Extracorporeal Membrane Oxygenation for Critically Ill Patients with COVID-19-related Acute Respiratory Distress Syndrome: Worth the Effort?

Multi-modal prediction of extracorporeal support-a resource intensive therapy, utilizing a large national database

Objective

Extracorporeal membrane oxygenation (ECMO) is among the most resource-intensive therapies in critical care. The COVID-19 pandemic highlighted the lack of ECMO resource allocation tools. We aimed to develop a continuous ECMO risk prediction model to enhance patient triage and resource allocation.

Material and Methods

We leveraged multimodal data from the National COVID Cohort Collaborative (N3C) to develop a hierarchical deep learning model, labeled "PreEMPT-ECMO" (Prediction, Early Monitoring, and Proactive Triage for ECMO) which integrates static and multi-granularity time series features to generate continuous predictions of ECMO utilization. Model performance was assessed across time points ranging from 0 to 96 hours prior to ECMO initiation, using both accuracy and precision metrics.

Results

Between January 2020 and May 2023, 101 400 patients were included, with 1298 (1.28%) supported on ECMO. PreEMPT-ECMO outperformed established predictive models, including Logistic Regression, Support Vector Machine, Random Forest, and Extreme Gradient Boosting Tree, in both accuracy and precision at all time points. Model interpretation analysis also highlighted variations in feature contributions through each patient's clinical course.

Discussion and Conclusions

We developed a hierarchical model for continuous ECMO use prediction, utilizing a large multicenter dataset incorporating both static and time series variables of various granularities. This novel approach reflects the nuanced decision-making process inherent in ECMO initiation and has the potential to be used as an early alert tool to guide patient triage and ECMO resource allocation. Future directions include prospective validation and generalizability on non-COVID-19 refractory respiratory failure, aiming to improve patient outcomes.

Mapping a Decade (2014-2024) of Research on Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome: A Visual Analysis with CiteSpace and VOSviewer

Background

Acute Respiratory Distress Syndrome (ARDS) stands as a primary cause of mortality among critically ill patients. Extracorporeal Membrane Oxygenation (ECMO) is increasingly employed in the rescue therapy of ARDS patients. However, the current status of research in the field of ECMO-assisted ARDS remains unclear.

Objective

This research aims to categorize and evaluate the literature regarding Extracorporeal Membrane Oxygenation (ECMO) support for Acute Respiratory Distress Syndrome (ARDS), offering a comprehensive analysis of bibliometric properties, research hotspots, and developmental trends within the domain of ECMO-assisted ARDS.

Methods

A literature search was conducted for ECMO-assisted support for patients with ARDS in the Web of Science Core Collection (WoSCC) database from 2014 to 2024. We employed visualization tools such as CiteSpace and VOSviewer to explore and assess connections among nations, institutions, researchers, and co-cited journals, authors, references, and keywords.

Results

This study included 1739 publications. The United States leads in publication volume with Columbia University at the forefront of ECMO research. Intensive Care Medicine has been identified as the most cited journal in this field. Alain Combes from France stands out as a key contributor, particularly in his 2018 publication in the New England Journal of Medicine, which is the most cited work in the discipline. Furthermore, keyword analysis identified three distinct research phases: examining complications associated with ECMO therapy, exploring optimal strategies for mechanical ventilation under ECMO support, and compiling insights into the application of ECMO in treating COVID-19 patients and in the development of predictive models for patient outcomes.

Conclusion

Using bibliometric visualization techniques, this study revealed significant progress in the use of ECMO for treating ARDS respiratory support, evaluated the impact of these findings, and outlined potential areas for future studies.

Fibrinolysis as a Causative Mechanism for Bleeding Complications on Extracorporeal Membrane Oxygenation: A Pilot Observational Prospective Study

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is associated with a high risk of bleeding complications. The specific impact of ECMO on fibrinolysis remains unexplored. The objective of the current pilot observational prospective study was to investigate the longitudinal dynamics of fibrinolytic markers-i.e., changes over time-in the context of bleeding events in patients on ECMO.

METHODS

Longitudinal dynamics of contact phase components (kininogen and bradykinin) and fibrinolysis markers (tissue plasminogen activator [tPA], plasminogen activator inhibitor-1 [PAI-1], their complexes [tPA•PAI-1], plasmin-antiplasmin complexes, plasminogen, and D-dimer) were measured in patients undergoing venovenous and venoarterial ECMO, before implantation, at 0, 6, and 12 h after implantation, and daily thereafter.

RESULTS

The cohort consisted of 30 patients (214 ECMO days). The concentrations of tPA, D-dimer, plasmin-antiplasmin complexes, PAI-1, and tPA•PAI-1 complexes were increased, whereas plasminogen decreased compared to normal values. A noteworthy divergence was observed between hemorrhagic and nonhemorrhagic patients: in bleeding patients, D-dimer, plasmin-antiplasmin, tPA, PAI-1, and tPA•PAI-1 followed an increasing kinetics before hemorrhage and then decreased to their baseline level; conversely, nonbleeding patients showed a decreasing kinetics in these markers. Also, D-dimer and tPA followed an increasing kinetics in bleeding patients compared to nonbleeding patients (median values for D-dimer dynamics: 1,080 vs. -440 ng/ml, P = 0.05; tPA dynamics: 0.130 vs. 0.100 nM, P = 0.038), and both markers significantly increased the day before hemorrhage. A tPA concentration above 0.304 nM was associated with bleeding events (odds ratio, 4.92; 95% CI, 1.01 to 24.08; P = 0.049).

CONCLUSIONS

Contact activation induces fibrinolysis in ECMO patients, especially in patients experiencing bleeding. This finding supports the role of this mechanism as a possible causal factor for hemorrhages during ECMO and open new avenues for novel therapeutic perspectives.

EDITOR’S PERSPECTIVE

Comparison of venovenous extracorporeal membrane oxygenation, prone position and supine mechanical ventilation for severely hypoxemic acute respiratory distress syndrome: a network meta-analysis

PURPOSE

Severe acute respiratory distress syndrome (ARDS) with PaO2/FiO2 < 80 mmHg is a life-threatening condition. The optimal management strategy is unclear. The aim of this meta-analysis was to compare the effects of low tidal volumes (Vt), moderate Vt, prone ventilation, and venovenous extracorporeal membrane oxygenation (VV-ECMO) on mortality in severe ARDS.

METHODS

We performed a frequentist network meta-analysis of randomised controlled trials (RCTs) with participants who had severe ARDS and met eligibility criteria for VV-ECMO or had PaO2/FiO2 < 80 mmHg. We applied the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) methodology to discern the relative effect of interventions on mortality and the certainty of the evidence.

RESULTS

Ten RCTs including 812 participants with severe ARDS were eligible. VV-ECMO reduces mortality compared to low Vt (risk ratio [RR] 0.77, 95% confidence interval [CI] 0.59-0.99, moderate certainty) and compared to moderate Vt (RR 0.75, 95% CI 0.57-0.98, low certainty). Prone ventilation reduces mortality compared to moderate Vt (RR 0.78, 95% CI 0.66-0.93, high certainty) and compared to low Vt (RR 0.81, 95% CI 0.63-1.02, moderate certainty). We found no difference in the network comparison of VV-ECMO compared to prone ventilation (RR 0.95, 95% CI 0.72-1.26), but inferences were based solely on indirect comparisons with very low certainty due to very wide confidence intervals.

CONCLUSIONS

In adults with ARDS and severe hypoxia, both VV-ECMO (low to moderate certainty evidence) and prone ventilation (moderate to high certainty evidence) improve mortality relative to low and moderate Vt strategies. The impact of VV-ECMO versus prone ventilation remains uncertain.

Mesenchymal stem cells-based therapies for severe ARDS with ECMO: a review

Acute respiratory distress syndrome (ARDS) is the primary cause of respiratory failure in critically ill patients. Despite remarkable therapeutic advances in recent years, ARDS remains a life-threatening clinical complication with high morbidity and mortality, especially during the global spread of the coronavirus disease 2019 (COVID-19) pandemic. Previous studies have demonstrated that mesenchymal stem cell (MSC)-based therapy is a potential alternative strategy for the treatment of refractory respiratory diseases including ARDS, while extracorporeal membrane oxygenation (ECMO) as the last resort treatment to sustain life can help improve the survival of ARDS patients. In recent years, several studies have explored the effects of ECMO combined with MSC-based therapies in the treatment of ARDS, and some of them have demonstrated that this combination can provide better therapeutic effects, while others have argued that some critical issues need to be solved before it can be applied to clinical practice. This review presents an overview of the current status, clinical challenges and future prospects of ECMO combined with MSCs in the treatment of ARDS.

Validation of extracorporeal membrane oxygenation mortality prediction and severity of illness scores in an international COVID-19 cohort

BACKGROUND

Veno-venous extracorporeal membrane oxygenation (V-V ECMO) is a lifesaving support modality for severe respiratory failure, but its resource-intensive nature led to significant controversy surrounding its use during the COVID-19 pandemic. We report the performance of several ECMO mortality prediction and severity of illness scores at discriminating survival in a large COVID-19 V-V ECMO cohort.

