Mechanical versus manual chest compression for out-of-hospital cardiac arrest (PARAMEDIC): a pragmatic, cluster randomised controlled trial

Emergency Medical Service Agency Practices and Cardiac Arrest Survival

Importance

Survival for out-of-hospital cardiac arrest (OHCA) varies widely across emergency medical service (EMS) agencies in the US. However, little is known about which EMS practices are associated with higher agency-level survival.

Objective

To identify resuscitation practices associated with favorable neurological survival for OHCA at EMS agencies.

Design, Setting, and Participants

This cohort study surveyed EMS agencies participating in the Cardiac Arrest Registry to Enhance Survival (CARES) with 10 or more OHCAs annually during January 2015 to December 2019; data analyses were performed from April to October 2023.

Exposure

Survey of resuscitation practices at EMS agencies.

Main Outcomes and Measures

Risk-standardized rates of favorable neurological survival for OHCA at each EMS agency were estimated using hierarchical logistic regression. Multivariable linear regression then examined the association of EMS practices with rates of risk-standardized favorable neurological survival.

Results

Of 577 eligible EMS agencies, 470 agencies (81.5%) completed the survey. The mean (SD) rate of risk-standardized favorable neurological survival was 8.1% (1.8%). A total of 7 EMS practices across 3 domains (training, cardiopulmonary resuscitation [CPR], and transport) were associated with higher rates of risk-standardized favorable neurological survival. EMS agencies with higher favorable neurological survival rates were more likely to use simulation to assess CPR competency (β = 0.54; P = .05), perform frequent reassessment (at least once every 6 months) of CPR competency in new staff (β = 0.51; P = .04), use full multiperson scenario simulation for ongoing skills training (β = 0.48; P = .01), perform simulation training at least every 6 months (β = 0.63; P < .001), and conduct training in the use of mechanical CPR devices at least once annually (β = 0.43; P = .04). EMS agencies with higher risk-standardized favorable neurological survival were also more likely to use CPR feedback devices (β = 0.58; P = .007) and to transport patients to a designated cardiac arrest or ST-segment elevation myocardial infarction receiving center (β = 0.57; P = .003). Adoption of more than half (≥4) of the 7 practices was more common at EMS agencies in the highest quartile of favorable neurological survival rates (70 of 118 agencies [59.3%]) vs the lowest quartile (42 of 118 agencies [35.6%]) (P < .001).

Conclusions and Relevance

In a national registry for OHCA, 7 practices associated with higher rates of favorable neurological survival were identified at EMS agencies. Given wide variability in neurological survival across EMS agencies, these findings provide initial insights into EMS practices associated with top-performing EMS agencies in OHCA survival. Future studies are needed to validate these findings and identify best practices for EMS agencies.

Ventilation during cardiopulmonary resuscitation with mechanical chest compressions: How often are two insufflations being given during the 3-second ventilation pauses?

BACKGROUND

Mechanical chest compression devices in 30:2 mode provide 3-second pauses to allow for two insufflations. We aimed to determine how often two insufflations are provided in these ventilation pauses, in order to assess if prehospital providers are able to ventilate out-of-hospital cardiac arrest (OHCA) patients successfully during mechanical chest compressions.

METHODS

Data from OHCA cases of the regional ambulance service of Utrecht, The Netherlands, were prospectively collected in the UTrecht studygroup for OPtimal registry of cardIAc arrest database (UTOPIA). Compression pauses and insufflations were visualized on thoracic impedance and waveform capnography signals recorded by manual defibrillators. Ventilation pauses were analyzed for number of insufflations, duration of the subintervals of the ventilation cycles, and ratio of successfully providing two insufflations over the course of the resuscitation. Generalized linear mixed effects models were used to accurately estimate proportions and means.

RESULTS

In 250 cases, 8473 ventilation pauses were identified, of which 4305 (51%) included two insufflations. When corrected for non-independence of the data across repeated measures within the same subjects with a mixed effects analysis, two insufflations were successfully provided in 45% of ventilation pauses (95% CI: 40-50%). In 19% (95% CI: 16-22%) none were given.

CONCLUSION

Providing two insufflations during pauses in mechanical chest compressions is mostly unsuccessful. We recommend developing strategies to improve giving insufflations when using mechanical chest compression devices. Increasing the pause duration might help to improve insufflation success.

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.

Accuracy of etiological classification of out-of-hospital cardiac arrest: A scoping review

INTRODUCTION

The Utstein reporting template classifies the etiology of OHCA into "presumed cardiac" and "obvious non-cardiac" or "medical" and "non-medical" categories; however, the accuracy of these classifications is unclear. Ascertaining more accurately the etiology of OHCA is important to tailor advanced life support and identify etiologically consistent patient cohorts for reporting incidence and outcome and enrollment in clinical trials. This scoping review was proposed to identify the state of agreement on etiological classification based on emergency medical service (EMS) data using the Utstein format against other sources.

METHOD

We searched Medline, EBM-Cochrane, and Embase databases from 1946-2023 to identify studies that reported initial and confirmed etiologies of OHCA. A descriptive review of the included studies was conducted.

RESULT

The search yielded 22,994 citations. After excluding duplicates, 16,932 citations were reviewed for titles and abstracts. Twelve studies met the inclusion criteria of this review. The frequency of presumed cardiac etiologies based on EMS data was higher than confirmed cardiac etiologies (88% vs 33%) with 83-94% sensitivity and 73-76% specificity. In contrast, the frequency of presumed non-cardiac etiologies was lower than confirmed non-cardiac etiologies (3% vs 27%) with 52-74% sensitivity and 90-97.7% specificity estimated for respiratory disease.

CONCLUSION

Major disparities exist between current etiological classifications based on the Utstein reporting template and robust sources such as autopsy and medical records. Data linkage and validation are necessary to confirm the etiology of OHCA. Further research is needed on how this misclassification affects reported incidence and outcomes, and how contributing factors may improve etiological classifications.

The association between mechanical CPR and outcomes from in-hospital cardiac arrest: An observational cohort study

AIM

We sought to investigate the relationship between mechanical cardiopulmonary resuscitation (CPR) during in-hospital cardiac arrest and survival to hospital discharge.

METHODS

Utilizing the prospectively collected American Heart Association's Get With The Guidelines database, we performed an observational study. Data from 153 institutions across the United States were reviewed with a total of 351,125 patients suffering cardiac arrest between 2011 and 2019 were screened. After excluding patients with cardiac arrests lasting less than 5 minutes, and patients who had incomplete data, a total of 111,143 patients were included. Our primary exposure was mechanical vs. manual CPR, and the primary outcome was survival to hospital discharge. Multivariate logistic regression models and propensity weighted analyses were used.

