Extracorporeal life support associated with hypothermia and normoxemia in refractory cardiac arrest

Extracorporeal cardiopulmonary resuscitation for refractory out-of-hospital cardiac arrest: Lessons learned from recent clinical trials

Cardiac arrest is a leading contributor to morbidity and mortality in the United States. Survival has been historically dependent on high-quality cardiopulmonary resuscitation (CPR) and rapid defibrillation. However, a large percentage of patients remain in refractory cardiac arrest despite adherence to structured advanced cardiac life support algorithms in which these factors are emphasized. Veno-arterial extracorporeal membrane oxygenation is becoming an increasingly used rescue therapy for patients in refractory cardiac arrest to restore oxygen delivery by extracorporeal CPR (ECPR). Recently published clinical trials have provided new insights into ECPR for patients who sustain an outside hospital cardiac arrest (OHCA). In this narrative review, we summarize the rationale for, results of, and remaining questions from these recently published clinical trials. The existing observational data combined with the latest clinical trials suggest ECPR improves mortality in patients in refractory arrest. However, a mixed methods trial is essential to understand the complexity, context, and effectiveness of implementing an ECPR program.

Scrutinizing the Role of Venoarterial Extracorporeal Membrane Oxygenation: Has Clinical Practice Outpaced the Evidence?

The use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) for temporary mechanical circulatory support in various clinical scenarios has been increasing consistently, despite the lack of sufficient evidence regarding its benefit and safety from adequately powered randomized controlled trials. Although the ARREST trial (Advanced Reperfusion Strategies for Patients with Out-of-Hospital Cardiac Arrest and Refractory Ventricular Fibrillation) and a secondary analysis of the PRAGUE OHCA trial (Prague Out-of-Hospital Cardiac Arrest) provided some evidence in favor of VA-ECMO in the setting of out-of-hospital cardiac arrest, the INCEPTION trial (Early Initiation of Extracorporeal Life Support in Refractory Out-of-Hospital Cardiac Arrest) has not found a relevant improvement of short-term mortality with extracorporeal cardiopulmonary resuscitation. In addition, the results of the recently published ECLS-SHOCK trial (Extracorporeal Life Support in Cardiogenic Shock) and ECMO-CS trial (Extracorporeal Membrane Oxygenation in the Therapy of Cardiogenic Shock) discourage the routine use of VA-ECMO in patients with infarct-related cardiogenic shock. Ongoing clinical trials (ANCHOR [Assessment of ECMO in Acute Myocardial Infarction Cardiogenic Shock, NCT04184635], REVERSE [Impella CP With VA ECMO for Cardiogenic Shock, NCT03431467], UNLOAD ECMO [Left Ventricular Unloading to Improve Outcome in Cardiogenic Shock Patients on VA-ECMO, NCT05577195], PIONEER [Hemodynamic Support With ECMO and IABP in Elective Complex High-risk PCI, NCT04045873]) may clarify the usefulness of VA-ECMO in specific patient subpopulations and the efficacy of combined mechanical circulatory support strategies. Pending further data to refine patient selection and management recommendations for VA-ECMO, it remains uncertain whether the present usage of this device improves outcomes.

Impact of clinical variables on outcomes in refractory cardiac arrest patients undergoing extracorporeal cardiopulmonary resuscitation

Background

In the past two decades, extracorporeal resuscitation (ECPR) has been increasingly used in the management of refractory cardiac arrest (CA) patients. Decision algorithms have been used to guide the care such patients, but the effectiveness of such decision-making tools is not well described. The aim of this study was to compare the rate of survival with a good neurologic outcome of patients treated with ECPR meeting all criteria of a clinical decision-making tool for the initiation of ECPR to those for whom ECPR was implemented outside of the algorithm.

Methods

All patients who underwent E-CPR between January 2014 and December 2021 at the Montreal Heart Institute were included in this retrospective analysis. We dichotomized the cohort according to adherence or non-adherence with the ECPR decision-making tool, which included the following criteria: age ≤65 years, initial shockable rhythm, no-flow time <5 min, serum lactate <13 mmol/L. Patients were included in the "IN" group when they met all criteria of the decision-making tool and in the "OUT" group when at least one criterion was not met.

Main outcomes and measures

The primary outcome was survival with intact neurological status at 30 days, defined by a Cerebral Performance Category (CPC) Scale 1 and 2.

Results

A total of 41 patients (IN group, n = 11; OUT group, n = 30) were included. A total of 4 (36%) patients met the primary outcome in the IN group and 7 (23%) in the OUT group [odds ratio (OR): 1.88 (95% CI, 0.42-8.34); P = 0.45]. However, survival with a favorable outcome decreased steadily with 2 or more deviations from the decision-making tool [2 deviations: 1 (11%); 3 deviations: 0 (0%)].

Conclusion and relevance

Most patients supported with ECPR fell outside of the criteria encompassed in a clinical decision-making tool, which highlights the challenge of optimal selection of ECPR candidates. Survival rate with a good neurologic outcome did not differ between the IN and OUT groups. However, survival with favorable outcome decreased steadily after one deviation from the decision-making tool. More studies are needed to help select proper candidates with refractory CA patients for ECPR.

Extracorporeal cardiopulmonary resuscitation in adults and children: A review of literature, published guidelines and pediatric single-center program building experience

Extracorporeal cardiopulmonary resuscitation (ECPR) is an adjunct supportive therapy to conventional cardiopulmonary resuscitation (CCPR) employing veno-arterial extracorporeal membrane oxygenation (VA-ECMO) in the setting of refractory cardiac arrest. Its use has seen a significant increase in the past decade, providing hope for good functional recovery to patients with cardiac arrest refractory to conventional resuscitation maneuvers. This review paper aims to summarize key findings from the ECPR literature available to date as well as the recommendations for ECPR set forth by leading national and international resuscitation societies. Additionally, we describe the successful pediatric ECPR program at Texas Children's Hospital, highlighting the logistical, technical and educational features of the program.

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).

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.

Brain Injury and Neurologic Outcome in Patients Undergoing Extracorporeal Cardiopulmonary Resuscitation: A Systematic Review and Meta-Analysis

OBJECTIVES

Extracorporeal cardiopulmonary resuscitation has shown survival benefit in select patients with refractory cardiac arrest but there is insufficient data on the frequency of different types of brain injury. We aimed to systematically review the prevalence, predictors of and survival from neurologic complications in patients who have undergone extracorporeal cardiopulmonary resuscitation.

