Extracorporeal membrane oxygenation for cardiogenic shock: a meta-analysis of mortality and complications

Anti-Xa-guided Anticoagulation With Unfractionated Heparin and Thrombosis During Extracorporeal Membrane Oxygenation Support: A Systematic Review and Meta-analysis

OBJECTIVE

The initiation of extracorporeal membrane oxygenation (ECMO) triggers complex coagulation processes necessitating systemic anticoagulation. Therefore, anticoagulation monitoring is crucial to avoid adverse events such as thrombosis and hemorrhage. The main aim of this work was to analyze the association between anti-Xa levels and thrombosis occurrence during ECMO support.

DESIGN

Systematic literature review and meta-analysis (Scopus and PubMed, up to July 29, 2023).

SETTING

All retrospective and prospective studies.

PARTICIPANTS

Patients receiving ECMO support.

INTERVENTION

Anticoagulation monitoring during ECMO support.

MEASUREMENTS AND MAIN RESULTS

A total of 16 articles with 1,968 patients were included in the review and 7 studies in the meta-analysis (n = 374). Patients with thrombosis had significantly lower mean anti-Xa values (standardized mean difference -0.36, 95% confidence interval [CI] -0.62 to -0.11, p < 0.01). Furthermore, a positive correlation was observed between unfractionated heparin infusion and anti-Xa levels (pooled estimate of correlation coefficients 0.31, 95% CI 0.19 to 0.43, p < 0.001). The most common adverse events were major bleeding (42%) and any kind of hemorrhage (36%), followed by thromboembolic events (30%) and circuit or oxygenator membrane thrombosis (19%). More than half of the patients did not survive to discharge (52%).

CONCLUSIONS

This work revealed significantly lower levels of anti-Xa in patients experiencing thromboembolic events and a positive correlation between anti-Xa and unfractionated heparin infusion. Considering the contemplative limitations of conventional monitoring tools, further research on the role of anti-Xa is warranted. New trials should be encouraged to confirm these findings and determine the most suitable monitoring strategy for patients receiving ECMO support.

Organ Utilization From Donors Following Extracorporeal Cardiopulmonary Resuscitation: A Systematic Review of Graft and Recipient Outcome

BACKGROUND

The global shortage of solid organs for transplantation is exacerbated by high demand, resulting in organ deficits and steadily growing waiting lists. Diverse strategies have been established to address this issue and enhance organ availability, including the use of organs from individuals who have undergone extracorporeal cardiopulmonary resuscitation (eCPR). The main aim of this work was to examine the outcomes for both graft and recipients of solid organ transplantations sourced from donors who underwent eCPR.

METHODS

We performed a systematic literature review using a combination of the terms related to extracorporeal life support and organ donation. Using Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, PubMed and Scopus databases were searched up to February 2024.

RESULTS

From 1764 considered publications, 13 studies comprising 130 donors and 322 organ donations were finally analyzed. On average, included patients were 36 y old, and the extracorporeal life support was used for 4 d. Kidneys were the most often transplanted organs (68%; 220/322), followed by liver (22%; 72/322) and heart (5%; 15/322); with a very good short-term graft survival rate (95% for kidneys, 92% for lungs, 88% for liver, and 73% for heart). Four studies with 230 grafts reported functional outcomes at the 1-y follow-up, with graft losses reported for 4 hearts (36%), 8 livers (17%), and 7 kidneys (4%).

CONCLUSIONS

Following eCPR, organs can be successfully used with very high graft and recipient survival. In terms of meeting demand, the use of organs from patients after eCPR might be a suitable method for expanding the organ donation pool.

Efficacy and safety of extracorporeal membrane oxygenation for cardiogenic shock complicating myocardial infarction: a systematic review and meta-analysis

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) has been presented as a potential therapeutic option for patients with cardiogenic shock complicating myocardial infarction (CS-MI). We aimed to investigate the efficacy and safety of ECMO in CS-MI.

METHODS

A systematic review and meta-analysis synthesizing evidence from randomized controlled trials obtained from PubMed, Embase, Cochrane, Scopus, and Web of Science until September 2023. We used the random-effects model to report dichotomous outcomes using risk ratio and continuous outcomes using mean difference with a 95% confidence interval. Finally, we implemented a trial sequential analysis to evaluate the reliability of our results.

RESULTS

We included four trials with 611 patients. No significant difference was observed between ECMO and standard care groups in 30-day mortality with pooled RR of 0.96 (95% CI: 0.81-1.13, p = 0.60), acute kidney injury (RR: 0.65, 95% CI: 0.41-1.03, p = 0.07), stroke (RR: 1.16, 95% CI: 0.38-3.57, p = 0.80), sepsis (RR: 1.06, 95% CI: 0.77-1.47, p = 0.71), pneumonia (RR: 0.99, 95% CI: 0.58-1.68, p = 0.96), and 30-day reinfarction (RR: 0.95, 95% CI: 0.25-3.60, p = 0.94). However, the ECMO group had higher bleeding events (RR: 2.07, 95% CI: 1.44-2.97, p < 0.0001).

CONCLUSION

ECMO did not improve clinical outcomes compared to the standard of care in patients with CS-MI but increased the bleeding risk.

