Right Ventricular Dysfunction is Associated with Increased Mortality in Patients Requiring Venovenous Extracorporeal Membrane Oxygenation for Coronavirus Disease 2019

Right Ventricular Injury Definition and Management in Veno-Venous Extracorporeal Membrane Oxygenation

Right ventricular injury (RVI) in respiratory failure receiving veno-venous extracorporeal membrane oxygenation (VV ECMO) is associated with significant mortality. A scoping review is necessary to map the current literature and guide future research regarding the definition and management of RVI in patients receiving VV ECMO. We searched for relevant publications on RVI in patients receiving VV ECMO in Medline, EMBASE, and Web of Science. Of 1,868 citations screened, 30 studies reported on RVI (inclusive of right ventricular dilation, right ventricular dysfunction, and right ventricular failure) during VV ECMO. Twenty-three studies reported on the definition of RVI including echocardiographic indices of RV function and dimensions, whereas 13 studies reported on the management of RVI, including veno-pulmonary (VP) ECMO, veno-arterial (VA) ECMO, positive inotropic agents, pulmonary vasodilators, ultra-lung-protective ventilation (Ultra-LPV), and optimization of positive end-expiratory pressure (PEEP). The definitions of RVI in patients receiving VV ECMO used in the literature are heterogeneous. Despite the high incidence of RVI during VV ECMO support and its strong association with mortality, studies investigating therapeutic strategies for RVI are also lacking. To fill the existing knowledge gaps, a consensus on the definition of RVI and research investigating RV-targeted therapies during VV ECMO is urgently warranted.

Echocardiographic Findings in Critically Ill COVID-19 Patients Treated With and Without Extracorporeal Membrane Oxygenation

OBJECTIVES

To describe echocardiographic findings among mechanically ventilated patients with COVID-19 acute respiratory distress syndrome, comparing those with and without venovenous extracorporeal membrane oxygenation (VV ECMO) support.

DESIGN

Single-center, retrospective cohort study.

SETTING

Intensive care unit (ICU) of a quaternary academic center.

PARTICIPANTS

Patients with COVID-19 admitted between March 2020 and June 2021 receiving mechanical ventilation, with an echocardiogram within 72 hours of admission.

INTERVENTIONS

Admission and follow-up echocardiograms during ICU stay.

MEASUREMENTS

Patient characteristics and echocardiographic findings were analyzed. Mortality odds ratio (OR) for right ventricular (RV) systolic dysfunction and acute cor pulmonale (ACP) was calculated.

MAIN RESULTS

Among 242 patients, 145 (60%) received VV ECMO. Median (IQR) PaO2/FiO2 was 76 (65-95) and 98 (85-140) in ECMO and non-ECMO patients, respectively (p ≤ 0.001). Initial echocardiograms showed no significant differences in left ventricular systolic dysfunction (10% v 15 %, p = 0.31) and RV systolic dysfunction (38% v. 27%, p = 0.27) between ECMO and non-ECMO patients. ACP was more frequent in the ECMO group at baseline (41% v. 26 %, p = 0.02). During the ICU stay, patients on ECMO exhibited a higher prevalence of RV systolic dysfunction (55% v 34%, p = 0.001) and ACP (51% v 26%, p = 0.002). RV systolic dysfunction (OR 1.99; 95% CI 1.09-3.63) and ACP (OR 2.95; 95% CI 1.55-5.62) on the follow-up echocardiograms were associated with higher odds of ICU mortality.

CONCLUSIONS

The prevalence of echocardiographic abnormalities, in particular RV dysfunction, was frequent among patients with COVID-19 receiving VV ECMO support and was associated with worse clinical outcomes.

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.

Assessing Right Ventricle Over Time in Patients on Veno-Venous Extracorporeal Membrane Oxygenation: Insights From Serial Echocardiography

Extracorporeal membrane oxygenation (ECMO) is often used in acute respiratory distress syndrome (ARDS) with refractory hypoxemia. There is limited literature highlighting the development of right ventricular (RV) failure while on ECMO. We conducted a retrospective multicenter observational study including 70 patients who were placed on veno-venous (VV)-ECMO for respiratory failure at Mayo Clinic, Jacksonville, and Mayo Clinic, Rochester, between January 2018 and June 2022 and had at least two post-ECMO transthoracic echoes. The primary outcomes were the incidence and progression of RV dysfunction and dilatation. The secondary outcome was in-patient mortality. Among 70 patients in our cohort, 60.6% had a normal RV function at the time of ECMO placement, whereas only 42% had a normal RV function at the second post-ECMO echo. On multinomial regression, a moderate decrease in RV function was associated with ECMO flow (odds ratio [OR] = 2.32, p = 0.001) and ECMO duration (OR = 1.01, p = 0.01). A moderately dilated RV size was also associated with ECMO flow (OR = 2.62, p < 0.001) and ECMO duration (OR = 1.02, p = 0.02). An increasing degree of RV dysfunction was associated with worse outcomes. Our study showed that the increasing duration and flow of VV-ECMO correlated with progressive RV dilatation and dysfunction, which were associated with poor survival.

