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

Extracorporeal Membrane Oxygenation Pathway for Management of Refractory Cardiac Arrest: a Retrospective Study From a National Center of Extracorporeal Cardiopulmonary Resuscitation

BACKGROUND

Cardiac arrest remains a critical condition with high mortality and catastrophic neurological impact. Extracorporeal cardiopulmonary resuscitation (ECPR) has been introduced as an adjunct in cardiopulmonary resuscitation modalities. However, survival with good neurological outcomes remains a major concern. This study aims to explore our early experience with ECPR and identify the factors associated with survival in patients presenting with refractory cardiac arrest.

METHODS

This is a retrospective cohort study analyzing 6-year data from a tertiary center, the country reference for ECPR. This study was conducted at a national center of ECPR. Participants of this study were adult patients who experienced witnessed refractory cardiopulmonary arrest and were supported by ECPR. ECPR was performed for eligible patients as per the local service protocols.

RESULTS

Data from 87 patients were analyzed; of this cohort, 62/87 patients presented with in-hospital cardiac arrest (IHCA) and 25/87 presented with out-of-hospital cardiac arrest (OHCA). Overall survival to decannulation and hospital discharge rates were 26.4% and 25.3%, respectively. Among survivors (n = 22), 19 presented with IHCA (30.6%), while only 3 survivors presented with OHCA (12%). A total of 15/87 (17%) patients were alive at 6-month follow-up. All survivors had good neurological function assessed as Cerebral Performance Category 1 or 2. Multivariate logistic regression to predict survival to hospital discharge showed that IHCA was the only independent predictor (odds ratio: 5.8, P = 0.042); however, this positive association disappeared after adjusting for the first left ventricular ejection fraction after resuscitation.

CONCLUSIONS

In this study, the use of ECPR for IHCA was associated with a higher survival to discharge compared to OHCA. This study demonstrated a comparable survival rate to other established centers, particularly for IHCA. Neurological outcomes were comparable in both IHCA and OHCA survivors. However, large multicenter studies are warranted for better understanding and improving the outcomes.

Assessing feasibility of proposed extracorporeal cardiopulmonary resuscitation programmes for out-of-hospital cardiac arrest in Scotland via geospatial modelling

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR) can improve survival for refractory out-of-hospital cardiac arrest (OHCA). We sought to assess the feasibility of a proposed ECPR programme in Scotland, considering both in-hospital and pre-hospital implementation scenarios.

METHODS

We included treated OHCAs in Scotland aged 16-70 between August 2018 and March 2022. We defined those clinically eligible for ECPR as patients where the initial rhythm was ventricular fibrillation, ventricular tachycardia, or pulseless electrical activity, and where pre-hospital return of spontaneous circulation was not achieved. We computed the call-to-ECPR access time interval as the amount of time from emergency medical service (EMS) call reception to either arrival at an ECPR-ready hospital or arrival of a pre-hospital ECPR crew. We determined the number of patients that had access to ECPR within 45 min, and estimated the number of additional survivors as a result.

RESULTS

A total of 6,639 OHCAs were included in the geospatial modelling, 1,406 of which were eligible for ECPR. Depending on the implementation scenario, 52.9-112.6 (13.8-29.4%) OHCAs per year had a call-to-ECPR access time within 45 min, with pre-hospital implementation scenarios having greater and earlier access to ECPR for OHCA patients. We further estimated that an ECPR programme in Scotland would yield 11.8-28.2 additional survivors per year, with the pre-hospital implementation scenarios yielding higher numbers.

CONCLUSION

An ECPR programme for OHCA in Scotland could provide access to ECPR to a modest number of eligible OHCA patients, with pre-hospital ECPR implementation scenarios yielding higher access to ECPR and higher numbers of additional survivors.

Prophylactic distal perfusion catheter and survival in patients with out-of-hospital cardiac arrest: Secondary analysis of the SAVE-J II study

PURPOSE

The effect of a prophylactic distal perfusion catheter (DPC) after extracorporeal cardiopulmonary resuscitation (ECPR) in patients with out-of-hospital cardiac arrest (OHCA) remains unclear. Therefore, we aimed to clarify the association between prophylactic DPC and prognosis in patients with OHCA undergoing ECPR.

MATERIALS AND METHODS

A secondary analysis of the Study of Advanced Life Support for Ventricular Fibrillation with Extracorporeal Circulation in Japan (SAVE-J II) database was performed to compare groups of patients with and without prophylactic DPCs. A multivariate analysis of survival at discharge was performed using factors that were significant in the two-arm comparison.