The use of venoarterial extracorporeal membrane oxygenation in cardiogenic shock: a narrative review

Aims

Cardiogenic shock (CS) develops in up to 10% of patients with acute myocardial infarction (AMI) and carries a 50% risk of mortality. Despite the paucity of evidence regarding its benefits, venoarterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly used in clinical practice in patients with AMI in CS (AMI-CS). This review aims to provide an in-depth description of the four available randomized controlled trials to date designed to evaluate the benefit of VA-ECMO in patients with AMI-CS.

Methods and results

The literature search was conducted on PubMed, Google Scholar, and clinicaltrials.gov to identify the four relevant randomized control trials from years of inception to October 2023. Despite differences in patient selection, nuances in trial conduction, and variability in trial endpoints, all four trials (ECLS-SHOCK I, ECMO-CS, EUROSHOCK, and ECLS-SHOCK) failed to demonstrate a mortality benefit with the use of VA-ECMO in AMI-CS, with high rates of device-related complications. However, the outcome of these trials is nuanced by the limitations of each study that include small sample sizes, challenging patient selection, and high cross-over rates to the intervention group, and lack of use of left ventricular unloading strategies.

Conclusion

The presented literature of VA-ECMO in CS does not support its routine use in clinical practice. We have yet to identify which subset of patients would benefit most from this intervention. This review emphasizes the need for designing adequately powered trials to properly assess the role of VA-ECMO in AMI-CS, in order to build evidence for best practices.

Prevalence and risk factors for in-hospital mortality of adult patients on veno-arterial extracorporeal membrane oxygenation for cardiogenic shock and cardiac arrest: A systematic review and meta-analysis

OBJECTIVES

To synthesize quantitative research findings on the prevalence and risk factors for in-hospital mortality of patients on veno-arterial extracorporeal membrane oxygenation (VA-ECMO).

METHODS

A comprehensive search was conducted for the period from May 2008 to December 2023 by searching the five electronic databases of PubMed, CINAHL, Web of Science, EMBASE, and Cochrane library. The quality of included studies was assessed using the Newcastle-Ottawa scale. The meta-analysis estimated the pooled odds ratio or standard mean difference and 95% confidence intervals.

RESULTS

A total of twenty-five studies with 10,409 patients were included in the analysis. The overall in-hospital mortality of patients on VA-ECMO was 56.7 %. In the subgroup analysis, in-hospital mortality of VA-ECMO for cardiogenic shock and cardiac arrest was 49.2 % and 75.2 %, respectively. The number of significant factors associated with an increased risk of in-hospital mortality in the pre-ECMO period (age, body weight, creatinine, chronic kidney disease, pH, and lactic acid) was greater than that in the intra- and post-ECMO periods. Renal replacement, bleeding, and lower limb ischemia were the most significant risk factors for in-hospital mortality in patients receiving VA-ECMO.

CONCLUSION

Early detection of the identified risk factors can contribute to reducing in-hospital mortality in patients on VA-ECMO. Intensive care unit nurses should provide timely and appropriate care before, during, and after VA-ECMO.

IMPLICATIONS FOR CLINICAL PRACTICE

Intensive care unit nurses should be knowledgeable about factors associated with the in-hospital mortality of patients on VA-ECMO to improve outcomes. The present findings may contribute to developing guidelines for reducing in-hospital mortality among patients considering ECMO.

Comparison of Outcomes in Patients Requiring Mechanical Circulatory Support Who Received Cangrelor in Addition to Anticoagulation Versus Anticoagulation Alone

OBJECTIVES

To evaluate the safety of cangrelor administered concurrently with heparin or bivalirudin in patients on mechanical circulatory support.

DESIGN

A single-center, retrospective cohort study of adult patients consecutively admitted between January 2016 and October 2020.

SETTING

A tertiary medical center.

PARTICIPANTS

Adult patients admitted to the cardiovascular intensive care unit put on mechanical circulatory support for acute myocardial infarction (AMI) or non-AMI indications. Patients who received cangrelor underwent percutaneous coronary intervention with stenting during the index event or within the last year.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the incidence of major bleeding, defined by the Extracorporeal Life Support Organization criteria, in patients with mechanical circulatory support receiving cangrelor plus anticoagulation with heparin or bivalirudin with or without aspirin versus patients who did not receive cangrelor. Sixty-eight patients were included in the study. Twenty-nine patients received cangrelor, and 39 did not. Cangrelor was not associated with an increase in major bleeding; however, the CI was wide (adjusted hazard ratio 1.93, 95% CI 0.61-6.11; p = 0.262).

CONCLUSIONS

Patients receiving cangrelor did not appear to be at higher risk of major bleeding compared to patients not receiving cangrelor. Larger trials should be conducted to better evaluate the safety of cangrelor in patients with mechanical circulatory support.