RESULTS

11.8% of patients who received mechanical CPR survived to hospital discharge versus 16.9% in the manual CPR group. Patients who received mechanical CPR had a lower probability of survival to discharge compared to patients who received manual CPR (OR 0.66 95% CI 0.58-0.75; p < 0.001). This association persisted with multi-variable adjustment (OR 0.57 95% CI 0.46-0.70, p < 0.0001) and propensity weighted analysis (OR 0.68 95% CI 0.44-0 0.92, p < 0.0001). Mechanical CPR was associated with decrease likelihood of return of spontaneous circulation after multivariate adjustment (OR 0.68, 95% CI 0.60-0.76; p < 0.001).

CONCLUSIONS

Mechanical CPR was associated with a decreased likelihood of survival to hospital discharge and ROSC compared to manual CPR. This finding should be interpreted within the context of important limitations of this study and randomized trials are needed to better investigate this relationship.

Oxygenation and ventilation during prolonged experimental cardiopulmonary resuscitation with either continuous or 30:2 compression-to-ventilation ratios together with 10 cmH20 positive end-expiratory pressure

BACKGROUND

In refractory out-of-hospital cardiac arrest, the patient is commonly transported to hospital with mechanical continuous chest compressions (CCC). Limited data are available on the optimal ventilation strategy. Accordingly, we compared arterial oxygenation and haemodynamics during manual asynchronous continuous ventilation and compressions with a 30:2 compression-to-ventilation ratio together with the use of 10 cmH2O positive end-expiratory pressure (PEEP).

METHODS

Intubated and anaesthetized landrace pigs with electrically induced ventricular fibrillation were left untreated for 5 min (n = 31, weight ca. 55 kg), after which they were randomized to either the CCC group or the 30:2 group with the the LUCAS® 2 piston device and bag-valve ventilation with 100% oxygen targeting a tidal volume of 8 ml/kg with a PEEP of 10 cmH2O for 35 min. Arterial blood samples were analysed every 5 min, vital signs, near-infrared spectroscopy and electrical impedance tomography (EIT) were measured continuously, and post-mortem CT scans of the lungs were obtained.

RESULTS

The arterial blood values (median + interquartile range) at the 30-min time point were as follows: PaO2: 180 (86-302) mmHg for the 30:2 group; 70 (49-358) mmHg for the CCC group; PaCO2: 41 (29-53) mmHg for the 30:2 group; 44 (21-67) mmHg for the CCC group; and lactate: 12.8 (10.4-15.5) mmol/l for the 30:2 group; 14.7 (11.8-16.1) mmol/l for the CCC group. The differences were not statistically significant. In linear mixed models, there were no significant differences between the groups. The mean arterial pressures from the femoral artery, end-tidal CO2, distributions of ventilation from EIT and mean aeration of lung tissue in post-mortem CTs were similar between the groups. Eight pneumothoraces occurred in the CCC group and 2 in the 30:2 group, a statistically significant difference (p = 0.04).

CONCLUSIONS

The 30:2 and CCC protocols with a PEEP of 10 cmH2O resulted in similar gas exchange and vital sign outcomes in an experimental model of prolonged cardiac arrest with mechanical compressions, but the CCC protocol resulted in more post-mortem pneumothoraces.

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.

Prehospital optimal shock energy for defibrillation (POSED): A cluster randomised controlled feasibility trial

Background

We explored the feasibility of a large-scale UK ambulance services trial of optimal defibrillation shock energy for out-of-hospital cardiac arrest. The primary objective of this feasibility study was to establish the number of eligible patients and the number recruited. Secondary outcomes were adherence to allocated treatment and data completeness.

Methods

We conducted a three-arm parallel group cluster randomised controlled feasibility study in a single ambulance service in southern England. Adult patients in out-of-hospital cardiac arrest treated for a shockable rhythm were included. Zoll X series defibrillators (clusters) were randomised to deliver 120-150-200 J, 150-200-200 J, or 200-200-200 J shock strategies.

Results

Between March 2022 and February 2023, we randomised 38 eligible patients (120-150-200 J (n = 12), 150-200-200 J (n = 10), 200-200-200 J (n = 16)) to the study. The recruitment rate per cluster was 0.07 per month. The median patient age was 71 years (IQR 59-81 years); 79% were male. Twenty-eight cardiac arrests (74%) occurred in a private residence, 29 (76%) were witnessed and 32 (84%) patients received bystander CPR. Treatment adherence was 93% and completeness of clinical and electrical outcomes was 86%. At 30 days, 3/36 (8.3%) patients survived; we were unable to collect survival outcomes for two patients. Defibrillation data collection became difficult when defibrillators became separated from their allocated vehicles.

Conclusion

We have demonstrated the feasibility of a cluster randomised controlled trial of optimal shock energy for defibrillation in a UK ambulance service. We have identified possible solutions to issues relating to trial design.

Route of drug administration in out-of-hospital cardiac arrest: A protocol for a randomised controlled trial (PARAMEDIC-3)

Aims

The PARAMEDIC-3 trial evaluates the clinical and cost-effectiveness of an intraosseous first strategy, compared with an intravenous first strategy, for drug administration in adults who have sustained an out-of-hospital cardiac arrest.

Methods

PARAMEDIC-3 is a pragmatic, allocation concealed, open-label, multi-centre, superiority randomised controlled trial. It will recruit 15,000 patients across English and Welsh ambulance services. Adults who have sustained an out-of-hospital cardiac arrest are individually randomised to an intraosseous access first strategy or intravenous access first strategy in a 1:1 ratio through an opaque, sealed envelope system. The randomised allocation determines the route used for the first two attempts at vascular access. Participants are initially enrolled under a deferred consent model.The primary clinical-effectiveness outcome is survival at 30-days. Secondary outcomes include return of spontaneous circulation, neurological functional outcome, and health-related quality of life. Participants are followed-up to six-months following cardiac arrest. The primary health economic outcome is incremental cost per quality-adjusted life year gained.

Conclusion

The PARAMEDIC-3 trial will provide key information on the clinical and cost-effectiveness of drug route in out-of-hospital cardiac arrest.Trial registration: ISRCTN14223494, registered 16/08/2021, prospectively registered.

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.

