Extracorporeal Cardiopulmonary Resuscitation for Patients With Out-of-Hospital Cardiac Arrest of Cardiac Origin: A Propensity-Matched Study and Predictor Analysis*

Hyperoxia Is Not Associated With 30-day Survival in Out-of-Hospital Cardiac Arrest Patients Who Undergo Extracorporeal Cardiopulmonary Resuscitation

Introduction

The appropriate arterial partial pressure of oxygen (PaO2) in patients undergoing extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest (OHCA) remains unclear. The present study aimed to investigate the relationship between hyperoxia and 30-day survival in patients who underwent ECPR.

Materials and Methods

This single-center retrospective cohort study was conducted between January 2010 and December 2018. OHCA patients who underwent ECPR were included in the study. Exclusion criteria were (1) age <18 years, (2) death within 24 h after admission, (3) return of spontaneous circulation at hospital arrival, and (4) hypoxia (PaO2 < 60 mmHg) 24 h after admission. Based on PaO2 at 24 h after admission, patients were classified into normoxia (60 mmHg ≤ PaO2 ≤ 100 mmHg), mild hyperoxia (100 mmHg < PaO2 ≤ 200 mmHg), and severe hyperoxia (PaO2 > 200 mmHg) groups. The primary outcome was 30-day survival after cardiac arrest, while the secondary outcome was 30-day favorable neurological outcome. Multivariate logistic regression analysis for 30-day survival or 30-day favorable neurological outcome was performed using multiple propensity scores as explanatory variables. To estimate the multiple propensity score, we fitted a multinomial logistic regression model using the patients' demographic, pre-hospital, and in-hospital characteristics.

Results

Of the patients who underwent ECPR in the study center, 110 were eligible for the study. The normoxia group included 29 cases, mild hyperoxia group included 46 cases, and severe hyperoxia group included 35 cases. Mild hyperoxia was not significantly associated with survival, compared with normoxia as the reference (adjusted odds ratio, 1.06; 95% confidence interval: 0.30-3.68; p = 0.93). Severe hyperoxia was also not significantly associated with survival compared to normoxia (adjusted odds ratio, 1.05; 95% confidence interval: 0.27-4.12; p = 0.94). Furthermore, no association was observed between oxygenation and 30-day favorable neurological outcomes.

Conclusions

There was no significant association between hyperoxia at 24 h after admission and 30-day survival in OHCA patients who underwent ECPR.

Association between short-term neurological outcomes and extreme hyperoxia in patients with out-of-hospital cardiac arrest who underwent extracorporeal cardiopulmonary resuscitation: a retrospective observational study from a multicenter registry

Background

To investigate the impact of hyperoxia that developed immediately after extracorporeal membrane oxygenation (ECMO)-assisted cardiopulmonary resuscitation (ECPR) on patients’ short-term neurological outcomes after out-of-hospital cardiac arrest (OHCA).

Methods

This study retrospectively analyzed data from the Japanese OHCA registry from June 2014 to December 2017. We analyzed adult patients (≥ 18 years) who had undergone ECPR. Eligible patients were divided into the following three groups based on their initial partial pressure of oxygen in arterial blood (PaO₂) levels after ECMO pump-on: normoxia group, PaO₂ ≤ 200 mm Hg; moderate hyperoxia group, 200 mm Hg < PaO₂ ≤ 400 mm Hg; and extreme hyperoxia group, PaO₂ > 400 mm Hg. The primary and secondary outcomes were 30-day favorable neurological outcomes. Logistic regression statistical analysis model of 30-day favorable neurological outcomes was performed after adjusting for multiple propensity scores calculated using pre-ECPR covariates and for confounding factors post-ECPR.

Results

Of the 34,754 patients with OHCA enrolled in the registry, 847 were included. The median PaO₂ level was 300 mm Hg (interquartile range: 148–427 mm Hg). Among the eligible patients, 277, 313, and 257 were categorized as normoxic, moderately hyperoxic, and extremely hyperoxic, respectively. Moderate hyperoxia was not significantly associated with 30-day neurologically favorable outcomes compared with normoxia as a reference (adjusted odds ratio, 0.86; 95% confidence interval: 0.55–1.35; p = 0.51). However, extreme hyperoxia was associated with less 30-day neurologically favorable outcomes when compared with normoxia (adjusted odds ratio, 0.48; 95% confidence interval: 0.29–0.82; p = 0.007).

Conclusions

For patients with OHCA who received ECPR, extreme hyperoxia (PaO₂ > 400 mm Hg) was associated with 30-day poor neurological outcomes. Avoidance of extreme hyperoxia may improve neurological outcomes in patients with OHCA treated with ECPR.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02598-6.

A Comparison between Conventional and Extracorporeal Cardiopulmonary Resuscitation in Out-of-Hospital Cardiac Arrest: A Systematic Review and Meta-Analysis

There is limited evidence comparing the use of extracorporeal cardiopulmonary resuscitation (ECPR) to CPR in the management of refractory out-of-hospital cardiac arrest (OHCA). We conducted a systematic review and meta-analysis to compare survival and neurologic outcomes associated with ECPR versus CPR in the management of OHCA. We searched PubMed, EMBASE, and Scopus to identify observational studies and randomized controlled trials comparing ECPR and CPR. We used the Newcastle−Ottawa Scale and Cochrane’s risk-of-bias tool to assess studies’ quality. We used random-effects models to compare outcomes between the pooled populations and moderator analysis to identify sources of heterogeneity and perform subgroup analysis. We identified 2088 articles and included 13, with 18,620 patients with OHCA. A total of 16,701 received CPR and 1919 received ECPR. Compared with CPR, ECPR was associated with higher odds of achieving favorable neurologic outcomes at 3 (OR 5, 95% CI 1.90−13.1, p < 0.01) and 6 months (OR 4.44, 95% CI 2.3−8.5, p < 0.01). We did not find a significant survival benefit or impact on neurologic outcomes at hospital discharge or 1 month following arrest. ECPR is a promising but resource-intensive intervention with the potential to improve long-term outcomes among patients with OHCA.

A Comprehensive Review of Mechanical Circulatory Support Devices

Treatment strategies to combat cardiogenic shock (CS) have remained stagnant over the past decade. Mortality rates among patients who suffer CS after acute myocardial infarction (AMI) remain high at 50%. Mechanical circulatory support (MCS) devices have evolved as novel treatment strategies to restore systemic perfusion to allow cardiac recovery in the short term, or as durable support devices in refractory heart failure in the long term. Haemodynamic parameters derived from right heart catheterization assist in the selection of an appropriate MCS device and escalation of mechanical support where needed. Evidence favouring the use of one MCS device over another is scant. An intra-aortic balloon pump is the most commonly used short-term MCS device, despite providing only modest haemodynamic support. Impella CP® has been increasingly used for CS in recent times and remains an important focus of research for patients with AMI-CS. Among durable devices, Heartmate® 3 is the most widely used in the USA. Adequately powered randomized controlled trials are needed to compare these MCS devices and to guide the operator for their use in CS. This article provides a brief overview of the types of currently available MCS devices and the indications for their use.

Extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest: A systematic review and meta-analysis of randomized and propensity score-matched studies

BACKGROUND

In selected patients with refractory out-of-hospital cardiac arrest, extracorporeal cardiopulmonary resuscitation represents a promising approach when conventional cardiopulmonary resuscitation fails to achieve return of spontaneous circulation. This systematic review and meta-analysis aimed to compare extracorporeal cardiopulmonary resuscitation to conventional cardiopulmonary resuscitation.

METHODS

We searched PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials up to November 28, 2021, for randomized trials and observational studies reporting propensity score-matched data and comparing adults with out-of-hospital cardiac arrest treated with extracorporeal cardiopulmonary resuscitation with those treated with conventional cardiopulmonary resuscitation. The primary outcome was survival with favorable neurological outcome at the longest follow-up available. Secondary outcomes were survival at the longest follow-up available and survival at hospital discharge/30 days.

