Treatment of Severe Hypercapnic Respiratory Failure Caused by SARS-CoV-2 Lung Injury with ECCO 2 R Using the Hemolung Respiratory Assist System

摘要

Acute respiratory distress syndrome (ARDS) due to COVID-19 leads to a high rate of mortality in the intensive care unit (ICU). A lung-protective mechanical ventilation strategy using low tidal volumes is a cornerstone to management, but uncontrolled hypercapnia is a life-threatening consequence among severe cases. A mechanism to prevent progressive hypercapnia may offset hemodynamic instability among patients who develop hypercapnia. We present the case of a woman in her mid-60’s with severe acute hypercapnic respiratory failure secondary to COVID-19 pneumonia who was successfully treated with early implementation of lung-protective ventilation facilitated by extracorporeal carbon dioxide removal (ECCO 2 R). This patient’s multiple comorbid conditions included obesity, hypertension, type 2 diabetes mellitus, and hypercholesterolemia. On her fifth day of admission at the referring hospital, her worsening hypoxemia prompted endotracheal intubation during which she developed pneumothorax. She was transferred to our institution for advanced care where upon arrival, she had profound hypercapnia and respiratory acidosis. She met the criteria for treatment with an investigational ECCO 2 R device (Hemolung Respiratory Assist System) available through FDA Emergency Use Authorization. ECCO 2 R is similar to extracorporeal membrane oxygenation (ECMO) but operates at much lower blood flows (350–550?mL/min) through a smaller 15.5 French central venous catheter. Standard heparinization was provided intravenously to achieve appropriate levels of anticoagulation during ECCO 2 R therapy. Unlike ECMO, ECCO 2 R does not provide clinically meaningful oxygenation but is simpler to implement and manage. The use of ECCO 2 R successfully corrected and controlled the patient’s hypercapnia and acidosis and enabled meaningful reductions in ventilator tidal volumes, respiratory rates, and mean airway pressures. The patient was weaned from ECCO 2 R after 17 days and from mechanical ventilation 10 days later. With low tidal volume ventilation facilitated by expeditious implementation of ECCO 2 R, the patient survived to discharge despite her many risk factors for a poor outcome and an extended duration of invasive mechanical ventilation.