Real-world comparison between mechanical and manual cardiopulmonary resuscitation during the COVID-19 pandemic

BACKGROUND

The COVID-19 pandemic has posed significant challenges to healthcare systems worldwide, including an increase in out-of-hospital cardiac arrests (OHCA). Healthcare providers are now required to use personal protective equipment (PPE) during cardiopulmonary resuscitation (CPR). Additionally, mechanical CPR devices have been introduced to reduce the number of personnel required for resuscitation. This study aimed to compare the outcomes of CPR performed with a mechanical device and the outcomes of manual CPR performed by personnel wearing PPE.

METHODS

This multicenter observational study utilized data from the Korean Cardiac Arrest Research Consortium registry. The study population consisted of OHCA patients who underwent CPR in emergency departments (EDs) between March 2020 and June 2021. Patients were divided into two equal propensity score matched groups: mechanical CPR group (n = 421) and PPE-equipped manual CPR group (n = 421). Primary outcomes included survival rates and favorable neurological outcomes at discharge. Total CPR duration in the ED was also assessed.

RESULTS

There were no significant between-group differences with respect to survival rate at discharge (mechanical CPR: 7.4% vs PPE-equipped manual CPR: 8.3%) or favorable neurological outcomes (3.3% vs. 3.8%, respectively). However, the mechanical CPR group had a longer duration of CPR in the ED compared to the manual CPR group.

CONCLUSION

This study found no significant differences in survival rates and neurological outcomes between mechanical CPR and PPE-equipped manual CPR in the ED setting. However, a longer total CPR duration was observed in the mechanical CPR group. Further research is required to explore the impact of PPE on healthcare providers' performance and fatigue during CPR in the context of the pandemic and beyond.

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.

Challenges and Experiences in Multicenter Prehospital Stroke Research: Narrative Data from the Rapid Intervention with Glyceryl Trinitrate in Hypertensive Stroke Trial-2 (RIGHT-2)

BACKGROUND

Ambulance services are increasingly research active and the Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial-2 (RIGHT-2) is the largest United Kingdom (UK) ambulance-based randomized controlled trial in stroke. We explore the complexities and challenges encountered during RIGHT-2.

METHODS

Five hundred and sixteen of 1487 paramedics from eight UK ambulance services serving 54 comprehensive or primary stroke care centers screened and consented 1149 patients presenting within 4 h of FAST-positive stroke and with systolic blood pressure >120 mmHg; participants were randomized to treatment with transdermal glyceryl trinitrate versus sham patch in the ambulance.

KEY FINDINGS

Working with multiple ambulance services demanded flexibility in the trial protocol to overcome variation in operating procedures to ensure deliverability. Many paramedics are novice researchers, and research concepts and practices are emerging including consent strategies in emergency stroke care. Regional variation in hospital participation and hours/days of operation presented paramedics with additional considerations prior to patient recruitment. The working hours of hospital research staff often do not reflect the 24/7 nature of ambulance work, which challenged deliverability until trial processes became fully embedded. Management of investigational medicinal product between ambulance stations, in-transit when on ambulance vehicles and on handover at hospital, necessitated an in-depth review to maintain accountability.

CONCLUSION

RIGHT-2 demonstrated that although there are significant practical challenges to conducting multicenter ambulance-based research in a time-dependent environment, careful planning and management facilitated delivery. Lessons learned here will help inform the design and conduct of future ambulance-based trials.

Prehospital factors associated with out-of-hospital cardiac arrest outcomes in a metropolitan city: a 4-year multicenter study

BACKGROUND

Prehospital factors play a vital role in out-of-hospital cardiac arrest (OHCA) survivability, and they vary between countries and regions. We investigated the prehospital factors associated with OHCA outcomes in a single metropolitan city in the Republic of Korea.

METHODS

This study included adult medical OHCA patients enrolled prospectively, using data from the citywide OHCA registry for patients registered between 2018 and 2021. The primary outcome was survival to hospital discharge. Multivariable logistic regression analysis was conducted to determine the factors associated with the study population's clinical outcomes, adjusting for covariates. We performed a sensitivity analysis for clinical outcomes only for patients without prehospital return of spontaneous circulation prior to emergency medical service departure from the scene.

RESULTS

In multivariable logistic regression analysis, older age (odds ratio [OR] 0.96; 95% confidence interval [CI] 0.95-0.97), endotracheal intubation (adjusted odds ratio [aOR] 0.29; 95% [CIs] 0.17-0.51), supraglottic airway (aOR 0.29; 95% CI 0.17-0.51), prehospital mechanical chest compression device use (OR 0.13; 95% CI 0.08-0.18), and longer scene time interval (OR 0.96; 95% CI 0.93-1.00) were negatively associated with survival. Shockable rhythm (OR 24.54; 95% CI 12.99-42.00), pulseless electrical activity (OR 3.11; 95% CI 1.74-5.67), and witnessed cardiac arrest (OR 1.59; 95% CI 1.07-2.38) were positively associated with survival. In the sensitivity analysis, endotracheal intubation, supraglottic airway, prehospital mechanical chest compression device use, and longer scene time intervals were associated with significantly lower survival to hospital discharge.

CONCLUSIONS

Regional resuscitation protocol should be revised based on the results of this study, and modifiable prehospital factors associated with lower survival of OHCA should be improved.

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.

Extracorporeal cardiopulmonary resuscitation for refractory out-of-hospital cardiac arrest: a systematic review and meta-analysis of randomized clinical trials

INTRODUCTION

Extracorporeal cardiopulmonary resuscitation (ECPR) is currently recommended as a rescue therapy for selected patients in refractory out-of-hospital cardiac arrest (OHCA). However, there is conflicting evidence regarding its effect on survival and neurological outcomes. We conducted a systematic review and meta-analysis of randomized clinical trials (RCTs) to evaluate whether ECPR is superior to standard CPR in refractory OHCA.

METHODS

We performed a systematic search of electronic databases (PubMed, CENTRAL, and Scopus) until March 2023. Studies were eligible if they a) were RCTs, and b) compared ECPR vs. standard CPR for OHCA. Outcomes were defined as survival with a favorable neurological status (cerebral performance category 1 or 2) at both the shortest follow-up and at 6 months, and in-hospital mortality. Meta-analyses using a random-effects model were undertaken.

RESULTS

Three RCTs, with a total of four hundred and eighteen patients, were included. Compared with standard CPR, ECPR was associated with a non-statistically significant higher rate of survival with a favorable neurological outcome at the shortest follow-up (26.4% vs. 17.2%; RR 1.47 [95% CI 0.91-2.40], P = 0.12) and at 6 months (28.3% vs. 18.6%; RR 1.48 [95% CI 0.88-2.49], P = 0.14). The mean absolute rate of in-hospital mortality was not significantly lower in the ECPR group (RR 0.89 [95% CI 0.74-1.07], P = 0.23).