RESULTS

We included six studies, two randomized and four propensity score-matched studies. Patients treated with extracorporeal cardiopulmonary resuscitation had higher rates of survival with favorable neurological outcome (81/584 [14%] vs. 46/593 [7.8%]; OR = 2.11; 95% CI, 1.41-3.15; p < 0.001, number needed to treat 16) and of survival (131/584 [22%] vs. 102/593 [17%]; OR = 1.40; 95% CI, 1.05-1.87; p = 0.02) at the longest follow-up available compared with conventional cardiopulmonary resuscitation. Survival at hospital discharge/30 days was similar between the two groups (142/584 [24%] vs. 122/593 [21%]; OR = 1.26; 95% CI, 0.95-1.66; p = 0.10).

CONCLUSIONS

Evidence from randomized trials and propensity score-matched studies suggests increased survival and favorable neurological outcome in patients with refractory out-of-hospital cardiac arrest treated with extracorporeal cardiopulmonary resuscitation. Large, multicentre randomized studies are still ongoing to confirm these findings.

Effect of Intra-arrest Transport, Extracorporeal Cardiopulmonary Resuscitation, and Immediate Invasive Assessment and Treatment on Functional Neurologic Outcome in Refractory Out-of-Hospital Cardiac Arrest: A Randomized Clinical Trial

IMPORTANCE

Out-of-hospital cardiac arrest (OHCA) has poor outcome. Whether intra-arrest transport, extracorporeal cardiopulmonary resuscitation (ECPR), and immediate invasive assessment and treatment (invasive strategy) is beneficial in this setting remains uncertain.

OBJECTIVE

To determine whether an early invasive approach in adults with refractory OHCA improves neurologically favorable survival.

DESIGN, SETTING, AND PARTICIPANTS

Single-center, randomized clinical trial in Prague, Czech Republic, of adults with a witnessed OHCA of presumed cardiac origin without return of spontaneous circulation. A total of 256 participants, of a planned sample size of 285, were enrolled between March 2013 and October 2020. Patients were observed until death or day 180 (last patient follow-up ended on March 30, 2021).

INTERVENTIONS

In the invasive strategy group (n = 124), mechanical compression was initiated, followed by intra-arrest transport to a cardiac center for ECPR and immediate invasive assessment and treatment. Regular advanced cardiac life support was continued on-site in the standard strategy group (n = 132).

MAIN OUTCOMES AND MEASURES

The primary outcome was survival with a good neurologic outcome (defined as Cerebral Performance Category [CPC] 1-2) at 180 days after randomization. Secondary outcomes included neurologic recovery at 30 days (defined as CPC 1-2 at any time within the first 30 days) and cardiac recovery at 30 days (defined as no need for pharmacological or mechanical cardiac support for at least 24 hours).

RESULTS

The trial was stopped at the recommendation of the data and safety monitoring board when prespecified criteria for futility were met. Among 256 patients (median age, 58 years; 44 [17%] women), 256 (100%) completed the trial. In the main analysis, 39 patients (31.5%) in the invasive strategy group and 29 (22.0%) in the standard strategy group survived to 180 days with good neurologic outcome (odds ratio [OR], 1.63 [95% CI, 0.93 to 2.85]; difference, 9.5% [95% CI, -1.3% to 20.1%]; P = .09). At 30 days, neurologic recovery had occurred in 38 patients (30.6%) in the invasive strategy group and in 24 (18.2%) in the standard strategy group (OR, 1.99 [95% CI, 1.11 to 3.57]; difference, 12.4% [95% CI, 1.9% to 22.7%]; P = .02), and cardiac recovery had occurred in 54 (43.5%) and 45 (34.1%) patients, respectively (OR, 1.49 [95% CI, 0.91 to 2.47]; difference, 9.4% [95% CI, -2.5% to 21%]; P = .12). Bleeding occurred more frequently in the invasive strategy vs standard strategy group (31% vs 15%, respectively).

CONCLUSIONS AND RELEVANCE

Among patients with refractory out-of-hospital cardiac arrest, the bundle of early intra-arrest transport, ECPR, and invasive assessment and treatment did not significantly improve survival with neurologically favorable outcome at 180 days compared with standard resuscitation. However, the trial was possibly underpowered to detect a clinically relevant difference.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01511666.

Extracorporeal life support in adult patients with out-of-hospital cardiac arrest

The use of extracorporeal life support in cardiopulmonary resuscitation (CPR) of adult patients experiencing out-of-hospital cardiac arrest by the application of veno-arterial extracorporeal membrane oxygenation (ECMO) during cardiac arrest has been increasing over the past decade. This can be attributed to the encouraging results of extracorporeal CPR (ECPR) in multiple observational studies. To date, only one randomised controlled trial has compared ECPR to conventional advanced life support measures. Patient selection is crucial for the success of ECPR programmes. A rapid and organised approach is required for resuscitation, i.e. cannula insertion with ECMO pump initiation in combination with other aspects of post-cardiac arrest care such as targeted temperature management and early coronary reperfusion. The provision of an ECPR service can be costly, resource intensive and technically challenging, as limited studies have reported on its cost-effectiveness.

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

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

Survival and Factors Associated with Survival with Extracorporeal Life Support During Cardiac Arrest: A Systematic Review and Meta-Analysis

The survival rate after cardiac arrest (CA) remains low. The utilization of extracorporeal life support is proposed to improve management. However, this resource-intensive tool is associated with complications and must be used in selected patients. We performed a meta-analysis to determine predictive factors of survival. Among the 81 studies included, involving 9256 patients, survival was 26.2% at discharge and 20.4% with a good neurologic outcome. Meta-regressions identified an association between survival at discharge and lower lactate values, intrahospital CA, and lower cardio pulmonary resuscitation (CPR) duration. After adjustment for age, intrahospital CA, and mean CPR duration, an initial shockable rhythm was the only remaining factor associated with survival to discharge (β = 0.02, 95% CI: 0.007-0.02; p = 0.0004).

Use of extracorporeal circulation (ECLS/ECMO) for cardiac and circulatory failure -A clinical practice Guideline Level 3

Aims Worldwide applications of extracorporeal circulation for mechanical support in cardiac and circulatory failure, which are referred to as extracorporeal life support (ECLS) or veno‐arterial extracorporeal membrane oxygenation (va‐ECMO), have dramatically increased over the past decade. In spite of the expanding use and the immense medical as well as socio‐economic impact of this therapeutic approach, there has been a lack of interdisciplinary recommendations considering the best available evidence for ECLS treatment.

Methods and Results In a multiprofessional, interdisciplinary scientific effort of all scientific societies involved in the treatment of patients with acute cardiac and circulatory failure, the first evidence‐ and expert consensus‐based guideline (level S3) on ECLS/ECMO therapy was developed in a structured approach under regulations of the AWMF (Association of the Scientific Medical Societies in Germany) and under use of GRADE (Grading of Recommendations Assessment, Development and Evaluation) criteria. This article presents all recommendations created by the expert panel, addressing a multitude of aspects for ECLS initiation, continuation, weaning and aftercare as well as structural and personnel requirements.

Conclusions This first evidence‐ and expert consensus‐based guideline (level S3) on ECLS/ECMO therapy should be used to apply the best available care nationwide. Beyond clinical practice advice, remaining important research aspects for future scientific efforts are formulated.

