Effectiveness of Mechanical Chest Compression Devices over Manual Cardiopulmonary Resuscitation: A Systematic Review with Meta-analysis and Trial Sequential Analysis

Emergency medicine updates: Cardiopulmonary resuscitation

INTRODUCTION

Cardiac arrest is the loss of functional cardiac activity; emergency clinicians are integral in the management of this condition.

OBJECTIVE

This paper evaluates key evidence-based updates concerning cardiopulmonary resuscitation (CPR).

DISCUSSION

Cardiac arrest includes shockable rhythms (i.e., pulseless ventricular tachycardia and ventricular fibrillation) and non-shockable rhythms (i.e., asystole and pulseless electrical activity). The goal of cardiac arrest management is to achieve survival with a good neurologic outcome, in part by restoring systemic perfusion and obtaining return of spontaneous circulation (ROSC), while seeking to diagnose and treat the underlying etiology of the arrest. CPR includes high-quality chest compressions to optimize coronary and cerebral perfusion pressure. Chest compressions should be centered over the mid-sternum, with the compressor's body weight over the middle of the chest. A compression depth of 5-6 cm is recommended at a rate of 100-120 compressions per minute, while allowing the chest to fully recoil between each compression. Clinicians should seek to minimize any interruptions in compressions. When performed by bystanders, compression-only CPR may be associated with improved survival to hospital discharge when compared to conventional CPR with ventilations. However, in trained personnel, there is likely no difference with compression-only versus conventional CPR. Mechanical approaches for CPR are not associated with improved patient outcomes, including ROSC or survival with good neurologic function, but mechanical compression devices may be beneficial in select circumstances (e.g., few rescuers available, prolonged arrest/transport). Monitoring of chest compressions is not associated with improved ROSC, survival, or neurologic outcomes, but it can improve guideline adherence. Types of monitoring include real-time feedback, a CPR coach, end tidal CO2, arterial line monitoring, regional cerebral tissue oxygenation, and point-of-care ultrasound.

CONCLUSIONS

An understanding of CPR literature updates can improve the ED care of patients in cardiac arrest.

Mechanical chest compression increases intrathoracic hemorrhage complications in patients receiving extracorporeal cardiopulmonary resuscitation

Background

Mechanical cardiopulmonary resuscitation (CPR) devices address the limitations of manual CPR, but their impact on intrathoracic injuries during extracorporeal CPR (ECPR) remains unclear. This study investigated the relationship between mechanical CPR and severe intrathoracic hemorrhage during ECPR compared to manual CPR.

Methods

We conducted a single-center retrospective study of consecutive patients who underwent ECPR from April 2017 to March 2024 according to a standard institutional protocol. Patients were divided into a mechanical CPR group (piston-driven compressions before veno-arterial extracorporeal membrane oxygenation [VA-ECMO]) and a manual CPR group. The primary outcome was intrathoracic hemorrhage requiring transcatheter arterial embolization (TAE). Secondary outcomes included other intrathoracic injuries and 180-day survival.

Results

A total of 91 patients were enrolled (mechanical n = 48, manual n = 43). Intrathoracic hemorrhage requiring TAE occurred more frequently in the mechanical CPR group (18.8% vs. 2.3%, p = 0.030). On multivariate analysis, mechanical CPR was independently associated with this outcome (adjusted odds ratio 6.29; 95% confidence interval 1.20-65.10). In the mechanical group, older age and larger thoracic transverse diameter were significantly related to intrathoracic hemorrhage requiring TAE. Mediastinal hematoma (18.8% vs. 2.3%, p = 0.030) and hemothorax (20.8% vs. 4.7%, p = 0.049) were also more frequent in the mechanical group. The 180-day survival rates did not differ significantly between groups (27.7% vs. 25.0%, log-rank p = 0.540).

Conclusions

Mechanical CPR during ECPR is associated with an increased risk of severe intrathoracic hemorrhage. While mechanical CPR devices may provide benefits in certain scenarios, clinicians should carefully consider individual patient characteristics and closely monitor for complications.

CO2 and aerosol concentration during manual and mechanical chest compression while cardiopulmonary resuscitation

BACKGROUND

This study investigates the staff-to-staff transmission risk of Coronavirus disease 2019 during cardiopulmonary resuscitation in an ambulance vehicle.

METHODS

Comparing manual and mechanical chest compressions, CO2 concentrations were monitored as a proxy for infection risk.

