Low-flow Extracorporeal Carbon Dioxide Removal in COVID-19-associated Acute Respiratory Distress Syndrome

The prevalence of acute respiratory distress syndrome (ARDS) caused by COVID-19 is approximately 8%. Lung-protective ventilation is the current standard of care for ARDS. It limits lung and distal organ impairment, but is associated with hypercapnia in approximately 14% of patients with mild to moderate ARDS and almost all patients with severe ARDS. In this setting, early implementing of an extracorporeal CO2 removal (ECCO2R) therapy may prevent further escalation of invasiveness of therapy (eg, need for extracorporeal membrane oxygenation (ECMO)). A number of low-flow ECCO2R devices are now available and some of those can be integrated into a renal replacement therapy (RRT) platform. This study aims to investigate the efficacy of an original ECCO2R system used in conjunction with a RRT platform in hypercapnic patients with COVID-19-associated mild-to-moderate ARDS with or without acute kidney injury (AKI) necessitating RRT.

Inclusion criteria

• mild-to-moderate ARDS according to the Berlin definition
• lung-protective ventilation with positive end-expiratory pressure (PEEP) > 5 cm of water on mechanical ventilation expected to last > 24 h
• hypercapnia <80 mmHg
• bilateral opacities on chest imaging

Exclusion criteria

• age < 18 years
• pregnancy
• patients with decompensated heart failure or acute coronary syndrome
• respiratory acidosis with persistent partial pressure of blood carbon dioxide (PCO2) levels >80 mmHg
• acute brain injury
• severe liver insufficiency (Child-Pugh scores > 7) or fulminant hepatic failure
• decision to limit therapeutic interventions
• catheter access to femoral vein or jugular vein impossible
• pneumothorax