CONCLUSION

ECPR was not associated with a significant improvement in survival with favorable neurologic outcomes in refractory OHCA patients. Nevertheless, these results constitute the rationale for a well-conducted, large-scale RCT, aiming to clarify the effectiveness of ECPR compared to standard CPR.

Benefits, key protocol components, and considerations for successful implementation of extracorporeal cardiopulmonary resuscitation: a review of the recent literature

The application of venoarterial extracorporeal membrane oxygenation (ECMO) in patients unresponsive to conventional cardiopulmonary resuscitation (CPR) has significantly increased in recent years. To date, three published randomized trials have investigated the use of extracorporeal CPR (ECPR) in adults with refractory out-of-hospital cardiac arrest. Although these trials reported inconsistent results, they suggest that ECPR may have a significant survival benefit over conventional CPR in selected patients only when performed with strict protocol adherence in experienced emergency medical services-hospital systems. Several studies suggest that identifying suitable ECPR candidates and reducing the time from cardiac arrest to ECMO initiation are key to successful outcomes. Prehospital ECPR or the rendezvous approach may allow more patients to receive ECPR within acceptable timeframes than ECPR initiation on arrival at a capable hospital. ECPR is only one part of the system of care for resuscitation of cardiac arrest victims. Optimizing the chain of survival is critical to improving outcomes of patients receiving ECPR. Further studies are needed to find the optimal strategy for the use of ECPR.

State of the art post-cardiac arrest care: evolution and future of post cardiac arrest care

Out-of-hospital cardiac arrest is a leading cause of mortality. In the pre-hospital setting, bystander response with cardiopulmonary resuscitation and the use of publicly available automated external defibrillators have been associated with improved survival. Early in-hospital treatment still focuses on emergency coronary angiography for selected patients. For patients remaining comatose, temperature control to avoid fever is still recommended, but former hypothermic targets have been abandoned. For patients without spontaneous awakening, the use of a multimodal prognostication model is key. After discharge, follow-up with screening for cognitive and emotional disabilities is recommended. There has been an incredible evolution of research on cardiac arrest. Two decades ago, the largest trials include a few hundred patients. Today, undergoing studies are planning to include 10-20 times as many patients, with improved methodology. This article describes the evolution and perspectives for the future in post-cardiac arrest care.

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

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

Successful transplantation of LUCAS device assisted uncontrolled DCD kidneys with prolonged relative warm ischemia time: An underutilized option in North America

Approximately 25% of deceased donors in the United States are procured in a donation after circulatory death (DCD) setting. Successful transplant outcomes from uncontrolled DCD (uDCD) practices have been reported in multiple European programs. They utilize established protocols for uDCD procurement with normo-thermic or hypothermic regional perfusion to reduce ischemic damage. Further, manual or mechanical chest compressions using extrinsic devices, such as the LUCAS device, are implemented to maintain circulation before organ retrieval. Currently, uDCDs are not a major part of DCD organ utilization in the United States. We report our experience with utilization of kidneys from uDCD with the use of the LUCAS device without normothermic or hypothermic regional perfusion. We transplanted four kidneys from three uDCD donors without utilization of in situ regional perfusion and with prolonged relative warm ischemia time (rWIT) (>100 min). All recipients had functional renal allografts and improved renal function after the transplant. To our knowledge, this is the 1st successful series reported in the United States of the utilization of kidneys from uDCDs without the utilization of in situ perfusion to maintain organ preservation with prolonged rWIT.

In-Hospital Cardiac Arrest

This article reviews the epidemiology and management of in-hospital cardiac arrest.

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.

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.

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.

Use of a novel smartphone-based application tool for enrolment and randomisation in pre-hospital clinical trials

The effective recruitment and randomisation of patients in pre-hospital clinical trials presents unique challenges. Owing to the time critical nature of many pre-hospital emergencies and limited resourcing, the use of traditional methods of randomisation that may include centralised telephone or web-based systems are often not practicable or feasible. Previous technological limitations have necessitated that pre-hospital trialists strike a compromise between implementing pragmatic, deliverable study designs, and robust enrolment and randomisation methodologies. In this commentary piece, we present a novel smartphone-based solution that has the potential to align pre-hospital clinical trial recruitment processes to that of best-in-practice in-hospital and ambulatory care setting studies. Running title: Smartphone application based randomisation in pre-hospital clinical trials.

LUCAS Device Use Associated with Prolonged Pauses during Application and Long Chest Compression Intervals

BACKGROUND

Tenets of high-quality out-of-hospital cardiac arrest (OHCA) resuscitation include early recognition and treatment of shockable rhythms, and minimizing interruptions in compressions. Little is known about how use of a mechanical compression device affects these elements. We hypothesize that use of such a device is associated with prolonged pauses in compressions to apply the device, and long compression intervals overall.

METHODS

We systematically abstracted CPR metrics from 4 months of adult non-traumatic OHCA cases, each of which had at least 10 minutes of resuscitation, used a LUCAS device, and had a valid monitor file attached to the patient care report. Our primary outcomes of interest were the duration of each pause in compressions and the duration of compressions between pauses, stratified by whether or not the LUCAS device was used/applied during the segment. Each pause was further evaluated for a possible associated procedure based on pre-defined criteria. Descriptive statistics, chi-square, and Kruskal-Wallis tests were used as appropriate.

RESULTS

Fifty-eight cases were included, median age 62.5 years (IQR 49.3-70.8), 47% female, 66% nonwhite. Overall, 633 compression-pause segments were analyzed (517 with and 116 without LUCAS applied). Spacing of pauses was significantly longer with the LUCAS than without [median (IQR) 133 (82-213) seconds vs. 38 (18-62) seconds, p < 0.05]. When using a LUCAS, compressions were continuous for at least 3 min in 166/517 segments, at least 4 min in 89/517 segments, and at least 5 min in 56/517 segments. Without a LUCAS, compressions were longer than 3 min in 7/116 segments. Pauses exceeded 10 s more frequently with LUCAS application (32/38) than airway management or defibrillation (27/80, p < 0.05). Peri-LUCAS pauses exceeded 30 s in 6/38 cases.