METHODS

We validated ECMOnet, PRESET (PREdiction of Survival on ECMO Therapy-Score), Roch, SOFA (Sequential Organ Failure Assessment), APACHE II (acute physiology and chronic health evaluation), 4C (Coronavirus Clinical Characterisation Consortium), and CURB-65 (Confusion, Urea nitrogen, Respiratory Rate, Blood Pressure, age >65 years) scores on the ISARIC (International Severe Acute Respiratory and emerging Infection Consortium) database. We report discrimination via Area Under the Receiver Operative Curve (AUROC) and Area under the Precision Recall Curve (AURPC) and calibration via Brier score.

RESULTS

We included 1147 patients and scores were calculated on patients with sufficient variables. ECMO mortality scores had AUROC (0.58-0.62), AUPRC (0.62-0.74), and Brier score (0.286-0.303). Roch score had the highest accuracy (AUROC 0.62), precision (AUPRC 0.74) yet worst calibration (Brier score of 0.3) despite being calculated on the fewest patients (144). Severity of illness scores had AUROC (0.52-0.57), AURPC (0.59-0.64), and Brier Score (0.265-0.471). APACHE II had the highest accuracy (AUROC 0.58), precision (AUPRC 0.64), and best calibration (Brier score 0.26).

CONCLUSION

Within a large international multicenter COVID-19 cohort, the evaluated ECMO mortality prediction and severity of illness scores demonstrated inconsistent discrimination and calibration highlighting the need for better clinically applicable decision support tools.

Venovenous extracorporeal membrane oxygenation for coronavirus disease 2019 patients: A systematic review and meta-analysis

OBJECTIVE

Although the application of venovenous extracorporeal membrane oxygenation (VV-ECMO) in coronavirus disease 2019 (COVID-19) patients with acute respiratory distress syndrome (ARDS) is accumulating, the feasibility and safety of this therapy remain controversial. We aimed to evaluate the effect of VV-ECMO in the treatment of these patients.

METHODS

A comprehensive literature search was performed using PubMed, Embase, the Cochrane Library, and International Clinical Trials Registry Platform databases through November 2021. According to the inclusion and exclusion criteria, the included studies were screened, and meta-analysis was performed by R software (version 4.0.2).

RESULTS

Forty-two studies including 2037 COVID-19 patients supported with VV-ECMO due to ARDS were identified. The pooled analysis revealed that 30-, 60-, and 90-day mortality among patients were respectively 46% (95% CI 37%-57%, I2 = 66%), 46% (95% CI 30%-70%, I2 = 93%), and 49% (95% CI 43%-58%, I2 = 52%), and the pooled incidence rate of in-hospital mortality, major bleeding, hemorrhagic stroke, thrombosis, pulmonary embolism, deep venous thrombosis, and renal replacement therapy were respectively 35%, 39%, 11%, 40%, 15%, 21%, and 44%.

CONCLUSION

Although COVID-19 patients may have a higher risk of bleeding, hemorrhagic stroke, and acute kidney injury during ECMO therapy, the survival rate was more than half of the cases. Our data may support the application of VV-ECMO in COVID-19 patients.

Validation of extracorporeal membrane oxygenation mortality prediction and severity of illness scores in an international COVID‐19 cohort

Background

Veno‐venous extracorporeal membrane oxygenation (V‐V ECMO) is a lifesaving support modality for severe respiratory failure, but its resource‐intensive nature led to significant controversy surrounding its use during the COVID‐19 pandemic. We report the performance of several ECMO mortality prediction and severity of illness scores at discriminating survival in a large COVID‐19 V‐V ECMO cohort.

Methods

We validated ECMOnet, PRESET (PREdiction of Survival on ECMO Therapy‐Score), Roch, SOFA (Sequential Organ Failure Assessment), APACHE II (acute physiology and chronic health evaluation), 4C (Coronavirus Clinical Characterisation Consortium), and CURB‐65 (Confusion, Urea nitrogen, Respiratory Rate, Blood Pressure, age >65 years) scores on the ISARIC (International Severe Acute Respiratory and emerging Infection Consortium) database. We report discrimination via Area Under the Receiver Operative Curve (AUROC) and Area under the Precision Recall Curve (AURPC) and calibration via Brier score.

Results

We included 1147 patients and scores were calculated on patients with sufficient variables. ECMO mortality scores had AUROC (0.58–0.62), AUPRC (0.62–0.74), and Brier score (0.286–0.303). Roch score had the highest accuracy (AUROC 0.62), precision (AUPRC 0.74) yet worst calibration (Brier score of 0.3) despite being calculated on the fewest patients (144). Severity of illness scores had AUROC (0.52–0.57), AURPC (0.59–0.64), and Brier Score (0.265–0.471). APACHE II had the highest accuracy (AUROC 0.58), precision (AUPRC 0.64), and best calibration (Brier score 0.26).

Conclusion

Within a large international multicenter COVID‐19 cohort, the evaluated ECMO mortality prediction and severity of illness scores demonstrated inconsistent discrimination and calibration highlighting the need for better clinically applicable decision support tools.

Multi-horizon predictive models for guiding extracorporeal resource allocation in critically ill COVID-19 patients

OBJECTIVE

Extracorporeal membrane oxygenation (ECMO) resource allocation tools are currently lacking. We developed machine learning (ML) models for predicting COVID-19 patients at risk of receiving ECMO to guide patient triage and resource allocation.

MATERIAL AND METHODS

We included COVID-19 patients admitted to intensive care units for >24 h from March 2020 to October 2021, divided into training and testing development and testing-only holdout cohorts. We developed ECMO deployment timely prediction model ForecastECMO using Gradient Boosting Tree (GBT), with pre-ECMO prediction horizons from 0 to 48 h, compared to PaO2/FiO2 ratio, Sequential Organ Failure Assessment score, PREdiction of Survival on ECMO Therapy score, logistic regression, and 30 pre-selected clinical variables GBT Clinical GBT models, with area under the receiver operator curve (AUROC) and precision recall curve (AUPRC) metrics.

RESULTS

ECMO prevalence was 2.89% and 1.73% in development and holdout cohorts. ForecastECMO had the best performance in both cohorts. At the 18-h prediction horizon, a potentially clinically actionable pre-ECMO window, ForecastECMO, had the highest AUROC (0.94 and 0.95) and AUPRC (0.54 and 0.37) in development and holdout cohorts in identifying ECMO patients without data 18 h prior to ECMO.

DISCUSSION AND CONCLUSIONS

We developed a multi-horizon model, ForecastECMO, with high performance in identifying patients receiving ECMO at various prediction horizons. This model has potential to be used as early alert tool to guide ECMO resource allocation for COVID-19 patients. Future prospective multicenter validation would provide evidence for generalizability and real-world application of such models to improve patient outcomes.

The effect of therapeutic plasma exchange therapy on veno-venous ECMO weaning success in severe COVID-19 ARDS patients

INTRODUCTION

Primarily, this study aimed to investigate the effect of TPE (therapeutic plasma exchange) treatment on successful ECMO weaning in severe COVID-19 ARDS patients treated with V-V ECMO.

METHODS

The study was applied retrospectively on patients over the age of 18 who were hospitalized in the ICU between January 1, 2020 and March 1, 2022.

RESULTS

The study was performed on 33 patients, 36.3% (n: 12) of whom received TPE treatment. The rate of successful ECMO weaning was statistically higher in the TPE treatment group (without TPE: 14.3% [n: 3], with TPE: 50% [n: 6], p = 0.044). The 1-month mortality was also statistically lower in the TPE treatment group (p = 0.044). In the logistic analysis, It was found that the risk of unsuccessful ECMO weaning increased 6 times in those who did not receive TPE treatment (OR; 6.0, 95% CI; 1.134-31.735, p = 0.035).

CONCLUSION

TPE treatment may increase the success rate of V-V ECMO weaning in severe COVID-19 ARDS patients treated with V-V ECMO.

Extracorporeal Membrane Oxygenation for COVID-19: Comparison of Outcomes to Non-COVID-19-Related Viral Acute Respiratory Distress Syndrome From the Extracorporeal Life Support Organization Registry

To compare complications and mortality between patients that required extracorporeal membrane oxygenation (ECMO) support for acute respiratory distress syndrome (ARDS) due to COVID-19 and non-COVID-19 viral pathogens.

DESIGN

Retrospective observational cohort study.

SETTING

Adult patients in the Extracorporeal Life Support Organization registry.

PATIENTS

Nine-thousand two-hundred ninety-one patients that required ECMO for viral mediated ARDS between January 2017 and December 2021.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The primary outcomes of interest were mortality during ECMO support and prior to hospital discharge. Time-to-event analysis and logistic regression were used to compare outcomes between the groups. Among 9,291 included patients, 1,155 required ECMO for non-COVID-19 viral ARDS and 8,136 required ECMO for ARDS due to COVID-19. Patients with COVID-19 had longer duration of ECMO (19.6 d [interquartile range (IQR), 10.1-34.0 d] vs 10.7 d [IQR, 6.3-19.7 d]; p < 0.001), higher mortality during ECMO support (44.4% vs 27.5%; p < 0.001), and higher in-hospital mortality (50.2% vs 34.5%; p < 0.001). Further, patients with COVID-19 were more likely to experience mechanical and clinical complications (membrane lung failure, pneumothorax, intracranial hemorrhage, and superimposed infection). After adjusting for pre-ECMO disease severity, patients with COVID-19 were more than two times as likely to die in the hospital compared with patients with non-COVID-19 viral ARDS.