RESULTS

Results suggest that mechanical chest compressions generate lower CO2 levels, indicating a reduced risk of infection among healthcare workers compared to manual compressions.

CONCLUSIONS

These findings highlight the potential benefits of employing mechanical chest compressions to mitigate staff-to-staff infections in small, confined spaces during aerosol-transmitted diseases.

Description of current status of implementation and management of cardiac arrest in China

Variation in the incidence, survival rate and factors associated with survival after cardiac arrest in China is reported. Some studies have tried to fill the knowledge gap regarding the epidemiology of cardiac arrest in China but were unable to identify reasons for the reported differences. Therefore, the purpose of this study was to describe Chinese management of cardiac arrest, particularly from the perspective of compression, ventilation, monitoring, treatment, and extracorporeal cardiopulmonary resuscitation. An online questionnaire with 56 questions was designed about demographic characteristics, management of cardiac arrest, compression, ventilation, treatment and medicine, as well as advanced life support and resuscitation skill training. A total of 814 copies of questionnaire were received from 23 provinces, 4 autonomous regions and 4 municipalities of China. Results were combined with official information on population density. Throughout China, hospitals resuscitate according to the guideline, however, there are still differences varies in implement with regard to chest compression, ventilation, medicine, monitoring, as well as advanced life support and resuscitation skills training because of economical and developmental level from different regions. All the startup of chest compression is manual, whereas mechanical compression instruments are increasingly involved in sequential resuscitation. Most of clinicians rotate during resuscitation every five cycles other than the guideline recommends every 2 min or when they are tired. About half of the participants don't build the advanced airway rather than use bag valve mask to ventilate, and 75% of the rest use mechanical ventilation whether they succeed to ROSC. Most of rescuers choose endotracheal intubation which is consistent with many other clinical trials results. Various compression feedback devices play increasingly significant roles in assessment of ROSC. More and more regional hospitals have access to ECPR and implement TTM, but still lead to various divergences. Thus, more elaborate clinical trials need to be designed to verify and explore every procedure in the CPR life cycle.

Factors affecting the return of spontaneous circulation in cardiac arrest patients

The aim of this study was to determine the factors affecting the return of spontaneous circulation (ROSC) in cardiac arrest patients who underwent quality chest compressions as recommended by international guidelines. In this retrospective observational study, the data of nontraumatic out-of-hospital cardiac arrest (OHCA) patients (n = 784) brought by an ambulance to emergency between January 2018 and December 2019 were extracted from the validated hospital automation system. About 452 patients met inclusion criteria. All eligible patients for analysis were treated with an automatic cardiopulmonary resuscitation (CPR) device for chest compression.. Significance threshold for P-value was < 0.05. Logistic regression analysis was used to determine the factors affecting mortality. 61.7% (n = 279) of the study population was male and 65.0% of patients (n = 294) had OHCA. 88 patients (19.5%) had a shockable rhythm and were defibrillated. There was a 0.5-fold increase in mortality rate in patients with thrombocyte count < 199 × 109/L (OR: 0.482, 95% CI: 0.280-0.828) and CPR duration longer than 42 minutes led to a 6.2-fold increase in the probability of ROSC (OR: 6.232, 95% CI: 3.551-10.936) (P < .05). There is no clear consensus on the ideal resuscitation duration; however, our study suggests that it should last at least 42 minutes.

Development of an algorithm to guide management of cardiorespiratory arrest in a diving bell

Aim

The management of cardiorespiratory arrest in a diving bell presents multiple clinical, technical, and environmental considerations that standard resuscitation algorithms do not address, and no situation-specific algorithm exists. The development and testing of an algorithm to guide the management of cardiorespiratory arrest in a bell is described.

Methods

An iterative approach to algorithm development was used. Phase 1 involved a small multidisciplinary group and took place in a simulation centre and a decommissioned diving bell. The algorithm was then refined in a purpose-build simulation complex with repeated simulation by a group of divers, and with input from industry experts. ALS principles were followed unless contextual or technical factors necessitated deviation.

Results

Clinical and technical aspects of the resuscitation are addressed. Key priorities that conflict with standard ALS principles are: prioritisation of rescue breaths; use of mechanical CPR when available; and the provision of CPR with the casualty in a seated position where necessary.

Conclusion

This is the first algorithm to guide the delivery of resuscitation in a diving bell. It incorporates adapted ALS principles and available data concerning compression technique effectiveness, and was informed by industry and clinical expertise. It provides guiding principles that can be adapted to setting-specific needs, and we would encourage its industry-wide international adoption.