DATA SOURCES

MEDLINE (PubMed) and six other databases (EMBASE, Cochrane Library, CINAHL Plus, Web of Science, and Scopus) from inception to August 2019.

STUDY SELECTION

Randomized controlled trials and observational studies in patients greater than 18 years old.

DATA EXTRACTION

Two independent reviewers extracted the data. Study quality was assessed by the Cochrane Risk of Bias tool for randomized controlled trials, the Newcastle-Ottawa Scale for cohort and case-control studies, and the Murad tool for case series. Random-effects meta-analyses were used to pool data.

DATA SYNTHESIS

The 78 studies included in our analysis encompassed 50,049 patients, of which 6,261 (12.5%) received extracorporeal cardiopulmonary resuscitation. Among extracorporeal cardiopulmonary resuscitation patients, the median age was 56 years (interquartile range, 52-59 yr), 3,933 were male (63%), 3,019 had out-of-hospital cardiac arrest (48%), and 2,289 had initial shockable heart rhythm (37%). The most common etiology of cardiac arrest was acute coronary syndrome (n = 1,657, 50% of reported). The median extracorporeal cardiopulmonary resuscitation duration was 3.2 days (interquartile range, 2.1-4.9 d). Overall, 27% (95% CI, 0.17-0.39%) had at least one neurologic complication, 23% (95% CI, 0.14-0.32%) hypoxic-ischemic brain injury, 6% (95% CI, 0.02-0.11%) ischemic stroke, 6% (95% CI, 0.01-0.16%) seizures, and 4% (95% CI, 0.01-0.1%) intracerebral hemorrhage. Seventeen percent (95% CI, 0.12-0.23%) developed brain death. The overall survival rate after extracorporeal cardiopulmonary resuscitation was 29% (95% CI, 0.26-0.33%) and good neurologic outcome was achieved in 24% (95% CI, 0.21-0.28%).

CONCLUSIONS

One in four patients developed acute brain injury after extracorporeal cardiopulmonary resuscitation and the most common type was hypoxic-ischemic brain injury. One in four extracorporeal cardiopulmonary resuscitation patients achieved good neurologic outcome. Further research on assessing predictors of extracorporeal cardiopulmonary resuscitation-associated brain injury is necessary.

A Systematic Literature Review of Packed Red Cell Transfusion Usage in Adult Extracorporeal Membrane Oxygenation

Background: Blood product administration plays a major role in the management of patients treated with extracorporeal membrane oxygenation (ECMO) and may be a contributor to morbidity and mortality. Methods: We performed a systematic review of the published literature to determine the current usage of packed red cell transfusions. Predefined search criteria were used to identify journal articles reporting transfusion practice in ECMO by interrogating EMBASE and Medline databases and following the PRISMA statement. Results: Out of 1579 abstracts screened, articles reporting ECMO usage in a minimum of 10 adult patients were included. Full texts of 331 articles were obtained, and 54 were included in the final analysis. All studies were observational (2 were designed prospectively, and two were multicentre). A total of 3808 patients were reported (range 10–517). Mean exposure to ECMO was 8.2 days (95% confidence interval (CI) 7.0–9.4). A median of 5.6% was not transfused (interquartile range (IQR) 0–11.3%, 19 studies). The mean red cell transfusion per ECMO run was 17.7 units (CI 14.2–21.2, from 52 studies) or 2.60 units per day (CI 1.93–3.27, from 49 studies). The median survival to discharge was 50.8% (IQR 40.0–64.9%). Conclusion: Current evidence on transfusion practice in ECMO is mainly drawn from single-centre observational trials and varies widely. The need for transfusions is highly variable. Confounding factors influencing transfusion practice need to be identified in prospective multicentre studies to mitigate potential harmful effects and generate hypotheses for interventional trials.

Extracorporeal cardiopulmonary resuscitation for adults with shock-refractory cardiac arrest

BACKGROUND

Veno-arterial extracorporeal membrane oxygenation has increasingly emerged as a feasible treatment to mitigate the progressive multiorgan dysfunction that occurs during cardiac arrest, in support of further resuscitation efforts.

OBJECTIVES

Because the recent systematic review commissioned in 2018 by the International Liaison Committee on Resuscitation Advanced Life Support task did not include studies without a control group, our objective was to conduct a review incorporating these studies to increase available evidence supporting the use of extracorporeal cardiopulmonary resuscitation (ECPR) for cardiac arrest patients, while waiting for high-quality evidence from randomized controlled trials (RCTs).

METHODS

MEDLINE, Embase, and Science Citation Index (Web of Science) were searched for eligible studies from database inception to July 20, 2020. The population of interest was adult patients who had suffered cardiac arrest in any setting. We included all cohort studies with 1 exposure/1 group and descriptive studies (ie, case series studies). We excluded RCTs, non-RCTs, and observational analytic studies with a control group. Outcomes included short-term survival and favorable neurological outcome. Short-term outcomes (ie, hospital discharge, 30 days, and 1 month) were combined into a single category.

RESULTS

Our searches of databases and other sources yielded a total of 4302 citations. Sixty-two eligible studies were included (including a combined total of 3638 participants). Six studies were of in-hospital cardiac arrest, 34 studies were of out-of-hospital cardiac arrest, and 22 studies included both in-hospital and out-of-hospital cardiac arrest. Seven hundred and sixty-eight patients of 3352 (23%) had short-term survival; whereas, 602 of 3366 (18%) survived with favorable neurological outcome, defined as a cerebral performance category score of 1 or 2.

CONCLUSIONS

Current clinical evidence is mostly drawn from observational studies, with their potential for confounding selection bias. Although studies without controls cannot supplant case-control or cohort studies, several ECPR studies without a control group show successful resuscitation with impressive results that may provide valuable information to inform a comparison.

Resuscitating Resuscitation: Advanced Therapies for Resistant Ventricular Dysrhythmias

BACKGROUND

More than 640,000 combined in-hospital and out-of-hospital cardiac arrests occur annually in the United States. However, survival rates and meaningful neurologic recovery remain poor. Although "shockable" rhythms (i.e., ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT)) have the best outcomes, many of these ventricular dysrhythmias fail to return to a perfusing rhythm (resistant VF/VT), or recur shortly after they are resolved (recurrent VF/VT).

OBJECTIVE

This review discusses 4 emerging therapies in the emergency department for treating these resistant or recurrent ventricular dysrhythmias: beta-blocker therapy, dual simultaneous external defibrillation, stellate ganglion blockade, and extracorporeal cardiopulmonary resuscitation. We discuss the underlying physiology of each therapy, review relevant literature, describe when these approaches should be considered, and provide evidence-based recommendations for these techniques.