New Right Ventricular Dysfunction in Pediatric Acute Respiratory Distress Syndrome on Venovenous Extracorporeal Membrane Oxygenation

The development of new right ventricular (RV) dysfunction after cannulation to venovenous (VV) extracorporeal membrane oxygenation (ECMO) and its association with worse outcomes is increasingly recognized in adult patients, however, no studies have evaluated this phenomenon in pediatric patients. We report results of a single-center retrospective cohort study at a large academic children's hospital. New RV systolic dysfunction was present in 48% (12/25) of pediatric patients on VV ECMO for acute respiratory distress syndrome (ARDS). There was no statistically significant difference in survival, duration of mechanical ventilation, or hospital length of stay between those with and without RV dysfunction. Over half (5/9, 56%) of survivors with RV dysfunction on ECMO had RV dilation or RV hypertrophy on post-ECMO echocardiograms, and in two patients the RV dysfunction persisted for months following decannulation. Cardiac catheterization and autopsy reports suggested that echocardiographic assessment of RV systolic function alone may not be sufficient to diagnose clinically relevant RV injury. This is the first study to report the prevalence of RV dysfunction on VV ECMO for pediatric ARDS. Future multicenter collaboration is needed to create a clinically relevant definition of pediatric "RV injury" and to further evaluate risk factors and outcomes of RV dysfunction.

Use of Extracorporeal Membrane Oxygenation for Patients with Coronavirus Disease 2019 Infection

The coronavirus disease 2019 (COVID-19) pandemic was a cataclysmic event that infected over 772 million and killed over 6.9 million people worldwide. The pandemic pushed hospitals and society to their limits and resulted in incredibly severe respiratory disease in millions of people. This severe respiratory disease often necessitated maximum medical therapy, including the use of extracorporeal membrane oxygenation. While our understanding of COVID-19 and its treatment continue to evolve, we review the current evidence to guide the care of patients with severe COVID-19 infection.

Outcomes associated with prolonged ECMO in COVID-19 associated ARDS: A single center experience

PURPOSE OF STUDY

The COVID-19 pandemic has led to a significant increase in the use of veno-venous extracorporeal membrane oxygenation (V-V ECMO) as a bridge to transplantation versus recovery. Unlike other etiologies of acute respiratory distress syndrome (ARDS), utilization of V-V ECMO in COVID-19 has been associated with longer duration of ECMO support requirements. Our team sought to evaluate outcomes associated with prolonged duration of ECMO support in this patient population.

METHODS

Single-center retrospective review of patients who were placed on ECMO due to COVID-19 associated ARDS. Specifically examining outcomes-transplant free survival, mortality and discharge rates-of patients requiring V-V ECMO support for greater than 50 days.

RESULTS

The median age of the cohort was 48 years and 13 patients (72%) were males. The median duration of ECMO support was 84 days (IQR 55-106). 11 patients (61%) had right ventricular dysfunction and 13 patients (72%) had pneumothoraces. There was a 33% percent (n = 6) mortality rate within cohort. One patient continues to require ECMO support at time of abstract submission. 11 patients (61%) patients were discharged, of which 3 patients required a lung transplant.

SUMMARY

Prolonged V-V ECMO can be associated with comparable outcomes to conventional V-V ECMO runs that are relatively shorter in duration. With availability of device and staffing, prolonged ECMO runs can potentially be justified in a highly selected patient population.

Predictors and outcomes associated with right ventricular function in patients with acute respiratory distress syndrome treated with Veno-venous extracorporeal membrane oxygenation

INTRODUCTION

Right ventricular dysfunction is associated with mortality in patients with acute respiratory distress syndrome (ARDS) but information in veno-venous extracorporeal membrane oxygenation (ECMO) settings is limited. Study objectives were to examine factors associated with right ventricular (RV) systolic dysfunction (RVSD) and RV dilation in ECMO patients with ARDS, to compare outcomes in those with and without RVSD and RV dilation defined by qualitative and quantitative parameters, and to describe RVSD evolution during ECMO.