Temporary mechanical circulatory support in cardiogenic shock

Cardiogenic shock (CS) represents one of the foremost concerns in the field of acute cardiovascular medicine. Despite major advances in treatment, mortality of CS remains high. International societies recommend the development of expert CS centers with standardized protocols for CS diagnosis and treatment. In these terms, devices for temporary mechanical circulatory support (MCS) can be used to support the compromised circulation and could improve clinical outcome in selected patient populations presenting with CS. In the past years, we have witnessed an immense increase in the utilization of MCS devices to improve the clinical problem of low cardiac output. Although some treatment guidelines include the use of temporary MCS up to now no large randomized controlled trial confirmed a reduction in mortality in CS patients after MCS and additional research evidence is necessary to fully comprehend the clinical value of MCS in CS. In this article, we provide an overview of the most important diagnostic and therapeutic modalities in CS with the main focus on contemporary MCS devices, current state of art and scientific evidence for its clinical application and outline directions of future research efforts.

Extracorporeal Life Support for Cardiac Arrest and Cardiogenic Shock

The rising incidence and recognition of cardiogenic shock has led to an increase in the use of veno-arterial extracorporeal membrane oxygenation (VA-ECMO). As clinical experience with this therapy has increased, there has also been a rapid growth in the body of observational and randomized data describing the clinical and logistical considerations required to institute a VA-ECMO program with successful clinical outcomes. The aim of this review is to summarize this contemporary data in the context of four key themes that pertain to VA-ECMO programs: the principles of patient selection; basic hemodynamic and technical principles underlying VA-ECMO; contraindications to VA-ECMO therapy; and common complications and intensive care considerations that are encountered in the setting of VA-ECMO therapy.

Extracorporeal Cardiopulmonary Resuscitation and Survival After Refractory Cardiac Arrest: Is ECPR Beneficial?

The level of evidence of expert recommendations for starting extracorporeal cardiopulmonary resuscitation (ECPR) in refractory out-of-hospital cardiac arrest (OHCA) and in-hospital cardiac arrest (IHCA) is low. Therefore, we reported our experience in the field to identify factors associated with hospital mortality. We conducted a retrospective cohort study of all consecutive patients treated with ECPR for refractory cardiac arrest without return to spontaneous circulation, regardless of cause, at the Caen University Hospital. Factors associated with hospital mortality were analyzed. Eighty-six patients (i.e., 35 OHCA and 51 IHCA) were included. The overall hospital mortality rate was 81% (i.e., 91% and 75% in the OHCA and IHCA groups, respectively). Factors independently associated with mortality were: sex, age > 44 years, and time from collapse until extracorporeal life support (ECLS) initiation. Interestingly, no-shockable rhythm was not associated with mortality. The receiver operating characteristic-area under the curve values of pH value (0.75 [0.60-0.90]) and time from collapse until ECLS initiation over 61 minutes (0.87 [0.76-0.98]) or 74 minutes (0.90 [0.80-1.00]) for predicting hospital mortality showed good discrimination performance. No-shockable rhythm should not be considered a formal exclusion criterion for ECPR. Time from collapse until ECPR initiation is the cornerstone of success of an ECPR strategy in refractory cardiac arrest.

Association Between Converting Asystole From Initial Shockable ECG Rhythm Before Extracorporeal Cardiopulmonary Resuscitation and Outcome

BACKGROUND

Initial electrocardiogram (ECG) rhythm is a predictor of outcomes in out-of-hospital cardiac arrest (OHCA) in patients receiving extracorporeal cardiopulmonary resuscitation (ECPR). However, ECG rhythm often changes before ECPR, and the consequence of this change remains unclear. This study aimed to assess the relationship between the conversion of ECG rhythm from initial shockable rhythm before ECPR and mortality.

PATIENTS AND METHODS

This was a retrospective cohort study of OHCA patients with initial shockable rhythm who underwent ECPR between January 2010 and September 2020. Patients were classified into two groups: asystole (patients whose ECG rhythm converted to asystole at any time before initiating ECPR) and non-asystole (patients whose ECG rhythm did not convert to asystole at any time before initiating ECPR) groups. The primary outcome was in-hospital mortality.

RESULTS

A total of 102 patients were included in the study; in-hospital mortality rate was 46.1% (n = 47) and 76 (74.5%) patients had unfavorable neurological outcomes (Cerebral Performance Category: 3-5). There were 33 and 69 patients in the asystole and non-asystole groups, respectively. The mortality rates in the asystole and non-asystole groups were 69.7% and 34.8%, respectively (P = 0.001). On multivariable analysis, the asystole group showed a significant association with mortality (odds ratio, 5.42; 95% confidence interval, 2.11-15.36; P < 0.001).

CONCLUSION

Conversion to asystole before ECPR at any time in patients with OHCA is associated with mortality in patients with an initial shockable ECG rhythm.

[Extracorporeal cardiopulmonary resuscitation for treatment of out-of-hospital cardiac arrest]

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) affects ca. 75,000 people each year in Germany and is associated with a limited prognosis and a high mortality. Extracorporeal cardiopulmonary resuscitation (eCPR) using arteriovenous extracorporeal membrane oxygenation (av-ECMO) systems is an additional option for treatment, which is increasingly more widespread and since 2020 anchored in the guideline algorithm.

METHODS

A selective search of the literature was carried out in PubMed and Embase focusing on studies that investigated eCPR for OHCA. Furthermore, clinical studies on this topic that are currently recruiting and running are summarized.

RESULTS

The available data on the benefits of eCPR for OHCA are mostly based on retrospective cohort studies. A survival advantage and an advantage in the neurological outcome could be derived from these data for selected patients treated with eCPR vs. conventionally resuscitated patients (CPR). This effect could be confirmed by two current randomized controlled studies. Studies which are currently running are investigating if out-of-hospital ECMO cannulation at the earliest time possible at the site of OHCA of patients could be associated with a better survival.

CONCLUSION

Despite a current scarcity of data, a survival advantage for eCPR treatment in selected OHCA patients must be assumed. If this can be substantiated by other high-quality studies, it seems to be indicated to evaluate if and to what extent resource-intensive eCPR programs can be comprehensively established.

[Use of extracorporeal circulation (ECLS/ECMO) for cardiac and circulatory failure : Short version of the S3 guideline]

In Germany, a remarkable increase regarding the usage of extracorporeal membrane oxygenation (ECMO) and extracorporeal life support (ECLS) systems has been observed in recent years with approximately 3000 ECLS/ECMO implantations annually since 2015. Despite the widespread use of ECLS/ECMO, evidence-based recommendations or guidelines are still lacking regarding indications, contraindications, limitations and management of ECMO/ECLS patients. Therefore in 2015, the German Society of Thoracic and Cardiovascular Surgery (GSTCVS) registered the multidisciplinary S3 guideline "Use of extracorporeal circulation (ECLS/ECMO) for cardiac and circulatory failure" to develop evidence-based recommendations for ECMO/ECLS systems according to the requirements of the Association of the Scientific Medical Societies in Germany (AWMF). Although the clinical application of ECMO/ECLS represents the main focus, the presented guideline also addresses structural and economic issues. Experts from 17 German, Austrian and Swiss scientific societies and a patients' organization, guided by the GSTCVS, completed the project in February 2021. In this report, we present a summary of the methodological concept and tables displaying the recommendations for each chapter of the guideline.

[Use of extracorporeal circulation (ECLS/ECMO) for cardiac and circulatory failure : Short version of the S3 guideline]

In Germany, a remarkable increase regarding the usage of extracorporeal membrane oxygenation (ECMO) and extracorporeal life support (ECLS) systems has been observed in recent years with approximately 3000 ECLS/ECMO implantations annually since 2015. Despite the widespread use of ECLS/ECMO, evidence-based recommendations or guidelines are still lacking regarding indications, contraindications, limitations and management of ECMO/ECLS patients. Therefore in 2015, the German Society of Thoracic and Cardiovascular Surgery (GSTCVS) registered the multidisciplinary S3 guideline "Use of extracorporeal circulation (ECLS/ECMO) for cardiac and circulatory failure" to develop evidence-based recommendations for ECMO/ECLS systems according to the requirements of the Association of the Scientific Medical Societies in Germany (AWMF). Although the clinical application of ECMO/ECLS represents the main focus, the presented guideline also addresses structural and economic issues. Experts from 17 German, Austrian and Swiss scientific societies and a patients' organization, guided by the GSTCVS, completed the project in February 2021. In this report, we present a summary of the methodological concept and tables displaying the recommendations for each chapter of the guideline.