DISCUSSION

Esmolol may mitigate some of epinephrine's negative effects when used during resuscitation, improving both postresuscitation cardiac function and long-term survival. Dual simultaneous external defibrillation targets the region of the heart where ventricular fibrillation typically resumes and may apply a more efficient defibrillation across the heart, leading to higher rates of successful defibrillation. Stellate ganglion blocks, recently described in the emergency medicine literature, have been used to treat patients with recurrent VF/VT, resulting in significant dysrhythmia suppression. Finally, extracorporeal cardiopulmonary resuscitation is used to provide cardiopulmonary support while clinicians correct reversible causes of arrest, potentially resulting in improved survival and good neurologic functional outcomes.

CONCLUSION

These emerging therapies do not represent standard practice; however, they may be considered in the appropriate clinical scenario when standard therapies are exhausted without success.

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.

Neurological outcome after extracorporeal cardiopulmonary resuscitation for in-hospital cardiac arrest: a systematic review and meta-analysis

BACKGROUND

In-hospital cardiac arrest (IHCA) is a major adverse event with a high mortality rate if not treated appropriately. Extracorporeal cardiopulmonary resuscitation (ECPR), as adjunct to conventional cardiopulmonary resuscitation (CCPR), is a promising technique for IHCA treatment. Evidence pertaining to neurological outcomes after ECPR is still scarce.

METHODS

We performed a comprehensive systematic search of all studies up to December 20, 2019. Our primary outcome was neurological outcome after ECPR at any moment after hospital discharge, defined by the Cerebral Performance Category (CPC) score. A score of 1 or 2 was defined as favourable outcome. Our secondary outcome was post-discharge mortality. A fixed-effects meta-analysis was performed.

RESULTS

Our search yielded 1215 results, of which 19 studies were included in this systematic review. The average survival rate was 30% (95% CI 28-33%, I2 = 0%, p = 0.24). In the surviving patients, the pooled percentage of favourable neurological outcome was 84% (95% CI 80-88%, I2 = 24%, p = 0.90).

CONCLUSION

ECPR as treatment for in-hospital cardiac arrest is associated with a large proportion of patients with good neurological outcome. The large proportion of favourable outcome could potentially be explained by the selection of patients for treatment using ECPR. Moreover, survival is higher than described in the conventional CPR literature. As indications for ECPR might extend to older or more fragile patient populations in the future, research should focus on increasing survival, while maintaining optimal neurological outcome.

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

INTRODUCTION

In this systematic review and meta-analysis of propensity score-matched cohort studies, we quantitatively summarize whether venoarterial extracorporeal membrane oxygenation (VA-ECMO) used as extracorporeal cardiopulmonary resuscitation (ECPR), compared with conventional cardiopulmonary resuscitation (CCPR), is associated with improved rates of 30-day and long-term favorable neurological outcomes and survival in patients resuscitated from in- and out-of-hospital cardiac arrest.

METHODS

We searched MEDLINE via PubMed, Embase, Scopus, and Google Scholar for eligible studies on January 14, 2019. All searches were limited to studies published between January 2000 and January 2019. Two investigators independently evaluated the quality (or certainty) of evidence according to GRADE guidelines. Pooled results are presented as relative risks (RRs) with 95% confidence intervals (CIs).

RESULTS

Six cohort studies using propensity score-matched analysis were included, totaling 1108 matched patients. Pooled analyses showed that ECPR was likely associated with improved 30-day and long-term favorable neurological outcome in adults compared to CCPR for in- and out-of-hospital cardiac arrest (RR = 2.02, 95% CI = 1.29-3.16; I2 = 20%, P = 0.002; very low-quality evidence) and (RR = 2.86, 95% CI = 1.64-5.01; I2 = 0%, P = 0.0002; moderate-quality evidence), respectively. When we analyzed in- and out-of-hospital cardiac arrest separately, ECPR was likely associated with improved 30-day favorable neurological outcome compared to CCPR for in-hospital cardiac arrest (RR = 2.18, 95% CI = 1.24-3.81; I2 = 9%, P = 0.006; very low-quality evidence), but not for out-of-hospital cardiac arrest (RR = 2.61, 95% CI = 0.56-12.20; I2 = 59%, P = 0.22; very low-quality evidence). ECPR was also likely associated with improved long-term favorable neurological outcome compared to CCPR for in-hospital cardiac arrest (RR = 2.50, 95% CI = 1.33-4.71; I2 = 0%, P = 0.005; moderate-quality evidence) and out-of-hospital cardiac arrest (RR = 4.64, 95% CI = 1.41-15.25; I2 = 0%, P = 0.01; moderate-quality evidence).

CONCLUSIONS

Our analysis suggests that VA-ECMO used as ECPR may improve long-term favorable neurological outcomes and survival when compared to the best standard of care in a selected patient population. Therefore, it is imperative for well-designed randomized clinical trials to obtain a higher level of scientific evidence to ensure optimal outcomes for cardiac arrest patients.

A systematic review of current ECPR protocols. A step towards standardisation

Aim

Extracorporeal cardiopulmonary resuscitation (ECPR) can treat cardiac arrest refractory to conventional therapies. Our goal was to identify the best protocol for survival with good neurological outcome through the evaluation of current inclusion criteria, exclusion criteria, cannulation strategies and additional therapeutic measures.

Methods

A systematic literature search was used to identify eligible publications from PubMed, Embase, Web of Science and Cochrane for articles published from 29 June 2009 until 29 June 2019.

Results

The selection process led to a total of 24 eligible articles, considering 1723 patients in total. A good neurological outcome at hospital discharge was found in 21.3% of all patients. The most consistent criterion for inclusion was refractory cardiac arrest (RCA), used in 21/25 (84%) of the protocols. The preferred cannulation method was the percutaneous Seldinger technique (44%).

Conclusion

ECPR is a feasible option for cardiac arrest and should already be considered in an early stage of CPR. One of the key findings is that time-to-ECPR seems to be correlated with good neurological survival. An important contributing factor is the definition of RCA. Protocols defining RCA as >10 ​min had a mean good neurological survival of 26.7%. Protocols with a higher cut-off, between 15 and 30 ​min, had a mean good neurological survival of 14.5%. Another factor contributing to the time-to-ECPR is the preferred access technique. A percutaneous Seldinger technique combined with ultrasonography and fluoroscopic guidance leads to a reduced cannulation time and complication rate. Conclusive research around prehospital cannulation still needs to be conducted.