CONCLUSIONS

Patients with COVID-19 that require ECMO have longer duration of ECMO, more complications, and higher in-hospital mortality compared with patients with non-COVID-19-related viral ARDS. Further study in patients with COVID-19 is critical to identify the patient phenotype most likely to benefit from ECMO and to better define the role of ECMO in the management of this disease process.

Impact of Prone Position in COVID-19 Patients on Extracorporeal Membrane Oxygenation

OBJECTIVES

Prone positioning and venovenous extracorporeal membrane oxygenation (ECMO) are both useful interventions in acute respiratory distress syndrome (ARDS). Combining the two therapies is feasible and safe, but the effectiveness is not known. Our objective was to evaluate the potential survival benefit of prone positioning in venovenous ECMO patients cannulated for COVID-19-related ARDS.

DESIGN

Retrospective analysis of a multicenter cohort.

PATIENTS

Patients on venovenous ECMO who tested positive for severe acute respiratory syndrome coronavirus 2 by reverse transcriptase polymerase chain reaction or with a diagnosis on chest CT were eligible.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

All patients on venovenous ECMO for respiratory failure in whom prone position status while on ECMO and in-hospital mortality were known were included. Of 647 patients in 41 centers, 517 were included. Median age was 55 (47-61), 78% were male and 95% were proned before cannulation. After cannulation, 364 patients (70%) were proned and 153 (30%) remained in the supine position for the whole ECMO run. There were 194 (53%) and 92 (60%) deaths in the prone and the supine groups, respectively. Prone position on ECMO was independently associated with lower in-hospital mortality (odds ratio = 0.49 [0.29-0.84]; p = 0.010). In 153 propensity score-matched pairs, mortality rate was 49.7% in the prone position group versus 60.1% in the supine position group (p = 0.085). Considering only patients alive at decannulation, propensity-matched proned patients had a significantly lower mortality rate (22.4% vs 37.8%; p = 0.029) than nonproned patients.

CONCLUSIONS

Prone position may be beneficial in patients supported by venovenous ECMO for COVID-19-related ARDS but more data are needed to draw definitive conclusions.

Impact of Prone Position in COVID-19 Patients on Extracorporeal Membrane Oxygenation

OBJECTIVES

Prone positioning and venovenous extracorporeal membrane oxygenation (ECMO) are both useful interventions in acute respiratory distress syndrome (ARDS). Combining the two therapies is feasible and safe, but the effectiveness is not known. Our objective was to evaluate the potential survival benefit of prone positioning in venovenous ECMO patients cannulated for COVID-19-related ARDS.

DESIGN

Retrospective analysis of a multicenter cohort.

PATIENTS

Patients on venovenous ECMO who tested positive for severe acute respiratory syndrome coronavirus 2 by reverse transcriptase polymerase chain reaction or with a diagnosis on chest CT were eligible.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

All patients on venovenous ECMO for respiratory failure in whom prone position status while on ECMO and in-hospital mortality were known were included. Of 647 patients in 41 centers, 517 were included. Median age was 55 (47-61), 78% were male and 95% were proned before cannulation. After cannulation, 364 patients (70%) were proned and 153 (30%) remained in the supine position for the whole ECMO run. There were 194 (53%) and 92 (60%) deaths in the prone and the supine groups, respectively. Prone position on ECMO was independently associated with lower in-hospital mortality (odds ratio = 0.49 [0.29-0.84]; p = 0.010). In 153 propensity score-matched pairs, mortality rate was 49.7% in the prone position group versus 60.1% in the supine position group (p = 0.085). Considering only patients alive at decannulation, propensity-matched proned patients had a significantly lower mortality rate (22.4% vs 37.8%; p = 0.029) than nonproned patients.

CONCLUSIONS

Prone position may be beneficial in patients supported by venovenous ECMO for COVID-19-related ARDS but more data are needed to draw definitive conclusions.

COVID-19-Associated Lung Fibrosis: Two Pathways and Two Phenotypes, Lung Transplantation, and Antifibrotics

COVID-19 can be associated with lung fibrosis. Although lung fibrosis after COVID-19 is a relatively rare finding, the mere fact that globally a very large number of patients have had COVID-19 leads to a significant burden of disease. However, patients with COVID-19-associated lung fibrosis have different clinical and radiological features. The aim of this review is to define the different phenotypes of COVID-19-associated lung fibrosis, based on the medical literature. We found that two phenotypes have emerged. One phenotype is COVID-19-related acute respiratory distress syndrome (CARDS); the other phenotype is post-COVID-19 pulmonary fibrosis (PCPF). Both phenotypes have different risk factors, clinical, and radiological features, and differ in their pathophysiological mechanisms and prognoses. A long-term follow-up of patients with pulmonary complications after COVID-19 is warranted, even in patients with only discrete fibrosis. Further studies are needed to determine the optimal treatment because currently the literature is scarce, and evidence is only based on small case series or case reports.

Temporary mechanical circulatory support for COVID-19 patients: A systematic review of literature

OBJECTIVE

Myocardial damage occurs in up to 25% of coronavirus disease 2019 (COVID-19) cases. While veno-venous extracorporeal life support (V-V ECLS) is used as respiratory support, mechanical circulatory support (MCS) may be required for severe cardiac dysfunction. This systematic review summarizes the available literature regarding MCS use rates, disease drivers for MCS initiation, and MCS outcomes in COVID-19 patients.

METHODS

PubMed/EMBASE were searched until October 14, 2021. Articles including adults receiving ECLS for COVID-19 were included. The primary outcome was the rate of MCS use. Secondary outcomes included mortality at follow-up, ECLS conversion rate, intubation-to-cannulation time, time on ECLS, cardiac diseases, use of inotropes, and vasopressors.

RESULTS

Twenty-eight observational studies (comprising both ECLS-only populations and ECLS patients as part of larger populations) included 4218 COVID-19 patients (females: 28.8%; median age: 54.3 years, 95%CI: 50.7-57.8) of whom 2774 (65.8%) required ECLS with the majority (92.7%) on V-V ECLS, 4.7% on veno-arterial ECLS and/or Impella, and 2.6% on other ECLS. Acute heart failure, cardiogenic shock, and cardiac arrest were reported in 7.8%, 9.7%, and 6.6% of patients, respectively. Vasopressors were used in 37.2%. Overall, 3.1% of patients required an ECLS change from V-V ECLS to MCS for heart failure, myocarditis, or myocardial infarction. The median ECLS duration was 15.9 days (95%CI: 13.9-16.3), with an overall survival of 54.6% and 28.1% in V-V ECLS and MCS patients. One study reported 61.1% survival with oxy-right ventricular assist device.

CONCLUSION

MCS use for cardiocirculatory compromise has been reported in 7.3% of COVID-19 patients requiring ECLS, which is a lower percentage compared to the incidence of any severe cardiocirculatory complication. Based on the poor survival rates, further investigations are warranted to establish the most appropriated indications and timing for MCS in COVID-19.

Evolving outcomes of extracorporeal membrane oxygenation during the first 2 years of the COVID-19 pandemic: a systematic review and meta-analysis

Background

Extracorporeal membrane oxygenation (ECMO) has been used extensively for coronavirus disease 2019 (COVID-19)-related acute respiratory distress syndrome (ARDS). Reports early in the pandemic suggested that mortality in patients with COVID-19 receiving ECMO was comparable to non-COVID-19-related ARDS. However, subsequent reports suggested that mortality appeared to be increasing over time. Therefore, we conducted an updated systematic review and meta-analysis, to characterise changes in mortality over time and elucidate risk factors for poor outcomes.

Methods

We conducted a meta-analysis (CRD42021271202), searching MEDLINE, Embase, Cochrane, and Scopus databases, from 1 December 2019 to 26 January 2022, for studies reporting on mortality among adults with COVID-19 receiving ECMO. We also captured hospital and intensive care unit lengths of stay, duration of mechanical ventilation and ECMO, as well as complications of ECMO. We conducted random-effects meta-analyses, assessed risk of bias of included studies using the Joanna Briggs Institute checklist and evaluated certainty of pooled estimates using GRADE methodology.

Results

Of 4522 citations, we included 52 studies comprising 18,211 patients in the meta-analysis. The pooled mortality rate among patients with COVID-19 requiring ECMO was 48.8% (95% confidence interval 44.8–52.9%, high certainty). Mortality was higher among studies which enrolled patients later in the pandemic as opposed to earlier (1st half 2020: 41.2%, 2nd half 2020: 46.4%, 1st half 2021: 62.0%, 2nd half 2021: 46.5%, interaction p value = 0.0014). Predictors of increased mortality included age, the time of final patient enrolment from 1 January 2020, and the proportion of patients receiving corticosteroids, and reduced duration of ECMO run.