Outcomes of Venoarterial Extracorporeal Membrane Oxygenation for Cardiac Arrest in Adult Patients in the United States

Background

Factors associated with poor prognosis following receipt of extracorporeal membrane oxygenation (ECMO) in adults with cardiac arrest remain unclear. We aimed to identify predictors of mortality in adults with cardiac arrest receiving ECMO in a nationally representative sample.

Methods and Results

The US Healthcare Cost and Utilization Project's National Inpatient Sample was used to identify 782 adults hospitalized with cardiac arrest who received ECMO between 2006 and 2014. The primary outcome of interest was all‐cause in‐hospital mortality. Factors associated with mortality were analyzed using multivariable logistic regression. The overall in‐hospital mortality rate was 60.4% (n=472). Patients who died were older and more often men, of non‐White race, and with lower household income than those surviving to discharge. In the risk‐adjusted analysis, independent predictors of mortality included older age, male sex, lower annual income, absence of ventricular arrhythmia, absence of percutaneous coronary intervention, and presence of therapeutic hypothermia.

Conclusions

Demographic and therapeutic factors are independently associated with mortality in patients with cardiac arrest receiving ECMO. Identification of which patients with cardiac arrest may receive the utmost benefit from ECMO may aid with decision‐making regarding its implementation. Larger‐scale studies are warranted to assess the appropriate candidates for ECMO in cardiac arrest.

Reliability of prognostic biomarkers after prehospital extracorporeal cardiopulmonary resuscitation with target temperature management

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR) performed at the emergency scene in out-of-hospital cardiac arrest (OHCA) can minimize low-flow time. Target temperature management (TTM) after cardiac arrest can improve neurological outcome. A combination of ECPR and TTM, both implemented as soon as possible on scene, appears to have promising results in OHCA. To date, it is still unknown whether the implementation of TTM and ECPR on scene affects the time course and value of neurological biomarkers.

METHODS

69 ECPR patients were examined in this study. Blood samples were collected between 1 and 72 h after ECPR and analyzed for S100, neuron-specific enolase (NSE), lactate, D-dimers and interleukin 6 (IL6). Cerebral performance category (CPC) scores were used to assess neurological outcome after ECPR upon hospital discharge. Resuscitation data were extracted from the Regensburg extracorporeal membrane oxygenation database and all data were analyzed by a statistician. The data were analyzed using non-parametric methods. Diagnostic accuracy of biomarkers was determined by area under the curve (AUC) analysis. Results were compared to the relevant literature.

RESULTS

Non-hypoxic origin of cardiac arrest, manual chest compression until ECPR, a short low-flow time until ECPR initiation, low body mass index (BMI) and only a minimal need of extra-corporeal membrane oxygenation support were associated with a good neurological outcome after ECPR. Survivors with good neurological outcome had significantly lower lactate, IL6, D-dimer, and NSE values and demonstrated a rapid decrease in the initial S100 value compared to non-survivors.

CONCLUSIONS

A short low-flow time until ECPR initiation is important for a good neurological outcome. Hypoxia-induced cardiac arrest has a high mortality rate even when ECPR and TTM are performed at the emergency scene. ECPR patients with a higher BMI had a worse neurological outcome than patients with a normal BMI. The prognostic biomarkers S100, NSE, lactate, D-dimers and IL6 were reliable indicators of neurological outcome when ECPR and TTM were performed at the emergency scene.

How effective is extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest? A systematic review and meta-analysis

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR) has gained increasing as a promising but resource-intensive intervention for out-of-hospital cardiac arrest (OHCA). There is little data to quantify the impact of this intervention and the patients likely to benefit from its use. We conducted a meta-analysis of the literature to assess the survival benefit associated with ECPR for OHCA.

METHODS

We searched PubMed, Embase, and Scopus databases to identify relevant observational studies and randomized control trials. We used the Newcastle-Ottawa Scale and Cochrane risk-of-bias tool to assess studies' quality. We performed random-effects meta-analysis for the primary outcome of survival to hospital discharge and used meta-regressions to assess heterogeneity.

RESULTS

We identified 1287 articles, reviewed the full text of 209 and included 44 in our meta-analysis. Our analysis included 3097 patients with OHCA. Patients' mean age was 52, 79% were male, and 60% had primary ventricular fibrillation/ventricular tachycardia arrest. We identified a survival-to-discharge rate of 24%; 18% survived with favorable neurologic function. 30- and 90-days survival rates were both around 18%. The majority of included articles were high quality studies.

CONCLUSIONS

Extracorporeal cardiopulmonary resuscitation is a promising but resource-intensive intervention that may increase rates of survival to hospital discharge among patients who experience OHCA.

Severe Myocardial Dysfunction after Non-Ischemic Cardiac Arrest: Effectiveness of Percutaneous Assist Devices

Introduction: Despite the improvements in standardized cardiopulmonary resuscitation, survival remains low, mainly due to initial myocardial dysfunction and hemodynamic instability. Our goal was to compare the efficacy of two left ventricular assist devices on resuscitation and hemodynamic supply in a porcine model of ventricular fibrillation (VF) cardiac arrest. Methods: Seventeen anaesthetized pigs had 12 min of untreated VF followed by 6 min of chest compression and boluses of epinephrine. Next, a first defibrillation was attempted and pigs were randomized to any of the three groups: control (n = 5), implantation of an percutaneous left ventricular assist device (Impella, n = 5) or extracorporeal membrane oxygenation (ECMO, n = 7). Hemodynamic and myocardial functions were evaluated invasively at baseline, at return of spontaneous circulation (ROSC), after 10–30–60–120–240 min post-resuscitation. The primary endpoint was the rate of ROSC. Results: Only one of 5 pigs in the control group, 5 of 5 pigs in the Impella group, and 5 of 7 pigs in the ECMO group had ROSC (p < 0.05). Left ventricular ejection fraction at 240 min post-resuscitation was 37.5 ± 6.2% in the ECMO group vs. 23 ± 3% in the Impella group (p = 0.06). No significant difference in hemodynamic parameters was observed between the two ventricular assist devices. Conclusion: Early mechanical circulatory support appeared to improve resuscitation rates in a shockable rhythm model of cardiac arrest. This approach appears promising and should be further evaluated.