RESULTS

A total of 2044 patients were included in the analysis after excluding those who met the exclusion criteria. Survival at discharge was observed in 548 (26.9%) patients. In total, 100 (4.9%) patients developed limb ischemia, among whom 14 (0.7%) required therapeutic intervention. Multivariate analysis showed that prophylactic DPC did not result in a significant difference in survival at discharge (odds ratio: 0.898 [0.652-1.236], p = 0.509).

CONCLUSIONS

The implementation of prophylactic DPC after ECPR for patients with OHCA may not contribute to survival at discharge.

Factors associated with favourable neurological outcomes following cardiopulmonary resuscitation for out-of-hospital cardiac arrest: A retrospective multi-centre cohort study

Aim

To investigate the factors associated with favourable neurological outcomes in adult patients undergoing extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest (OHCA).

Methods

This retrospective observational study used secondary analysis of the SAVE-J II multicentre registry data from 36 institutions in Japan. Between 2013 and 2018, 2157 patients with OHCA who underwent ECPR were enrolled in SAVE-J II. A total of 1823 patients met the study inclusion criteria. Adult patients (aged ≥ 18 years) with OHCA, who underwent ECPR before admission to the intensive care unit, were included in our secondary analysis. The primary outcome was a favourable neurological outcome at hospital discharge, defined as a Cerebral Performance Category score of 1 or 2. We used a multivariate logistic regression model to examine the association between factors measured at the incident scene or upon hospital arrival and favourable neurological outcomes.

Results

Multivariable analysis revealed that shockable rhythm at the scene [odds ratio (OR); 2.11; 95% confidence interval (CI), 1.16-3.95] and upon hospital arrival (OR 2.59; 95% CI 1.60-4.30), bystander CPR (OR 1.63; 95% CI 1.03-1.88), body movement during resuscitation (OR 7.10; 95% CI 1.79-32.90), gasping (OR 4.33; 95% CI 2.57-7.28), pupillary reflex on arrival (OR 2.93; 95% CI 1.73-4.95), and male sex (OR 0.43; 95% CI 0.24-0.75) significantly correlated with neurological outcomes.

Conclusions

Shockable rhythm, bystander CPR, body movement during resuscitation, gasping, pupillary reflex, and sex were associated with favourable neurological outcomes in patients with OHCA treated with ECPR.

In-hospital extracorporeal cardiopulmonary resuscitation for patients with out-of-hospital cardiac arrest: an analysis by time-dependent propensity score matching using a nationwide database in Japan

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR) has been proposed as a rescue therapy for patients with refractory cardiac arrest. This study aimed to evaluate the association between ECPR and clinical outcomes among patients with out-of-hospital cardiac arrest (OHCA) using risk-set matching with a time-dependent propensity score.

METHODS

This was a secondary analysis of the JAAM-OHCA registry data, a nationwide multicenter prospective study of patients with OHCA, from June 2014 and December 2019, that included adults (≥ 18 years) with OHCA. Initial cardiac rhythm was classified as shockable and non-shockable. Patients who received ECPR were sequentially matched with the control, within the same time (minutes) based on time-dependent propensity scores calculated from potential confounders. The odds ratios with 95% confidence intervals (CI) for 30-day survival and 30-day favorable neurological outcomes were estimated for ECPR cases using a conditional logistic model.

RESULTS

Of 57,754 patients in the JAAM-OHCA registry, we selected 1826 patients with an initial shockable rhythm (treated with ECPR, n = 913 and control, n = 913) and a cohort of 740 patients with an initial non-shockable rhythm (treated with ECPR, n = 370 and control, n = 370). In these matched cohorts, the odds ratio for 30-day survival in the ECPR group was 1.76 [95%CI 1.38-2.25] for shockable rhythm and 5.37 [95%CI 2.53-11.43] for non-shockable rhythm, compared to controls. For favorable neurological outcomes, the odds ratio in the ECPR group was 1.11 [95%CI 0.82-1.49] for shockable rhythm and 4.25 [95%CI 1.43-12.63] for non-shockable rhythm, compared to controls.

CONCLUSION

ECPR was associated with increased 30-day survival in patients with OHCA with initial shockable and even non-shockable rhythms. Further research is warranted to investigate the reproducibility of the results and who is the best candidate for ECPR.