CONCLUSION

LUCAS use was associated with long compression intervals without identifiable pauses to assess for pulse or cardiac rhythm, and device application was associated with longer pauses than airway management or defibrillation. The clinical significance and effect on patient outcomes remain uncertain and require further study.

Measuring the Effect of Off-Balancing Vectors on the Delivery of High-Quality CPR during Ambulance Transport: A Proof of Concept Study

AIM

This study aims to demonstrate the feasibility of quantifying the off-balancing vectors experienced during ambulance transport and comparing them to high-quality cardiopulmonary resuscitation (HQ-CPR) metrics.

METHODS

Ten participants completed a total of 20 evolutions of compression-only HQ-CPR in an ambulance driven in a manner that minimized or increased linear and angular off-balancing vectors. Linear and angular velocity, linear and angular acceleration, and linear jerk were recorded. HQ-CPR variables measured were compression fraction and proportion of compressions with depth >5 cm (depth%), rate 100-120 (rate%), full chest recoil (recoil%), and hand position (hand%). A composite score was calculated: [(depth% + rate% + recoil% + hand%)/4) * compression fraction]. Difficulty of HQ-CPR performance was measured with the Borg rating of perceived exertion (RPE) Scale. A series of mixed effects models were fitted regressing each HQ-CPR metric on each off-balancing vector.

RESULTS

HQ-CPR data and vector quantity data were successfully recorded in all evolutions. Rate% was negatively associated with increasing linear velocity (slope = -3.82, standard error [SE] 1.12, p = 0.005), linear acceleration (slope = -5.52, SE 1.93, p = 0.013), linear jerk (slope = -17.60, SE 5.78, p = 0.007), angular velocity (slope = -75.74, SE 22.72, p = 0.004), and angular acceleration (slope = -152.53, SE 59.60, p = 0.022). Compression fraction was negatively associated with increasing linear velocity (slope = -1.35, SE 0.37, p = 0.004), linear acceleration (slope = -1.67, SE 0.48, p = 0.003), linear jerk (slope = -4.90, SE 1.86, p = 0.018), angular velocity (slope = -25.66, SE 6.49, p = 0.001), and angular acceleration (slope = -45.35, SE 18.91, p = 0.031). Recoil% was negatively associated with increasing linear velocity (slope = -5.80, SE 2.21, p = 0.023) and angular velocity (slope = -116.96, SE 44.24, p = 0.019)). Composite score was negatively associated with increasing linear velocity (slope = -4.49, SE 1.45, p = 0.009) and angular velocity (slope = -86.13, SE 31.24, p = 0.014) and approached a negative association with increasing magnitudes of linear acceleration (slope -5.54, SE 2.93, p = 0.075), linear jerk (slope = -17.43, SE 8.80, p = 0.064), and angular acceleration (slope = -170.43, SE 80.73, p = 0.051). Borg RPE scale was positively associated with all off-balancing vectors. Depth%, hand%, mean compression depth, and mean compression rate were not correlated with any off-balancing vector.

CONCLUSION

Off-balancing vector data can be successfully quantified during ambulance transport and compared with HQ-CPR performance parameters. Increasing off-balancing vectors experienced during ambulance transport are associated with worse HQ-CPR metrics and increased perceived physical exertion. These data may help guide future drive styles, ambulance design, or use of mechanical CPR devices to improve HQ-CPR delivery during selected patient transport scenarios.

The RESearch PARamedic Experience (RESPARE) study: a qualitative study exploring the experiences of research paramedics working in the United Kingdom

Background

The research paramedic position is a relatively niche role undertaken by a small number of paramedics who support, deliver and promote research. Research paramedic roles provide opportunities to develop talented researchers who are recognised as vital elements of developing a research culture within ambulance services. The benefits of research-active clinicians have been recognised at a national level. The aim of this study was to explore the experience of people who work, or have worked, as research paramedics.

Methods

A generic qualitative approach underpinned by phenomenological concepts was used. Volunteers were recruited via ambulance research leads and social media. Online focus groups allowed participants to discuss their roles with peers who may be geographically distant. Semi-structured interviews expanded on the focus group findings. Data were recorded, transcribed verbatim and analysed using framework analysis.

Results

Eighteen paramedics (66% female, median involvement in research six (interquartile range 2-7) years) representing eight English NHS ambulance trusts participated in three focus groups and five interviews lasting around one hour, in November and December 2021.Six key themes were identified: starting as a research paramedic; barriers and facilitators to working as a research paramedic; research careers; opportunities; the community (support and networking); and the value of a clinical identity.

Conclusions

Many research paramedics had similar experiences in terms of starting their career by delivering research for large studies, then building on this experience and the networks they create to develop their own research. There are common organisational and financial barriers to working as a research paramedic. Career progression in research beyond the research paramedic role is not well defined, but often involves building links outside of the ambulance service.

Cardiac arrest and cardiopulmonary resuscitation in “hostile” environments: Using automated compression devices to minimize the rescuers’ danger

Mechanical automated compression devices are being used in cardiopulmonary resuscitation instead of manual, “hands-on”, rescuer-delivered chest compressions. The -theoretical- advantages include high-quality non-stop compressions, thus freeing the rescuer performing the compressions and additionally the ability of the rescuer to stand reasonably away from a potentially “hazardous” victim, or from hazardous and/or difficult resuscitation conditions. Such circumstances involve cardiopulmonary resuscitation (CPR) in the Cardiac Catheterization Laboratory, especially directly under the fluoroscopy panel, where radiation is well known to cause detrimental effects to the rescuer, and CPR during/after land or air transportation of cardiac arrest victims. Lastly, CPR in a coronavirus disease 2019 patient/ward, where the danger of contamination and further serious illness of the health provider is very existent. The scope of this review is to review and present literature and current guidelines regarding the use of mechanical compressions in these “hostile” and dangerous settings, while comparing them to manual compressions.

Mechanical chest compression and extracorporeal life support for out-of-hospital cardiac arrest. A 30-month observational study in the metropolitan area of Milan, Italy

BACKGROUND

Return of spontaneous circulation (ROSC) is achieved in 25% of out-of-hospital cardiac arrest (OHCA) patients. Mechanical chest compression (mechCPR) may maintain better perfusion during transport, allowing hospital treatments like extracorporeal circulation life support (ECLS). We aim to assess the effectiveness of a pre-hospital protocol introduction.

METHODS

Observational, retrospective study assessing all OHCA patients aged 12-75, with no-flow time <20 min in a metropolitan area (Milan, Italy, 2013-2016).