Ethics of ECPR research

The design of emergency medicine trials can raise several ethical concerns - risks may be greater, and randomisation may have to occur before consent. Research in emergency medicine is thus an illuminating context to explore the interplay between risk and randomisation, and the consequences for consent. Using a currently running trial, we describe possible concerns, considerations, and solutions to reconcile the conflicting interests of scientific inquiry, ethical principles, and clinical reality in emergency medicine research.

eCPR Combined With Therapeutic Hypothermia Could Improve Survival and Neurologic Outcomes for Patients With Cardiac Arrest: A Meta-Analysis

Background: Extracorporeal membrane oxygenation with CPR (eCPR) or therapeutic hypothermia (TH) seems to be a very effective CPR strategy to save patients with cardiac arrest (CA). Furthermore, the subsequent post-CA neurologic outcomes have become the focus. Therefore, there is an urgent need to find a way to improve survival and neurologic outcomes for CA. Objective: We conducted this meta-analysis to find a more suitable CPR strategy for patients with CA. Method: We searched four online databases (PubMed, Embase, CENTRAL, and Web of Science). From an initial 1,436 articles, 23 studies were eligible into this meta-analysis, including a total of 2,035 patients. Results: eCPR combined with TH significantly improved the short-term (at discharge or 28 days) survival [OR = 2.27, 95% CIs (1.60-3.23), p < 0.00001] and neurologic outcomes [OR = 2.60, 95% CIs (1.92-3.52), p < 0.00001). At 3 months of follow-up, the results of survival [OR = 3.36, 95% CIs (1.65-6.85), p < 0.0008] and favorable neurologic outcomes [OR = 3.02, 95% CIs (1.38-6.63), p < 0.006] were the same as above. Furthermore, there was no difference in any bleeding needed intervention [OR = 1.33, 95% CIs (0.09-1.96), p = 0.16] between two groups. Conclusions: From this meta-analysis, we found that eCPR combined with TH might be a more suitable CPR strategy for patients with CA in improving survival and neurologic outcomes, and eCPR with TH did not increase the risk of bleeding. Furthermore, single-arm meta-analyses showed a plausible way of temperature and occasion of TH.

Overview of Veno-Arterial Extracorporeal Membrane Oxygenation (VA-ECMO) Support for the Management of Cardiogenic Shock

Cardiogenic shock accounts for ~100,000 annual hospital admissions in the United States. Despite improvements in medical management strategies, in-hospital mortality remains unacceptably high. Multiple mechanical circulatory support devices have been developed with the aim to provide hemodynamic support and to improve outcomes in this population. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is the most advanced temporary life support system that is unique in that it provides immediate and complete hemodynamic support as well as concomitant gas exchange. In this review, we discuss the fundamental concepts and hemodynamic aspects of VA-ECMO support in patients with cardiogenic shock of various etiologies. In addition, we review the common indications, contraindications and complications associated with VA-ECMO use.

Characteristics of Pediatric Extracorporeal Membrane Oxygenation Programs in the United States and Canada

The aim of this study was to evaluate the current infrastructure and practice characteristics of pediatric extracorporeal membrane oxygenation (ECMO) programs. A 40-question survey of center-specific demographics, practice structure, program experience, and support network utilized to cannulate and maintain a pediatric patient on ECMO was designed via a web-based survey tool. The survey was distributed to pediatric ECMO programs in the United States and Canada. Of the 101 centers that were identified to participate, 41 completed the survey. The majority of responding centers are university affiliated (73%) and have an intensive care unit (ICU) with 15-25 beds (58%). Extracorporeal membrane oxygenation has been offered for >10 years in 85% of the centers. The median number of total cannulations per center in 2017 was 15 (interquartile range [IQR] = 5-30), with the majority occurring in the cardiovascular intensive care unit (median = 13, IQR = 5-25). Fifty-seven percent of responding centers offer ECPR, with a median number of four cases per year (IQR = 2-7). Most centers cannulate in an operating room or ICU; 11 centers can cannulate in the pediatric ED. Sixty-three percent of centers have standardized protocols for postcannulation management. The majority of protocols guide anticoagulation, sedation, or ventilator management; left ventricle decompression and reperfusion catheter placement are the least standardized procedures. The majority of pediatric ECMO centers have adopted the infrastructure recommendations from the Extracorporeal Life Support Organization. However, there remains broad variability of practice characteristics and organizational infrastructure for pediatric ECMO centers across the United States and Canada.

SAVE score with lactate modification predicts in-hospital mortality in patients with ongoing cardiac arrest during VA-ECMO cannulation

The survival after veno-arterial extracorporeal membrane oxygenation score and its lactate modification predict in-hospital mortality in patients based on pre-extracorporeal membrane oxygenation variables. Cardiac arrest history is a significant variable in these scores; however, patients with ongoing cardiac arrest during cannulation were excluded from these models. The goal of this study is to validate the survival after veno-arterial extracorporeal membrane oxygenation score with a lactate modification among patients with ongoing cardiac arrest. In our study, the survival after veno-arterial extracorporeal membrane oxygenation score predicted mortality in all patients, but did so with higher discrimination among ongoing cardiac arrest patients with a lactate modification.

Impact of a Modified Institutional Protocol on Outcomes After Extracorporeal Cardiopulmonary Resuscitation for Refractory Out-Of-Hospital Cardiac Arrest

OBJECTIVE

To analyze the impact of the modification of the authors' institutional protocol on outcomes after extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest (OHCA).

DESIGN

An observational analysis. The protocol complied with national recommendations. A further eligibility criterion was added since January 2015: the presence of sustained shockable rhythm at extracorporeal life support (ECLS) implantation. To assess the impact of this change, patients were divided into two groups: (1) from January 2010 to December 2014 (group A) and (2) from January 2015 to December 2019 (group B). The primary endpoint was survival to hospital discharge with good neurologic outcome. Predictors of survival were searched with multivariate analyses.

SETTING

University hospital.

PARTICIPANTS

Adult patients supported with ECPR for refractory OHCA.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

From January 2010 to December 2019, 85 patients had ECLS for OHCA (group A, n = 68, 80%; group B, n = 17, 20%). The mean age was 42.4 years, 78.8% were male. The rate of implantation of ECLS was significantly lower in group B (p = 0.01). Mortality during ECLS support was significantly lower (58.8 v 86.8%; p = 0.008), and the weaning rate was significantly higher (41.2 v 13.2%; p = 0.008) in group B. Survival to discharge with good neurologic outcome was significantly improved (23.5 v 4.4%; p = 0.027) in group B. A sustained shockable rhythm was the only independent predictor of survival to hospital discharge with good neurologic outcome.

CONCLUSIONS

The modification of the authors' institutional protocol throughout the further criterion of sustained shockable rhythm yielded a favorable impact on outcomes after ECPR for OHCA.

Association between age and neurological outcomes in out-of-hospital cardiac arrest patients resuscitated with extracorporeal cardiopulmonary resuscitation: a nationwide multicentre observational study

AIMS

Little is known about the difference in outcomes between young and old patients who received extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest (OHCA). Therefore, we aimed to investigate the differences in outcomes between those aged ≥75 years and <75 years who experienced OHCA and were resuscitated with ECPR.

METHODS AND RESULTS

We performed a secondary analysis of a nationwide prospective cohort study using the Japanese Association for Acute Medicine OHCA registry. We identified patients aged ≥18 years with OHCA who received ECPR. The patients were classified into three age groups (18-59 years, 60-74 years, and ≥75 years). The primary outcome was a 1-month neurological outcome. To examine the association between age and 1-month neurological outcome, we performed logistic regression analyses fitted with generalized estimating equations. From 2014 to 2017, we identified 875 OHCA patients aged ≥18 years who received ECPR. The proportion of patients who survived with favourable neurological outcome in the patients aged 18-59 years, 60-74 years, and ≥75 years were 15% (64/434), 8.9% (29/326), and 1.7% (2/115), respectively. In the multivariable analysis, compared with the age of 18-59 years, the proportions of favourable neurological outcomes were significantly lower in patients aged 60-74 years [adjusted odds ratio (OR), 0.44; 95% confidence interval (CI), 0.32-0.61] and those aged ≥75 years (adjusted OR, 0.26; 95% CI, 0.11-0.59).

CONCLUSION

Advanced age (age ≥75 years in particular) was significantly associated with poor neurological outcomes in patients with OHCA who received ECPR.

Association between the number of prehospital defibrillation attempts and neurologic outcomes in out-of-hospital cardiac arrest patients without on-scene return of spontaneous circulation

Objective

Delivery of prehospital defibrillation for shockable rhythms by emergency medical service providers is crucial for successful resuscitation in out-of-hospital cardiac arrest (OHCA) patients. The optimal range of prehospital defibrillation attempts for refractory shockable rhythms is unknown. This study evaluated the association between the number of prehospital defibrillation attempts and neurologic outcomes in OHCA patients.