How effective is extracorporeal life support for patients with out-of-hospital cardiac arrest initiated at the emergency department? A systematic review and meta-analysis

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR) is commonly initiated for adults experiencing cardiac arrest within the cardiac catheterization lab or the intensive care unit. However, the potential benefit of ECPR for these patients in the emergency department (ED) remains undocumented. This study aims to assess the benefit of ECPR initiated in the ED for patients with out-of-hospital cardiac arrest (OHCA).

METHODS

We conducted a systematic review and meta-analysis of studies comparing ECPR initiated in the ED versus conventional CPR. Relevant articles were identified by searching several databases including PubMed, EMBASE, Web of Science, and Cochrane collaborations up to July 31, 2022. Pooled estimates were calculated using the inverse variance heterogeneity method, while heterogeneity was evaluated using Q and I2 statistics. The risk of bias in included studies was evaluated using validated bias assessment tools. The primary outcome was a favorable neurological outcome at hospital discharge, and the secondary outcome was survival to hospital discharge or 30-day survival. Sensitivity analyses were performed to explore the benefits of ED-initiated ECPR in studies utilizing propensity score (PPS) analysis. Publication bias was assessed using Doi plots and the Luis Furuya-Kanamori (LFK) index.

RESULTS

The meta-analysis included a total of eight studies comprising 51,173 patients. ED-initiated ECPR may not be associated with a significant increase in favorable neurological outcomes (odds ratio [OR] 1.43, 95% confidence interval [CI] 0.30-6.70, I2 = 96%). However, this intervention may be linked to improved survival to hospital discharge (OR 3.34, 95% CI 2.23-5.01, I2 = 17%). Notably, when analyzing only PPS data, ED-initiated ECPR demonstrated efficacy for both favorable neurological outcomes (OR 1.89, 95% CI 1.26-2.83, I2 = 21%) and survival to hospital discharge (OR 3.37, 95% CI 1.52-7.49, I2 = 57%). Publication bias was detected for primary (LFK index 2.50) and secondary (LFK index 2.14) outcomes.

CONCLUSION

The results of this study indicate that ED-initiated ECPR may not offer significant benefits in terms of favorable neurological outcomes for OHCA patients. However, it may be associated with increased survival to hospital discharge. Future studies should prioritize randomized trials with larger sample sizes and strive for homogeneity in patient populations to obtain more robust evidence in this area.

Time-saving effect of real-time ultrasound-guided cannulation for extracorporeal cardiopulmonary resuscitation: A multicenter retrospective cohort study

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR), a bridge to treatments for cardiac arrest patients, can be technically challenging and requires expertise. While ultrasound guidance is frequently used for vascular access, its effects on cannulation time in patients treated with ECPR are poorly defined. We hypothesized that real-time ultrasound guidance would contribute to faster and safer cannulation for ECPR.

METHODS

This nationwide, multicenter, retrospective study analyzed data from 36 Japanese institutions. Patients who were over age 18 years and underwent ECPR between January 1, 2013, and December 31, 2018, were included. Patients who underwent open surgical vascular access were excluded. Cannulation time and outcomes of patients who underwent real-time ultrasound-guided cannulation (i.e., ultrasound-guided group) were compared to those cannulated without the use of real-time ultrasound guidance (control group) using propensity score matching analysis.

RESULTS

The ultrasound-guided group comprised 510 cases, whereas the control group comprised 941 cases. Of those, 443 propensity score-matched pairs were evaluated. Cannulation time in the ultrasound-guided group was 2.5 minutes shorter than in the control group [difference, -2.5 minutes; 95% Confidence interval (CI), -3.7 to -1.3, p < 0.001]. The incidence of catheter-related complications and the incidence of the poor neurological outcomes (Cerebral Performance Category ≥3) did not differ between groups [Odds ratio (OR), 1.51; 95% CI, 0.64-3.74; OR, 1.08; 95% CI, 0.83-1.59].

CONCLUSION

Real-time ultrasound-guided cannulation was associated with shorter cannulation time of ECPR.

Potential role for extracorporeal membrane oxygenation cardiopulmonary resuscitation (E-CPR) during in-hospital cardiac arrest in Australia: A nested cohort study

Objective

This study aims to evaluate the characteristics and outcomes of patients who fulfilled extracorporeal membrane oxygenation cardiopulmonary resuscitation (E-CPR) selection criteria during in-hospital cardiac arrest (IHCA).

Design

This is a nested cohort study.

Setting

Code blue data were collected across seven hospitals in Australia between July 2017 and August 2018.