PRIMARY OUTCOMES

ROSC and Cerebral Performance Category score (CPC) ≤2 at hospital discharge. Logistic regressions with multiple comparison adjustments balanced with propensity scores calculated with inverse probability of treatment weighting were performed.

RESULTS

1366 OHCA were analysed; 305 received mechCPR, 1061 manual chest compressions (manCPR), and 108 ECLS. ROSC and CPC ≤2 were associated with low-flow minutes (odds ratio [95% confidence interval] 0.90 [0.88-0.91] and 0.90 [0.87-0.93]), shockable rhythm (2.52 [1.71-3.72] and 10.68 [5.63-20.28]), defibrillations number (1.15 [1.07-1.23] and 1.15 [1.04-1.26]), and mechCPR (1.86 [1.17-2.96] and 2.06 [1.11-3.81]). With resuscitation times >13 min, mechCPR achieved more frequently ROSC compared to manCPR. Among ECLS patients, 70% had time exceeding protocol: 8 (7.5%) had CPC ≤2 (half of them with low-flow times between 45 and 90 min), 2 (1.9%) survived with severe neurological disabilities, and 13 brain-dead (12.0%) became organ donors.

CONCLUSIONS

MechCPR patients achieved ROSC more frequently than manual CPR patients; mechCPR was a crucial factor in an ECLS protocol for refractory OHCA. ECLS offered a chance of survival to patients who would otherwise die.

Advanced and Invasive Cardiopulmonary Resuscitation (CPR) Techniques as an Adjunct to Advanced Cardiac Life Support

BACKGROUND

Despite numerous promising innovations, the chance of survival from sudden cardiac arrest has remained virtually unchanged for decades. Recently, technological advances have been made, user-friendly portable devices have been developed, and advanced invasive procedures have been described that could improve this unsatisfactory situation.

METHODS

A selective literature search in the core databases with a focus on randomized controlled trials and guidelines.

RESULTS

Technical aids, such as feedback systems or automated mechanical cardiopulmonary resuscitation (CPR) devices, can improve chest compression quality. The latter, as well as extracorporeal CPR, might serve as a bridge to treatment (with extracorporeal CPR even as a bridge to recovery). Sonography may be used to improve thoracic compressions on the one hand and to rule out potentially reversible causes of cardiac arrest on the other. Resuscitative endovascular balloon occlusion of the aorta might enhance myocardial and cerebral perfusion. Minithoracostomy, pericardiocentesis, or clamshell thoracotomy might resolve reversible causes of cardiac arrest.

CONCLUSIONS

It is crucial to identify those patients who may benefit from an advanced or invasive procedure and make the decision to implement the intervention in a timely manner. As with all infrequently performed procedures, sound education and regular training are paramount.

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.

Comparison of Sustained Return of Spontaneous Circulation Rate Between Manual and Mechanical Chest Compression in Adult Cardiac Arrest

Objective

This study aimed to compare the rates of sustained return of spontaneous circulation (ROSC) between manual and mechanical chest compression in adult non-traumatic cardiac arrest.

Methods

A retrospective cohort study was conducted from 2017 to 2019. The medical records were reviewed in 227 cardiac arrest patients aged ≥18 years who experienced out-of-hospital cardiac arrest or cardiac arrest while visiting the emergency department (ED). The patients were divided into manual chest compression and mechanical chest compression groups. The two groups were compared in terms of baseline characteristics, time to arrive at the ED, time to basic life support, initial rhythm, time to defibrillation in the shockable group, time to the first dose of adrenaline, and possible cause of arrest. A multivariate logistic regression model was used to determine the factors associated with ROSC.

Results

A total of 227 patients met the inclusion criteria:193 patients in the manual chest compression group and 34 patients in the mechanical chest compression group. The rate of sustained ROSC in the manual chest compression group was higher (43% vs 8.8%; P < 0.001). The significant factors associated with ROSC were witnessed cardiac arrest (odds ratio (OR) = 3.41; 95% confidence interval (CI) 0.94–12.4), ED arrival by basic ambulance service (OR = 1.93; 95% CI 0.86–4.35), cardiac arrest at the ED (OR = 3.69; 95% CI 1.73–7.88), and cardiac arrest from hypoxia (OR = 2.01; 95% CI 1.02–3.97).

Conclusion

Mechanical chest compression was not associated with sustained ROSC and tended to be selectively used in patients with a prolonged duration of cardiac arrest.

Protocol for a cluster randomised controlled feasibility study of Prehospital Optimal Shock Energy for Defibrillation (POSED)

AIMS

The Prehospital Optimal Shock Energy for Defibrillation (POSED) study will assess the feasibility of conducting a cluster randomised controlled study of clinical effectiveness in UK ambulance services to identify the optimal shock energy for defibrillation.

METHODS

POSED is a pragmatic, allocation concealed, open label, cluster randomised, controlled feasibility study. Defibrillators within a single UK ambulance service will be randomised in an equal ratio to deliver one of three shock strategies 120-150-200 J, 150-200-200 J, 200-200-200 J. Consecutive adults (≥18 years) presenting with out of hospital cardiac arrest requiring defibrillation will be eligible. The study plans to enrol 90 patients (30 in each group). Patients (or their relatives for non-survivors) will be informed about trial participation after the initial emergency has resolved. Survivors will be invited to consent to participate in follow-up (i.e., at 30 days or discharge).The primary feasibility outcome is the proportion of eligible patients who receive the randomised study intervention. Secondary feasibility outcomes will include recruitment rate, adherence to allocated treatment and data completeness. Clinical outcomes will include Return of an Organised Rhythm (ROOR) at 2 minutes post-shock, refibrillation rate, Return of Spontaneous Circulation (ROSC) at hospital handover, survival and neurological outcome at 30 days.

CONCLUSION

The POSED study will assess the feasibility of a large-scale trial and explore opportunities to optimise the trial protocol.Trial registration: ISRCTN16327029.

LUCAS compression device-related severe injuries in a series of patients presenting with outside hospital cardiac arrest

This case series presents patients who presented to the hospital with an outside hospital cardiac arrest and were initially resuscitated successfully. All patients suffered fatal traumatic injuries during the resuscitation process with the common variable being the use of mechanical cardiopulmonary resuscitation (CPR) device. The goal of this case series is to describe the limitations and potential fatal side effects of CPR. We also present a review of literature with our impressions of the appropriate indications for the use of mechanical CPR.

Learning objectives

1) Recognize appropriate indications for the use of mechanical vs manual cardiopulmonary resuscitation (CPR). 2) Identify signs and symptoms of mechanical CPR-related complications.