Extracorporeal Cardiopulmonary Resuscitation for Out-of-Hospital Cardiac Arrest in Adult Patients

Extracorporeal cardiopulmonary resuscitation (ECPR) followed by targeted temperature management has been demonstrated to significantly improve the outcomes of out-of-hospital cardiac arrest (OHCA) in adult patients. Although recent narrative and systematic reviews on extracorporeal life support in the emergency department are available in the literature, they are focused on the efficacy of ECPR, and no comprehensively summarized review on ECPR for OHCA in adult patients is available. In this review, we aimed to clarify the prevalence, pathophysiology, predictors, management, and details of the complications of ECPR for OHCA, all of which have not been reviewed in previous literature, with the aim of facilitating understanding among acute care physicians. The leading countries in the field of ECPR are those in East Asia followed by those in Europe and the United States. ECPR may reduce the risks of reperfusion injury and deterioration to secondary brain injury. Unlike conventional cardiopulmonary resuscitation, however, no clear prognostic markers have been identified for ECPR for OHCA. Bleeding was identified as the most common complication of ECPR in patients with OHCA. Future studies should combine ECPR with intra-aortic balloon pump, extracorporeal membrane oxygenation flow, target blood pressure, and seizure management in ECPR.

Associations of therapeutic hypothermia with clinical outcomes in patients receiving ECPR after cardiac arrest: systematic review with meta-analysis

BACKGROUND

Therapeutic hypothermia has been recommended for eligible patients after cardiac arrest (CA) in order to improve outcomes. Up to now, several comparative observational studies have evaluated the combined use of extracorporeal cardiopulmonary resuscitation (ECPR) and therapeutic hypothermia in adult patients with CA. However, the effects of therapeutic hypothermia in adult CA patients receiving ECPR are inconsistent.

METHODS

Relevant studies in English databases (PubMed, ISI web of science, OVID, and Embase) were systematically searched up to September 2019. Odds ratios (ORs) from eligible studies were extracted and pooled to summarize the associations of therapeutic hypothermia with favorable neurological outcomes and survival in adult CA patients receiving ECPR.

RESULTS

13 articles were included in the present meta-analysis study. There were nine studies with a total of 806 cases reporting the association of therapeutic hypothermia with neurological outcomes in CA patients receiving ECPR. Pooling analysis suggested that therapeutic hypothermia was significantly associated with favorable neurological outcomes in overall (N = 9, OR = 3.507, 95%CI = 2.194-5.607, P < 0.001, fixed-effects model) and in all subgroups according to control type, regions, sample size, CA location, ORs obtained methods, follow-up period, and modified Newcastle Ottawa Scale (mNOS) scores. There were nine studies with a total of 806 cases assessing the association of therapeutic hypothermia with survival in CA patients receiving ECPR. After pooling the ORs, therapeutic hypothermia was found to be significantly associated with survival in overall (N = 9, OR = 2.540, 95%CI = 1.245-5.180, P = 0.010, random-effects model) and in some subgroups. Publication bias was found when evaluating the association of therapeutic hypothermia with neurological outcomes in CA patients receiving ECPR. Additional trim-and-fill analysis estimated four "missing" studies, which adjusted the effect size to 2.800 (95%CI = 1.842-4.526, P < 0.001, fixed-effects model) for neurological outcomes.

CONCLUSIONS

Therapeutic hypothermia may be associated with favorable neurological outcomes and survival in adult CA patients undergoing ECPR. However, the result should be treated carefully because it is a synthesis of low-level evidence and other limitations exist in present study. It is necessary to perform randomized controlled trials to validate our result before considering the result in clinical practices.

Comparison of extracorporeal and conventional cardiopulmonary resuscitation: a retrospective propensity score matched study

Background

The potential benefit of extracorporeal cardiopulmonary resuscitation (ECPR) compared to conventional CPR (CCPR) for patients with refractory cardiac arrest (CA) remains unclear.

Methods

This study is a retrospective analysis of a prospective database of CA patients, which includes all consecutive adult patients admitted to the Department of Intensive Care after CA between January 2012 and December 2017. The decision to initiate ECPR was made by the attending physician and ECPR performed by the ECPR team, which is composed of ICU physicians. A propensity score was derived using a logistic regression model, including characteristics that varied between groups with a p <  0.10 and were potentially related to outcome. Primary outcomes were survival to ICU discharge and favorable 3-month neurologic outcome, assessed by a Cerebral Performance Category (CPC) score of 1–2.

Results

From a total of 635 patients with CA during the study period (ECPR, n = 112), 80 ECPR patients were matched to 80 CCPR patients. The time from arrest to termination of CPR (i.e., return of spontaneous circulation [ROSC], extracorporeal membrane oxygenation [ECMO] initiation, or death) was 54 ± 22 and 54 ± 19 min in the ECPR and CCPR groups, respectively. ROSC rates were 77/80 (96%) for ECPR and 30/80 (38%) for CCPR (p <  0.001). Survival to ICU discharge was 18/80 (23%) vs. 14/80 (18%) in the ECPR and CCPR groups, respectively (p = 0.42). At 3 months, 17/80 (21%) ECPR patients and 9/80 (11%) CCPR patients had a favorable outcome (p = 0.11). Cox regression analysis stratified by matched pairs showed a significantly higher neurologic outcome rate in the ECPR group than in the CCPR group (log-rank test p = 0.003).

Conclusions

ECPR after CA may be associated with improved long-term neurological outcome.

Controversial Issues: Pro Mechanical Cardiopulmonary Resuscitation

High-quality cardiopulmonary resuscitation, in particular chest compressions, is a key aspect of out-of-hospital cardiac arrest (OHCA) resuscitation. Manual chest compressions remain the standard of care; however, the extrication and transport of patients with OHCA undermine the quality of manual chest compressions and risk the safety of paramedics. Therefore, in circumstances whereby high-quality manual chest compressions are difficult or unsafe, paramedics should consider using a mechanical device. By combining high-quality manual chest compressions and judicious application of mechanical chest compressions, emergency medical service agencies can optimize paramedic safety and patient outcomes.

Neurologic outcomes after extracorporeal membrane oxygenation assisted CPR for resuscitation of out-of-hospital cardiac arrest patients: A systematic review

INTRODUCTION

Extracorporeal membrane oxygenation-assisted CPR (ECPR) is an evolving adjunct for resuscitation of OHCA patients. The primary objective of this systematic review was to assess survival-to-hospital discharge with good neurologic recovery after OHCA among patients treated with ECPR compared to conventional CPR (CCPR).