Methods

A retrospective observational study was conducted using the nationwide OHCA registry. Adult OHCA patients who were treated by emergency medical service providers due to presumed cardiac origin with initial shockable rhythm were enrolled from 2013 to 2016. The final analysis was performed on patients without on-scene return of spontaneous circulation. The number of prehospital defibrillation attempts was categorized as follows: 2–3, 4–5, and ≥6 attempts. The primary outcome was a good neurologic recovery at hospital discharge. Multivariate logistic regression analysis was performed to evaluate the association between neurologic outcomes and the number of prehospital defibrillation attempts.

Results

A total of 4,513 patients were included in the final analysis. The numbers of patients for whom 2–3, 4–5, and ≥6 defibrillation attempts were made were 2,720 (60.3%), 1,090 (24.2%), and 703 (15.5%), respectively. Poorer outcomes were associated with ≥6 defibrillation attempts: survival to hospital discharge (adjusted odds ratio, 0.38; 95% confidence interval, 0.21–0.65) and good neurologic recovery (adjusted odds ratio, 0.42; 95% confidence interval, 0.21–0.84).

Conclusion

Six or more prehospital defibrillation attempts were associated with poorer neurologic outcomes in OHCA patients with an initial shockable rhythm who were unresponsive to on-scene defibrillation and resuscitation.

ECPR-extracorporeal cardiopulmonary resuscitation

Extracorporeal cardiopulmonary resuscitation (ECPR) is a salvage procedure in which extracorporeal membrane oxygenation (ECMO) is initiated emergently on patients who have had cardiac arrest (CA) and on whom the conventional cardiopulmonary resuscitation (CCPR) has failed. Awareness and usage of ECPR are increasing all over the world. Significant advancements have taken place in the ECPR initiation techniques, in its device and in its post-procedure care. ECPR is a team work requiring multidisciplinary experts, highly skilled health care workers and adequate infrastructure with appropriate devices. Perfect coordination and communication among team members play a vital role in the outcome of the ECPR patients. Ethical, legal and financial issues need to be considered before initiation of ECPR and while withdrawing the support when the ECPR is futile. Numerous studies about ECPR are being published more frequently in the last few years. Hence, keeping updated about the ECPR is very important for proper selection of cases and its management. This article reviews various aspects of ECPR and relevant literature to date.

Outcome in refractory out-of-hospital cardiac arrest before and after implementation of an ECPR protocol

AIM

To compare the outcomes in patients with refractory out-of-hospital cardiac arrest (OHCA) fulfilling the criteria for extracorporeal cardiopulmonary resuscitation (ECPR) before and after implementation of an ECPR protocol, whether the patient received ECPR or not.

METHODS

We compared cardiac arrest registry data before (2014-2015) and after (2016-2019) implementation of the ECPR protocol. The ECPR criteria were presumed cardiac origin, witnessed arrest with ventricular fibrillation, bystander CPR, age 18-65, advanced life support (ALS) within 15 min and ALS > 10 min without return of spontaneous circulation (ROSC). The primary outcome was 30-day survival; the secondary outcomes were sustained ROSC, neurological outcome and the proportion of patients transported with ongoing ALS.

RESULTS

There were 1086 and 3135 patients in the pre- and post-implementation sample; 48 (4%) and 100 (3%) met the ECPR criteria, respectively. Of these, 21 (44%) vs. 37 (37%) were alive after 30 days, p = 0.4, and 30 (63%) vs. 50 (50%) achieved sustained ROSC, p = 0.2. All survivors in the pre-implementation sample had cerebral performance category 1-2 vs. 30 (81%) in the post-implementation sample, p = 0.03. Of the patients fulfilling the ECPR criteria, 7 (15%) and 26 (26%), p = 0.1, were transported with ongoing ALS in the pre- and post-implementation sample, respectively.

CONCLUSIONS

There were no differences in 30-day survival or prehospital ROSC in patients with refractory OHCA before and after initiation of an ECPR protocol.

A review of ECMO for cardiac arrest

Cardiac arrest is an important public health concern, affecting an estimated 356,500 people in the out-of-hospital setting and 209,000 people in the in-hospital setting each year. The causes of cardiac arrest include acute coronary syndromes, pulmonary embolism, dyskalemia, respiratory failure, hypovolemia, sepsis, and poisoning among many others. In order to tackle the enormous issue of high mortality among sufferers of cardiac arrest, ongoing research has been seeking improved treatment protocols and novel therapies. One of the mechanical devices that has been increasingly utilized for cardiac arrest is venoarterial extracorporeal membrane oxygenation (VA-ECMO). Presently there is only one published randomized controlled trial examining the use of VA-ECMO as part of cardiopulmonary resuscitation (CPR), a process referred to as extracorporeal cardiopulmonary resuscitation (ECPR). Recently there has been significant progress in providing ECPR for refractory cardiac arrest patients. This narrative review seeks to outline the use of ECPR for both in-hospital and out-of-hospital cardiac arrest, as well as provide information on the expected outcomes associated with its use.

Extracorporeal cardiopulmonary resuscitation for refractory cardiac arrest: a scoping review

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR) is an emerging concept in cardiac arrest and cardiopulmonary resuscitation. Recent research has documented a significant improvement in favorable outcomes, notable survival to discharge, and neurologically intact survival.

OBJECTIVES

The present study undertakes a scoping review to summarize the available evidence by assessing the use of ECPR, compared with no ECPR or the standard of care, for adult patients who sustain cardiac arrest in any setting, in studies which record survival and neurologic outcomes.

METHODS

This review followed the PRISMA extension for scoping reviews (PRISMA-ScR) guidelines. Four online databases were used to identify papers published from database inception to July 12, 2020. We selected 23 observational studies from Asia, Europe, and North America that used survival to discharge or neurologically intact survival as a primary or secondary endpoint variable in patients with cardiac arrest refractory to standard treatment.

RESULTS

Twenty-three observational studies were included in the review. Eleven studies were of out-of-hospital cardiac arrest, 7 studies were of in-hospital cardiac arrest, and 5 studies included mixed populations. Ten studies reported long-term favorable neurological outcomes (ie, Cerebral Performance Category score of 1 - 2 at 3 months [n = 3], 6 months [n = 3], and 1 year [n = 4]), of which only 4 had statistical significance at 5% significance levels. Current knowledge is mostly drawn from single-center observations, with most of the evidence coming from case series and cohort studies, hence is prone to publication bias. No randomized control trials were included.

CONCLUSIONS

This scoping review highlights the need for high-quality studies to increase the level of evidence and reduce knowledge gaps to change the paradigm of care for patients with shock-refractory cardiac arrest.

Promising candidates for extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest

Precise criteria for extracorporeal cardiopulmonary resuscitation (ECPR) are still lacking in patients with out-of-hospital cardiac arrest (OHCA). We aimed to investigate whether adopting our hypothesized criteria for ECPR to patients with refractory OHCA could benefit. This before-after study compared 4.5 years after implementation of ECPR for refractory OHCA patients who met our criteria (Jan, 2015 to May, 2019) and 4 years of undergoing conventional CPR (CCPR) prior to ECPR with patients who met the criteria (Jan, 2011 to Jan, 2014) in the emergency department. The primary and secondary outcomes were good neurologic outcome at 6-months and 1-month respectively, defined as 1 or 2 on the Cerebral Performance Category score. A total of 70 patients (40 with CCPR and 30 with ECPR) were included. For a good neurologic status at 6-months and 1-month, patients with ECPR (33.3%, 26.7%) were superior to those with CCPR (5.0%, 5.0%) (all Ps < 0.05). Among patients with ECPR, a group with a good neurologic status showed shorter low-flow time, longer extracorporeal membrane oxygenation duration and hospital stays, and lower epinephrine doses used (all Ps < 0.05). The application of the detailed indication before initiating ECPR appears to increase a good neurologic outcome rate.