Feasibility of a 4 French resuscitative endovascular balloon occlusion of the aorta (REBOA) device for nontraumatic cardiac arrest in a randomized controlled study using a large porcine model

Aim

The objectives of this study were to assess the return of spontaneous circulation rates and hemodynamic response of large swine (>65Kg) during cardiopulmonary resuscitation after nontraumatic cardiac arrest using the COBRA-OS® aortic occlusion balloon and to address limitations of large swine closed-chest cardiopulmonary resuscitation by comparing closed-chest vs. open-chest cardiopulmonary resuscitation.

Methods

Yorkshire pigs (n = 10) weighing >65 kg were anesthetized and ventilated. After 7 min of untreated ventricular fibrillation (VF), animals were randomized to receive mechanical closed-chest cardiopulmonary resuscitation or open-chest cardiac massage. Following a 5-minute low-flow state, advanced cardiac life support algorithms were started and the COBRA-OS® was inflated in the thoracic aorta. Animals that achieved return of spontaneous circulation were re-started on mechanical ventilation and medications, CPR, defibrillation, and aortic occlusion were discontinued. The primary outcome was return of spontaneous circulation and secondary outcomes were mean arterial pressures generated in the low flow and aortic occlusion states before return of spontaneous circulation. Groups were compared with a t-test or Mann-Whitney U test for normal and non-parametric data, respectively, while categorical data was compared with the chi square test.

Results

Return of spontaneous circulation was obtained in 4 animals (80%) in the open cardiac massage group and none in the mechanical closed-chest CPR group (p < 0.05). The COBRA-OS® successfully occluded all aortas and animals experienced higher mean arterial pressures in both groups with aortic occlusion (median 15 mm Hg, IQR 13-23 mm Hg), but with a higher MAP difference in the open cardiac massage group (-12.2 mm Hg, [-2.581, -21.819]).

Conclusions

Consideration should be given to intra-thoracic cardiac massage to increase cardiopulmonary resuscitation effectiveness and therefore return of spontaneous circulation rates in large (>65 kg) swine models of nontraumatic cardiac arrest. The COBRA-OS® demonstrated feasibility for use in this model.The Keenan Research Center, Li Ka Shing Knowledge Institute of St. Michael's Hospital Animal Care Committee: ACC Protocol #726.

Mechanical versus manual cardiopulmonary resuscitation (CPR): an umbrella review of contemporary systematic reviews and more

BACKGROUND

High-quality cardiopulmonary resuscitation (CPR) can restore spontaneous circulation (ROSC) and neurological function and save lives. We conducted an umbrella review, including previously published systematic reviews (SRs), that compared mechanical and manual CPR; after that, we performed a new SR of the original studies that were not included after the last published SR to provide a panoramic view of the existing evidence on the effectiveness of CPR methods.

METHODS

PubMed, EMBASE, and Medline were searched, including English in-hospital (IHCA) and out-of-hospital cardiac arrest (OHCA) SRs, and comparing mechanical versus manual CPR. A Measurement Tool to Assess Systematic Reviews (AMSTAR-2) and GRADE were used to assess the quality of included SRs/studies. We included both IHCA and OHCA, which compared mechanical and manual CPR. We analyzed at least one of the outcomes of interest, including ROSC, survival to hospital admission, survival to hospital discharge, 30-day survival, and survival to hospital discharge with good neurological function. Furthermore, subgroup analyses were performed for age, gender, initial rhythm, arrest location, and type of CPR devices.

RESULTS

We identified 249 potentially relevant records, of which 238 were excluded. Eleven SRs were analyzed in the Umbrella review (January 2014-March 2022). Furthermore, for a new, additional SR, we identified eight eligible studies (not included in any prior SR) for an in-depth analysis between April 1, 2021, and February 15, 2024. The higher chances of using mechanical CPR for male patients were significantly observed in three studies. Two studies showed that younger patients received more mechanical treatment than older patients. However, studies did not comment on the outcomes based on the patient's gender or age. Most SRs and studies were of low to moderate quality. The pooled findings did not show the superiority of mechanical compared to manual CPR except in a few selected subgroups.

CONCLUSIONS

Given the significant heterogeneity and methodological limitations of the included studies and SRs, our findings do not provide definitive evidence to support the superiority of mechanical CPR over manual CPR. However, mechanical CPR can serve better where high-quality manual CPR cannot be performed in selected situations.

