Safety of mechanical and manual chest compressions in cardiac arrest patients: A systematic review and meta-analysis

The effects of bystander interventions for foreign body airway obstruction on survival and neurological outcomes: Findings of the MOCHI registry

INTRODUCTION

Foreign body airway obstruction (FBAO) is a life-threatening condition. We aimed to quantify the impact of bystander FBAO interventions on survival and neurological outcomes.

METHODS

We conducted a Japan-wide prospective, multi-center, observational study including all FBAO patients who presented to the Emergency Department from April 2020 to March 2023. Information on bystander FBAO interventions was collected through interviews with emergency medical services personnel. Primary outcomes included 1-month survival and favorable neurologic outcome defined as Cerebral Performance Category 1 or 2. We performed a multivariable logistic regression and a Cox proportional hazards modeling to adjust for confounders.

RESULTS

We analyzed a total of 407 patients in the registry who had the median age of 82 years old (IQR 73-88). The FBAO incidents were often witnessed (86.5%, n = 352/407) and the witnesses intervened in just over half of the cases (54.5%, n = 192/352). The incidents frequently occurred at home (54.3%, n = 221/407) and nursing home (21.6%, n = 88/407). Common first interventions included suction (24.8%, n = 101/407) and back blow (20.9%, n = 85/407). The overall success rate of bystander interventions was 48.4% (n = 93/192). About half (48.2%, n = 196/407) survived to 1-month and 23.8% patients (n = 97/407) had a favorable neurological outcome. Adjusting for pre-specified confounders, bystander interventions were independently associated with survival (hazard ratio, 0.55; 95% CI, 0.39-0.77) and a favorable neurological outcome (adjusted OR, 2.18; 95% CI, 1.23-3.95).

CONCLUSION

Bystander interventions were independently associated with survival and favorable neurological outcome, however, they were performed only in the half of patients.

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.

Liver Hemorrhage Following Mechanical CPR With the Lund University Cardiopulmonary Assist System (LUCAS) Device: A Focused Case Report

Cardiac arrest is a leading cause of mortality globally, and mechanical CPR devices like the LUCAS system are designed to improve outcomes by enhancing consistency and reducing rescuer fatigue. However, this case report of a 76-year-old female who suffered cardiac arrest post-flight reveals significant complications associated with mechanical CPR. Despite achieving initial resuscitation, she developed extensive liver damage and additional complications, which ultimately led to her death. This case underscores the importance of precise training and strict adherence to guidelines when using mechanical CPR devices. It highlights that while these devices offer potential benefits, they also pose risks, especially for vulnerable patients, necessitating careful consideration and ongoing evaluation to optimize safety and effectiveness.

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.

Is the occurrence of reversed airflow in manual ventilation during cardiopulmonary resuscitation associated with reduced net tidal volumes?

Background

During cardiopulmonary resuscitation, following advanced airway placement, chest compressions and ventilations are performed simultaneously. During inspiration, chest compressions and positive pressure ventilation exert opposite forces on the respiratory system, frequently resulting in reversed airflow.

Methods

Following endotracheal intubation, a flow sensor was connected to the respiratory circuit of intubated, adult out-of-hospital cardiac arrest patients receiving manual chest compressions and manual ventilations. Chest compression parameters were measured using an accelerometer. Inspiratory and expiratory volumes during the inspiratory phase of positive pressure ventilations were quantified. Duration of the inspiratory and expiratory phases was calculated.

Results

In this study, 25 patients were included, 682 ventilations were analyzed. Reversed airflow was observed in 23 patients, occurring 389 times during 270 ventilations. Median volume of reversed airflow was 2 mL (IQR 1.4-7 mL). There was no difference between net tidal volumes of ventilations during which reversed airflow did (median 420 mL, IQR 315-549) or did not occur (median 406 mL, IQR 308-530). When reversed airflow occurred, the duration of the inspiratory phase was longer (median 1.2 sec, IQR 0.9-1.4) compared to ventilations without reversed airflow (median 0.9 sec, IQR 0.9-1.4). Univariate analysis showed a weak correlation between chest compression depth and volume of reversed airflow.

Conclusion

Reversed airflow frequently occurs during cardiopulmonary resuscitation. Volumes of reversed airflow were small, showing a weak correlation with chest compression depth. The occurrence of reversed airflow was not associated with reduced net tidal volumes.

Study of risk factors for injuries due to cardiopulmonary resuscitation with special focus on the role of the heart: A machine learning analysis of a prospective registry with multiple sources of information (ReCaPTa Study)

Background

The study of thoracic injuries and biomechanics during CPR requires detailed studies that are very scarce. The role of the heart in CPR biomechanics has not been determined. This study aimed to determine the risk factors importance for serious ribcage damage due to CPR.