Outcomes of Adult Patients With COVID-19 Transitioning From Venovenous to Venoarterial or Hybrid Extracorporeal Membrane Oxygenation in the Extracorporeal Life Support Organization Registry

This retrospective analysis of the Extracorporeal Life Support Organization (ELSO) registry evaluates the outcomes and identifies risk factors associated with conversion from initial venovenous extracorporeal membrane oxygenation (ECMO) support to venoarterial or hybrid ECMO in patients with coronavirus disease 2019 (COVID-19). We collected deidentified data on all adult patients (≥18 years old) diagnosed with COVID who received venovenous extracorporeal membrane oxygenation between March 2020 and November 2022. Patients initially placed on an ECMO configuration other than venovenous (VV) ECMO were excluded from the analysis. Our analysis included data from 12,850 patients, of which 393 (3.1%) transitioned from VV ECMO to an alternative mode. The primary outcome measure was in-hospital mortality, and the conversion group exhibited a higher in-hospital mortality rate. We also examined baseline variables, including demographic information, biochemical labs, and inotrope requirements. Univariate analysis revealed that pre-ECMO arrest, the need for renal replacement therapy, and the use of inotropic agents, particularly milrinone, were strongly associated with the risk of conversion. Notably, even after implementing a 3:1 propensity score matching, the impact of conversion on both mortality and complications remained substantial. Our study underscores an elevated risk of mortality for COVID-19 patients initially treated with VV ECMO who subsequently require conversion to VA-ECMO or hybrid ECMO.

ICU Nurses' Perception of Sensitive Indicators of Quality of Care for ECMO Patients in Guizhou Province, China: A Cross-Sectional Study

Purpose

This study aimed to investigate the cognitive evaluation level of ICU nurses in Guizhou Province, China, on the sensitivity indicators of nursing quality for ECMO patients.

Patients and Methods

This was a cross-sectional observational study conducted in Guizhou Province, China, from May to July 2023, 259 ICU nurses were surveyed. Objective sampling method was used to select the participants from 10 hospitals in Guizhou Province that carried out ECMO. Data were collected through questionnaire survey. Two researchers checked and recorded Epidata 3.1. SPSS 25.0 was used for statistical analysis of the data, and frequency, mean and component ratio were used for descriptive statistical analysis. The importance rating was used to reflect the degree of nurses' agreement with the indicators.

Results

The results of this study showed that 79.1% of the 253 ICU nurses in Guizhou Province, China, had not participated in training and courses related to indicators of quality of care evaluation for ECMO patients. The main way for ICU nurses to acquire knowledge related to indicators of quality of care sensitivity for ECMO patients was departmental training, which accounted for 87.4%. And the other ways, in descending order, were public, the matic lectures or academic conferences, journals and magazines; their evaluation scores of the importance of most of the quality of care sensitivity indicators for ECMO patients was moderate, with the scores ranging from 73 to 150. Among them, the range of importance evaluation scores for each indicator was 4.01 ~ 4.48.

Conclusion

The overall cognitive evaluation of ICU nurses in Guizhou Province, China, on most sensitivity indicators of quality of care for ECMO patients was moderate, and there is a general lack of systematic courses and training on the knowledge related to ECMO care quality sensitive indicators.

Mechanical Circulatory Support in Cardiogenic Shock: Uses in the Emergency Setting

Cardiogenic shock is a lethal condition with significant morbidity, characterized by myocardial insults leading to low cardiac output and ensuing systemic hypoperfusion. While mortality rates remain high, we have improved upon our recognition and definition of cardiogenic shock, now with an emphasis on defining stages of shock to help guide effective treatment strategies with either pharmacologic or mechanical circulatory support. In this review, the authors summarize these stages as well as discuss indications, function, selection, and troubleshooting of the various temporary mechanical circulatory support devices.

Association of anti-factor Xa-guided anticoagulation with hemorrhage during ECMO support: A systematic review and meta-analysis

BACKGROUND

The use of extracorporeal membrane oxygenation (ECMO) is associated with complex hemostatic changes. Systemic anticoagulation is initiated to prevent clotting in the ECMO system, but this comes with an increased risk of bleeding. Evidence on the use of anti-Xa-guided monitoring to prevent bleeding during ECMO support is limited. Therefore, we aimed to analyze the association between anti-factor Xa-guided anticoagulation and hemorrhage during ECMO.

METHODS

A systematic review and meta-analysis was performed (up to August 2023).

PROSPERO

CRD42023448888.

RESULTS

Twenty-six studies comprising 2293 patients were included in the analysis, with six works being part of the meta-analysis. The mean anti-Xa values did not show a significant difference between patients with and without hemorrhage (standardized mean difference -0.05; 95% confidence interval [CI]: -0.19; 0.28, p = .69). We found a positive correlation between anti-Xa levels and unfractionated heparin dose (UFH; pooled estimate of correlation coefficients 0.44; 95% CI: 0.33; 0.55, p < .001). The most frequent complications were any type of hemorrhage (pooled 36%) and thrombosis (33%). Nearly half of the critically ill patients did not survive to hospital discharge (47%).

CONCLUSIONS

The most appropriate tool for anticoagulation monitoring in ECMO patients is uncertain. Our analysis did not reveal a significant difference in anti-Xa levels in patients with and without hemorrhagic events. However, we found a moderate correlation between anti-Xa and the UFH dose, supporting its utilization in monitoring UFH anticoagulation. Given the limitations of time-guided monitoring methods, the role of anti-Xa is promising and further research is warranted.