Physiology-Guided Resuscitation: Monitoring and Augmenting Perfusion during Cardiopulmonary Arrest

Given the high morbidity and mortality associated with cardiopulmonary arrest, there have been multiple trials aimed at better monitoring and augmenting coronary, cerebral, and systemic perfusion. This article aims to elucidate these interventions, first by detailing the physiology of cardiopulmonary resuscitation and the available tools for managing cardiopulmonary arrest, followed by an in-depth examination of the newest advances in the monitoring and delivery of advanced cardiac life support.

Mechanical Cardiopulmonary Resuscitation Devices: Evidence Synthesis with an Umbrella Review

AIM

Sudden cardiac arrest is a significant cause of death worldwide. Good quality cardiopulmonary resuscitation increases patients' survival. Manual cardiopulmonary resuscitation is often ineffective as rescuers may experience physical and mental fatigue. Mechanical cardiopulmonary resuscitation devices are designed to address this issue, providing an automated approach for high-quality resuscitation. In the present comprehensive umbrella review we summarize current evidence on mechanical devices.

METHODS

We searched systematic reviews on mechanical devices in MEDLINE/PubMed. Effect estimates were obtained from original reports, including 95% confidence intervals and p values, when applicable and available, focusing on return of spontaneous circulation, survival to discharge or 30 days, survival with good neurological outcome, and resuscitation-related injuries.

RESULTS

From 21 potentially pertinent publications, we shortlisted 10 reviews, each including between 5 and 22 studies. AutoPulse, LUCAS, and LUCAS-2 were among the investigated devices. Most reviews concluded toward mechanical devices being similar or better than manual resuscitation for return of spontaneous circulation and 30-days survival. Regarding survival with good neurological function, some reviews lacked data, while the remaining ones reported similar results or worse outcomes in patients undergoing mechanical resuscitation. Focusing on resuscitation-related injuries, data were limited or conflicting with one review reporting higher rates of injuries with mechanical devices, and two others suggesting similar outcomes.

CONCLUSIONS

Manual and mechanical cardiopulmonary resuscitation appear to be similar in terms of return of spontaneous circulation and short-term survival. Mechanical devices appear to be associated with higher resuscitation-related injuries, while there are conflicting data in terms of survival with good neurological outcomes. A comprehensive and large dedicated randomized trial is urgently needed.

Optimal chest compression for cardiac arrest until the establishment of ECPR: Secondary analysis of the SAVE-J II study

INTRODUCTION

The widespread incorporation of extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest requires the delivery of effective and high-quality chest compressions prior to the initiation of ECPR. The aim of this study was to evaluate and compare the effectiveness of mechanical and manual chest compressions until the initiation of ECPR.

METHODS

This study was a secondary analysis of the Japanese retrospective multicenter registry "Study of Advanced Life Support for Ventricular Fibrillation by Extracorporeal Circulation II (SAVE-J II)". Patients were divided into two groups, one receiving mechanical chest compressions and the other receiving manual chest compressions. The primary outcome measure was mortality at hospital discharge, while the secondary outcome was the cerebral performance category (CPC) score at discharge.

RESULTS

Of the 2157 patients enrolled in the SAVE-J II trial, 453 patients (329 in the manual compression group and 124 in the mechanical compression group) were included in the final analysis. Univariate analysis showed a significantly higher mortality rate at hospital discharge in the mechanical compression group compared to the manual compression group (odds ratio [95% CI] = 2.32 [1.34-4.02], p = 0.0026). Multivariate analysis showed that mechanical chest compressions were an independent factor associated with increased mortality at hospital discharge (adjusted odds ratio [95% CI] = 2.00 [1.11-3.58], p = 0.02). There was no statistically significant difference in CPC between the two groups.

CONCLUSION

For patients with out-of-hospital cardiopulmonary arrest who require ECPR, extreme caution should be used when performing mechanical chest compressions.