What are ambulance crews' experiences of using a mechanical chest compression device for out-of-hospital resuscitation? A constructivist qualitative study utilising online focus groups

Introduction

Mechanical chest compression devices (MCCDs) provide chest compressions mechanically to a person in cardiac arrest. Those chest compressions would usually be provided manually. Previous studies into the use of MCCDs have focused on the quantitative outcomes, with little emphasis on the qualitative experiences of those using MCCDs.

Purpose

To collect and report ambulance crews' experiences of using MCCDs for out-of-hospital resuscitation attempts.

Methods

The philosophical approach was constructivist, the methodology qualitative and the data collection method online focus groups. Convenience sampling was used to recruit participants who met the inclusion criteria, which broadly were to have experience of using MCCDs for out-of-hospital resuscitation. There have been two types of MCCD used locally. Participants were included regardless of which type of device they had experience of. Similarly, participants were included whether they had active or passive experience of the devices. The focus groups were recorded, fully transcribed and then analysed using constant comparison.

Results

Four selective codes emerged. These were factors directly affecting ambulance crew members; practicalities of a resuscitation attempt; ambulance crew members' perceptions, experiences and thoughts; negatives of MCCDs.

Conclusion

The main perceptions arising from the participants' discussion in this work were that MCCD use could potentially provide psychological protection to ambulance crew members when reflecting on resuscitation attempts, and participants felt there is an overall reduction of cognitive load for ambulance crew members when using MCCDs for resuscitation attempts. There were particularly timely benefits expressed of MCCDs easing the physical fatigue of a resuscitation attempt when responding wearing personal protective equipment, as has been required during the COVID-19 pandemic. MCCDs were felt to be of benefit when transporting a patient in cardiac arrest but differences were expressed as to whether the LUCAS-2 in particular helps or hinders extrication of a patient.

Rationale and design of a randomized controlled clinical trial; Titration of Oxygen Levels (TOOL) during mechanical ventilation

BACKGROUND

Both hyperoxemia and hypoxemia are deleterious in critically ill patients. Targeted oxygenation is recommended to prevent both of these extremes, however this has not translated to the bedside. Hyperoxemia likely persists more than hypoxemia due to absence of immediate discernible adverse effects, cognitive biases and delay in prioritization of titration.

METHODS

We present the methodology for the Titration Of Oxygen Levels (TOOL) trial, an open label, randomized controlled trial of an algorithm-based FiO2 titration with electronic medical record-based automated alerts. We hypothesize that the study intervention will achieve targeted oxygenation by curbing episodes of hyperoxemia while preventing hypoxemia. In the intervention arm, electronic alerts will be used to titrate FiO2 if SpO2 is ≥94% with FiO2 levels ≥0.4 over 45 min. FiO2 will be titrated per standard practice in the control arm. This study is being carried out with deferred consent. The sample size to determine efficacy is 316 subjects, randomized in a 1:1 ratio to the intervention vs. control arm. The primary outcome is proportion of time during mechanical ventilation spent with FiO2 ≥ 0.4 and SpO2 ≥ 94%. We will also assess proportion of time during mechanical ventilation spent with SpO2 < 88%, duration of mechanical ventilation, length of ICU and hospital stay, hospital mortality, and adherence to electronic alerts as secondary outcomes.

CONCLUSION

This study is designed to evaluate the efficacy of a high fidelity, bioinformatics-based, electronic medical record derived electronic alert system to improve targeted oxygenation in mechanically ventilated patients by reducing excessive FiO2 exposure.

Manual versus Mechanical Delivery of High-Quality Cardiopulmonary Resuscitation on a River-Based Fire Rescue Boat

Objectives:

Studies have demonstrated the efficacy of mechanical devices at delivering high-quality cardiopulmonary resuscitation (HQ-CPR) in various transport settings. Herein, this study investigates the efficacy of manual and mechanical HQ-CPR delivery on a fire rescue boat.

Methods:

A total of 15 active firefighter-paramedics were recruited for a prospective manikin-based trial. Each paramedic performed two minutes manual compression-only CPR while navigating on a river-based fire rescue boat. The boat was piloted in either a stable linear manner or dynamic S-turn manner to simulate obstacle avoidance. For each session of manual HQ-CPR, a session of mechanical HQ-CPR was also performed with a LUCAS 3 (Stryker; Kalamazoo, Michigan USA). A total of 60 sessions were completed. Parameters recorded included compression fraction (CF) and the percentage of compressions with correct depth >5cm (D%), correct rate 100-120 (R%), full release (FR%), and correct hand position (HP%). A composite HQ-CPR score was calculated as follows: ((D% + R% + FR% + HP%)/4) * CF%). Differences in magnitude of change seen in stable versus dynamic navigation within study conditions were evaluated with a Z-score calculation. Difficulty of HQ-CPR delivery was assessed utilizing the Borg Rating of Perceived Exertion Scale.

Results:

Participants were mostly male and had a median experience of 20 years. Manual HQ-CPR delivered during stable navigation out-performed manual HQ-CPR delivered during dynamic navigation for composite score and trended towards superiority for FR% and R%. There was no difference seen for any measured variable when comparing mechanical HQ-CPR delivered during stable navigation versus dynamic navigation. Mechanical HQ-CPR out-performed manual HQ-CPR during both stable and dynamic navigation in terms of composite score, FR%, and R%. Z-score calculation demonstrated that manual HQ-CPR delivery was significantly more affected by drive style than mechanical HQ-CPR delivery in terms of composite HQ-CPR score and trended towards significance for FR% and R%. Borg Rating of Perceived Exertion was higher for manual CPR delivered during dynamic sessions than for stable sessions.

Conclusion:

Mechanical HQ-CPR delivery is superior to manual HQ-CPR delivery during both stable and dynamic riverine navigation. Whereas manual HQ-CPR delivery was worse during dynamic transportation conditions compared to stable transport conditions, mechanical HQ-CPR delivery was unaffected by drive style. This suggests the utility of routine use of mechanical HQ-CPR devices in the riverine patient transport setting.

Objective performance of emergency medical technicians in the use of mechanical cardiopulmonary resuscitation compared with subjective self-evaluation: a cross-sectional, simulation-based study

OBJECTIVE

To evaluate the subjective and objective resuscitation performance of emergency medical technicians (EMTs) using mechanical cardiopulmonary resuscitation (MCPR) devices.

DESIGN AND SETTING

This was a cross-sectional simulation-based study where participants installed the MCPR device on a training manikin.

