Venoarterial Extracorporeal Membrane Oxygenation in Cardiogenic Shock: Lifeline of Modern Day CICU

Adult Highlights From the Extracorporeal Life Support Organization Registry: 2017-2022

The Extracorporeal Life Support Organization (ELSO) registry captures clinical data and outcomes on patients receiving extracorporeal membrane oxygenation (ECMO) support across the globe at participating centers. It provides a very unique opportunity to benchmark outcomes and analyze the clinical course to help identify ways of improving patient outcomes. In this review, we summarize select adult ECMO articles published using the ELSO registry over the past 5 years. These articles highlight innovative utilization of the registry data in generating hypotheses for future clinical trials. Members of the ELSO Scientific Oversight Committee can be found here: https://www.elso.org/registry/socmembers.aspx .

Extracorporeal Life Support for Cardiogenic Shock in Adult Congenital Heart Disease-An ELSO Registry Analysis

There are minimal data on the use of venoarterial extracorporeal membrane life support (VA-ECLS) in adult congenital heart disease (ACHD) patients presenting with cardiogenic shock (CS). This study sought to describe the population of ACHD patients with CS who received VA-ECLS in the Extracorporeal Life Support Organization (ELSO) Registry. This was a retrospective analysis of adult patients with diagnoses of ACHD and CS in ELSO from 2009-2021. Anatomic complexity was categorized using the American College of Cardiology/American Heart Association 2018 guidelines. We described patient characteristics, complications, and outcomes, as well as trends in mortality and VA-ECLS utilization. Of 528 patients who met inclusion criteria, there were 32 patients with high-complexity anatomy, 196 with moderate-complexity anatomy, and 300 with low-complexity anatomy. The median age was 59.6 years (interquartile range, 45.8-68.2). The number of VA-ECLS implants increased from five implants in 2010 to 81 implants in 2021. Overall mortality was 58.3% and decreased year-by-year (β= -2.03 [95% confidence interval, -3.36 to -0.70], p = 0.007). Six patients (1.1%) were bridged to heart transplantation and 21 (4.0%) to durable ventricular assist device. Complications included cardiac arrhythmia/tamponade (21.6%), surgical site bleeding (17.6%), cannula site bleeding (11.4%), limb ischemia (7.4%), and stroke (8.7%). Utilization of VA-ECLS for CS in ACHD patients has increased over time with a trend toward improvement in survival to discharge.

Weaning from venous-arterial extracorporeal membrane oxygenation: The hemodynamic and clinical aspects of flow challenge test

The cardiac function reserve is crucial for the successful weaning of V-A ECMO. During the V-A ECMO weaning phase, the gradual reduction in pump flow converts the blood flow originally driven by the pump to native cardiac output and also transforms afterload (caused by retrograde flow) into ventricular preload, thus introducing a “flow challenge” to the native heart. In this perspective, we propose to use this flow challenge as a test to simulate the preload-to-afterload conversion to assess cardiac functional reserve quantitatively. With this short article we offer the hemodynamic and clinical aspects regarding the flow challenge test.

Intraoperative use of extracorporeal CO2 removal (ECCO2R) and emergency ECMO requirement in patients undergoing lung transplant: a case-matched cohort retrospective study

BACKGROUND

The use of extracorporeal carbon dioxide removal (ECCO₂R) is less invasive than extracorporeal membrane oxygenation (ECMO), and intraoperative control of gas exchange could be feasible. The aim of this study in intermediate intraoperative severity patients undergoing LT was to assess the role of intraoperative ECCO₂R on emergency ECMO requirement in patients.

METHODS

Thirty-eight consecutive patients undergoing lung transplantation (LT) with "intermediate" intraoperative severity in the intervals 2007 to 2010 or 2011 to 2014 were analyzed as historical comparison of case-matched cohort retrospective study. The "intermediate" intraoperative severity was defined as the development of intraoperative severe respiratory acidosis with maintained oxygenation function (i.e., pH <7.25, PaCO₂ >60 mmHg, and PaO₂/FiO₂ >150), not associated with hemodynamic instability. Of these 38 patients, twenty-three patients were treated in the 2007-2010 interval by receiving "standard intraoperative treatment," while 15 patients were treated in the 2011-2014 interval by receiving "standard intraoperative treatment + ECCO₂R."

RESULTS

ECMO requirement was more frequent among patients that received "standard intraoperative treatment" alone than in those treated with "standard intraoperative treatment + ECCO₂R" (17/23 vs. 3/15; p = 0.004). The use of ECCO₂R improved pH and PaCO₂ while mean pulmonary artery pressure (mPAP) decreased.

CONCLUSION

In intermediate intraoperative severity patients, the use of ECCO₂R reduces the ECMO requirement.

Left Ventricular Unloading during Extracorporeal Life Support: Current Practice

Veno-arterial extracorporeal life support (VA-ECLS) is a powerful tool that can provide complete cardiopulmonary support for patients with refractory cardiogenic shock. However, VA-ECLS increases left ventricular afterload resulting in greater myocardial oxygen demand, which can impair myocardial recovery and worsen pulmonary edema. These complications can be ameliorated by various LV venting strategies to unload the LV. Evidence suggests that LV venting improves outcomes in VA-ECLS, but there is a paucity of randomized trials to help guide optimal strategy and the timing of venting. In this review, we discuss the available evidence regarding LV venting in VA-ECLS, explain important hemodynamic principles involved, and propose a practical approach to LV venting in VA-ECLS.

Outcomes from adult veno-arterial extracorporeal membrane oxygenation in a cardiovascular disease center from 2009 to 2019

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) is an imperative short-term cardiopulmonary support device now. We aimed to provide a single-center experience of veno-arterial (V-A) ECMO management and identify the risk factors of in-hospital mortality.

METHODS

We conducted a retrospective review of adult patients who received V-A ECMO between 2009 and 2019 in a cardiovascular disease center. The risk factor analysis of in-hospital mortality was conducted.

RESULTS

The study reviewed 236 patients, with an overall survival rate of 68.2%. The survivors' blood lactate concentration is significantly lower than non-survivors [7.4 (7.8) vs 11.1 (9.7), p = 0.002]. Patients who received heart transplantation were with higher in-hospital survival rate. Survivors developed less hepatic dysfunction, acute kidney injury and myocardial damage [23 (14.3%) vs 19 (25.3%), p = 0.039; 81 (50.3%) vs 51 (68%), p = 0.011; 24 (14.9%) vs 22 (29.3%), p = 0.009, respectively], with higher rate of continuous renal replacement therapy (CRRT) [56 (34.8%) vs 53 (70.7%), p < 0.001]. Fewer survivors' 24 hours and total chest drainage was over 1000 mL, and the rate of re-exploration as well as red blood cell and platelet transfusion were lower in survivors. In multivariate analysis, female, pre-ECMO blood lactate concentration, hyperlipidemia, CRRT, and 24 hours chest drainage ⩾ 1000 mL were risk factors of early mortality.

CONCLUSIONS

By providing a general description of V-A ECMO practice at a single-center in China. Post-heart transplant graft failure was associated with numerically, the greatest survival in our practice. Furthermore, female sex, pre-ECMO blood lactate concentration, hyperlipidemia, CRRT, and high blood loss in chest drains are predictors of mortality in patients who undergo V-A ECMO.