Optimal duration and timing of basic-life-support-only intervention for patients with out-of-hospital cardiac arrest

To elucidate the relationship between the interval from cardiopulmonary resuscitation initiation to return of spontaneous circulation (ROSC) and neurologically favourable 1-month survival in order to determine the appropriate duration of basic life support (BLS) without advanced interventions. This population-based cohort study included patients aged ≥ 18 years with 9132 out-of-hospital cardiac arrest of presumed cardiac origin who were bystander-witnessed and had achieved ROSC between 2018 and 2020. Patients were classified into two groups based on the resuscitation methods as the "BLS-only" and the "BLS with administered epinephrine (BLS-AE)" groups. Receiver operating characteristic (ROC) curve analysis indicated that administering BLS for 9 min yielded the best neurologically outcome for patients with a shockable rhythm [sensitivity, 0.42; specificity, 0.27; area under the ROC curve (AUC), 0.60] in the BLS-only group. Contrastingly, for patients with a non-shockable rhythm, performing BLS for 6 min yielded the best neurologically outcome (sensitivity, 0.65; specificity, 0.43; AUC, 0.63). After propensity score matching, multivariate analysis revealed that BLS-only resuscitation [6.44 (5.34-7.77)] was associated with neurologically favourable 1-month survival. This retrospective study revealed that BLS-only intervention had a significant impact in the initial minutes following CPR initiation. Nevertheless, its effectiveness markedly declined thereafter. The optimal duration for effective BLS-only intervention varied depending on the patient's initial rhythm. Consequently, advanced interventions should be administered within the first few minutes to counteract the diminishing effectiveness of BLS-only intervention.

Prognostic influence of mechanical cardiopulmonary resuscitation on survival in patients with out-of-hospital cardiac arrest undergoing ECPR on VA-ECMO

Introduction

The use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) in extracorporeal cardiopulmonary resuscitation (ECPR) in selected patients after out-of-hospital cardiac arrest (OHCA) is an established method if return of spontaneous circulation cannot be achieved. Automated chest compression devices (ACCD) facilitate transportation of patients under ongoing CPR and might improve outcome. We thus sought to evaluate prognostic influence of mechanical CPR using ACCD in patients presenting with OHCA treated with ECPR including VA-ECMO.

Methods

We retrospectively analyzed data of 171 consecutive patients treated for OHCA using ECPR in our cardiac arrest center from the years 2016 to 2022. A Cox proportional hazards model was used to identify characteristics related with survival.

Results

Of the 171 analyzed patients (84% male, mean age 56 years), 12% survived the initial hospitalization with favorable neurological outcome. The primary reason for OHCA was an acute coronary event (72%) followed by primary arrhythmia (9%) and non-ischemic cardiogenic shock (6.7%). In most cases, the collapse was witnessed (83%) and bystander CPR was performed (83%). The median time from collapse to VA-ECMO was 81 min (Q1: 69 min, Q3: 98 min). No survival benefit was seen for patients resuscitated using ACCD. Patients in whom an ACCD was used presented with overall longer times from collapse to ECMO than those who were resuscitated manually [83 min (Q1: 70 min, Q3: 98 min) vs. 69 min (Q1: 57 min, Q3: 84 min), p = 0.004].

Conclusion

No overall survival benefit of the use of ACCD before ECPR is established was found, possibly due to longer overall CPR duration. This may arguably be because of the limited availability of ACCD in pre-clinical paramedic service at the time of observation. Increasing the availability of these devices might thus improve treatment of OHCA, presumably by providing efficient CPR during transportation and transfer.

Comparison of hemodynamic effects of chest compression delivered via machine or human in asphyxiated piglets

BACKGROUND

High-quality chest compressions (CC) are an important factor of neonatal resuscitation. Mechanical CC devices may provide superior CC delivery and improve resuscitation outcomes. We aimed to compare the hemodynamic effects of CC delivered by machine and human using a neonatal piglet model.

METHODS

Twelve asphyxiated piglets were randomized to receive CC during resuscitation using an automated mechanical CC device ("machine") or the two-thumb encircling technique ("human"). CC was superimposed with sustained inflations.

RESULTS

Twelve newborn piglets (age 0-3 days, weight 2.12 ± 0.17 kg) were included in the study. Machine-delivered CC resulted in an increase in stroke volume, and minimum and maximum rate of left ventricle pressure change (dp/dtmin and dp/dtmax) compared to human-delivered CC.

CONCLUSIONS

During machine-delivered CC, stroke volume and left ventricular contractility were significantly improved. Mechanical CC devices may provide improved cardiopulmonary resuscitation outcomes in neonatal cardiac arrest induced by asphyxia.