PARTICIPANTS

We assessed EMT-Intermediates (EMT-Is) and EMT-Paramedics (EMT-Ps) of the Emergency Medical Services (Ambulance) Division of the Taipei City Fire Department.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the gap between self-perceived (subjective) and actual (objective) no-flow time during resuscitation, which we hypothesised as statistically insignificant. The secondary outcome was the association between resuscitation performance and personal attributes like knowledge, attitude and self-confidence.

RESULTS

Among 210 participants between 21 and 45 years old, only six were female. There were 144 EMT-Is and 66 EMT-Ps. During a simulated resuscitation lasting between four and a half and 5 min, EMTs had longer actual no-flow time compared with self-perceived no-flow time (subjective, 38 s; objective, 57.5 s; p value<0.001). This discrepancy could cause a 6.5% drop of the chest compression fraction in a resuscitation period of 5 min. Among the EMT personal factors, self-confidence was negatively associated with objective MCPR deployment performance (adjusted OR (aOR) 0.66, 95% CI 0.45 to 0.97, p=0.033) and objective teamwork performance (aOR 0.57, 95% CI 0.34 to 0.97, p=0.037) for EMT-Ps, whereas knowledge was positively associated with objective MCPR deployment performance (aOR 2.15, 95% CI 1.31 to 3.52, p=0.002) and objective teamwork performance (aOR 1.77, 95% CI 1.02 to 3.08, p=0.043) for EMT-Is. Moreover, regarding the self-evaluation of no-flow time, both self-satisfaction and self-abasement were associated with objectively poor teamwork performance.

CONCLUSIONS

EMTs' subjective and objective performance was inconsistent during the MCPR simulation. Self-confidence and knowledge were personal factors associated with MCPR deployment and teamwork performance. Both self-satisfaction and self-abasement were detrimental to teamwork during resuscitation.

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.  

Mechanical chest compression devices under special circumstances

AIM

According to the current resuscitation guidelines, the use of mechanical chest compression devices could be considered under special circumstances like transport with ongoing resuscitation or long-term resuscitation. The aim of this study was to investigate whether survival is improved using mechanical devices under such circumstances.

METHODS

Out-of-hospital cardiac arrests from all high-quality data centres of the German Resuscitation Registry from 2007 to 2020 were investigated. The use of mechanical devices was compared separately for transport with ongoing resuscitation, prolonged resuscitation (>45 min), and resuscitation with fibrinolytic agents applied. Baseline characteristics, 30-day survival/discharged alive, and neurological function at discharge were analysed descriptively; and 30-day survival/discharged alive was additionally analysed using multivariate logistic regression.

RESULTS

Overall, patients who were treated with a mechanical device tended to be younger and were significantly more likely to have a witnessed cardiac arrest and a shockable initial rhythm. During the study period, 4,851 patients were transported to hospital with ongoing resuscitation (devices used in 44.2%). The 30-day survival was equal (odds ratio, OR: 1.13, 95%-CI: 0.79-1.60). In 3,920 cases, a resuscitation duration > 45 min was documented (9.5% with device). When a device was used, 30-day survival was significantly increased (OR 2.33, 95%-CI: 1.30-4.15). Fibrinolytic agents were used in 2,106 patients (22.2% with device). Here, 30-day survival was significantly worse with a device (OR: 0.52, 95%-CI: 0.30-0.91).

CONCLUSION

Mechanical devices are not associated with better survival when used during transport, but rescuer safety could still be an important argument for their use. Devices are associated with better survival in prolonged resuscitation, but worse survival when a fibrinolytic was used.

Early Titration of Oxygen During Mechanical Ventilation Reduces Hyperoxemia in a Pilot, Feasibility, Randomized Control Trial for Automated Titration of Oxygen Levels

Timely regulation of oxygen (Fio₂) is essential to prevent hyperoxemia or episodic hypoxemia. Exposure to excessive Fio₂ is often noted early after onset of mechanical ventilation. In this pilot study, we examined the feasibility, safety, and efficacy of a clinical trial to prioritize Fio₂ titration with electronic alerts to respiratory therapists.

Pectus excavatum and mechanical chest compression of a dangerous bond

Pectus excavatum (PE) is a malformation of the chest characterized by a median depression of the sternum. The incidence of PE is between 0.1% and 0.8%. In the last decade mechanical chest compression devices (MCCD) became of particular interest in cardiopulmonary resuscitation. Different devices became available and this resulted in an increase in their use during CPR mainly for practical reasons. Despite their increasing use, little evidence existed for their effectiveness and little was known about complications. Skin lesions and fractures of sternum or ribs are the ones with the highest incidence. Whereas subdiaphragmatic lesions, in particular fatal liver injuries are uncommon and described only in few case reports. In a recent retrospective study, CT was used to determine the proper compression landmark and depth of cardiopulmonary resuscitation in PE patients. The authors showed that the mean Haller Index in PE patients was higher than in controls, thus exposing internal organs to a higher injury risk during standard CPR maneuvers. We report the first case, to our knowledge, of liver injury during mechanical CPR in a patient with PE. Awareness is being raised on tailoring mechanical CPR in patients with chest deformities. Further exploration is needed to determine if there is a strong correlation between mechanical CPR and organ damage in PE. We believe that this case highlights the importance of individualizing CPR techniques.

Resuscitation guideline highlights

PURPOSE OF REVIEW

The purpose of this review was to give an overview of the most significant updates in resuscitation guidelines and provide some insights into the new topics being considered in upcoming reviews.

RECENT FINDINGS

Recent updates to resuscitation guidelines have highlighted the importance of the earlier links in the chain-of-survival aimed to improve early recognition, early cardiopulmonary resuscitation (CPR) and defibrillation. Empowering lay rescuers with the support of emergency medical dispatchers or telecommunicators and engaging the community through dispatching volunteers and Automated External Defibrillators, are considered key in improving cardiac arrest outcomes. Novel CPR strategies such as passive insufflation and head-up CPR are being explored, but lack high-certainty evidence. Increased focus on survivorship also highlights the need for more evidence based guidance on how to facilitate the necessary follow-up and rehabilitation after cardiac arrest. Many of the systematic and scoping reviews performed within cardiac arrest resuscitation domains identifies significant knowledge gaps on key elements of our resuscitation practices. There is an urgent need to address these gaps to further improve survival from cardiac arrest in all settings.

SUMMARY

A continuous evidence evaluation process for resuscitation after cardiac arrest is triggered by new evidence or request by the resuscitation community, and provides more current and relevant guidance for clinicians.