Methods

Data were collected from a prospective registry of out-of-hospital cardiac arrest between April 2014 and April 2017. This study included consecutive out-of-hospital CPR attempts undergoing an autopsy study focused on CPR injuries. Cardiac mass ratio was defined as the ratio of real to expected heart mass. Pearson's correlation coefficient was used to select clinically relevant variables and subsequently classification tree models were built. The Gini index was used to determine the importance of the associated serious ribcage damage factors. The LUCAS® chest compressions device forces and the cardiac mass were analyzed by linear regression.

Results

Two hundred CPR attempts were included (133 manual CPR and 67 mechanical CPR). The mean age of the sample was 60.4 ± 13.5, and 56 (28%) were women. In all, 65.0% of the patients presented serious ribcage damage. From the classification tree build with the clinically relevant variables, age (0.44), cardiac mass ratio (0.26), CPR time (0.22), and mechanical CPR (0.07), in that order, were the most influential factors on serious ribcage damage. The chest compression forces were greater in subjects with higher cardiac mass.

Conclusions

The heart plays a key role in CPR biomechanics being cardiac mass ratio the second most important risk factor for CPR injuries.

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.

Cardiac Catheterization Laboratory Management of the Comatose Adult Patient With an Out-of-Hospital Cardiac Arrest: A Scientific Statement From the American Heart Association

Out-of-hospital cardiac arrest is a leading cause of death, accounting for ≈50% of all cardiovascular deaths. The prognosis of such individuals is poor, with <10% surviving to hospital discharge. Survival with a favorable neurologic outcome is highest among individuals who present with a witnessed shockable rhythm, received bystander cardiopulmonary resuscitation, achieve return of spontaneous circulation within 15 minutes of arrest, and have evidence of ST-segment elevation on initial ECG after return of spontaneous circulation. The cardiac catheterization laboratory plays an important role in the coordinated Chain of Survival for patients with out-of-hospital cardiac arrest. The catheterization laboratory can be used to provide diagnostic, therapeutic, and resuscitative support after sudden cardiac arrest from many different cardiac causes, but it has a unique importance in the treatment of cardiac arrest resulting from underlying coronary artery disease. Over the past few years, numerous trials have clarified the role of the cardiac catheterization laboratory in the management of resuscitated patients or those with ongoing cardiac arrest. This scientific statement provides an update on the contemporary approach to managing resuscitated patients or those with ongoing cardiac arrest.

Rib fractures and other injuries after cardiopulmonary resuscitation for non-traumatic cardiac arrest: a systematic review and meta-analysis

PURPOSE

This study aims to ascertain the prevalence of rib fractures and other injuries resulting from CPR and to compare manual with mechanically assisted CPR. An additional aim was to summarize the literature on surgical treatment for rib fractures following CPR.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Embase, Medline Ovid, Cochrane Central, Web of Science, and Google Scholar.

REVIEW METHODS

The databases were searched to identify studies reporting on CPR-related injuries in patients who underwent chest compressions for a non-traumatic cardiopulmonary arrest. Subgroup analysis was conducted to compare the prevalence of CPR-related injuries in manual versus mechanically assisted chest compressions. Studies reporting on surgery for CPR-related rib fractures were also reviewed and summarized.

RESULTS

Seventy-four studies reporting CPR-related injuries were included encompassing a total of 16,629 patients. Any CPR-related injury was documented in 60% (95% confidence interval [95% CI] 49-71) patients. Rib fractures emerged as the most common injury, with a pooled prevalence of 55% (95% CI 48-62). Mechanically assisted CPR, when compared to manual CPR, was associated with a higher risk ratio for CPR-related injuries of 1.36 (95% CI 1.17-1.59). Eight studies provided information on surgical stabilization of CPR-related rib fractures. The primary indication for surgery was the inability to wean from mechanical ventilation in the presence of multiple rib fractures.

CONCLUSION

Rib fractures and other injuries frequently occur in patients who undergo CPR after a non-traumatic cardiopulmonary arrest, especially when mechanical CPR is administered. Surgical stabilization of CPR-related rib fractures remains relatively uncommon.

LEVEL OF EVIDENCE

Level III, systematic review and meta-analysis.