Conclusions

The mortality rate for patients receiving ECMO for COVID-19-related ARDS has increased as the pandemic has progressed. The reasons for this are likely multifactorial; however, as outcomes for these patients evolve, the decision to initiate ECMO should include the best contextual estimate of mortality at the time of ECMO initiation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04011-2.

Extracorporeal Membrane Oxygenation in Patients With COVID-19

Coronavirus disease 2019 (COVID-19) is characterized by a clinical spectrum of diseases ranging from asymptomatic or mild cases to severe pneumonia with acute respiratory distress syndrome (ARDS) requiring mechanical ventilation. Extracorporeal membrane oxygenation (ECMO) has been used as rescue therapy in appropriate patients with COVID-19 complicated by ARDS refractory to mechanical ventilation. In this study, we review the indications, challenges, complications, and clinical outcomes of ECMO utilization in critically ill patients with COVID-19-related ARDS. Most of these patients required venovenous ECMO. Although the risk of mortality and complications is very high among patients with COVID-19 requiring ECMO, it is similar to that of non-COVID-19 patients with ARDS requiring ECMO. ECMO is a resource-intensive therapy, with an inherent risk of complications, which makes its availability limited and its use challenging in the midst of a pandemic. Well-maintained data registries, with timely reporting of outcomes and evidence-based clinical guidelines, are necessary for the careful allocation of resources and for the development of standardized utilization protocols.

Extracorporeal Membrane Oxygenation for Respiratory Failure Related to COVID-19: A Nationwide Cohort Study

BACKGROUND

Despite expanding use, knowledge on extracorporeal membrane oxygenation support during the COVID-19 pandemic remains limited. The objective was to report characteristics, management, and outcomes of patients receiving extracorporeal membrane oxygenation with a diagnosis of COVID-19 in France and to identify pre-extracorporeal membrane oxygenation factors associated with in-hospital mortality. A hypothesis of similar mortality rates and risk factors for COVID-19 and non-COVID-19 patients on venovenous extracorporeal membrane oxygenation was made.

METHODS

The Extracorporeal Membrane Oxygenation for Respiratory Failure and/or Heart failure related to Severe Acute Respiratory Syndrome-Coronavirus 2 (ECMOSARS) registry included COVID-19 patients supported by extracorporeal membrane oxygenation in France. This study analyzed patients included in this registry up to October 25, 2020, and supported by venovenous extracorporeal membrane oxygenation for respiratory failure with a minimum follow-up of 28 days after cannulation. The primary outcome was in-hospital mortality. Risk factors for in-hospital mortality were analyzed.

RESULTS

Among 494 extracorporeal membrane oxygenation patients included in the registry, 429 were initially supported by venovenous extracorporeal membrane oxygenation and followed for at least 28 days. The median (interquartile range) age was 54 yr (46 to 60 yr), and 338 of 429 (79%) were men. Management before extracorporeal membrane oxygenation cannulation included prone positioning for 411 of 429 (96%), neuromuscular blockage for 419 of 427 (98%), and NO for 161 of 401 (40%). A total of 192 of 429 (45%) patients were cannulated by a mobile extracorporeal membrane oxygenation unit. In-hospital mortality was 219 of 429 (51%), with a median follow-up of 49 days (33 to 70 days). Among pre-extracorporeal membrane oxygenation modifiable exposure variables, neuromuscular blockage use (hazard ratio, 0.286; 95% CI, 0.101 to 0.81) and duration of ventilation (more than 7 days compared to less than 2 days; hazard ratio, 1.74; 95% CI, 1.07 to 2.83) were independently associated with in-hospital mortality. Both age (per 10-yr increase; hazard ratio, 1.27; 95% CI, 1.07 to 1.50) and total bilirubin at cannulation (6.0 mg/dl or more compared to less than 1.2 mg/dl; hazard ratio, 2.65; 95% CI, 1.09 to 6.5) were confounders significantly associated with in-hospital mortality.

CONCLUSIONS

In-hospital mortality was higher than recently reported, but nearly half of the patients survived. A high proportion of patients were cannulated by a mobile extracorporeal membrane oxygenation unit. Several factors associated with mortality were identified. Venovenous extracorporeal membrane oxygenation support should be considered early within the first week of mechanical ventilation initiation.

EDITOR’S PERSPECTIVE

Trend of extracorporeal membrane oxygenation support in patients with acute respiratory distress syndrome in South Korea

We examined and compared the clinical characteristics of acute respiratory distress syndrome (ARDS) patients who received and did not receive extracorporeal membrane oxygenation (ECMO) support. The national health insurance database of South Korea was used to obtain real-world data. All adult patients admitted to intensive care units for ARDS treatment between 1 January 2014 and 31 December 2019 were included in this study. Of the 10,173 patients with ARDS included in the analysis, 740 (7.3%) received ECMO support for a mean duration of 1.6 days (standard deviation [SD]: 2.8 days) and were assigned to the ECMO group. The ECMO group had a significantly lower mean age at 57.0 years (SD: 15.7 years) than the non-ECMO group (71.8 Â years [SD: 15.1 Â years], P < 0.001). In multivariable logistic regression, a 1-year increase in age was associated with a 5% lower prevalence of ECMO support. The annual case volume was classified into four groups by quartile ratio (Q1 [lowest], Q2, Q3, and Q4 [highest]), and Q2, Q3, and Q4 groups showed a higher prevalence of ECMO support than the Q1 group. ECMO support was also performed more frequently in high case volume centers than in low case volume centers for ARDS patients.

Survival benefit of extracorporeal membrane oxygenation in severe COVID-19: a multi-centre-matched cohort study

Purpose

Extracorporeal membrane oxygenation (ECMO) has become an established therapy for severe respiratory failure in coronavirus disease 2019 (COVID-19). The added benefit of receiving ECMO in COVID-19 remains uncertain. The aim of this study is to analyse the impact of receiving ECMO at specialist centres on hospital mortality.

Methods

A multi-centre retrospective study was conducted in COVID-19 patients from 111 hospitals, referred to two specialist ECMO centres in the United Kingdom (UK) (March 2020 to February 2021). Detailed covariate data were contemporaneously curated from electronic referral systems. We analysed added benefit of ECMO treatment in specialist centres using propensity score matching techniques.

Results

1363 patients, 243 receiving ECMO, were analysed. The best matching technique generated 209 matches, with a marginal odds ratio (OR) for mortality of 0.44 (95% CI 0.29–0.68, p < 0.001) and absolute mortality reduction of 18.2% (44% vs 25.8%, p < 0.001) for treatment with ECMO in a specialist centre.

Conclusion

We found ECMO provided at specialist centres conferred significant survival benefit. Where resources and specialism allow, ECMO should be widely offered.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-022-06645-w.

Therapeutic Effects of Inhaled Nitric Oxide Therapy in COVID-19 Patients

The global COVID-19 pandemic has become the largest public health challenge of recent years. The incidence of COVID-19-related acute hypoxemic respiratory failure (AHRF) occurs in up to 15% of hospitalized patients. Antiviral drugs currently available to clinicians have little to no effect on mortality, length of in-hospital stay, the need for mechanical ventilation, or long-term effects. Inhaled nitric oxide (iNO) administration is a promising new non-standard approach to directly treat viral burden while enhancing oxygenation. Along with its putative antiviral affect in COVID-19 patients, iNO can reduce inflammatory cell-mediated lung injury by inhibiting neutrophil activation, lowering pulmonary vascular resistance and decreasing edema in the alveolar spaces, collectively enhancing ventilation/perfusion matching. This narrative review article presents recent literature on the iNO therapy use for COVID-19 patients. The authors suggest that early administration of the iNO therapy may be a safe and promising approach for the treatment of COVID-19 patients. The authors also discuss unconventional approaches to treatment, continuous versus intermittent high-dose iNO therapy, timing of initiation of therapy (early versus late), and novel delivery systems. Future laboratory and clinical research is required to define the role of iNO as an adjunct therapy against bacterial, viral, and fungal infections.

Mobile Extracorporeal Membrane Oxygenation for Covid-19 Does Not Pose Extra Risk to Transport Team

Previous experience has shown that transporting patients on extracorporeal membrane oxygenation (ECMO) is a safe and effective mode of transferring critically ill patients requiring maximum mechanical ventilator support to a quaternary care center. The coronavirus disease 2019 (COVID-19) pandemic posed new challenges. This is a multicenter, retrospective study of 113 patients with confirmed severe acute respiratory syndrome coronavirus 2, cannulated at an outside hospital and transported on ECMO to an ECMO center. This was performed by a multidisciplinary mobile ECMO team consisting of physicians for cannulation, critical care nurses, and an ECMO specialist or perfusionist, along with a driver or pilot. Teams practised strict airborne contact precautions with eyewear while caring for the patient and were in standard Personal Protective Equipment. The primary mode of transportation was ground. Ten patients were transported by air. The average distance traveled was 40 miles (SD ±56). The average duration of transport was 133 minutes (SD ±92). When stratified by mode of transport, the average distance traveled for ground transports was 36 miles (SD ±52) and duration was 136 minutes (SD ±93). For air, the average distance traveled was 66 miles (SD ±82) and duration was 104 minutes (SD ±70). There were no instances of transport-related adverse events including pump failures, cannulation complications at outside hospital, or accidental decannulations or dislodgements in transit. There were no instances of the transport team members contracting COVID-19 infection within 21 days after transport. By adhering to best practices and ACE precautions, patients with COVID-19 can be safely cannulated at an outside hospital and transported to a quaternary care center without increased risk to the transport team.