IMPACT

Machine chest compression leads to changes in hemodynamic parameters during resuscitation of asphyxiated neonatal piglets, namely greater stroke volume and left ventricular contractility, compared with standard two-thumb compression technique. Mechanical chest compression devices may provide improved cardiopulmonary resuscitation outcomes in neonatal and pediatric asphyxia-induced cardiac arrest.

An evaluation of the NUI Compact Chest Compression Device (NCCD), a mechanical CPR device suitable for use in the saturation diving environment

Introduction

Provision of manual chest compressions in a diving bell using a conventional technique is often impossible, and alternative techniques are poorly evidenced in terms of efficacy and sustainability. The first mechanical cardiopulmonary resuscitation (CPR) device suitable for use in this environment, the NUI Compact Chest Compression Device (NCCD), has recently been designed and manufactured. This study assessed both the efficacy of the device in delivering chest compressions to both prone and seated manikins, and the ability of novice users to apply and operate it.

Methods

Compression efficacy was assessed using a Resusi Anne QCPR intelligent manikin, and the primary outcome was the proportion of compressions delivered to target depth (50-60 mm). The gold standard was that achieved by expert CPR providers delivering manual CPR; the LUCAS 3 mCPR device was a further comparator.

Results

The NCCD delivered 100% of compressions to target depth compared to 98% for the gold standard (interquartile range 1.5%) and 98% for the LUCAS 3 when applied to both supine and seated manikins. The NCCD sometimes became dislodged and had to be reapplied when used with a seated manikin.

Conclusions

The NCCD can deliver chest compressions at target rate and depth to both supine and seated manikins with efficacy equivalent to manual CPR and the LUCAS 3. It can become dislodged when applied to a seated manikin; its design has now been altered to prevent this. New users can be trained in use of the NCCD quickly, but practise is required to ensure effective use.

Delivering manual cardiopulmonary resuscitation (CPR) in a diving bell: an analysis of head-to-chest and knee-to-chest compression techniques

Introduction

Chest compression often cannot be administered using conventional techniques in a diving bell. Multiple alternative techniques are taught, including head-to-chest and both prone and seated knee-to-chest compressions, but there are no supporting efficacy data. This study evaluated the efficacy, safety and sustainability of these techniques.

Methods

Chest compressions were delivered by a team of expert cardiopulmonary resuscitation (CPR) providers. The primary outcome was proportion of chest compressions delivered to target depth compared to conventional CPR. Techniques found to be safe and potentially effective by the study team were further trialled by 20 emergency department staff members.

Results

Expert providers delivered a median of 98% (interquartile range [IQR] 1.5%) of chest compressions to the target depth using conventional CPR. Only 32% (IQR 60.8%) of head-to-chest compressions were delivered to depth; evaluation of the technique was abandoned due to adverse effects. No study team member could register sustained compression outputs using prone knee-to-chest compressions. Seated knee-to-chest were delivered to depth 12% (IQR 49%) of the time; some compression providers delivered > 90% of compressions to depth.

Conclusions

Head-to-chest compressions have limited efficacy and cause harm to providers; they should not be taught or used. Prone knee-to-chest compressions are ineffective. Seated knee-to-chest compressions have poor overall efficacy but some providers deliver them well. Further research is required to establish whether this technique is feasible, effective and sustainable in a diving bell setting, and whether it can be taught and improved with practise.

Cardiopulmonary Resuscitation: The Importance of the Basics

Cardiac arrest is the loss of organized cardiac activity. Unfortunately, survival to hospital discharge is poor, despite recent scientific advances. The goals of cardiopulmonary resuscitation (CPR) are to restore circulation and identify and correct an underlying etiology. High-quality compressions remain the foundation of CPR, optimizing coronary and cerebral perfusion pressure. High-quality compressions must be performed at the appropriate rate and depth. Interruptions in compressions are detrimental to management. Mechanical compression devices are not associated with improved outcomes but can assist in several situations.

Use of Mechanical Chest Compression for Resuscitation in Out-Of-Hospital Cardiac Arrest-Device Matters: A Propensity-Score-Based Match Analysis

BACKGROUND

Devices for mechanical cardiopulmonary resuscitation (CPR) are recommended when high quality CPR cannot be provided. Different devices are available, but the literature is poor in direct comparison studies. Our aim was to assess whether the type of mechanical chest compressor could affect the probability of return of spontaneous circulation (ROSC) and 30-day survival in Out-of-Hospital Cardiac Arrest (OHCA) patients as compared to manual standard CPR.