Thrombolysis and mechanical cardiopulmonary resuscitation for pulmonary embolism complicated by hepatic and splenic lacerations resulting in major haemorrhage

Thrombolysis with prolonged cardiopulmonary resuscitation may be required for the successful resuscitation of patients presenting with massive pulmonary embolism leading to cardiac arrest. A rare, recognised complication of cardiopulmonary resuscitation is traumatic hepatic and splenic laceration. The incidence of complications is believed to be increased in those who receive automated mechanical cardiopulmonary resuscitation, compared to those who receive standard chest compressions. We present a case of a patient with massive pulmonary embolism leading to cardiac arrest which was successfully treated with thrombolysis and mechanical automated cardiopulmonary resuscitation. The patient suffered hepatic and splenic lacerations resulting in major haemorrhage. This required emergency resuscitation with blood products and splenic embolisation. This case highlights the importance of continual re-assessment of patients, the early recognition of complications and an awareness of the potential complications of treatments we deliver.

Management of Patients After Cardiac Arrest

Cardiac arrest remains a significant cause of morbidity and mortality, although contemporary care now enables potential survival with good neurologic outcome. The core acute management goals for survivors of cardiac arrest are to provide organ support, sustain adequate hemodynamics, and evaluate the underlying cause of the cardiac arrest. In this article, the authors review the current state of knowledge and clinical intensive care unit practice recommendations for patients after cardiac arrest, particularly focusing on important areas of uncertainty, such as targeted temperature management, neuroprognostication, coronary evaluation, and hemodynamic targets.

Injury pattern and clinical outcome in patients with and without chest wall injury after cardiopulmonary resuscitation

BACKGROUND

Cardiopulmonary resuscitation (CPR), although lifesaving may cause chest wall injury (CWI) because of the physical force exerted on the thorax. The impact of CWI on clinical outcome in this patient group is unclear. The primary aim of this study was to investigate the incidence of CPR-related CWI and the secondary aim to study injury pattern, length of stay (LOS), and mortality in patients with and without CWI.

METHODS

This is a retrospective study of adult patients who were admitted to our hospital due to cardiac arrest (CA) during 2012 to 2020. Patients were identified in the Swedish CPR Registry and those undergoing CT of the thorax within 2 weeks after CPR were included. Patients with traumatic CA, chest wall surgery prior or after CA were excluded. Demographic data, type and length of CPR, type of CWI, LOS on mechanical ventilator (MV), in intensive care unit (ICU) and in hospital (H), and mortality were studied.

RESULTS

Of 1,715 CA patients, 245 met the criteria for inclusion. The majority (79%) of the patients suffered from CWI. Chondral injuries and rib fractures were more common than sternum fractures (95% vs. 57%), and 14% had a radiological flail segment. Patients with CWI were older (66.5 ± 15.4 vs. 52.5 ± 15.2, p < 0.001). No difference was seen in MV-LOS (3 [0-43] vs. 3 [0-22]; p = 0.430), ICU-LOS (3 [0-48] vs. 3 [0-24]; p = 0.427), and H-LOS (5.5 [0-85] vs. 9.0 [1-53]; p = 0.306) in patients with or without CWI. Overall mortality within 30 days was higher with CWI (68% vs. 47%, p = 0.007).

CONCLUSION

Chest wall injuries are common after CPR and 14% of patients had a flail segment on CT. Elderly patients have an increased risk of CWI, and a higher overall mortality is seen in patients with CWI.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level IV.

Termination of Cardiopulmonary Resuscitation in Mountain Rescue: A Scoping Review and ICAR MedCom 2023 Recommendations

Lugnet, Viktor, Miles McDonough, Les Gordon, Mercedes Galindez, Nicolas Mena Reyes, Alison Sheets, Ken Zafren, and Peter Paal. Termination of cardiopulmonary resuscitation in mountain rescue: a scoping review and ICAR MedCom 2023 recommendations. High Alt Med Biol. 24:274-286, 2023. Background: In 2012, the International Commission for Mountain Emergency Medicine (ICAR MedCom) published recommendations for termination of cardiopulmonary resuscitation (CPR) in mountain rescue. New developments have necessitated an update. This is the 2023 update for termination of CPR in mountain rescue. Methods: For this scoping review, we searched the PubMed and Cochrane libraries, updated the recommendations, and obtained consensus approval within the writing group and the ICAR MedCom. Results: We screened a total of 9,102 articles, of which 120 articles met the inclusion criteria. We developed 17 recommendations graded according to the strength of recommendation and level of evidence. Conclusions: Most of the recommendations from 2012 are still valid. We made minor changes regarding the safety of rescuers and responses to primary or traumatic cardiac arrest. The criteria for termination of CPR remain unchanged. The principal changes include updated recommendations for mechanical chest compression, point of care ultrasound (POCUS), extracorporeal life support (ECLS) for hypothermia, the effects of water temperature in drowning, and the use of burial times in avalanche rescue.