Participants

Participants who fulfilled E-CPR selection criteria during IHCA were included.

Main outcome measures

Return of spontaneous circulation and survival and functional outcome at hospital discharge. Functional outcome was measured using the modified Rankin scale, with scores dichotomised into good and poor functional outcome.

Results

Twenty-three (23/144; 16%) patients fulfilled E-CPR selection criteria during IHCA, and 11/23 (47.8%) had a poor outcome. Patients with a poor outcome were more likely to have a non-shockable rhythm (81.8% vs. 16.7%; p = 0.002), and a longer duration of CPR (median 12.5 [5.5, 39.5] vs. 1.5 [0.3, 2.5] minutes; p < 0.001) compared to those with a good outcome. The majority of patients (18/19 [94.7%]) achieved sustained return of spontaneous circulation within 15 minutes of CPR. All five patients who had CPR >15 minutes had a poor outcome.

Conclusion

Approximately one in six IHCA patients fulfilled E-CPR selection criteria during IHCA, half of whom had a poor outcome. Non-shockable rhythm and longer duration of CPR were associated with poor outcome. Patients who had CPR for >15 minutes and a poor outcome may have benefited from E-CPR. The feasibility, effectiveness and risks of commencing E-CPR earlier in IHCA and among those with non-shockable rhythms requires further investigation.

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.

Hyperoxemia is Associated With Poor Neurological Outcomes in Patients With Out-of-Hospital Cardiac Arrest Rescued by Extracorporeal Cardiopulmonary Resuscitation: Insight From the Nationwide Multicenter Observational JAAM-OHCA (Japan Association for Acute Medicine) Registry

BACKGROUND

Previous studies have shown an association between hyperoxemia and mortality in patients with out-of-hospital cardiac arrest (OHCA) after cardiopulmonary resuscitation (CPR); however, evidence is lacking in the extracorporeal CPR (ECPR) setting.

OBJECTIVE

The aim of this study was to test the hypothesis that hyperoxemia is associated with poor neurological outcomes in patients treated by ECPR.

METHODS

The Japanese Association for Acute Medicine OHCA Registry is a multicenter, prospective, observational registry of patients from 2014 to 2017. Adult (18 years or older) patients who had undergone ECPR after OHCA were included. Eligible patients were divided into two groups based on the partial pressure of oxygen in arterial blood (PaO₂) levels at 24 h after ECPR: the high-PaO₂ group (n = 242) defined as PaO₂ ≥ 157 mm Hg (median) and the low-PaO₂ group (n = 211) defined as PaO₂ 60 to < 157 mm Hg. The primary outcome was the favorable neurological outcome, defined as a Cerebral Performance Categories Scale score of 1 to 2 at 30 days after OHCA.

RESULTS

Of 34,754 patients with OHCA, 453 patients were included. The neurological outcome was significantly lower in the high-PaO₂ group than in the low-PaO₂ group (15.9 vs. 33.5%; p < 0.001). After adjusting for potential confounders, high PaO₂ was negatively associated with favorable neurological outcomes (adjusted odds ratio [aOR] 0.48; 95% confidence interval [CI] 0.24-0.97; p = 0.040). In a multivariate analysis with multiple imputation, high PaO₂ was also negatively associated with favorable neurological outcomes (aOR 0.63; 95% CI 0.49-0.81; p < 0.001).

CONCLUSIONS

Hyperoxemia was associated with worse neurological outcomes in OHCA patients with ECPR.

Extracorporeal cardiopulmonary resuscitation in adult patients with out-of-hospital cardiac arrest: a retrospective large cohort multicenter study in Japan

BACKGROUND

The prevalence of extracorporeal cardiopulmonary resuscitation (ECPR) in patients with out-of-hospital cardiac arrest (OHCA) has been increasing rapidly worldwide. However, guidelines or clinical studies do not provide sufficient data on ECPR practice. The aim of this study was to provide real-world data on ECPR for patients with OHCA, including details of complications.

METHODS

We did a retrospective database analysis of observational multicenter cohort study in Japan. Adult patients with OHCA of presumed cardiac etiology who received ECPR between 2013 and 2018 were included. The primary outcome was favorable neurological outcome at hospital discharge, defined as a cerebral performance category of 1 or 2.