Heart failure in COVID-19 patients: Critical care experience

Patients with heart failure (HF) may be at a higher risk of coronavirus disease 2019 (COVID-19) infection and may have a worse outcome due to their comorbid conditions and advanced age. In this narrative review, we aim to study the interaction between COVID-19 and HF from a critical care perspective. We performed a systematic search for studies that reported HF and critical care-related outcomes in COVID-19 patients in the PubMed and Medline databases. From a total of 1050 papers, we identified 26 that satisfied the eligibility criteria for our review. Data such as patient demographics, HF, intensive care unit (ICU) admission, management, and outcome were extracted from these studies and analyzed. We reported outcomes in heart-transplant patients with COVID-19 separately. In hospitalized patients with COVID-19, the prevalence of HF varied between 4% and 21%. The requirement for ICU admission was between 8% and 33%. HF patients with COVID-19 had an overall mortality rate between 20% and 40%. We identified that HF is an independent predictor of mortality in hospitalized COVID-19 patients, and patients with HF were more likely to require ventilation, ICU admission and develop complications. Patients with HF with reduced ejection fraction did worse than those with HF with midrange ejection fraction, and HF with preserved ejection fraction. COVID-19 patients with HF should be identified early and managed aggressively in an attempt to improve outcomes in this cohort of patients.

Effects of Prone Positioning on Respiratory Mechanics and Oxygenation in Critically Ill Patients With COVID-19 Requiring Venovenous Extracorporeal Membrane Oxygenation

Background:

The effect of prone positioning (PP) on respiratory mechanics remains uncertain in patients with severe acute respiratory distress syndrome (ARDS) requiring venovenous extracorporeal membrane oxygenation (VV-ECMO).

Methods:

We prospectively analyzed the effects of PP on respiratory mechanics from continuous data with over a thousand time points during 16-h PP sessions in patients with COVID-19 and ARDS under VV-ECMO conditions. The evolution of respiratory mechanical and oxygenation parameters during the PP sessions was evaluated by dividing each PP session into four time quartiles: first quartile: 0–4 h, second quartile: 4–8 h, third quartile: 8–12 h, and fourth quartile: 12–16 h.

Results:

Overall, 38 PP sessions were performed in 10 patients, with 3 [2–5] PP sessions per patient. Seven (70%) patients were responders to at least one PP session. PP significantly increased the PaO₂/FiO₂ ratio by 14 ± 21% and compliance by 8 ± 15%, and significantly decreased the oxygenation index by 13 ± 18% and driving pressure by 8 ± 12%. The effects of PP on respiratory mechanics but not on oxygenation persisted after supine repositioning. PP-induced changes in different respiratory mechanical parameters and oxygenation started as early as the first-time quartile, without any difference in PP-induced changes among the different time quartiles. PP-induced changes in driving pressure (−14 ± 14 vs. −6 ± 10%, p = 0.04) and mechanical power (−11 ± 13 vs. −0.1 ± 12%, p = 0.02) were significantly higher in responders (increase in PaO₂/FiO₂ ratio > 20%) than in non-responder patients.

Conclusions:

In patients with COVID-19 and severe ARDS, PP under VV-ECMO conditions improved the respiratory mechanical and oxygenation parameters, and the effects of PP on respiratory mechanics persisted after supine repositioning.

Long Runs and Higher Incidence of Bleeding Complications in COVID-19 Patients Requiring Venovenous Extracorporeal Membrane Oxygenation: A Case Series from the United Arab Emirates

Although the pathophysiology of pulmonary disease caused by coronavirus disease-2019 (COVID-19) is not yet fully understood, successful extracorporeal membrane oxygenation (ECMO) use has been reported for COVID-19-related severe acute respiratory distress syndrome (ARDS). We report a case series of 12 patients who received long venovenous ECMO (VV ECMO) runs for refractory hypoxia (median PF ratio of 71.8, interquartile range (IQR) 53.5–78.5) from COVID-19-related ARDS. A majority (75%) of the patients were males with a median age of 44 (IQR 37–53.5). Overall, six (50%) patients survived to hospital discharge with five of them (83.3%) noted to be cerebral performance category 1 or 2 at the time of discharge. Survivors consistently showed an improvement in sequential organ failure assessment scores within 72 hours of ECMO initiation. The median ECMO duration was 28 days (IQR 13.5–50). Despite using standard anticoagulation strategy, six (50%) of our patients had one or more major bleeding episodes, which proved to be directly fatal in four (25%) patients. Although the overall outcomes of our cohort were acceptable, our patients had much longer ECMO runs (mean 38 days in survivors) and with much higher, often fatal bleeding complications. We compare our data with other published COVID-19 VV ECMO series.

Longer Prehospitalization and Preintubation Periods in Intubated Non-survivors and ECMO Patients With COVID-19: A Systematic Review and Meta-Analysis

Purpose: There is no clear consensus on the clinical course of critical COVID-19 patients. We examined the clinical course among intubated survivors, non-survivors, and extracorporeal membrane oxygenation (ECMO) patients to reveal the standard clinical course and the difference among critical COVID-19 patients.

Methods: In this systematic review and meta-analysis, we searched PubMed, Web of Science, and Scopus for original studies published until December 11, 2020, including case accumulation and clinical course reporting. Pregnant patients and children were excluded. We followed PRISMA guidelines and registered them with PROSPERO (CRD42021235534).

Results: Of the 11,716 studies identified, 94 met the selection criteria, and 2,549 cases were included in this meta-analysis. The times from intubation to extubation and death were 12.07 days (95% confidence interval 9.80–14.33 days) and 10.14 days (8.18–12.10 days), respectively, and the ECMO duration was 14.72 days (10.57–18.87 days). The time from symptom onset to hospitalization (prehospitalization period) of intubated survivors, non-survivors, and ECMO patients was 6.15 (4.61–7.69 days), 6.45 (4.55–8.34 days), and 7.15 days (6.48–7.81 days), and that from symptom onset to intubation (preintubation period) was 8.58 (7.36–9.80 days), 9.14 (7.26–11.01 days), and 10.54 days (9.18–11.90 days), respectively. Sensitivity analysis showed that the time from intubation to extubation and death was longer in the US and Europe than in East Asia.

Conclusion: For COVID-19, we hypothesize that prehospitalization and preintubation periods are longer in intubated non-survivors and ECMO patients than in intubated survivors. These periods may serve as a predictor of disease severity or death and support therapeutic strategy determination.

Comparative Effectiveness of Protective Ventilation Strategies for Moderate and Severe Acute Respiratory Distress Syndrome. A Network Meta-Analysis

Rationale: Choosing the best ventilation strategy for acute respiratory distress syndrome (ARDS) is complex, yet it is highly relevant to clinicians during a respiratory pandemic. Objectives: To compare the effects of low Vt, high Vt, high positive end-expiratory pressure (PEEP), prone ventilation, high-frequency oscillation, and venovenous extracorporeal membrane oxygenation (VV ECMO) on mortality in ARDS. Methods: We performed a network meta-analysis of randomized trials. We applied the Grading of Recommendations Assessment, Development and Evaluation methodology to discern the relative effect of interventions on mortality. Measurements and Main Results: We analyzed 34 trials including 9,085 adults with primarily moderate-to-severe ARDS (median baseline Pa_O2/Fi_O2, 118; interquartile range, 110-143). Prone positioning combined with low Vt was the best strategy (risk ratio [RR], 0.74 [95% confidence interval (CI), 0.60-0.92] vs. low Vt; high certainty). VV ECMO was also rated among the best (RR, 0.78 [95% CI, 0.58-1.05] vs. low Vt; RR, 0.66; [95% CI, 0.49-0.88] vs. high Vt) but was rated with lower certainty because VV ECMO was restricted to very severe ARDS (mean baseline Pa_O2/Fi_O2<75). High PEEP combined with low Vt was rated intermediately (RR, 0.91 [95% CI, 0.81-1.03] vs. low Vt; low certainty; RR, 0.77 [95% CI, 0.65-0.91] vs. high Vt; moderate certainty). High Vt was rated worst (RR, 1.19 [95% CI, 1.02-1.37] vs. low Vt; moderate certainty), and we found no support for high-frequency oscillation or high Vt with prone ventilation. Conclusions: These findings suggest that combining low Vt with prone ventilation is associated with the greatest reduction in mortality for critically ill adults with moderate-to-severe ARDS.