Extracorporeal membrane oxygenation (ECMO) during aplasia: A bridge towards myopericarditis recovery after autologous hematopoietic stem cell transplant for systemic sclerosis and recent Coronarovirus disease (COVID-19) vaccination

Systemic sclerosis (SSc) is a rare autoimmune disease (AD), characterised by early diffuse vasculopathy, activation of the immune response and progressive skin and internal organ fibrosis. In severe progressive diffuse SSc (dSSc), autologous hematopoietic stem cell transplantation (aHSCT) improves survival, despite its own risk of complications and transplant related mortality (TRM). We present herein the case of a dSSc patient undergoing aHSCT with low dose cyclophosphamide conditioning and sudden acute myopericarditis and cardiogenic shock, four weeks after a second mRNA SARS-CoV-2 vaccine (Pfizer) injection. Four days of extracorporeal membrane oxygenation (ECMO) support during the aplasia period, allowed to observe full cardiac function recovery and progressive SSc rehabilitation with sustained disease response at 30 months follow-up. This report illustrates, for the first time to our knowledge, that ECMO can be indicated despite aplasia during aHSCT and successfully used as a bridge towards heart function recovery in highly selected and fragile AD patients. We review the factors that may contribute to endothelial and myocardial stunning and acute reversible cardiac failure in SSc and aggravate intrinsic endothelial injury during the aHSCT procedure. These classically include: cyclophosphamide drug toxicity, viral infections and autoimmune activation with disease flair per se. In the COVID-19 pandemic times, acute myocarditis due to recent viral infection or mRNA vaccine per se, must also be considered.

Clinical Application of Extracorporeal Membrane Oxygenation in the Treatment of Fulminant Myocarditis

Fulminant myocarditis (FM) is a rare but serious clinical syndrome which can be characterized by the rapid deterioration of cardiac function, with cardiogenic shock (CS) and arrhythmic electrical storms being common presentations, often requiring adjunctive support with mechanical circulatory devices. With the development of mechanical circulatory support (MCS) devices, there are now more and more studies investigating the application of MCS in FM patients, and the use of extracorporeal membrane oxygenation (ECMO) to treat FM has shown good survival rates. This review elucidates the treatment of FM, and the application and clinical outcomes associated with ECMO intervention.

Short-Term Mortality Among Pediatric Patients With Heart Diseases Undergoing Veno-Arterial Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-Analysis

BACKGROUND

Veno-arterial extracorporeal membrane oxygenation serves as a crucial mechanical circulatory support for pediatric patients with severe heart diseases, but the mortality rate remains high. The objective of this study was to assess the short-term mortality in these patients.

METHODS AND RESULTS

We systematically searched PubMed, Embase, and Cochrane Library for observational studies that evaluated the short-term mortality of pediatric patients undergoing veno-arterial extracorporeal membrane oxygenation. To estimate short-term mortality, we used random-effects meta-analysis. Furthermore, we conducted meta-regression and binomial regression analyses to investigate the risk factors associated with the outcome of interest. We systematically reviewed 28 eligible references encompassing a total of 1736 patients. The pooled analysis demonstrated a short-term mortality (defined as in-hospital or 30-day mortality) of 45.6% (95% CI, 38.7%-52.4%). We found a significant difference (P<0.001) in mortality rates between acute fulminant myocarditis and congenital heart disease, with acute fulminant myocarditis exhibiting a lower mortality rate. Our findings revealed a negative correlation between older age and weight and short-term mortality in patients undergoing veno-arterial extracorporeal membrane oxygenation. Male sex, bleeding, renal damage, and central cannulation were associated with an increased risk of short-term mortality.

CONCLUSIONS

The short-term mortality among pediatric patients undergoing veno-arterial extracorporeal membrane oxygenation for severe heart diseases was 45.6%. Patients with acute fulminant myocarditis exhibited more favorable survival rates compared with those with congenital heart disease. Several risk factors, including male sex, bleeding, renal damage, and central cannulation contributed to an increased risk of short-term mortality. Conversely, older age and greater weight appeared to be protective factors.

ECMO in Myocardial Infarction-Associated Cardiogenic Shock: Blood Biomarkers as Predictors of Mortality

BACKGROUND

Veno-arterial extracorporeal membrane oxygenation (va-ECMO) can provide circulatory and respiratory support in patients with cardiogenic shock. The main aim of this work was to investigate the association of blood biomarkers with mortality in patients with myocardial infarction needing va-ECMO support.

METHODS

We retrospectively analyzed electronic medical charts from patients receiving va-ECMO support in the period from 2008 to 2021 at the Medical University Innsbruck, Department of Anesthesiology and Intensive Care Medicine.

RESULTS

Of 188 patients, 57% (108/188) survived to discharge, with hemorrhage (46%) and thrombosis (27%) as the most frequent adverse events. Procalcitonin levels were markedly higher in non-survivors compared with survivors during the observation period. The multivariable model identified higher blood levels of procalcitonin (HR 1.01, p = 0.002) as a laboratory parameter associated with a higher risk of mortality.