METHODS

Retrospective observational study of adult ARDS patients supported with ECMO at a tertiary care hospital.

RESULTS

Of a total of 62 patients, 56% had RVSD and 61% had RV dilation by qualitative assessment. Male gender, COVID-19, hypercarbia, and pneumothorax were associated with RVSD and RV dilation. In-hospital mortality was significantly higher in patients with RV dilation vs. no dilation (42% vs. 17%, p = .05) but comparisons for patients with and without RVSD (37% vs. 26%, respectively) did not reach statistical significance. Findings were similar when RV size and function were quantified by right to left ventricle end-diastolic area ratio and fractional area change (39% vs. 21% and 36% vs. 20% respectively; p = NS). Of 39 patients with multiple echocardiograms, 9 of 18 with initially normal RV function developed RVSD while RV function normalized in 10 of 21 patients who began ECMO with RVSD.

CONCLUSIONS

Study results suggest an association of RV dilation and RVSD with worse outcomes and a dynamic nature of RV function necessitating close monitoring during the ECMO course.

Outcome of Veno-Pulmonary Extracorporeal Life Support in Lung Transplantation Using ProtekDuo Cannula: A Systematic Review and Description of Configurations

Background: Refractory end-stage pulmonary failure may benefit from extracorporeal life support (ECLS) as a bridge to lung transplantation. Veno-venous (VV) extracorporeal membrane oxygenation (ECMO) has been recommended for patients who have failed conventional medical therapy and mechanical ventilation. Veno-arterial (VA) ECMO may be used in patients with acute right ventricular (RV) failure, haemodynamic instability, or refractory respiratory failure. Peripheral percutaneous approaches, either dual-site single-lumen cannulation for veno-pulmonary (VP) ECMO or single-site dual-lumen (dl)VP ECMO, using the ProtekDuo right ventricular assist device (RVAD) cannula, has made this configuration a desirable option as a bridge to transplantation. These configurations support the right ventricle, prevent recirculation by placing the tricuspid and pulmonary valve between the drainage and return cannulas, provide the direct introduction of oxygenated blood into the pulmonary artery, and have been shown to decrease the incidence of acute kidney injury (AKI), requiring continuous renal replacement therapy (CRRT) in certain disease states. This promotes haemodynamic stability, potential sedation-weaning trials, extubation, mobilisation, and pre-transplant rehabilitation. Methods: A web-based literature search in PubMed and EMBASE was undertaken based on a combination of keywords. The PICOS and PRISMA approaches were used. Results: Four case series were identified out of 323 articles, with a total of 34 patients placed on VP ECMO as a bridge to lung transplantation. All relevant data are reviewed and integrated into the Discussion. Conclusions: Despite the limited available evidence, the use of ProtekDuo has become very promising for the management of end-stage lung disease as a bridge to lung transplantation.

Worse survival in patients with right ventricular dysfunction and COVID-19-associated acute respiratory distress requiring extracorporeal membrane oxygenation: A multicenter study from the ORACLE Group

OBJECTIVE

We sought to determine the impact of right ventricular dysfunction on the outcomes of mechanically ventilated patients with COVID-19 requiring veno-venous extracorporeal membrane oxygenation.

METHODS

Six academic centers conducted a retrospective analysis of mechanically ventilated patients with COVID-19 stratified by support with veno-venous extracorporeal membrane oxygenation during the first wave of the pandemic (March to August 2020). Echocardiograms performed for clinical indications were reviewed for right and left ventricular function. Baseline characteristics, hospitalization characteristics, and survival were compared.

RESULTS

The cohort included 424 mechanically ventilated patients with COVID-19, 126 of whom were cannulated for veno-venous extracorporeal membrane oxygenation. Right ventricular dysfunction was observed in 38.1% of patients who received extracorporeal membrane oxygenation and 27.4% of patients who did not receive extracorporeal membrane oxygenation with an echocardiogram. Biventricular dysfunction was observed in 5.5% of patients who received extracorporeal membrane oxygenation. Baseline patient characteristics were similar in both the extracorporeal membrane oxygenation and non-extracorporeal membrane oxygenation cohorts stratified by the presence of right ventricular dysfunction. In the extracorporeal membrane oxygenation cohort, right ventricular dysfunction was associated with increased inotrope use (66.7% vs 24.4%, P < .001), bleeding complications (77.1% vs 53.8%, P = .015), and worse survival independent of left ventricular dysfunction (39.6% vs 64.1%, P = .012). There was no significant difference in days ventilated before extracorporeal membrane oxygenation, length of hospital stay, hours on extracorporeal membrane oxygenation, duration of mechanical ventilation, vasopressor use, inhaled pulmonary vasodilator use, infectious complications, clotting complications, or stroke. The cohort without extracorporeal membrane oxygenation cohort demonstrated no statistically significant differences in in-hospital outcomes.