METHODS

We considered all OHCAs that occurred from 1 January 2015 to 31 December 2022 in seven provinces of the Lombardy region equipped with three different types of mechanical compressor: Autopulse^®(ZOLL Medical, MA), LUCAS^® (Stryker, MI), and Easy Pulse^® (Schiller, Switzerland).

RESULTS

Two groups, 2146 patients each (manual and mechanical CPR), were identified by propensity-score-based random matching. The rates of ROSC (15% vs. 23%, p < 0.001) and 30-day survival (6% vs. 14%, p < 0.001) were lower in the mechanical CPR group. After correction for confounders, Autopulse^® [OR 2.1, 95%CI (1.6-2.8), p < 0.001] and LUCAS^® [OR 2.5, 95%CI (1.7-3.6), p < 0.001] significantly increased the probability of ROSC, and Autopulse^® significantly increased the probability of 30-day survival compared to manual CPR [HR 0.9, 95%CI (0.8-0.9), p = 0.005].

CONCLUSION

Mechanical chest compressors could increase the rate of ROSC, especially in case of prolonged resuscitation. The devices were dissimilar, and their different performances could significantly influence patient outcomes. The load-distributing-band device was the only mechanical chest able to favorably affect 30-day survival.

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.

A Review of CPR Augmentation Devices

The study aims to assess cardiopulmonary resuscitation (CPR) outcomes in cardiac arrest patients when using CPR augmentation devices, such as the ZOLL ResQCPR system (Chelmsford, MA) or its components ResQPUMP and ResQPOD, which are manual active compression-decompression (ACD) device and impedance threshold device (ITD), respectively. The analysis included a Google Scholar-based literature review that took place between January 2015 and March 2023 and included recent publications with PubMed IDs or widely cited articles to assess the effectiveness of the ResQPUMP and ResQPOD or similar devices. This review also includes studies quoted by ZOLL, but those were not considered in our conclusion since the authors were employed by ZOLL. We found that in a study on human cadavers, the force of decompression increased the chest compliance of the chest wall by 30%-50% (p<0.05). Essentially, active compression-decompression improved the return of spontaneous circulation (ROSC) with meaningful neurologic outcomes by 50% in a blinded, randomized, and controlled human trial (n=1,653; p<0.02). The main study on the ResQPOD had a controversial human data pool with one randomized and controlled study arguing for no significant difference with or without the device (n=8,718; p=0.71). However, a post hoc analysis and the reorganization of the data by CPR quality demonstrated significance (n decreased to 2,799, reported in odds ratio without specific p-values). In conclusion to the limited number of studies presented, any manual ACD device is a great alternative to standard cardiopulmonary resuscitation regarding survivability with good neurologic function and should be utilized in prehospital emergency medical services and hospital emergency departments. ITDs are still controversial but promising with more future data.

Bystander-witnessed cardiopulmonary resuscitation by nonfamily is associated with neurologically favorable survival after out-of-hospital cardiac arrest in Miyazaki City District

BACKGROUND

Bystander intervention in cases of out-of-hospital cardiac arrest (OHCA) is a key factor in bridging the gap between the event and the arrival of emergency health services at the site. This study investigated the implementation rate of bystander cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) and 1-month survival after OHCA in Miyazaki prefecture and Miyazaki city district as well as compared them with those of eight prefectures in the Kyushu-Okinawa region in Japan. In addition, we analyzed prehospital factors associated with survival outcomes in Miyazaki city district.

METHODS

We used data from an annual report released by the Fire and Disaster Management Agency of Japan (n = 627,982) and the Utstein reporting database in Miyazaki city district (n = 1,686) from 2015 to 2019.

RESULT

Despite having the highest rate of bystander CPR (20.8%), the 1-month survival rate (15.7%) of witnessed OHCA cases of cardiac causes in Miyazaki city district was comparable with that in the eight prefectures between 2015 and 2019. However, rates of survival (10.7%) in Miyazaki prefecture were lower than those in other prefectures. In 1,686 patients with OHCA (74 ± 18 years old, 59% male) from the Utstein reporting database identical to the 5-year study period in Miyazaki city district, binary logistic regression analysis demonstrated that age of the recipient [odds ratio (OR) 0.979, 95% confidential interval (CI) 0.964-0.993, p = 0.004)], witness of the arrest event (OR 7.501, 95% CI 3.229-17.428, p < 0.001), AED implementation (OR 14.852, 95% CI 4.226-52.201, p < 0.001), and return of spontaneous circulation (ROSC) before transport (OR 31.070, 95% CI 16.585-58.208, p < 0.001) predicted the 1-month survival with favorable neurological outcomes. In addition, chest compression at a public place (p < 0.001) and by nonfamily members (p < 0.001) were associated with favorable outcomes (p = 0.015).