Impact of COVID-19 and lockdown regarding blood transfusion

BACKGROUND

The outbreak of a SARS-CoV-2 resulted in a massive afflux of patients in hospital and intensive care units with many challenges. Blood transfusion was one of them regarding both blood banks (safety, collection, and stocks) and consumption (usual care and unknown specific demand of COVID-19 patients). The risk of mismatch was sufficient to plan blood transfusion restrictions if stocks became limited.

STUDY DESIGN AND METHODS

Analyses of blood transfusion in a tertiary hospital and blood collection in the referring blood bank between February 24 and May 31, 2020.

RESULTS

Withdrawal of elective surgery and non-urgent care and admission of 2291 COVID-19 patients reduced global activity by 33% but transfusion by 17% only. Only 237 (10.3) % of COVID-19 patients required blood transfusion, including 45 (2.0%) with acute bleeding. Lockdown and cancellation of mobile collection resulted in an 11% reduction in blood donation compared to 2019. The ratio of reduction in blood transfusion to blood donation remained positive and stocks were slightly enhanced.

DISCUSSION

Reduction of admissions due to SARS-CoV-2 pandemic results only in a moderate decrease of blood transfusion. Incompressible blood transfusions concern urgent surgery, acute bleeding (including some patients with COVID-19, especially under high anticoagulation), or are supportive for chemotherapy-induced aplasia or chronic anemia. Lockdown results in a decrease of blood donation by cancellation of mobile donation but with little impact on a short period by mobilization of usual donors. No mismatch between demand and donation was evidenced and no planned restriction to blood transfusion was necessary.

A rational approach on the use of extracorporeal membrane oxygenation in severe hypoxemia: advanced technology is not a panacea

Veno-venous extracorporeal membrane oxygenation (ECMO) is a helpful intervention in patients with severe refractory hypoxemia either because mechanical ventilation cannot ensure adequate oxygenation or because lung protective ventilation is not feasible. Since ECMO is a highly invasive procedure with several, potentially devastating complications and its implementation is complex and expensive, simpler and less invasive therapeutic options should be first exploited. Low tidal volume and driving pressure ventilation, prone position, neuromuscular blocking agents and individualized ventilation based on transpulmonary pressure measurements have been demonstrated to successfully treat the vast majority of mechanically ventilated patients with severe hypoxemia. Veno-venous ECMO has a place in the small portion of severely hypoxemic patients in whom these strategies fail. A combined analysis of recent ARDS trials revealed that ECMO was used in only 2.15% of patients (n = 145/6736). Nevertheless, ECMO use has sharply increased in the last decade, raising questions regarding its thoughtful use. Such a policy could be harmful both for patients as well as for the ECMO technique itself. This narrative review attempts to describe together the practical approaches that can be offered to the sickest patients before going to ECMO, as well as the rationale and the limitations of ECMO. The benefit and the drawbacks associated with ECMO use along with a direct comparison with less invasive therapeutic strategies will be analyzed.

Extracorporeal membrane oxygenation for COVID-19: a systematic review and meta-analysis

BACKGROUND

There are several reports of extracorporeal membrane oxygenation (ECMO) use in patients with coronavirus disease 2019 (COVID-19) who develop severe acute respiratory distress syndrome (ARDS). We conducted a systematic review and meta-analysis to guide clinical decision-making and future research.

METHODS

We searched MEDLINE, Embase, Cochrane and Scopus databases from 1 December 2019 to 10 January 2021 for observational studies or randomised clinical trials examining ECMO in adults with COVID-19 ARDS. We performed random-effects meta-analyses and meta-regression, assessed risk of bias using the Joanna Briggs Institute checklist and rated the certainty of evidence using the GRADE approach. Survival outcomes were presented as pooled proportions while continuous outcomes were presented as pooled means, both with corresponding 95% confidence intervals [CIs]. The primary outcome was in-hospital mortality. Secondary outcomes were duration of ECMO therapy and mechanical ventilation, weaning rate from ECMO and complications during ECMO.

RESULTS

We included twenty-two observational studies with 1896 patients in the meta-analysis. Venovenous ECMO was the predominant mode used (98.6%). The pooled in-hospital mortality in COVID-19 patients (22 studies, 1896 patients) supported with ECMO was 37.1% (95% CI 32.3-42.0%, high certainty). Pooled mortality in the venovenous ECMO group was 35.7% (95% CI 30.7-40.7%, high certainty). Meta-regression found that age and ECMO duration were associated with increased mortality. Duration of ECMO support (18 studies, 1844 patients) was 15.1 days (95% CI 13.4-18.7). Weaning from ECMO (17 studies, 1412 patients) was accomplished in 67.6% (95% CI 50.5-82.7%) of patients. There were a total of 1583 ECMO complications reported (18 studies, 1721 patients) and renal complications were the most common.

CONCLUSION

The majority of patients received venovenous ECMO support for COVID-19-related ARDS. In-hospital mortality in patients receiving ECMO support for COVID-19 was 37.1% during the first year of the pandemic, similar to those with non-COVID-19-related ARDS. Increasing age was a risk factor for death. Venovenous ECMO appears to be an effective intervention in selected patients with COVID-19-related ARDS. PROSPERO CRD42020192627.

Outcome of acute respiratory distress syndrome requiring extracorporeal membrane oxygenation in Covid-19 or influenza: A single-center registry study

Veno-venous extracorporeal membrane oxygenation (V-V ECMO) is used to sustain blood oxygenation and decarboxylation in severe acute respiratory distress syndrome (ARDS). It is under debate if V-V ECMO is as appropriate for coronavirus disease 2019 (Covid-19) ARDS as it is for influenza. In this retrospective study, we analyzed all patients with confirmed SARS-CoV-2 or influenza A/B infection, ARDS and V-V ECMO, treated at our medical intensive care unit (ICU) between October 2010 and June 2020. Baseline and procedural characteristics as well as survival 30 days after ECMO cannulation were analyzed. A total of 62 V-V ECMO patients were included (15 with Covid-19 and 47 with influenza). Both groups had similar baseline characteristics at cannulation. Thirty days after ECMO cannulation, 13.3% of all patients with Covid-19 were discharged alive from our ICU compared to 44.7% with influenza (P = .03). Patients with Covid-19 had fewer ECMO-free days (0 (0-9.7) days vs. 13.2 (0-22.1) days; P = .05). Cumulative incidences of 30-day-survival showed no significant differences (48.6% in Covid-19 patients, 63.7% in influenza patients; P = .23). ICU treatment duration was significantly longer in ARDS patients with V-V ECMO for Covid-19 compared to influenza. Thirty-day mortality was higher in Covid-19, but not significant.

Experience of International Air Transportation and Subsequent Lung Transplant in a Patient with COVID-19-associated Acute Respiratory Distress Syndrome: a Case Report

We report an inspiring case of a 55-year-old Korean female diagnosed with coronavirus disease 2019 (COVID-19)-associated acute respiratory distress syndrome (ARDS) in Mexico. The patient was assessed for lung transplant as a salvage therapy for treatment-refractory ARDS following no signs of clinical improvement for > 7 weeks, despite best treatment. The patient was transported from Mexico to Korea by air ambulance under venovenous extracorporeal membrane oxygenation (ECMO) support. She was successfully bridged to lung transplant on day 88, 49 days after the initiation of ECMO support. ECMO was successfully weaned at the end of operation, and no bleeding or primary graft dysfunction was observed within the first 72 hours. The patient was liberated from mechanical ventilation on postoperative day 9 and transferred to the general ward 5 days later. Despite the high doses of immunosuppressants, there was no evidence of viral reactivation after transplant. At 3 months post-transplantation, she was discharged to home without complication. Our experience suggests that successful lung transplant for COVID-19-associated ARDS is feasible even in a patient with prolonged pre-transplant ECMO support. Lung transplant may be considered a salvage therapy for COVID-19-associated ARDS that does not respond to conventional treatments.

Guideline-directed management of COVID-19: Do's and Don'ts

The coronavirus disease 2019 (COVID-19) pandemic continues to dominate our daily lives. The “second wave” has slowed down in most regions around the globe, just to give way to the third wave of infections. Hospitalisations and death are again on the rise despite public health measures and vaccination programmes. Unfortunately, we have to expect that COVID-19 will persist as a major challenge for the delivery of medical care for a long while to go. Despite all efforts, a significant number of patients, in particular the elderly and those with risk factors, will get ill from this disease and some will eventually require hospitalisation.

This editorial summarises the highlights of the European Respiratory Society COVID-19 treatment guidelinehttps://bit.ly/3tClBRe

Changes of clinical characteristics of asymptomatic patients with positive SARS-Cov-2 nucleic acid test during treatment cycle and related risk factors

OBJECTIVE

This study was designed to explore the clinical characteristics, outcomes, and related influencing factors for asymptomatic patients with positive Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-Cov-2) nucleic acid test.

METHODS

Clinical data of 1568 patients with positive SARS-Cov-2 nucleic acid test (SNAT) were collected retrospectively. The patients were assigned to an asymptomatic group and a symptomatic group according to the existence of clinical symptoms when they got positive result in nucleic acid test, and the clinical data of the two groups were analyzed and compared. In addition, the data of asymptomatic patients who showed clinical symptoms later and the results of two-week follow-up after cure were analyzed.