CONCLUSIONS

In our study population of patients with myocardial infarction-associated cardiogenic shock, deceased patients had increased levels of inflammatory blood biomarkers throughout the whole study period. Increased procalcitonin levels have been associated with a higher risk of mortality. Future studies are needed to show the role of procalcitonin in patients receiving ECMO support.

Prevalence of delirium among critically ill patients who received extracorporeal membrane oxygenation therapy: A systematic review and proportional meta-analysis

OBJECTIVES

To pool the overall prevalence of delirium among critically ill patients who received extracorporeal membrane oxygenation (ECMO) support.

METHODOLOGY

This systematic review and proportional meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analysis of Observational Studies in Epidemiology (MOOSE) reporting guidelines. Six electronic databases including PubMed, Cochrane Library, Web of Science, EMBASE, CINAHL, and PsycINFO were searched from inception to March 2023. The Newcastle-Ottawa Scale was used to assess the methodological quality of the included studies. A random effects model was used to pool the summary prevalence estimates and 95% CIs using the score statistic and the exact binomial method and incorporates the Freeman-Tukey double arcsine transformation of proportions. Sensitivity analyses including subgroup analysis, meta-regression, and outlier detection were carried out.

SETTING

Intensive care units.

MAIN OUTCOME MEASURES

Prevalence of delirium.

RESULTS

A total of 10 studies involving 8,580 patients were included for meta-analysis. All studies had a low risk of bias in methodological quality. The pooled prevalence rate of 40.79% [95% CI, 17.58%-66.25%] was observed. The between-study heterogeneity (I2) was 98.28%. The subgroup analysis reveals the pooled prevalence of delirium for veno-arterial (V-A) ECMO, veno-venous (V-V) ECMO, and mixed sample of V-A and V-V ECMO were 63.57% [95% CI, 55.77%-71.04%], 51.84% [95% CI, 37.43%-66.12%] and 35.23% [95% CI, 11.84%-62.95%], respectively. Sample size (p = 0.024) was a significant factor associated with the heterogeneity. No evidence for small-study effects was observed (Egger's test: p = 0.5664).

CONCLUSION

This systematic review and proportional meta-analysis reveals a high prevalence of delirium among critically ill patients who received ECMO support.

IMPLICATIONS FOR CLINICAL PRACTICE

The results of this meta-analysis can be epidemiological evidence to inform the awareness of clinicians and researchers in critical care clinical practice and research.

Extracorporeal Life Support for Patients With Newly Diagnosed HIV and Acute Respiratory Distress Syndrome: A Systematic Review and Analysis of Individual Patient Data

Extracorporeal membrane oxygenation (ECMO) may improve survival in patients with severe acute respiratory distress syndrome (ARDS). However, presence of immunosuppression is a relative contraindication for ECMO, which is withheld in HIV patients. We performed a systematic review to investigate the outcome of newly diagnosed HIV patients with ARDS receiving ECMO support. Our search yielded 288 publications, with 22 studies finally included. Initial presentation included fever, respiratory distress, and cough. Severe immunodeficiency was confirmed in most patients. Deceased patients had a higher viral load, a lower Horovitz index, and antiretroviral therapy utilized before ECMO. Moreover, ECMO duration was longer ( p = 0.0134), and all deceased suffered from sepsis ( p = 0.0191). Finally, despite the development of therapeutic options for HIV patients, ECMO remains a relative contraindication. We found that ECMO may successfully bridge the time for pulmonary recovery in 93% of patients, with a very good outcome. Using ECMO, the time for antimicrobial therapy, lung-protective ventilation, and immune system restitution may be gained. Further studies clarifying the role of ECMO in HIV are crucial and until these data are available, ECMO might be appropriate in immunocompromised patients. This holds especially true in newly diagnosed HIV patients, who are usually young, without comorbidities, with a good rehabilitation potential.

Extracorporeal Membrane Oxygenation (VA-ECMO) in Management of Cardiogenic Shock

Cardiogenic shock is a critical condition of low cardiac output resulting in insufficient systemic perfusion and end-organ dysfunction. Though significant advances have been achieved in reperfusion therapy and mechanical circulatory support, cardiogenic shock continues to be a life-threatening condition associated with a high rate of complications and excessively high patient mortality, reported to be between 35% and 50%. Extracorporeal membrane oxygenation can provide full cardiopulmonary support, has been increasingly used in the last two decades, and can be used to restore systemic end-organ hypoperfusion. However, a paucity of randomized controlled trials in combination with high complication and mortality rates suggest the need for more research to better define its efficacy, safety, and optimal patient selection. In this review, we provide an updated review on VA-ECMO, with an emphasis on its application in cardiogenic shock, including indications and contraindications, expected hemodynamic and echocardiographic findings, recommendations for weaning, complications, and outcomes. Furthermore, specific emphasis will be devoted to the two published randomized controlled trials recently presented in this setting.

Subtypes and Mechanistic Advances of Extracorporeal Membrane Oxygenation-Related Acute Brain Injury

Extracorporeal membrane oxygenation (ECMO) is a frequently used mechanical cardiopulmonary support for rescuing critically ill patients for whom conventional medical therapies have failed. However, ECMO is associated with several complications, such as acute kidney injury, hemorrhage, thromboembolism, and acute brain injury (ABI). Among these, ABI, particularly intracranial hemorrhage (ICH) and infarction, is recognized as the primary cause of mortality during ECMO support. Furthermore, survivors often suffer significant long-term morbidities, including neurocognitive impairments, motor disturbances, and behavioral problems. This review provides a comprehensive overview of the different subtypes of ECMO-related ABI and the updated advance mechanisms, which could be helpful for the early diagnosis and potential neuromonitoring of ECMO-related ABI.