RESULTS

A total of 1644 patients with OHCA were included in this study. The patient age was 18-93 years (median: 60 years). Shockable rhythm in the initial cardiac rhythm at the scene was 69.4%. The median estimated low flow time was 55 min (interquartile range: 45-66 min). Favorable neurological outcome at hospital discharge was observed in 14.1% of patients, and the rate of survival to hospital discharge was 27.2%. The proportions of favorable neurological outcome at hospital discharge in terms of shockable rhythm, pulseless electrical activity, and asystole were 16.7%, 9.2%, and 3.9%, respectively. Complications were observed during ECPR in 32.7% of patients, and the most common complication was bleeding, with the rates of cannulation site bleeding and other types of hemorrhage at 16.4% and 8.5%, respectively.

CONCLUSIONS

In this large cohort, data on the ECPR of 1644 patients with OHCA show that the proportion of favorable neurological outcomes at hospital discharge was 14.1%, survival rate at hospital discharge was 27.2%, and complications were observed during ECPR in 32.7%.

Clinical Phenotyping of Out-of-Hospital Cardiac Arrest Patients With Shockable Rhythm - Machine Learning-Based Unsupervised Cluster Analysis

BACKGROUND

The hypothesis of this study is that latent class analysis could identify the subphenotypes of out-of-hospital cardiac arrest (OHCA) patients associated with the outcomes and allow us to explore heterogeneity in the effects of extracorporeal cardiopulmonary resuscitation (ECPR).Methods and Results:This study was a retrospective analysis of a multicenter prospective observational study (CRITICAL study) of OHCA patients. It included adult OHCA patients with initial shockable rhythm. Patients from 2012 to 2016 (development dataset) were included in the latent class analysis, and those from 2017 (validation dataset) were included for evaluation. The association between subphenotypes and outcomes was investigated. Further, the heterogeneity of the association between ECPR implementation and outcomes was explored. In the study results, a total of 920 patients were included for latent class analysis. Three subphenotypes (Groups 1, 2, and 3) were identified, mainly characterized by the distribution of partial pressure of O₂(PO₂), partial pressure of CO₂(PCO₂) value of blood gas assessment, cardiac rhythm on hospital arrival, and estimated glomerular filtration rate. The 30-day survival outcomes were varied across the groups: 15.7% in Group 1; 30.7% in Group 2; and 85.9% in Group 3. Further, the association between ECPR and 30-day survival outcomes by subphenotype groups in the development dataset was as varied. These results were validated using the validation dataset.

CONCLUSIONS

The latent class analysis identified 3 subphenotypes with different survival outcomes and potential heterogeneity in the effects of ECPR.

Extracorporeal cardiopulmonary resuscitation in-hospital cardiac arrest due to acute coronary syndrome

Background

The aim of this study was to analyze the effect of extracorporeal cardiopulmonary resuscitation on survival and neurological outcomes in in-hospital cardiac arrest patients.

Methods

Between January 2018 and December 2020, a total of 22 patients (17 males, 5 females; mean age: 52.8±9.0 years; range, 32 to 70 years) treated with extracorporeal cardiopulmonary resuscitation using veno-arterial extracorporeal membrane oxygenation support for in-hospital cardiac arrest after acute coronary syndrome were retrospectively analyzed. The patients were divided into two groups as those weaned (n=13) and non-weaned (n=9) from the veno-arterial extracorporeal membrane oxygenation. Demographic data of the patients, heart rhythms at the beginning of conventional cardiopulmonary resuscitation, the angiographic and interventional results, survival and neurological outcomes of the patients before and after extracorporeal cardiopulmonary resuscitation were recorded.

Results

There was no significant difference between the groups in terms of comorbidity and baseline laboratory test values. The underlying rhythm was ventricular fibrillation in 92% of the patients in the weaned group and there was no cardiac rhythm in 67% of the patients in the non-weaned group (p=0.125). The recovery in the mean left ventricular ejection fraction was significantly evident in the weaned group (36.5±12.7% vs. 21.1±7.4%, respectively; p=0.004). The overall wean rate from veno-arterial extracorporeal membrane oxygenation was 59.1%; however, the discharge rate from hospital of survivors without any neurological sequelae was 36.4%.

Conclusion

In-hospital cardiac arrest is a critical emergency situation requiring instantly life-saving interventions through conventional cardiopulmonary resuscitation. If it fails, extracorporeal cardiopulmonary resuscitation should be initiated, regardless the underlying etiology or rhythm disturbances. An effective conventional cardiopulmonary resuscitation is mandatory to prevent brain and body hypoperfusion.

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.

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.

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.