Bench Validation of a Compact Low-Flow CO₂ Removal Device

Area of Science:

• Cardiovascular Engineering
• Biomedical Engineering
• Respiratory Physiology

Background:

• Extracorporeal CO2 removal (ECCO2R) offers an alternative to mechanical ventilation for hypercapnia, mitigating ventilator-induced lung injury.
• ECCO2R facilitates lung-protective ventilation, prevents intubation, and aids in ventilator weaning.
• The Low-Flow Pittsburgh Ambulatory Lung (LF-PAL) is a novel, compact ECCO2R device designed for patient ambulation.

Purpose of the Study:

• To evaluate the performance of the LF-PAL device, focusing on pumping capacity, CO2 removal efficiency, and hemocompatibility.
• To assess the potential of the LF-PAL to enable ambulation in patients requiring ECCO2R therapy.

Main Methods:

• In vitro testing using a blood analog to assess pump performance at varying speeds.
• In vitro CO2 removal tests under normocapnic conditions and 6-hour hemolysis studies with bovine blood.
• Computational fluid dynamics and mass-transfer modeling to analyze LF-PAL performance.

Main Results:

• The integrated pump achieved blood flows up to 700 mL/min against the specified catheter.
• Maximum CO2 removal (vCO2) of 105 mL/min was observed at a blood flow rate of 700 mL/min.
• Hemolysis levels were within acceptable therapeutic and normalized indices (0.080 g/(100 min) and 0.158 g/(100 L), respectively).

Conclusions:

• The LF-PAL device successfully met its design targets for pumping, CO2 removal, and hemolysis.
• The LF-PAL demonstrates significant potential for facilitating patient ambulation during ECCO2R therapy.