Seventy-two hour gas exchange performance and hemodynamic properties of NOVALUNG®iLA as a gas exchanger for arteriovenous carbon dioxide removal

Objective: Acute respiratory failure is complicated by acidosis and altered end-organ perfusion. NOVA-LUNG®iLA is an interventional lung assist (ILA) device for arteriovenous carbon dioxide removal (AVCO₂R). The present study was conducted to evaluate the device for short-term CO₂ removal performance and hemodynamic response. Methods: Six adult sheep received cannulation of the jugular vein and carotid artery. The ILA-AVCO₂R circuit was placed on the sheep for 72 hours. Hemodynamics and PaCO₂ were measured; CO₂ removal was calculated while varying sweep gas flow rates (Q_g), device blood flow rates (Q_b), and PaCO₂. Results: Hemodynamic variables remained normal throughout the 72 hour study. CO₂ removal increased with increases in Q_g or Q_b. Mean CO₂ removal was 119.3 ml/min for Q_b 1 L/min, Q_g 5 L/min, and PaCO₂ 40-50 mmHg. PaCO₂ was directly proportional to CO₂ clearance (R=0.72, p <0.001). Conclusion: NOVALUNG®iLA can provide near total CO₂ removal with Q_b 1-2 L/min, Q_g 5 L/min, and minimal flow resistance (3.88±0.82 mmHg/L/min). PaCO₂, correlates with CO₂ removal and is dependent on Q_b and Q_g.