METHODS

A systematic search of MEDLINE® and EMBASE® electronic databases was performed from inception until July 2016 to identify studies reporting ECPR use in adults with OHCA and survival outcomes.

RESULTS

Of the 1512 citations identified, 75 studies met our inclusion criteria (63 case series and 12 cohort studies). Among case series, 0 to 71.4% of patients treated with ECPR survived to discharge with a good neurologic outcome. Subgroup analysis of the cohort studies demonstrated survival-to-hospital discharge with good neurologic recovery in the ECPR group ranging from 8.3 to 41.6% compared to 1.5 to 9.1% in the CCPR group. Five cohort studies adjusted for confounders, 3 of which demonstrated significantly increased adjusted odds ratios of survival among the ECPR-treated patients. Due to significant heterogeneity (I2 = 63%, p = 0.03), pooling of outcomes and a meta-analysis were not conducted.

CONCLUSION

Although a trend towards improved survival with good neurologic outcome was reported in controlled, low-risk of bias cohort studies, a preponderance of low quality evidence may ascribe an optimistic effect size of ECPR on survival among OHCA patients. Our confidence in a clinically relevant difference in outcomes compared to current standards of care for OHCA remains weak. In this state of equipoise, high quality RCT data is urgently needed.

Extracorporeal Life Support Increases Survival After Prolonged Ventricular Fibrillation Cardiac Arrest in the Rat

Background:

Extracorporeal life support (ECLS) for cardiopulmonary resuscitation (CPR) may increase end organ perfusion and thus survival when conventional CPR fails. The aim was to investigate, if after ventricular fibrillation cardiac arrest in rodents ECLS improves outcome compared with conventional CPR.

Methods:

In 24 adult male Sprague–Dawley rats (460–510 g) resuscitation was started after 10 min of no-flow with ECLS (consisting of an open reservoir, roller pump, and membrane oxygenator, connected to cannulas in the jugular vein and femoral artery, n = 8) or CPR (mechanical chest compressions plus ventilations, n = 8) and compared with a sham group (n = 8). After return of spontaneous circulation (ROSC), all rats were maintained at 33°C for 12 h. Survival to 14 days, neurologic deficit scores and overall performance categories were assessed.

Results:

ECLS leads to sustained ROSC in 8 of 8 (100%) and neurological intact survival to 14 days in 7 of 8 rats (88%), compared with 5 of 8 (63%) and 1 of 8 CPR rats. The median survival time was 14 days (IQR: 14–14) in the ECLS and 1 day (IQR: 0 to 5) for the CPR group (P = 0.004).

Conclusion:

In a rat model of prolonged ventricular fibrillation cardiac arrest, ECLS with mild hypothermia produces 100% resuscitability and 88% long-term survival, significantly better than conventional CPR.

Is initial rhythm in OHCA a predictor of preceding no flow time? Implications for bystander response and ECPR candidacy evaluation

OBJECTIVE

Shockable cardiac rhythms are associated with improved outcomes among out-of-hospital cardiac arrests (OHCA). Initial cardiac rhythm may also be predictive of a short preceding no-flow duration. We examined the relationship between no-flow duration and initial cardiac rhythm, which may demonstrate the urgency in rescuer response and assist with candidacy evaluation for extracorporeal-cardiopulmonary resuscitation (ECPR).

METHODS

We examined consecutive adult OHCA's identified by a prospective registry in British Columbia (2005-2016). We included those with witnessed OHCA but no bystander CPR. The variable of interest was no-flow duration, defined as time from 9-1-1 call to EMS arrival. We fit an adjusted logistic regression model to estimate the association of no-flow duration and initial cardiac rhythm. Among those with shockable initial rhythms, we calculated the cumulative proportion with no-flow durations under incremental time cut-offs.

RESULTS

Of 26 621 EMS-treated OHCA's, 2532 were included. Overall survival was 13.8%, and 34% had initial shockable rhythms. The probability of having an initial shockable rhythm decreased with increasing no-flow durations (adjusted OR 0.88 per minute, 95% CI 0.85-0.91). Among those found with initial shockable rhythms, 94% (95% CI 92-96%) had a no-flow time under 10 min.

CONCLUSION

The odds of a shockable initial rhythm declined with each additional minute of no-flow time, highlighting the importance of early access to defibrillation. Among those with initial shockable rhythms, the preceding no-flow duration was highly likely to be under 10 min, which may inform decisions about ECPR candidacy among select patients with unwitnessed arrests.

Reduction of Serious Adverse Events Demanding Study Exclusion in Model Development: Extracorporeal Life Support Resuscitation of Ventricular Fibrillation Cardiac Arrest in Rats

Extracorporeal life support is a promising concept for selected patients in refractory cardiogenic shock and for advanced life support of persistent ventricular fibrillation cardiac arrest. Animal models of ventricular fibrillation cardiac arrest could help to investigate new treatment strategies for successful resuscitation. Associated procedural pitfalls in establishing a rat model of extracorporeal life support resuscitation need to be replaced, refined, reduced, and reported.Anesthetized male Sprague-Dawley rats (350-600 g) (n = 126) underwent cardiac arrest induced with a pacing catheter placed into the right ventricle via a jugular cannula. Rats were resuscitated with extracorporeal life support, mechanical ventilation, defibrillation, and medication. Catheter and cannula explantation was performed if restoration of spontaneous circulation was achieved. All observed serious adverse events (SAEs) occurring in each of the experimental phases were analyzed.Restoration of spontaneous circulation could be achieved in 68 of 126 rats (54%); SAEs were observed in 76 (60%) experiments. Experimental procedures related SAEs were 62 (82%) and avoidable human errors were 14 (18%). The most common serious adverse events were caused by insertion or explantation of the venous bypass cannula and resulted in lethal bleeding, cannula dislocation, or air embolism.Establishing an extracorporeal life support model in rats has confronted us with technical challenges. Even advancements in small animal critical care management over the years delivered by an experienced team and technical modifications were not able to totally avoid such serious adverse events. Replacement, refinement, and reduction reports of serious adverse events demanding study exclusions to avoid animal resources are missing and are presented hereby.