Extracorporeal Membrane Oxygenation

The utilization of extracorporeal membrane oxygenation (ECMO) for cardiopulmonary support continues to increase globally, with > 190,000 ECMO cases reported to the international Extracorporeal Life Support Organization Registry. The present review aims to synthesize important contributions to the literature surrounding the management of mechanical ventilation, prone positioning, anticoagulation, bleeding complications, and neurologic outcomes for infants, children, and adults undergoing ECMO in 2022. Additionally, issues related to cardiac ECMO, Harlequin syndrome, and anticoagulation during ECMO will be discussed.

Initial Tumor Necrosis Factor-Alpha and Endothelial Activation Are Associated with Hemorrhagic Complications during Extracorporeal Membrane Oxygenation

Studies on inflammatory markers, endothelial activation, and bleeding during extracorporeal membrane oxygenation (ECMO) are lacking. Blood samples were prospectively collected after ECMO initiation from 150 adult patients who underwent ECMO for respiratory failure between 2018 and 2021. After excluding patients who died early (within 48 h), 132 patients were finally included. Their tumor necrosis factor-alpha (TNF-α), tissue factor (TF), soluble thrombomodulin (sTM), and E-selectin levels were measured. A Cox proportional hazards regression model was used to estimate the hazard ratio for hemorrhagic complications during ECMO. The 132 patients were divided into hemorrhagic (n = 23, H group) and non-complication (n = 109, N group) groups. The sequential organ failure assessment score, hemoglobin level, and ECMO type were included as covariates in all Cox models to exclude the effects of clinical factors. After adjusting for these factors, initial TNF-α, TF, sTM, E-selectin, and activated protein C levels were significantly associated with hemorrhagic complications (all p < 0.001). TNF-α, TF, and E-selectin better predicted hemorrhagic complications than the model that included only the aforementioned clinical factors (clinical factors only (area under the curve [AUC]: 0.804), reference; TNF-α (AUC: 0.914); TF (AUC: 0.915); E-selectin (AUC: 0.869)). Conclusions: TNF-α levels were significantly predictive of hemorrhagic complications during ECMO.

aPTT-guided anticoagulation monitoring during ECMO support: A systematic review and meta-analysis

INTRODUCTION

The initiation of the extracorporeal membrane oxygenation (ECMO) is associated with complex coagulatory and inflammatory processes and consequently needed anticoagulation. Systemic anticoagulation bears an additional risk of serious bleeding, and its monitoring is of immense importance. Therefore, our work aims to analyze the association of anticoagulation monitoring with bleeding during ECMO support.

MATERIAL AND METHODS

Systematic literature review and meta-analysis, complying with the PRISMA guidelines (PROSPERO-CRD42022359465).

RESULTS

Seventeen studies comprising 3249 patients were included in the final analysis. Patients experiencing hemorrhage had a longer activated partial thromboplastin time (aPTT), a longer ECMO duration, and higher mortality. We could not find strong evidence of any aPTT threshold association with the bleeding occurrence, as less than half of authors reported a potential relationship. Finally, we identified the acute kidney injury (66%, 233/356) and hemorrhage (46%, 469/1046) to be the most frequent adverse events, while almost one-half of patients did not survive to discharge (47%, 1192/2490).

CONCLUSION

The aPTT-guided anticoagulation is still the standard of care in ECMO patients. We did not find strong evidence supporting the aPTT-guided monitoring during ECMO. Based on the weight of the available evidence, further randomized trials are crucial to clarify the best monitoring strategy.

Association of aPTT-Guided Anticoagulation Monitoring with Thromboembolic Events in Patients Receiving V-A ECMO Support: A Systematic Review and Meta-Analysis

BACKGROUND

The initiation of extracorporeal membrane oxygenation (ECMO) is associated with complex inflammatory and coagulatory processes, raising the need for systemic anticoagulation. The balance of anticoagulatory and procoagulant factors is essential, as therapeutic anticoagulation confers a further risk of potentially life-threatening bleeding. Therefore, our study aims to systematize and analyze the most recent evidence regarding anticoagulation monitoring and the thromboembolic events in patients receiving veno-arterial ECMO support.

METHODS

Using the PRISMA guidelines, we systematically searched the Scopus and PubMed databases up to October 2022. A weighted effects model was employed for the meta-analytic portion of the study.

RESULTS

Six studies comprising 1728 patients were included in the final analysis. Unfractionated heparin was used for anticoagulation, with an activated partial thromboplastin time (aPTT) monitoring goal set between 45 and 80 s. The majority of studies aimed to investigate the incidence of adverse events and potential risk factors for thromboembolic and bleeding events. None of the authors found any association of aPTT levels with the occurrence of thromboembolic events. Finally, the most frequent adverse events were hemorrhage (pooled 43%, 95% CI 28.4; 59.5) and any kind of thrombosis (pooled 36%, 95% CI 21.7; 53.7), and more than one-half of patients did not survive to discharge (pooled 54%).