CONCLUSIONS

The presence of right ventricular dysfunction in patients with COVID-19-related acute respiratory distress syndrome supported with veno-venous extracorporeal membrane oxygenation was associated with increased in-hospital mortality. Additional studies are required to determine if mitigating right ventricular dysfunction in patients requiring veno-venous extracorporeal membrane oxygenation improves mortality.

Relationship between the Pre-ECMO and ECMO Time and Survival of Severe COVID-19 Patients: A Systematic Review and Meta-Analysis

BACKGROUND

Coronavirus disease 2019 (COVID-19) is the etiology of acute respiratory distress syndrome (ARDS). Extracorporeal membrane oxygenation (ECMO) is used to support gas exchange in patients who have failed conventional mechanical ventilation. However, there is no clear consensus on the timing of ECMO use in severe COVID-19 patients.

OBJECTIVE

The aim of this study is to compare the differences in pre-ECMO time and ECMO duration between COVID-19 survivors and non-survivors and to explore the association between them.

METHODS

PubMed, the Cochrane Library, Embase, and other sources were searched until 21 October 2022. Studies reporting the relationship between ECMO-related time and COVID-19 survival were included. All available data were pooled using random-effects methods. Linear regression analysis was used to determine the correlation between pre-ECMO time and ECMO duration. The meta-analysis was registered with PROSPERO under registration number CRD42023403236.

RESULTS

Out of the initial 2473 citations, we analyzed 318 full-text articles, and 54 studies were included, involving 13,691 patients. There were significant differences between survivors and non-survivors in the time from COVID-19 diagnosis (standardized mean difference (SMD) = -0.41, 95% confidence interval (CI): [-0.53, -0.29], p < 0.00001), hospital (SMD = -0.53, 95% CI: [-0.97, -0.09], p = 0.02) and intensive care unit (ICU) admission (SMD = -0.28, 95% CI: [-0.49, -0.08], p = 0.007), intubation or mechanical ventilation to ECMO (SMD = -0.21, 95% CI: [-0.32, -0.09], p = 0.0003) and ECMO duration (SMD = -0.18, 95% CI: [-0.30, -0.06], p = 0.003). There was no statistical association between a longer time from symptom onset to ECMO (hazard ratio (HR) = 1.05, 95% CI: [0.99, 1.12], p = 0.11) or time from intubation or mechanical ventilation (MV) and the risk of mortality (highest vs. lowest time groups odds ratio (OR) = 1.18, 95% CI: [0.78, 1.78], p = 0.42; per one-day increase OR = 1.14, 95% CI: [0.86, 1.52], p = 0.36; HR = 0.99, 95% CI: [0.95, 1.02], p = 0.39). There was no linear relationship between pre-ECMO time and ECMO duration.

CONCLUSION

There are differences in pre-ECMO time between COVID-19 survivors and non-survivors, and there is insufficient evidence to conclude that longer pre-ECMO time is responsible for reduced survival in COVID-19 patients. ECMO duration differed between survivors and non-survivors, and the timing of pre-ECMO does not have an impact on ECMO duration. Further studies are needed to explore the association between pre-ECMO and ECMO time in the survival of COVID-19 patients.

Extracorporeal membrane oxygenation for COVID-19-related acute respiratory distress syndrome: a narrative review

A growing body of evidence supports the use of extracorporeal membrane oxygenation (ECMO) for severe acute respiratory distress syndrome (ARDS) refractory to maximal medical therapy. ARDS may develop in a proportion of patients hospitalized for coronavirus disease 2019 (COVID-19) and ECMO may be used to manage patients refractory to maximal medical therapy to mitigate the risk of ventilator-induced lung injury and provide lung rest while awaiting recovery. The mortality of COVID-19-related ARDS was variously reassessed during the pandemic. Veno-venous (VV) ECMO was the default choice to manage refractory respiratory failure; however, with concomitant severe right ventricular dysfunction, venoarterial (VA) ECMO or mechanical right ventricular assist devices with extracorporeal gas exchange (Oxy-RVAD) were also considered. ECMO has also been used to manage special populations such as pregnant women, pediatric patients affected by severe forms of COVID-19, and, in cases with persistent and seemingly irreversible respiratory failure, as a bridge to successful lung transplantation. In this narrative review, we outline and summarize the most recent evidence that has emerged on ECMO use in different patient populations with COVID-19-related ARDS.