New Therapeutic Concepts in Post-Resuscitation Care

After the return of spontaneous circulation (ROSC), as a result of global ischaemia due to cardiac arrest followed by reperfusion, a condition develops called post-cardiac arrest syndrome. It manifests, alongside the pathology that caused the cardiac arrest, as a systemic inflammatory response, including severe cardio-circulatory and neurological dysfunction, leading to a fatal outcome. Th e aim of post-resuscitation care is to reduce the consequences of circulatory arrest, reperfusion, and the inflammatory response of the body on vital organ functions. The basis of post-resuscitation care comprises application of therapeutic hypothermia and early coronary angiography with PCI. However, after the initial enthusiasm, the validity of applying these aggressive methods in all comatose post-cardiac arrest patients was questioned. Currently, instead of therapeutic hypothermia, a strategy of maintaining a targeted body temperature, usually 36 °C, is being applied because there is no clear evidence of benefit for maintaining a lower body temperature in relation to the outcome. Additionally, patients with an obvious cardiac aetiology of cardiac arrest do not undergo early coronarography unless there is a clear indication of coronary artery occlusion. In the post-resuscitation period, the maintenance of adequate ventilation, maintaining levels of oxygen and carbon dioxide in the normal range, haemodynamic stability, control of blood glucose and electrolytes, and epileptic attack prevention are all strongly recommended measures. Th ere is no evidence to suggest that the application of the so-called neuroprotective agents affects the outcome of cardiac arrest.

ECMO in cardiac arrest and cardiogenic shock

Cardiogenic shock is an acute emergency, which is classically managed by medical support with inotropes or vasopressors and frequently requires invasive ventilation. However, both catecholamines and ventilation are associated with a worse prognosis, and many patients deteriorate despite all efforts. Mechanical circulatory support is increasingly considered to allow for recovery or to bridge until making a decision or definite treatment. Of all devices, extracorporeal membrane oxygenation (ECMO) is the most widely used. Here we review features and strategical considerations for the use of ECMO in cardiogenic shock and cardiac arrest.

Descriptive analysis of extracorporeal cardiopulmonary resuscitation following out-of-hospital cardiac arrest-An ELSO registry study

AIM

Extracorporeal cardiopulmonary resuscitation (ECPR) is an emerging therapy for refractory cardiac arrest. The purpose of this study was to analyze and report characteristics and outcomes of adult patients treated with ECPR after out-of-hospital cardiac arrest (OHCA) in a large international registry.

METHODS

The Extracorporeal Life Support Organization's Extracorporeal Life Support Registry was queried for adult cardiac arrests with arrest location of "EMT Transport" or "Outside Hospital."

RESULTS

From 2010-2016, 217 cases of ECPR following OHCA were reported in Europe (47%), Asia-Pacific (29%), and North America (24%). The median age was 52 years (IQR 45-62, range 18-87); 73% were male. The median duration of ECPR was 47h (IQR 17-94, range 0-711). Reported complications included hemorrhage (31.3%), limb complications (11.1%), circuit complications (8.8%), infection (7.4%), and seizures (5.5%). The rate of percutaneous coronary intervention (PCI) was higher in Europe (35.6%) and Asia-Pacific (25.8%) than North America (9.4%; p<0.01). Survival to hospital discharge was 27.6% (95% CI 22.1-34.0%), and male gender was independently associated with mortality (adjusted odds ratio 2.1 [95% CI 1.1-4.2], p<0.05). Survival did not differ by region, race, age, or year. Brain death was reported in 16.6% [95% CI 12.2-22.1%]; organ donation rate was not reported.

CONCLUSION

This international analysis of ECPR for refractory OHCA reveals a survival rate of 27.6%, demonstrates association of male gender with mortality, and highlights regional differences in PCI utilization. These results will help inform implementation and research of this potentially life-saving strategy for refractory OHCA.

Organ donation in cardiac arrest patients treated with extracorporeal CPR: A single centre observational study

AIM OF THE STUDY

In a consecutive cohort of cardiac arrest (CA) treated with extracorporeal cardiopulmonary resuscitation (eCPR), we describe the incidence of brain death (BD), the eligibility for organ donation and the short-term follow-up of the transplanted organs.

METHODS

All refractory in- and out-of-hospital CA admitted to our Cardiac Intensive Care Unit between January 2011 and September 2016 treated with eCPR were enrolled in the study.

RESULTS

112 CA patients received eCPR. 82 (73.2%) died in hospital, 25 BD (22.3%) and 57 for other causes (50.9%). At the time of first neurological evaluation after rewarming, variables related to evolution to BD were a lower GCS (3 [3-3] vs. 8 [3-11], p<0.001), a higher level of neuron specific enolase (269.3±49.4 vs. 55.2±37.2ng/ml, p<0.001), a higher presence of EEG indices of poor outcome (84% vs. 15%, p<0.001), absence of brainstem reflexes (p<0.001), absence of bilateral N20 SSEPS waves (66.7% vs. 3.7%, p<0.001). None of BD patients present a normal CT scan (at 2.5±2days), with 85% prevalence of diffuse hypoxic injury and a mean grey/white matter ratio of 1.1±0.1. Rate of donation in BD patients was 56%, with 39 donated organs: 23 kidneys, 12 livers, and 4 lungs. 89.74% of the transplanted organs reached an early good functional recovery.

CONCLUSION

In refractory CA patients treated with eCPR, the prevalence of BD is high. This population has a high potential for considering organ donation. Donated organs have a good outcome.

Extracorporeal cardiopulmonary resuscitation after out-of-hospital cardiac arrest in a Danish health region

BACKGROUND

Extracorporeal Cardiopulmonary Resuscitation (ECPR) has emerged as a feasible rescue therapy for refractory, normothermic out-of-hospital cardiac arrest (OHCA). Reported survival rates vary and comparison between studies is hampered by heterogeneous study populations, differences in bystander intervention and in pre-hospital emergency service organisation. We aimed to describe the first experiences, treatment details, complications and outcome with ECPR for OHCA in a Danish health region.

METHODS

Retrospective study of adult patients admitted at Aarhus University Hospital, Denmark between 1 January 2011 and 1 July 2015 with witnessed, refractory, normothermic OHCA treated with ECPR. OHCA was managed with pre-hospital advanced airway management and mechanical chest compression during transport. Relevant pre-hospital and in-hospital data were collected with special focus on low-flow time and ECPR duration. Survival to hospital discharge with Cerebral Performance Category (CPC) of 1 and 2 at hospital discharge was the primary endpoint.

RESULTS

Twenty-one patients were included. Median pre-hospital low-flow time was 54 min [range 5-100] and median total low-flow time was 121 min [range 55-192]. Seven patients survived (33%). Survivors had a CPC score of 1 or 2 at hospital discharge. Five survivors had a shockable initial rhythm. In all survivors coronary occlusion was the presumed cause of cardiac arrest.