Left rib fractures during cardiopulmonary resuscitation are associated with hemodynamic variations in a pig model of cardiac arrest

Background

Chest compressions (CC) are the cornerstone of cardiopulmonary resuscitation (CPR). But CC are also known to cause injuries, specifically rib fractures. The effects of such fractures have not been examined yet. This study aimed to investigate hemodynamic effects of rib fractures during mechanical CPR in a porcine model of cardiac arrest (CA).

Methods

We conducted a retrospective hemodynamic study in 31 pigs that underwent mechanical CC. Animals were divided into three groups based on the location of rib fractures: No Broken Ribs group (n = 11), Left Broken Ribs group (n = 13), and Right Broken Ribs group (n = 7). Hemodynamic measurements were taken at 10 seconds before and 10, 30, and 60 seconds after rib fractures.

Results

Baseline hemodynamic parameters did not differ between the three groups. Systolic aortic pressure was overall higher in the Left Broken Ribs group than in the No Broken Ribs group at 10, 30, and 60 seconds after rib fracture (p = 0.02, 0.01, and 0.006, respectively). The Left Broken Ribs group had a significantly higher right atrial pressure compared to the No Broken Rib group after rib fracture (p = 0.02, 0.01, and 0.03, respectively). There was no significant difference for any parameter for the Right Broken Ribs group, when compared to the No Broken Ribs group.

Conclusion

An increase in main hemodynamic parameters was observed after left rib fractures while right broken ribs were not associated with any change in hemodynamic parameters. Reporting fractures and their location seems worthwhile for future experimental studies.

Pediatric Chest Compression Improvement Via Augmented Reality Cardiopulmonary Resuscitation Feedback in Community General Emergency Departments: A Mixed-Methods Simulation-Based Pilot Study

BACKGROUND

Yearly, more than 20,000 children experience a cardiac arrest. High-quality pediatric cardiopulmonary resuscitation (CPR) is generally challenging for community hospital teams, where pediatric cardiac arrest is infrequent. Current feedback systems are insufficient. Therefore, we developed an augmented reality (AR) CPR feedback system for use in many settings.

OBJECTIVE

We aimed to evaluate whether AR-CPR improves chest compression (CC) performance in non-pediatric-specialized community emergency departments (EDs).

METHODS

We performed an unblinded, randomized, crossover simulation-based study. A convenience sample of community ED nonpediatric nurses and technicians were included. Each participant performed three 2-min cycles of CC during a simulated pediatric cardiac arrest. Participants were randomized to use AR-CPR in one of three CC cycles. Afterward, participants participated in a qualitative interview to inquire about their experience with AR-CPR.

RESULTS

Of 36 participants, 18 were randomized to AR-CPR in cycle 2 (group A) and 18 were randomized to AR-CPR in cycle 3 (group B). When using AR-CPR, 87-90% (SD 12-13%) of all CCs were in goal range, analyzed as 1-min intervals, compared with 18-21% (SD 30-33%) without feedback (p < 0.001). Analysis of qualitative themes revealed that AR-CPR may be usable without a device orientation, be effective at cognitive offloading, and reduce anxiety around and enhance confidence in the CC delivered.

CONCLUSIONS

The novel CPR feedback system, AR-CPR, significantly changed the CC performance in community hospital non-pediatric-specialized general EDs from 18-21% to 87-90% of CC epochs at goal. This study offers preliminary evidence suggesting AR-CPR improves CC quality in community hospital settings.

Compression-associated injuries using CLOVER3000 device in non-survivor patients of OHCA: A retrospective cohort study

AIM

The incidence of compression-associated injuries from using the CLOVER3000, a new mechanical cardiopulmonary resuscitation (CPR) device, is not well studied in the context of out-of-hospital cardiac arrest (OHCA). Thus, we aimed to compare compression-associated injuries between CLOVER3000 and manual CPR.

METHODS

This single-center, retrospective, cohort study used data from the medical records of a tertiary care center in Japan between April 2019 and August 2022. We included adult non-survivor patients with non-traumatic OHCA who were transported by emergency medical services and underwent post-mortem computed tomography. Compression-associated injuries were tested using logistic regression models adjusting for age, sex, bystander CPR performance, and CPR duration.

RESULTS

A total of 189 patients (CLOVER3000, 42.3%; manual CPR, 57.7%) were included in the analysis. The overall incidence of compression-associated injuries was similar between the two groups (92.5% vs. 94.54%; adjusted odds ratio (AOR), 0.62 [95% confidence interval (CI), 0.06-1.44]). The most common injury was anterolateral rib fractures with a similar incidence between the two groups (88.7% vs. 88.9%; AOR, 1.03 [95% CI, 0.38 to 2.78]). The second most common injury was sternal fracture in both groups (53.1% vs. 56.7%; AOR, 0.68 [95% CI, 0.36-1.30]). The incidence rates of other injuries were not statistically different between the both groups.