CONCLUSIONS

Despite the tremendous development of critical care, aPTT-guided systemic anticoagulation is still the standard monitoring tool. We did not find any association of aPTT levels with thrombosis. Further evidence and new trials should clarify the true incidence of thromboembolic events, along with the best anticoagulation and monitoring strategy in veno-arterial ECMO patients.

Cerebral Neural Changes in Venous-Arterial Extracorporeal Membrane Oxygenation Survivors

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is used as temporary cardiorespiratory support in patients with critical ailments, but very little is known about the functional cerebral changes in ECMO survivors. Degree centrality (DC), a graph-based assessment of network organization, was performed to explore the neural connectivity changes in ECMO survivors compared to controls and their correlation with cognitive and neurological measures.

METHODS

This exploratory observational study was conducted from August 2020 to May 2022. ECMO survivors and controls underwent functional magnetic resonance imaging (fMRI) of the brain. We performed DC analysis to identify voxels that showed changes in whole-brain functional connectivity with other voxels. DC was measured by the fMRI graph method and comparisons between the two groups were performed. All participants underwent neuropsychological assessment (Montreal Cognitive Assessment, MoCA). Blood serum neuron-specific enolase and the Glasgow Coma Scale (GCS) were assessed in ECMO survivors.

RESULTS

DC values in the right insula and right precuneus gyrus were lower in ECMO survivors and higher in the right medial superior frontal gyrus compared to controls (all p < 0.001). Decreased connectivity in the right insular and right precuneus gyrus correlated with total MoCA scores, delayed recollection, and calculation (all p < 0.05). Increased serum NSE levels, GCS score, and GCS-motor response correlated with decreased connectivity in the right insular and right precuneus gyrus and increased connectivity in the right medial superior frontal gyrus (all p < 0.05).

CONCLUSIONS

We showed that both functional impairment and adaptation were observed in survivors of ECMO, suggesting that neural connectivity changes may provide insights into the mechanisms that may potentially link ECMO survivors to neurological and cognitive disorders.

Efficacy and safety of extracorporeal membrane oxygenation for burn patients: a comprehensive systematic review and meta-analysis

BACKGROUND

Respiratory and circulatory dysfunction are common complications and the leading causes of death among burn patients, especially in severe burns and inhalation injury. Recently, extracorporeal membrane oxygenation (ECMO) has been increasingly applied in burn patients. However, current clinical evidence is weak and conflicting. This study aimed to comprehensively evaluate the efficacy and safety of ECMO in burn patients.

METHODS

A comprehensive search of PubMed, Web of Science and Embase from inception to 18 March 2022 was performed to identify clinical studies on ECMO in burn patients. The main outcome was in-hospital mortality. Secondary outcomes included successful weaning from ECMO and complications associated with ECMO. Meta-analysis, meta-regression and subgroup analyses were conducted to pool the clinical efficacy and identify influencing factors.

RESULTS

Fifteen retrospective studies with 318 patients were finally included, without any control groups. The commonest indication for ECMO was severe acute respiratory distress syndrome (42.1%). Veno-venous ECMO was the commonest mode (75.29%). Pooled in-hospital mortality was 49% [95% confidence interval (CI) 41-58%] in the total population, 55% in adults and 35% in pediatrics. Meta-regression and subgroup analysis found that mortality significantly increased with inhalation injury but decreased with ECMO duration. For studies with percentage inhalation injury ≥50%, pooled mortality (55%, 95% CI 40-70%) was higher than in studies with percentage inhalation injury <50% (32%, 95% CI 18-46%). For studies with ECMO duration ≥10 days, pooled mortality (31%, 95% CI 20-43%) was lower than in studies with ECMO duration <10 days (61%, 95% CI 46-76%). In minor and major burns, pooled mortality was lower than in severe burns. Pooled percentage of successful weaning from ECMO was 65% (95% CI 46-84%) and inversely correlated with burn area. The overall rate of ECMO-related complications was 67.46%, and infection (30.77%) and bleedings (23.08%) were the two most common complications. About 49.26% of patients required continuous renal replacement therapy.

CONCLUSIONS

ECMO seems to be an appropriate rescue therapy for burn patients despite the relatively high mortality and complication rate. Inhalation injury, burn area and ECMO duration are the main factors influencing clinical outcomes.

Thrombotic Events Develop in 1 Out of 5 Patients Receiving ECMO Support: An 11-Year Referral Centre Experience

BACKGROUND

The use of extracorporeal membrane oxygenation (ECMO) for critically ill patients is growing rapidly given recent developments in technology. However, adverse events are frequently reported that have potentially devastating impacts on patient outcomes. The information on predictors and risk factors for thrombotic events, especially that focusing on the comparison of veno-arterial and veno-venous ECMO configurations, are still inconsistent and sparse; therefore, we aimed to close this gap.

METHODS

We performed a retrospective analysis of all patients on extracorporeal life support admitted to the intensive care units of a tertiary university center in Europe.