CONCLUSION

Extracorporeal cardiopulmonary resuscitation is feasible as a rescue therapy in normothermic refractory OHCA in highly selected patients. Low-flow time was longer than previously reported. Survival with favourable neurological outcome is possible despite prolonged low-flow duration.

The Association of Fever with Total Mechanical Ventilation Time in Critically Ill Patients

This research aims to investigate the impact of fever on total mechanical ventilation time (TVT) in critically ill patients. Subgroup analysis was conducted using a previous prospective, multicenter observational study. We included mechanically ventilated patients for more than 24 hours from 10 Korean and 15 Japanese intensive care units (ICU), and recorded maximal body temperature under the support of mechanical ventilation (MAX(MV)). To assess the independent association of MAX(MV) with TVT, we used propensity-matched analysis in a total of 769 survived patients with medical or surgical admission, separately. Together with multiple linear regression analysis to evaluate the association between the severity of fever and TVT, the effect of MAX(MV) on ventilator-free days was also observed by quantile regression analysis in all subjects including non-survivors. After propensity score matching, a MAX(MV) ≥ 37.5°C was significantly associated with longer mean TVT by 5.4 days in medical admission, and by 1.2 days in surgical admission, compared to those with MAX(MV) of 36.5°C to 37.4°C. In multivariate linear regression analysis, patients with three categories of fever (MAX(MV) of 37.5°C to 38.4°C, 38.5°C to 39.4°C, and ≥ 39.5°C) sustained a significantly longer duration of TVT than those with normal range of MAX(MV) in both categories of ICU admission. A significant association between MAX(MV) and mechanical ventilator-free days was also observed in all enrolled subjects. Fever may be a detrimental factor to prolong TVT in mechanically ventilated patients. These findings suggest that fever in mechanically ventilated patients might be associated with worse mechanical ventilation outcome.

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

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

Current and Future Status of Extracorporeal Cardiopulmonary Resuscitation for In-Hospital Cardiac Arrest

Numerous series, propensity-matched trials, and meta-analyses suggest that appropriate use of extracorporeal cardiopulmonary resuscitation (E-CPR) for in-hospital cardiac arrest (IHCA) can be lifesaving. Even with an antecedent cardiopulmonary resuscitation (CPR) duration in excess of 45 minutes, 30-day survival with favourable neurologic outcome using E-CPR is approximately 35%-45%. Survival may be related to age, duration of CPR, or etiology. Associated complications include sepsis, renal failure, limb and neurologic complications, hemorrhage, and thrombosis. However, methodological biases-including small sample size, selection bias, publication bias, and inability to control for confounders-in these series prevent definitive conclusions. As such, the 2015 American Heart Association Advanced Cardiac Life Support guidelines update recommended E-CPR as a Level of Evidence IIb recommendation in appropriate cases. The absence of high-quality evidence presents an opportunity for clinician/scientists to generate practice-defining data through collaborative investigation and prospective trials. A multidisciplinary dialogue is required to standardize the field and promote multicentre investigation of E-CPR with data sharing and the development of a foundation for high-quality trials. The objectives of this review are to (1) provide an overview of the strengths and limitations of currently available studies investigating the use of E-CPR in patients with IHCA and highlight knowledge gaps; (2) create a framework for the standardization of terminology, clinical practice, data collection, and investigation of E-CPR for patients with IHCA that will help ensure congruence in future work in this area; and (3) propose suggestions to guide future research by the cardiovascular community to advance this important field.

The rate of brain death and organ donation in patients resuscitated from cardiac arrest: a systematic review and meta-analysis

BACKGROUND

The occurrence of brain death in patients with hypoxic-ischaemic brain injury after resuscitation from cardiac arrest creates opportunities for organ donation. However, its prevalence is currently unknown.

METHODS

Systematic review. MEDLINE via PubMed, ISI Web of Science and the Cochrane Database of Systematic Reviews were searched for eligible studies (2002-2016). The prevalence of brain death in adult patients resuscitated from cardiac arrest and the rate of organ donation among brain dead patients were summarised using a random effect model with double-arcsine transformation. The quality of evidence (QOE) was evaluated according to the GRADE guidelines.

RESULTS

26 studies [16 on conventional cardiopulmonary resuscitation (c-CPR), 10 on extracorporeal CPR (e-CPR)] included a total of 23,388 patients, 1830 of whom developed brain death at a mean time of 3.2 ± 0.4 days after recovery of circulation. The overall prevalence of brain death among patients who died before hospital discharge was 12.6 [10.2-15.2] %. Prevalence was significantly higher in e-CPR vs. c-CPR patients (27.9 [19.7-36.6] vs. 8.3 [6.5-10.4] %; p < 0.0001). The overall rate of organ donation among brain dead patients was 41.8 [20.2-51.0] % (9/26 studies, 1264 patients; range 0-100 %). The QOE was very low for both outcomes.

CONCLUSIONS

In patients with hypoxic-ischaemic brain injury following CPR, more than 10 % of deaths were due to brain death. More than 40 % of brain-dead patients could donate organs. Patients who are unconscious after resuscitation from cardiac arrest, especially when resuscitated using e-CPR, should be carefully screened for signs of brain death.

Practice characteristics of Emergency Department extracorporeal cardiopulmonary resuscitation (eCPR) programs in the United States: The current state of the art of Emergency Department extracorporeal membrane oxygenation (ED ECMO)

PURPOSE

To characterize the current scope and practices of centers performing extracorporeal cardiopulmonary resuscitation (eCPR) on the undifferentiated patient with cardiac arrest in the emergency department.

METHODS

We contacted all US centers in January 2016 that had submitted adult eCPR cases to the Extracorporeal Life Support Organization (ELSO) registry and surveyed them, querying for programs that had performed eCPR in the Emergency Department (ED ECMO). Our objective was to characterize the following domains of ED ECMO practice: program characteristics, patient selection, devices and techniques, and personnel.

RESULTS

Among 99 centers queried, 70 responded. Among these, 36 centers performed ED ECMO. Nearly 93% of programs are based at academic/teaching hospitals. 65% of programs are less than 5 years old, and 60% of programs perform ≤3 cases per year. Most programs (90%) had inpatient eCPR or salvage ECMO programs prior to starting ED ECMO programs. The majority of programs do not have formal inclusion and exclusion criteria. Most programs preferentially obtain vascular access via the percutaneous route (70%) and many (40%) use mechanical CPR during cannulation. The most commonly used console is the Maquet Rotaflow(®). Cannulation is most often performed by cardiothoracic (CT) surgery, and nearly all programs (>85%) involve CT surgeons, perfusionists, and pharmacists.