RESULTS

Among all enrolled patients, there were 1489 patients with positive symptoms and 79 asymptomatic patients, including 34 patients who developed symptoms during treatment. Logistic analysis revealed that age ≤45 years (OR=2.722, P<0.001), history of diabetes mellitus (OR=0.446, P=0.007), and history of cancer (OR=0.259, P=0.008) were independent factors for asymptomatic presentation in patients with positive SNAT, and age ≥46 years (OR=1.562, P=0.012) and history of hypertension (OR=2.077, P<0.001) were risk factors for the occurrence of clinical symptoms in asymptomatic patients with positive SNAT during hospitalization. During the follow-up after cure, 8 patients got reoccurring positive SNAT result.

CONCLUSION

Asymptomatic patients with positive SNAT are mostly young and middle-aged people, and old age and hypertension are risk factors for the occurrence of positive clinical characteristics in asymptomatic patients.

Quality of life following adult veno-venous extracorporeal membrane oxygenation for acute respiratory distress syndrome: a systematic review

BACKGROUND

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) has been used successfully for the past decade in adult patients with acute respiratory distress syndrome (ARDS) refractory to conventional ventilatory support. However, knowledge of the health-related quality of life (HRQoL) in VV-ECMO patients is still limited. Thus, this study aimed to provide a comprehensive overview of the HRQoL following VV-ECMO support in ARDS patients.

METHODS

A systematic search was performed on PubMed and Web of Science databases from January 1st, 2009 to October 19th, 2020. Studies reporting on HRQoL following VV-ECMO for ARDS in adults were included. Two authors independently selected studies, extracted data, and assessed methodological quality.

RESULTS

Eight studies were eligible for inclusion, consisting of seven observational studies and one randomized controlled trial (total N = 441). All eight studies had a quantitative design and reported 265 VV-ECMO survivors to have a reduced HRQoL compared to a generally healthy population. Follow-up time varied between six months to three years. Additionally, only four studies (total N = 335) compared the HRQoL of VV-ECMO (N = 159) to conventionally treated survivors (N = 176), with one study showing a significantly better HRQoL in VV-ECMO survivors, while three studies were stating comparable HRQoL across groups. Notably, most survivors in these studies appeared to experience varying degrees of anxiety, depression, and post-traumatic stress disorder (PTSD).

CONCLUSIONS

ARDS survivors supported by VV-ECMO have a decline in HRQoL and suffered from physical and psychological impairments. This HRQoL reduction is comparable or even better to the HRQoL in conventionally treated ARDS survivors.

Hypercoagulopathy, acquired coagulation disorders and anticoagulation before, during and after extracorporeal membrane oxygenation in COVID-19: a case series

BACKGROUND

Thromboembolism and bleeding contribute to Coronavirus disease 2019 (COVID-19)'s morbidity and mortality and are also frequent complications of venovenous extracorporeal membrane oxygenation (vvECMO). As the interaction of the underlying pathologies caused by vvECMO in COVID-19 is barely understood, we designed this study to better differentiate coagulation disorders in COVID-19 patients before, during and after vvECMO-support.

METHODS

Observational case series, six consecutive patients with Coronavirus acute respiratory distress syndrome supported with vvECMO treated in the anaesthesiologic ICU in a third level University ECMO-centre. We measured routine coagulation parameters and assessed coagulation factors. We also conducted advanced von Willebrand factor (VWF) multimer analysis, platelet aggregometry and immunological screening.

RESULTS

We identified various phases of coagulation disorders: Initially, intensely activated coagulation with highly increased VWF and factor VIII activity in acute COVID-19, then severe acquired von Willebrand syndrome and platelet dysfunction during vvECMO leading to spontaneous bleeding and finally, hypercoagulopathy after vvECMO explantation. Five of six patients developed immunological abnormalities enhancing coagulation.

CONCLUSIONS

Coronavirus-induced coagulopathy and bleeding disorders during vvECMO cannot be discriminated via 'routine' coagulation tests. Precise and specific analyses followed by the appropriate treatment of coagulation disorders may help us develop tailored therapeutic concepts to better manage the phases described above.

A Clinic Blueprint for Post-Coronavirus Disease 2019 RECOVERY: Learning From the Past, Looking to the Future

The severe acute respiratory syndrome coronavirus 2 pandemic poses extraordinary challenges. The tremendous number of coronavirus disease 2019 (COVID-19) cases in the United States has resulted in a large population of survivors with prolonged postinfection symptoms. The creation of multidisciplinary post-COVID-19 clinics to address both persistent symptoms and potential long-term complications requires an understanding of the acute disease and the emerging data regarding COVID-19 outcomes. Experience with severe acute respiratory syndrome and Middle East respiratory syndrome, post-acute respiratory distress syndrome complications, and post-intensive care syndrome also informs anticipated sequelae and clinical program design. Post-COVID-19 clinical programs should be prepared to care for individuals previously hospitalized with COVID-19 (including those who required critical care support), nonhospitalized individuals with persistent respiratory symptoms following COVID-19, and individuals with preexisting lung disease complicated by COVID-19. Effective multidisciplinary collaboration models leverage lessons learned during the early phases of the pandemic to overcome the unique logistical challenges posed by pandemic circumstances. Collaboration between physicians and researchers across disciplines will provide insight into survivorship that may shape the treatment of both acute disease and chronic complications. In this review, we discuss the aims, general principles, elements of design, and challenges of a successful multidisciplinary model to address the needs of COVID-19 survivors.

ECMO in COVID-19-prolonged therapy needed? A retrospective analysis of outcome and prognostic factors

BACKGROUND

The role of venovenous extracorporeal membrane oxygenation (VV ECMO) in patients with COVID-19-induced acute respiratory distress syndrome (ARDS) still remains unclear. Our aim was to investigate the clinical course and outcome of those patients and to identify factors associated with the need for prolonged ECMO therapy.

METHODS

A retrospective single-center study on patients with VV ECMO for COVID-19-associated ARDS was performed. Baseline characteristics, ventilatory and ECMO parameters, and laboratory and virological results were evaluated over time. Six months follow-up was assessed.

RESULTS

Eleven of 16 patients (68.8%) survived to 6 months follow-up with four patients requiring short-term (<28 days) and seven requiring prolonged (⩾28 days) ECMO support. Lung compliance before ECMO was higher in the prolonged than in the short-term group (28.1 (28.8-32.1) ml/cmH₂O vs 18.7 (17.7-25.0) ml/cmH₂O, p = 0.030). Mechanical ventilation before ECMO was longer (19 (16-23) days vs 5 (5-9) days, p = 0.002) and SOFA score was higher (12.0 (10.5-17.0) vs 10.0 (9.0-10.0), p = 0.002) in non-survivors compared to survivors. Low viral load during the first days on ECMO tended to indicate worse outcomes. Seroconversion against SARS-CoV-2 occurred in all patients, but did not affect outcome.

CONCLUSIONS

VV ECMO support for COVID-19-induced ARDS is justified if initiated early and at an experienced ECMO center. Prolonged ECMO therapy might be required in those patients. Although no relevant predictive factors for the duration of ECMO support were found, the decision to stop therapy should not be made dependent of the length of ECMO treatment.

ECMO in COVID-19-prolonged therapy needed? A retrospective analysis of outcome and prognostic factors

Background:

The role of venovenous extracorporeal membrane oxygenation (VV ECMO) in patients with COVID-19-induced acute respiratory distress syndrome (ARDS) still remains unclear. Our aim was to investigate the clinical course and outcome of those patients and to identify factors associated with the need for prolonged ECMO therapy.

Methods:

A retrospective single-center study on patients with VV ECMO for COVID-19-associated ARDS was performed. Baseline characteristics, ventilatory and ECMO parameters, and laboratory and virological results were evaluated over time. Six months follow-up was assessed.

Results:

Eleven of 16 patients (68.8%) survived to 6 months follow-up with four patients requiring short-term (<28 days) and seven requiring prolonged (⩾28 days) ECMO support. Lung compliance before ECMO was higher in the prolonged than in the short-term group (28.1 (28.8–32.1) ml/cmH₂O vs 18.7 (17.7–25.0) ml/cmH₂O, p = 0.030). Mechanical ventilation before ECMO was longer (19 (16–23) days vs 5 (5–9) days, p = 0.002) and SOFA score was higher (12.0 (10.5–17.0) vs 10.0 (9.0–10.0), p = 0.002) in non-survivors compared to survivors. Low viral load during the first days on ECMO tended to indicate worse outcomes. Seroconversion against SARS-CoV-2 occurred in all patients, but did not affect outcome.

Conclusions:

VV ECMO support for COVID-19-induced ARDS is justified if initiated early and at an experienced ECMO center. Prolonged ECMO therapy might be required in those patients. Although no relevant predictive factors for the duration of ECMO support were found, the decision to stop therapy should not be made dependent of the length of ECMO treatment.