RESULTS

From 645 patients, 417 who received extracorporeal life support due to cardiogenic shock (290, 70%), respiratory failure (116, 28%) or hypothermia (11, 3%) were included. In total, 22% (92) of the patients experienced thrombotic events with a similar incidence in both ECMO configurations. Anticoagulation consisted of unfractionated heparin (296, 71%) and argatroban (70, 17%). Univariate Cox analyses identified hemoconcentration and increased maximal clot firmness (thromboelastometry) as risk factors for thrombosis. Moreover, the patients experiencing thrombosis had longer ECMO duration and intensive care stays.

CONCLUSIONS

ECMO is a specialized life-support modality with a high risk of complications. A longer ECMO duration is associated with thrombosis occurrence in patients receiving ECMO support. Following hemorrhage, thromboembolic complications are common adverse events. However, in contrast to major bleeding, no impact on mortality was observed. The question arises if a protocol with less anticoagulation may have a role to play in the future.

Mechanical Assist Device-Assisted Percutaneous Coronary Intervention: The Use of Impella Versus Extracorporeal Membrane Oxygenation as an Emerging Frontier in Revascularization in Cardiogenic Shock

The extracorporeal membrane oxygenation (ECMO) procedure aids in the provision of prolonged cardiopulmonary support, whereas the Impella device (Abiomed, Danvers, MA) is a ventricular assist device that maintains circulation by pumping blood into the aorta from the left ventricle. Blood is circulated in parallel with the heart by Impella. It draws blood straight into the aorta from the left ventricle, hence preserving the physiological flow. ECMO bypasses the left atrium and the left ventricle, and the end consequence is a non-physiological flow. In this article, we conducted a detailed analysis of various publications in the literature and examined various modalities pertaining to the use of ECMO and Impella for cardiogenic shocks, such as efficacy, clinical outcomes, cost-effectiveness, device-related complications, and limitations. The Impella completely unloads the left ventricle, thereby significantly reducing the effort of the heart. Comparatively, ECMO only stabilizes a patient with cardiogenic shock for a short stretch of time and does not lessen the efforts of the left ventricle ("unload" it). In the acute setting, both devices reduced left ventricular end-diastolic pressure and provided adequate hemodynamic support. By comparing patients on Impella to those receiving ECMO, it was found that patients on Impella were associated with better clinical results, quicker recovery, limited complications, and reduced healthcare costs; however, there is a lack of conclusive studies performed demonstrating the reduction in long-term mortality rates. Considering the effectiveness of given modalities and taking into account the various studies described in the literature, Impella has reported better clinical outcomes although more clinical trials are needed for establishing the effectiveness of these interventional approaches in revascularization in cardiogenic shock.

ECMO in Cardiogenic Shock: Time Course of Blood Biomarkers and Associated Mortality

BACKGROUND

Veno-arterial extracorporeal membrane oxygenation (va-ECMO) is a temporary life support for severe cardiogenic shock, gaining time for organ recovery, permanent assistance, or transplantation. In this work, we aimed to investigate the trends of blood biomarkers over the period of ECMO support and their role in patient outcome.

METHODS

This retrospective study comprised patients receiving va-ECMO support over the period of 14 years at a tertiary university center.

RESULTS

Of 435 patients, 62% (268/435) survived to discharge, and the most frequent adverse event was hemorrhage (46%), followed by thrombosis (25%). Deceased patients had increased blood levels of C-reactive protein, procalcitonin, and white blood cells during the whole observation period, with higher peaks compared with survivors. The multivariable model identified hemorrhage (HR 1.73, p = 0.005) and higher levels of procalcitonin (HR 1.01, p = 0.001) as independent risk factors for death.

CONCLUSIONS

In our population of critically ill patients receiving va-ECMO support, deceased patients had increased inflammatory biomarkers during the whole observation period. Patients having higher values of procalcitonin and experiencing bleeding events showed an increased risk for mortality. Further studies focusing on inflammation in ECMO patients, clarifying its role in patient outcome and potential therapeutic interventions, are warranted.

ECMO Support in Refractory Cardiogenic Shock: Risk Factors for Mortality

BACKGROUND

Veno-arterial extracorporeal membrane oxygenation (va-ECMO) is a specialized temporary support for patients with refractory cardiogenic shock. The true value of this potentially lifesaving modality is still a subject of debate. Therefore, we aimed to investigate the overall in-hospital mortality and identify potential risk factors for mortality.

METHODS

We retrospectively analyzed the data of 453 patients supported with va-ECMO over a period of 14 years who were admitted to intensive care units of a tertiary university center in Austria.

RESULTS

We observed in-hospital mortality of 40% for patients with refractory cardiogenic shock. Hemorrhage, ECMO initiation on weekends, higher SAPS III score, and sepsis were identified as significant risk factors for mortality. Hemorrhage was the most common adverse event (46%), with major bleeding events dominating in deceased patients. Thromboembolic events occurred in 25% of patients, followed by sepsis (18%).

CONCLUSIONS

Although the rates of complications are substantial, a well-selected proportion of patients with refractory cardiogenic shock can be rescued from probable death. The reported risk factors could be used to increase the awareness of clinicians towards the development of new therapeutic concepts that may reduce their incidence.