Long-term neurologically intact survival after extracorporeal cardiopulmonary resuscitation for in-hospital or out-of-hospital cardiac arrest: A systematic review and meta-analysis

BACKGROUND

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has been used as extracorporeal cardiopulmonary resuscitation (ECPR) to support further resuscitation efforts in patients with cardiac arrest, yet its clinical effectiveness remains uncertain.

OBJECTIVES

This study reviews the role of ECPR in contemporary resuscitation care compared to no ECPR and/or standard care, e.g. conventional CPR, and quantitatively summarize the rates of long-term neurologically intact survival after adult in-hospital cardiac arrest (IHCA) or out-of-hospital cardiac arrest (OHCA).

METHODS

We searched the following databases on January 31 st, 2020: CENTRAL, MEDLINE, Embase, and Web of Science. We followed PRISMA guidelines and used PICO format to summarize the research questions. Risk of bias was assessed using the ROBINS-I tool. Pooled risk ratios (RRs) for each outcome of interest were calculated. Quality of evidence was evaluated according to GRADE guidelines.

RESULTS

Six cohort studies were included, totaling 1750 patients. Of these, 530 (30.3%) received the intervention, and 91 (17.2%) survived with long-term neurologically intact survival. ECPR compared to no ECPR is likely associated with improved long-term neurologically intact survival after cardiac arrest in any setting (risk ratio [RR] 3.11, 95% confidence interval [CI] 2.06-4.69; p < 0.00001) (GRADE: Very low quality). Similar results were found for long-term neurologically intact survival after IHCA (RR 3.21, 95% CI 1.74-5.94; p < 0.0002) (GRADE: Very low quality) and OHCA (RR 3.11, 95% CI 1.50-6.47; p < 0.002) (GRADE: Very low quality). Long-term time frames for neurologically intact survival (three months to two years) were combined into a single category, defined a priori as a Glasgow-Pittsburgh cerebral performance category (CPC) of 1 or 2.

CONCLUSIONS

VA-ECMO used as ECPR is likely associated with improved long-term neurologically intact survival after cardiac arrest. Future evidence from randomized trials is very likely to have an important impact on the estimated effect of this intervention and will further define optimal clinical practice. Review registration: PROSPERO CRD42020171945.

Association between Extracorporeal Membrane Oxygenation (ECMO) and Mortality in the Patients with Cardiac Arrest: A Nation-Wide Population-Based Study with Propensity Score Matched Analysis

We attempted to determine the impact of extracorporeal membrane oxygenation (ECMO) on short-term and long-term outcomes and find potential resource utilization differences between the ECMO and non-ECMO groups, using the National Health Insurance Service database. We selected adult patients (≥20 years old) with non-traumatic cardiac arrest from 2007 to 2015. Data on age, sex, insurance status, hospital volume, residential area urbanization, and pre-existing diseases were extracted from the database. A total of 1.5% (n = 3859) of 253,806 patients were categorized into the ECMO group. The ECMO-supported patients were more likely to be younger, men, more covered by national health insurance, and showed, higher usage of tertiary level and large volume hospitals, and a lower rate of pre-existing comorbidities, compared to the non-ECMO group. After propensity score-matching demographic data, hospital factors, and pre-existing diseases, the odds ratio (ORs) of the ECMO group were 0.76 (confidence interval, (CI) 0.68–0.85) for 30-day mortality and 0.66 (CI 0.58–0.79) for 1-year mortality using logistic regression. The index hospitalization was longer, and the 30-day and 1-year hospital costs were greater in the matched ECMO group. Although ECMO support needed longer hospitalization days and higher hospital costs, the ECMO support reduced the risk of 30-day and 1-year mortality compared to the non-ECMO patients.

Clinical Significance of Low-Flow Time in Patients Undergoing Extracorporeal Cardiopulmonary Resuscitation: Results from the RESCUE Registry

Limited data are available on the association between low-flow time and survival in patients with in-hospital cardiac arrest (IHCA) who undergo extracorporeal cardiopulmonary resuscitation (ECPR). We evaluated data from 183 IHCA patients who underwent ECPR as a rescue procedure. Patients were divided into two groups: patients undergoing extracorporeal membrane oxygenation as an adjunct to standard cardiopulmonary resuscitation for less than 38 min (n = 110) or for longer than 38 min (n = 73). The ECPR ≤ 38 min group had a significantly greater incidence of survival to discharge compared to the ECPR > 38 min group (40.0% versus 24.7%, p = 0.032). The incidence of good neurologic outcomes at discharge tended to be greater in the ECPR ≤ 38 min group than in the ECPR > 38 min group (35.5% versus 24.7%, p = 0.102). The incidences of limb ischemia (p = 0.354) and stroke (p = 0.805) were similar between the two groups, but major bleeding occurred less frequently in the ECPR ≤ 38 min group compared to the ECPR > 38 min group (p = 0.002). Low-flow time ≤ 38 min may reduce the risk of mortality and fatal neurologic damage and could be a measure of optimal management in patients with IHCA.

Outcomes of Veno-Arterial Extracorporeal Membrane Oxygenation for In-Hospital Cardiac Arrest

Veno-arterial extracorporeal membrane oxygenation (VA ECMO) is increasingly used in cardiac arrest. Currently, public registries report the outcomes of cardiac arrest regardless of the setting (out-of-hospital versus in-hospital). Meanwhile, in-hospital cardiac arrest represents a more favorable setting for ECMO-assisted cardiopulmonary resuscitation than out-of-hospital cardiac arrest. Survival to discharge varies, but looks promising overall, ranging from 18.9 to 65%, with the bulk of the studies reporting survival to discharge between 30% and 50%, with about one-third to half of the patients discharged with no or minimal neurologic deficit. Based on the reported outcomes, in-hospital cardiac arrests can become a next focus for studies on successful implementation of VA ECMO.

Rationale and methods of the Advanced R2Eperfusion STrategies for Refractory Cardiac Arrest (ARREST) trial

BACKGROUND

Venoarterial extracorporeal membrane oxygenation has emerged as a prominent therapy for patients with refractory cardiac arrest. However, the optimal time of initiation remains unknown.

AIM

The aim was to assess the rate of survival to hospital discharge in adult patients with refractory ventricular fibrillation/pulseless ventricular tachycardia out-of-hospital cardiac arrest treated with 1 of 2 local standards of care: (1) early venoarterial extracorporeal membrane oxygenation-facilitated resuscitation for circulatory support and percutaneous coronary intervention, when needed, or (2) standard advanced cardiac life support resuscitation.

DESIGN

Phase II, single-center, partially blinded, prospective, intention-to-treat, safety and efficacy clinical trial.

POPULATION

Adults (aged 18-75), initial out-of-hospital cardiac arrest rhythm of ventricular fibrillation/pulseless ventricular tachycardia, no ROSC following 3 shocks, body morphology to accommodate a Lund University Cardiac Arrest System automated cardiopulmonary resuscitation device, and transfer time of <30 minutes.

SETTING

Hospital-based.

OUTCOMES

Primary: survival to hospital discharge. Secondary: safety, survival, and functional assessment at hospital discharge and 3 and 6 months, and cost.

SAMPLE SIZE

Assuming success rates of 12% versus 37% in the 2 arms and 90% power, a type 1 error rate of .05, and a 15% rate of withdrawal prior to hospital discharge, the required sample size is N = 174 evaluated patients.

CONCLUSIONS

The ARREST trial will generate safety/effectiveness data and comparative costs associated with extracorporeal cardiopulmonary resuscitation, informing broader implementation and a definitive Phase III clinical trial.