Extracorporeal membrane oxygenation in patients with severe respiratory failure from COVID-19

PURPOSE

Limited data are available on venovenous extracorporeal membrane oxygenation (ECMO) in patients with severe hypoxemic respiratory failure from coronavirus disease 2019 (COVID-19).

METHODS

We examined the clinical features and outcomes of 190 patients treated with ECMO within 14 days of ICU admission, using data from a multicenter cohort study of 5122 critically ill adults with COVID-19 admitted to 68 hospitals across the United States. To estimate the effect of ECMO on mortality, we emulated a target trial of ECMO receipt versus no ECMO receipt within 7 days of ICU admission among mechanically ventilated patients with severe hypoxemia (PaO₂/FiO₂ < 100). Patients were followed until hospital discharge, death, or a minimum of 60 days. We adjusted for confounding using a multivariable Cox model.

RESULTS

Among the 190 patients treated with ECMO, the median age was 49 years (IQR 41-58), 137 (72.1%) were men, and the median PaO₂/FiO₂ prior to ECMO initiation was 72 (IQR 61-90). At 60 days, 63 patients (33.2%) had died, 94 (49.5%) were discharged, and 33 (17.4%) remained hospitalized. Among the 1297 patients eligible for the target trial emulation, 45 of the 130 (34.6%) who received ECMO died, and 553 of the 1167 (47.4%) who did not receive ECMO died. In the primary analysis, patients who received ECMO had lower mortality than those who did not (HR 0.55; 95% CI 0.41-0.74). Results were similar in a secondary analysis limited to patients with PaO₂/FiO₂ < 80 (HR 0.55; 95% CI 0.40-0.77).

CONCLUSION

In select patients with severe respiratory failure from COVID-19, ECMO may reduce mortality.

Occurrence of Invasive Pulmonary Fungal Infections in Patients with Severe COVID-19 Admitted to the ICU

Rationale: Whether severe coronavirus disease (COVID-19) is a significant risk factor for the development of invasive fungal superinfections is of great medical interest and remains, for now, an open question.Objectives: We aim to assess the occurrence of invasive fungal respiratory superinfections in patients with severe COVID-19.Methods: We conducted the study on patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related pneumonia admitted to five ICUs in France who had respiratory and serum sampling performed for specific screening of fungal complications.Measurements and Main Results: The study population included a total of 145 patients; the median age was 55 years old. Most of them were male (n = 104; 72%), were overweight (n = 99; 68%), and had hypertension (n = 83; 57%) and diabetes (n = 46; 32%). Few patients presented preexisting host risk factors for invasive fungal infection (n = 20; 14%). Their global severity was high; all patients were on invasive mechanical ventilation, and half (n = 73, 54%) were on extracorporeal membrane oxygenation support. Mycological analysis included 2,815 mycological tests (culture, galactomannan, β-glucan, and PCR) performed on 475 respiratory samples and 532 sera. A probable/putative invasive pulmonary mold infection was diagnosed in 7 (4.8%) patients and linked to high mortality. Multivariate analysis indicates a significantly higher risk for solid organ transplant recipients (odds ratio,  = 4.66; interquartile range, 1.98-7.34; P = 0.004). False-positive fungal test and clinically irrelevant colonization, which did not require the initiation of antifungal treatment, was observed in 25 patients (17.2%).Conclusions: In patients with no underlying immunosuppression, severe SARS-CoV-2-related pneumonia seems at low risk of invasive fungal secondary infection, especially aspergillosis.

SARS-CoV-2 Versus Influenza-associated Acute Respiratory Distress Syndrome Requiring Veno-venous Extracorporeal Membrane Oxygenation Support

No study has compared patients with COVID-19-related refractory ARDS requiring veno-venous extracorporeal membrane oxygenation (V-V ECMO) to a relevant and homogenous control population. We aimed to compare the outcomes, the clinical characteristics, and the adverse effects of COVID-19 patients to a retrospective cohort of influenza patients. This retrospective case-control study was conducted in the ICUs of Lille and Rouen University Hospitals between January 2014 and May 2020. Two independent cohorts of patients with ARDS requiring V-V ECMO infected with either COVID-19 (n = 30) or influenza (n = 22) were compared. A 3-month follow-up was completed for all patients. Median age of COVID-19 and influenza patients was similar (57 vs. 55 years; p = 0.62). The 28-day mortality rate did not significantly differ between COVID-19 (43.3%) and influenza patients (50%, p = 0.63). There was no significant difference considering the cumulative incidence of ECMO weaning, hospital discharge, and 3-month survival. COVID-19 patients had a lower SAPS II score (58 [37-64] vs. 68 [52-83]; p = 0.039), a higher body mass index (33 [29-38] vs. 30 [26-34] kg/m2; p = 0.05), and were cannulated later (median delay between mechanical support and V-V ECMO 6 vs. 3 days, p = 0.004) compared with influenza patients. No difference in overall adverse events was observed between COVID-19 and influenza patients (70% vs. 95.5% respectively; p = 0.23). Despite differences in clinical presentation before V-V ECMO implantation, 28-day and 3-month mortality rate did not differ between COVID-19 and influenza patients. Considering the lack of specific treatment for COVID-19, V-V ECMO should be considered as a relevant rescue organ support.

Veno-Venous Extracorporeal Membrane Oxygenation in COVID-19-Where Are We Now?

The recent development in extracorporeal life support (ECLS) has created new therapeutic opportunities for critically ill patients. An interest in extracorporeal membrane oxygenation (ECMO), the pinnacle of ECLS techniques, has recently increased, as for the last decade, we have observed improvements in the survival of patients suffering from severe acute respiratory distress syndrome (ARDS) while on ECMO. Although there is a paucity of conclusive data from clinical research regarding extracorporeal oxygenation in COVID-19 patients, the pathophysiology of the disease makes veno-venous ECMO a promising option.

Cytokine adsorption in patients with severe COVID-19 pneumonia requiring extracorporeal membrane oxygenation: protocol for a randomised, controlled, open-label intervention, multicentre trial

INTRODUCTION

Veno-venous extracorporeal membrane oxygenation (V-V ECMO) is a last resort treatment option in patients with severe COVID-19 related acute respiratory distress syndrome (ARDS). Mortality in these critically ill patients is high. Elevated interleukin-6 (IL-6) levels in these severe courses are associated with poor outcome. Extracorporeal cytokine adsorption is an approach to lower elevated IL-6 levels. However, there is no randomised controlled data on the efficacy of cytokine adsorption and its effect on patient outcome in severe COVID-19 related ARDS requiring V-V ECMO support.

METHODS AND ANALYSIS

We here report the protocol of a 1:1 randomised, controlled, parallel group, open-label intervention, superiority multicentre trial to evaluate the effect of extracorporeal cytokine adsorption using the CytoSorb device in severe COVID-19 related ARDS treated with V-V ECMO. We hypothesise that extracorporeal cytokine adsorption in these patients is effectively reducing IL-6 levels by 75% or more after 72 hours as compared with the baseline measurement and also reducing time to successful V-V ECMO explantation. We plan to include a total of 80 patients at nine centres in Germany.

ETHICS AND DISSEMINATION

The protocol of this study was approved by the ethical committee of the University of Freiburg as the leading institution (EK 285/20). Additional votes will be obtained at all participating centres.

TRIAL REGISTRATION NUMBERS

NCT04385771 and DRKS 00021248.

Use of Venovenous Extracorporeal Membrane Oxygenation in Critically-Ill Patients With COVID-19

Acute respiratory distress syndrome (ARDS) related to Coronavirus disease (COVID-19) is associated with high mortality. It has been suggested that venovenous extracorporeal membrane oxygenation (ECMO) was suitable in this indication, albeit the effects of ECMO on the mechanical respiratory parameters have been scarcely described. In this case-series, we prospectively described the use of venovenous ECMO and its effects on mechanical respiratory parameters in eleven COVID-19 patients with severe ARDS. Implantation of ECMO occurred 6 [3–11] days after the onset of mechanical ventilation. At the time of ECMO implantation, all patients received neuromuscular blocking agents, three (27%) received inhaled nitric oxide and prone positioning was performed in all patients with 4 [3−5] sessions of PP per patient. Under ECMO, the tidal volume was significantly decreased from 6.1 [4.0–6.3] to 3.4 [2.5–3.6] mL/kg of predicted body weight and the positive end-expiratory pressure level was increased by 25 ± 27% whereas the driving pressure and the mechanical power decreased by 33 ± 25% and 71 ± 27%, respectively. The PaO₂/FiO₂ ratio significantly increased from 68 [58–89] to 168 [137–218] and the oxygenation index significantly decreased from 28 [26–35] to 13 [10–15]. The duration of ECMO was 12 [8–25] days. Nine (82%) patients experienced ECMO-related complications and the main complication was major bleeding requiring blood transfusions. Intensive care unit mortality rate was 55% but no patient died from ECMO-related complications. In COVID-19 patients with severe ARDS, venovenous ECMO allowed ultra-protective ventilation, improved oxygenation and should be considered in highly selected patients with the most severe ARDS.