quality in relation to each outcome was assessed using the GRADE system.

DATA SOURCES

Studies were identified using electronic databases searches (Cochrane Central, MEDLINE, EMBASE, CINAHL), forward and backward citation searching, and review of reference lists of manufacturer documentation.

RESULTS

Eight papers, containing nine studies [689 participants], were included. Three studies were randomised controlled trials. Meta-analyses showed an association between use of mechanical chest compression device and improved hospital or 30-day survival (odds ratio 2.34, 95% CI 1.42-3.85) and short-term survival (odds ratio 2.14, 95% CI 1.11-4.13). There was also evidence of improvements in physiological outcomes. Overall evidence quality in relation to all outcomes was very low.

CONCLUSIONS

Mechanical chest compression devices may improve patient outcome, when used at in-hospital cardiac arrest. However, the quality of current evidence is very low. There is a need for randomised trials to evaluate the effect of mechanical chest compression devices on survival for in-hospital cardiac arrest.

Mechanical chest compression for out of hospital cardiac arrest: Systematic review and meta-analysis

AIM

To summarise the evidence from randomised controlled trials of mechanical chest compression devices used during resuscitation after out of hospital cardiac arrest.

METHODS

Systematic review of studies evaluating the effectiveness of mechanical chest compression. We included randomised controlled trials or cluster randomised trials that compared mechanical chest compression (using any device) with manual chest compression for adult patients following out-of-hospital cardiac arrest. Outcome measures were return of spontaneous circulation, survival of event, overall survival, survival with good neurological outcome. Results were combined using random-effects meta-analysis.

DATA SOURCES

Studies were identified by searches of electronic databases, reference lists of other studies and review articles.

RESULTS

Five trials were included, of which three evaluated the LUCAS or LUCAS-2 device and two evaluated the AutoPulse device. The results did not show an advantage to the use of mechanical chest compression devices for survival to discharge/30 days (average OR 0.89, 95% CI 0.77, 1.02) and survival with good neurological outcome (average OR 0.76, 95% CI 0.53, 1.11).

CONCLUSIONS

Existing studies do not suggest that mechanical chest compression devices are superior to manual chest compression, when used during resuscitation after out of hospital cardiac arrest.