CONCLUSION

We observed a similar overall incidence of compression-associated injuries between the CLOVER3000 and manual CPR groups on small sample size.

Delayed massive bleeding from minor splenic injury due to mechanical chest compression for cardiopulmonary resuscitation

Background

Splenic injury due to chest compressions is a rare and fatal complication that occurs immediately after cardiopulmonary resuscitation.

Case Presentation

Cardiopulmonary resuscitation was carried out using a mechanical chest compression device in a 74-year-old Japanese female patient who underwent cardiac arrest. Computed tomography postresuscitation revealed bilateral anterior rib fractures. Other traumatic findings were not observed. Coronary angiography revealed no new lesions; the cause of the arrest was hypokalemia. She received mechanical support with venoarterial extracorporeal membrane oxygenation and multiple antithrombotic agents. Her hemodynamic and coagulative condition became life-threatening on day 4; abdominal ultrasound revealed massive bloody ascites. Only a minor splenic laceration was observed intraoperatively, despite massive bleeding. Furthermore, her condition stabilized after splenectomy and blood transfusion. Venoarterial extracorporeal membrane oxygenation was discontinued on day 5.

Conclusion

In patients with postcardiac arrest, delayed bleeding due to minor visceral injury should be considered, particularly for coagulation abnormalities.

Mechanical Cardiopulmonary Resuscitation's Role in Helicopter Air Ambulances: A Narrative Review

Helicopter emergency medical services (HEMS) frequently respond to out-of-hospital cardiac arrest (OHCA) situations. Some have speculated mechanical cardiopulmonary resuscitation (mCPR) may be able to rectify the inadequacy of human performance of cardiopulmonary resuscitation (CPR) during transport. A number of studies have examined the performance of mCPR devices in the air medical setting specifically. Many aspects of the HEMS environment seem uniquely conducive to mCPR, and a growing body of research seems to suggest mCPR holds promise for the treatment of cardiac arrest by HEMS clinicians. Simulation studies show that mCPR leads to improved CPR performance compared with manual CPR in HEMS. Case reports and the experience of several HEMS programs suggest that mCPR can be effectively integrated into HEMS care. However, further research regarding the effectiveness of mCPR in the HEMS environment and in general cardiac arrest care is needed.

Chest wall mechanics during mechanical chest compression and its relationship to CPR-related injuries and survival

Aim

To determine compression force variation (CFV) during mechanical cardiopulmonary resuscitation (CPR) and its relationship with CPR-related injuries and survival.

Methods

Adult non-traumatic OHCA patients who had been treated with mechanical CPR were evaluated for CPR-related injuries using chest X-rays, thoracic computed tomography or autopsy. The CFV exerted by the LUCAS 2 device was calculated as the difference between the maximum and the minimum force values and was categorised into three different groups (high positive CFV ≥ 95 newton (N), high negative CFV ≤ -95 N, and low variation for intermediate CFV). The CFV was correlated with the CPR injuries findings and survival data.

Results

Fifty-two patients were included. The median (IQR) age was 57 (49-66) years, and 13 (25%) cases survived until hospital admission. High positive CFV was found in 21 (40.4%) patients, high negative CFV in 9 (17.3%) and a low CFV in 22 (42.3%). The median (IQR) number of rib fractures was higher in the high positive and negative CFV groups compared with the low CFV group [7(1-9) and 9 (4-11) vs 0 (0-6) (p = 0.021)]. More bilateral fracture cases were found in the high positive and negative CFV groups [16 (76.2%) and 6 (66.7%) vs 6 (27.3%) (p = 0.004)]. In the younger half of the sample more patients survived until hospital admission in the low CFV group compared with the high CFV groups [5 (41.7%) vs 1 (7.1%) (p = 0.037)].

Conclusions

High CFV was associated with ribcage injuries. In the younger patients low CFV was associated with survival until hospital admission.

Resuscitation highlights in 2021

BACKGROUND

This review is the latest in a series of regular annual reviews undertaken by the editors and aims to highlight some of the key papers published in Resuscitation during 2021.

METHODS

Hand-searching by the editors of all papers published in Resuscitation during 2021. Papers were selected based on then general interest and novelty and were categorised into themes.

RESULTS

98 papers were selected for brief mention.

CONCLUSIONS

Resuscitation science continues to evolve and incorporates all links in the chain of survival.