CONCLUSIONS

We found differences in 1-month survival rates after OHCA in the Kyushu-Okinawa region of Japan. Our results suggest that on-field ROSC with defibrillation performed by nonfamily bystanders who witnessed the event determines 1-month neurological outcomes after OHCA in Miyazaki city district. Continued education of citizens on CPR techniques and better access to AED devices may improve outcomes.

Traumatic Injuries Following Mechanical versus Manual Chest Compression

Objective

Survival after out-of-hospital cardiac arrest (OHCA) depends on multiple factors, mostly quality of chest compressions. Studies comparing manual compression with a mechanical active compression-depression device (ACD) have yielded controversial results in terms of outcomes and injury. The aim of the present study was to determine whether out-of-hospital ACD cardiopulmonary resuscitation (CPR) use is associated with more skeletal fractures and/or internal injuries than manual compression, with similar duration of cardiopulmonary resuscitation (CPR) between the groups.

Methods

The cohort included all patients diagnosed with out-of-hospital cardiac arrest (OHCA) at a tertiary medical center between January 2018 and June 2019 who achieved return of spontaneous circulation (ROSC). The primary outcome measure was the incidence of skeletal fractures and/or internal injuries in the two groups. Secondary outcome measures were clinical factors contributing to skeletal fracture/internal injuries and to achievement of ROSC during CPR.

Results

Of 107 patients enrolled, 45 (42%) were resuscitated with manual chest compression and 62 (58%) with a piston-based ACD device (LUCAS). The duration of chest compression was 46.0 minutes vs. 48.5 minutes, respectively (p=0.82). There were no differences in rates of ROSC (53.2% vs.50.8%, p=0.84), cardiac etiology of OHCA (48.9% vs.43.5%, p=0.3), major complications (ribs/sternum fracture, pneumothorax, hemothorax, lung parenchymal damage, major bleeding), or any complication (20.5% vs.12.1%, p=0.28). On multivariate logistic regression analysis, factors with the highest predictive value for ROSC were cardiac etiology (OR 1.94;CI 2.00-12.94) and female sex (OR 1.94;CI 2.00-12.94). Type of arrhythmia had no significant effect. Use of the LUCAS was not associated with ROSC (OR 0.73;CI 0.34-2.1).

Conclusion

This is the first study to compare mechanical and manual out-of-hospital chest compression of similar duration to ROSC. The LUCAS did not show added benefit in terms of ROSC rate, and its use did not lead to a higher risk of traumatic injury. ACD devices may be more useful in cases of delayed ambulance response times, or events in remote locations.

Comparison between Prehospital Mechanical Cardiopulmonary Resuscitation (CPR) Devices and Manual CPR for Out-of-Hospital Cardiac Arrest: A Systematic Review, Meta-Analysis, and Trial Sequential Analysis

In pre-hospital settings, efficient cardiopulmonary resuscitation (CPR) is challenging; therefore, the application of mechanical CPR devices continues to increase. However, the evidence of the benefits of using mechanical CPR devices in pre-hospital settings for adult out-of-hospital cardiac arrest (OHCA) is controversial. This meta-analysis compared the effects of mechanical and manual CPR applied in the pre-hospital stage on clinical outcomes after OHCA. Cochrane Library, PubMed, Embase, and ClinicalTrials.gov were searched from inception until October 2021. Studies comparing mechanical and manual CPR applied in the pre-hospital stage for survival outcomes of adult OHCA were eligible. Data abstraction, quality assessment, meta-analysis, trial sequential analysis (TSA), and grading of recommendations, assessment, development, and evaluation were conducted. Seven randomized controlled and 15 observational studies were included. Compared to manual CPR, pre-hospital use of mechanical CPR showed a positive effect in achieving return of spontaneous circulation (ROSC) and survival to admission. No difference was found in survival to discharge and discharge with favorable neurological status, with inconclusive results in TSA. In conclusion, pre-hospital use of mechanical CPR devices may benefit adult OHCA in achieving ROSC and survival to admission. With low certainty of evidence, more well-designed large-scale randomized controlled trials are needed to validate these findings.