Efficient CO₂ removal using extracorporeal lung and renal assist device

Area of Science:

• Biomedical Engineering
• Respiratory Physiology
• Critical Care Medicine

Background:

• Acid-base balance is crucial in critical care.
• Efficient carbon dioxide (CO2) removal is vital for patients with respiratory failure.
• Existing CO2 removal systems often require high blood flow rates, limiting their application.

Purpose of the Study:

• To develop and evaluate a novel system for efficient CO2 removal at low blood flow.
• To assess the efficacy of acid infusion combined with a membrane lung for CO2 elimination.
• To determine the impact of lactic acid and hydrochloric acid on CO2 removal efficiency.

Main Methods:

• An ex vivo swine blood model was utilized.
• A system integrating acid infusion, a membrane lung, and continuous renal replacement therapy (CRRT) console was employed.
• Blood samples were analyzed at various circuit points to quantify CO2 elimination under different acid loads (0, 10, 20 mEq/L of lactic or hydrochloric acid).

Main Results:

• The novel system demonstrated significant CO2 removal, increasing with higher acid concentrations.
• CO2 elimination was 3.9 times higher with lactic acid and 2.0 times higher with hydrochloric acid compared to controls.
• Acid-base equilibrium was restored post-hemodiafiltration, with normalized lactate and chloride ion levels.

Conclusions:

• The developed system provides a safe and effective method for CO2 removal.
• Acid infusion significantly enhances CO2 elimination efficiency in the membrane lung.
• This system offers a promising solution for CO2 management, particularly in scenarios requiring low blood flow.