CONCLUSIONS

Over a third of centers that submitted adult eCPR cases to ELSO have performed ED ECMO. These programs are largely based at academic hospitals, new, and have low volumes. They do not have many formal inclusion or exclusion criteria, and devices and techniques are variable.

Thrombolytic-Enhanced Extracorporeal Cardiopulmonary Resuscitation After Prolonged Cardiac Arrest

OBJECTIVE

To investigate the effects of the combination of extracorporeal cardiopulmonary resuscitation and thrombolytic therapy on the recovery of vital organ function after prolonged cardiac arrest.

DESIGN

Laboratory investigation.

SETTING

University laboratory.

SUBJECTS

Pigs.

INTERVENTIONS

Animals underwent 30-minute untreated ventricular fibrillation cardiac arrest followed by extracorporeal cardiopulmonary resuscitation for 6 hours. Animals were allocated into two experimental groups: t-extracorporeal cardiopulmonary resuscitation (t-ECPR) group, which received streptokinase 1 million units, and control extracorporeal cardiopulmonary resuscitation (c-ECPR), which did not receive streptokinase. In both groups, the resuscitation protocol included the following physiologic targets: mean arterial pressure greater than 70 mm Hg, cerebral perfusion pressure greater than 50 mm Hg, PaO2 150 ± 50 torr (20 ± 7 kPa), PaCO2 40 ± 5 torr (5 ± 1 kPa), and core temperature 33°C ± 1°C. Defibrillation was attempted after 30 minutes of extracorporeal cardiopulmonary resuscitation.

MEASUREMENTS AND MAIN RESULTS

A cardiac resuscitability score was assessed on the basis of success of defibrillation, return of spontaneous heart beat, weanability from extracorporeal cardiopulmonary resuscitation, and left ventricular systolic function after weaning. The addition of thrombolytic to extracorporeal cardiopulmonary resuscitation significantly improved cardiac resuscitability (3.7 ± 1.6 in t-ECPR vs 1.0 ± 1.5 in c-ECPR). Arterial lactate clearance was higher in t-ECPR than in c-ECPR (40% ± 15% vs 18% ± 21%). At the end of the experiment, the intracranial pressure was significantly higher in c-ECPR than in t-ECPR. Recovery of brain electrical activity, as assessed by quantitative analysis of electroencephalogram signal, and ischemic neuronal injury on histopathologic examination did not differ between groups. Animals in t-ECPR group did not have increased bleeding complications, including intracerebral hemorrhages.

CONCLUSIONS

In a porcine model of prolonged cardiac arrest, t-ECPR improved cardiac resuscitability and reduced brain edema, without increasing bleeding complications. However, early electroencephalogram recovery and ischemic neuronal injury were not improved.

Relationship between Time-to-ROSC and Survival in Out-of-hospital Cardiac Arrest ECPR Candidates: When is the Best Time to Consider Transport to Hospital?

OBJECTIVE

Extracorporeal cardiopulmonary resuscitation (ECPR) may improve outcomes for refractory out-of-hospital cardiac arrest (OHCA). Transport of intra-arrest patients to hospital however, may decrease CPR quality, potentially reducing survival for those who would have achieved return-of-spontaneous-circulation (ROSC) with further on-scene resuscitation. We examined time-to-ROSC and patient outcomes for the optimal time to consider transport.

METHODS

From a prospective registry of consecutive adult non-traumatic OHCA's, we identified a hypothetical ECPR-eligible cohort of EMS-treated patients with age ≤ 65, witnessed arrest, and bystander CPR or EMS arrival < 10 minutes. We assessed the relationship between time-to-ROSC and survival, and constructed a ROC curve to illustrate the ability of a pulseless state to predict non-survival with conventional resuscitation.

RESULTS

Of 6,571 EMS-treated cases, 1,206 were included with 27% surviving. Increasing time-to-ROSC (per minute) was negatively associated with survival (adjusted OR 0.91; 95%CI 0.89-0.93%). The yield of survivors per minute of resuscitation increased from commencement and started to decline in the 8th minute. Fifty percent and 90% of survivors had achieved ROSC by 8.0 and 24 min, respectively, at which times the probability of survival for those with initial shockable rhythms was 31% and 10%, and for non-shockable rhythms was 5.2% and 1.6%. The ROC curve illustrated that the 16th minute of resuscitation maximized sensitivity and specificity (AUC = 0.87, 95% CI 0.85-0.89).

CONCLUSION

Transport for ECPR should be considered between 8 to 24 minutes of professional on-scene resuscitation, with 16 minutes balancing the risks and benefits of early and later transport. Earlier transport within this window may be preferred if high quality CPR can be maintained during transport and for those with initial non-shockable rhythms.

Potential Candidates for a Structured Canadian ECPR Program for Out-of-Hospital Cardiac Arrest

OBJECTIVE

Extracorporeal cardiopulmonary resuscitation (ECPR), while resource-intensive, may improve outcomes in selected patients with refractory out-of-hospital cardiac arrest (OHCA). We sought to identify patients who fulfilled a set of ECPR criteria in order to estimate: (1) the proportion of patients with refractory cardiac arrest who may have benefited from ECPR; and (2) the outcomes achieved with conventional resuscitation.

METHODS

We performed a secondary analysis from a 52-month prospective registry of consecutive adult non-traumatic OHCA cases from a single urban Canadian health region serving one million patients. We developed a hypothetical ECPR-eligible cohort including adult patients <60 years of age with a witnessed OHCA, and either bystander CPR or EMS arrival within five minutes. The primary outcome was the proportion of ECPR-eligible patients who had refractory cardiac arrest, defined as termination of resuscitation pre-hospital or in the ED. The secondary outcome was the proportion of EPCR-eligible patients who survived to hospital discharge.

RESULTS

Of 1,644 EMS-treated OHCA, 168 (10.2%) fulfilled our ECPR criteria. Overall, 54/1644 (3.3%; 95% CI 2.4%-4.1%) who were ECPR-eligible had refractory cardiac arrest. Of ECPR-eligible patients, 114/168 (68%, 95% CI 61%-75%) survived to hospital admission, and 70/168 (42%; 95% CI 34-49%) survived to hospital discharge.

CONCLUSION

In our region, approximately 10% of EMS-treated cases of OHCA fulfilled our ECPR criteria, and approximately one-third of these (an average of 12 patients per year) were refractory to conventional resuscitation. The integration of an ECPR program into an existing high-performing system of care may have a small but clinically important effect on patient outcomes.