Out-of-hospital cardiac arrest patients with an initial non-shockable rhythm could be candidates for extracorporeal cardiopulmonary resuscitation: a retrospective study

Background

Extracorporeal cardiopulmonary resuscitation (ECPR) is a promising treatment for refractory out-of-hospital cardiac arrest (OHCA). Most studies evaluating the effectiveness of ECPR include patients with an initial shockable rhythm. However, the effectiveness of ECPR for patients with an initial non-shockable rhythm remains unknown. This retrospective single-center study aimed to evaluate the effectiveness of ECPR for patients with an initial non-shockable rhythm, with reference to the outcomes of OHCA patients with an initial shockable rhythm.

Methods

Adult OHCA patients treated with ECPR at our center during 2011–2018 were included in the study. Patients were classified into the initial shockable rhythm group and the non-shockable rhythm group. The primary outcome was the cerebral performance category (CPC) scale score at hospital discharge. A CPC score of 1 or 2 was defined as a good outcome.

Results

In total, 186 patients were eligible. Among them, 124 had an initial shockable rhythm and 62 had an initial non-shockable rhythm. Among all patients, 158 (85%) were male, with a median age of 59 (interquartile range [IQR], 48–65) years, and the median low flow time was 41 (IQR, 33–48) min. Collapse was witnessed in 169 (91%) patients, and 36 (19%) achieved return of spontaneous circulation (ROSC) transiently. Proportion of female patients, presence of bystander cardiopulmonary resuscitation, and collapse after the arrival of emergency medical service personnel were significantly higher in the non-shockable rhythm group. The rate of good outcomes at hospital discharge was not significantly different between the shockable and non-shockable groups (19% vs. 16%, p = 0.69). Initial shockable rhythm was not significantly associated with good outcome after controlling for potential confounders (adjusted odds ratio 1.58, 95% confidence interval: 0.66–3.81, p = 0.31). In the non-shockable group, patients with good outcomes had a higher rate of transient ROSC, and pulmonary embolism was the leading etiology.

Conclusions

The outcomes of patients with an initial non-shockable rhythm are comparable with those having an initial shockable rhythm. OHCA patients with an initial non-shockable rhythm could be candidates for ECPR, if they are presumed to have reversible etiology and potential for good neurological recovery.

Development and Evaluation of An Abbreviated Extracorporeal Membrane Oxygenation (ECMO) Course for Nonsurgical Physicians and Nurses

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is a modification of cardiopulmonary bypass that allows prolonged support of patients with severe respiratory or cardiac failure. ECMO indications arse rapidly evolving and there is growing interest in its use for cardiac arrest and cardiogenic shock. However, ECMO training programs are limited. Training of emergency medicine and critical care clinicians could expand the use of this lifesaving intervention. Our objective was to develop and evaluate an abbreviated ECMO course that can be taught to emergency and critical care physicians and nurses.

METHODS

We developed a training model using Yorkshire swine (Sus scrofa), a procedure instruction checklist, a confidence assessment, and a knowledge assessment. Participants were assigned to teams of one emergency medicine or critical care physician and one nurse and completed an abbreviated 8-hour ECMO course. An ECMO specialist trained participants on preparation of the ECMO circuit and oversaw vascular access and ECMO initiation. We used the instruction checklist to evaluate performance. Participants completed confidence and knowledge assessments before and after the course.

RESULTS

Seventeen teams (34 clinicians) completed the abbreviated ECMO course. None had previously completed an ECMO certification course. Immediately following the course, all teams successfully primed and prepared the ECMO circuit. Fifteen teams (88%, 95% confidence interval [CI] = 64% to 99%) successfully initiated ECMO. Participants improved their knowledge (difference 21.2, 95% CI = 16.5 to 25.8) and confidence (difference 40.3, 95% CI = 35.6 to 45.0) scores after completing the course.

CONCLUSIONS

We developed an accelerated 1-day ECMO course. Clinicians' confidence and knowledge assessments improved and 88% of teams could successfully initiate venoarterial ECMO after the course.

Esmolol in the management of pre-hospital refractory ventricular fibrillation: A systematic review and meta-analysis

BACKGROUND

Esmolol has been proposed as a viable adjunctive therapy for pre-hospital refractory ventricular fibrillation/pulseless ventricular tachycardia (VF/pVT).

OBJECTIVES

We performed a systematic review and meta-analysis to assess the effectiveness of esmolol on pre-hospital refractory VF/pVT, compared with standard of care.

METHODS

MEDLINE, Embase, Scopus, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched for eligible studies. Two investigators independently extracted relevant data and assessed the methodological quality of each included study using the ROBINS-I tool. The quality of evidence for summary estimates was assessed according to GRADE guidelines. Pooled risk ratios (RRs) with 95% confidence intervals (CIs) for each outcome of interest were calculated.

RESULTS

The search yielded 3253 unique records, of which two studies were found to be in accordance with the research purpose, totaling 66 patients, of whom 33.3% (n = 22) received esmolol. Additional evidence was provided in the paper but was not relevant to the analysis and was therefore not included. Esmolol was likely associated with an increased rate of survival to discharge (RR 2.82, 95% CI 1.01-7.93, p = 0.05) (GRADE: Very low) and survival with favorable neurological outcome (RR 3.44, 95% CI 1.11-10.67, p = 0.03) (GRADE: Very low). Similar results were found for return of spontaneous circulation (ROSC) (RR 2.63, 95% CI 1.37-5.07, p = 0.004) (GRADE: Very low) and survival to intensive care unit (ICU)/hospital admission (RR 2.63, 95% CI 1.37-5.07, p = 0.004) (GRADE: Very low).

CONCLUSION

The effectiveness of esmolol for refractory VF/pVT remains unclear. Trial sequential analysis (TSA) indicates that the evidence is inconclusive and that further trials are required in order to reach a conclusion. Therefore, it is imperative to continue to accumulate evidence in order to obtain a higher level of scientific evidence.

Gasping during refractory out-of-hospital cardiac arrest is a prognostic marker for favourable neurological outcome following extracorporeal cardiopulmonary resuscitation: a retrospective study

Background

Gasping during cardiac arrest is associated with favourable neurological outcomes for out-of-hospital cardiac arrest. Moreover, while extracorporeal cardiopulmonary resuscitation (ECPR) performed for refractory cardiac arrest can improve outcomes, factors for favourable neurological outcomes remain unknown. This study aimed to examine whether gasping during cardiac arrest resuscitation during transport by emergency medical services (EMS) was independently associated with a favourable neurological outcome for patients who underwent ECPR. This retrospective study was based on medical records of all adult patients who underwent ECPR due to refractory cardiac arrest. The primary endpoint was neurologically intact survival at discharge. The study was undertaken at Sapporo Medical University Hospital, a tertiary care centre approved by the Ministry of Health, Labour and Welfare, located in the city of Sapporo, Japan, between January 2012 and December 2018.

Results

Overall, 166 patients who underwent ECPR were included. During transportation by EMS, 38 patients exhibited gasping, and 128 patients did not. Twenty patients who exhibited gasping during EMS transportation achieved a favourable neurological outcome (20/38; 52.6%); 14 patients who did not exhibit gasping achieved a favourable neurological outcome (14/128; 10.9%). Gasping during transportation by EMS was independently associated with favourable neurological outcome irrespective of the type of analysis performed (multiple logistic regression analysis, odds ratio [OR] 9.52; inverse probability of treatment weighting using propensity score, OR 9.14).

Conclusions

The presence of gasping during transportation by EMS was independently associated with a favourable neurological outcome in patients who underwent ECPR. The association of gasping with a favourable neurological outcome in patients with refractory cardiac arrest suggests that ECPR may be considered in such patients.