Although total liquid ventilation (TLV) is an effective treatment for ARDS, there still remains the problem with CO2 removal. CO2 removal performance depends on the pressure difference between the liquid side and the gas side in a membrane lung. In this study, we newly developed an oxygenator for TLV (TLV-OX) to improve this problem. We examined gas exchange performance (GEP) in vitro. In newly developed TLV-OX, the gas flow length was shortened to 50mm from 160mm, and gas inlets were increased to flow fresh 100% O2 gas constantly. GEP was evaluated using the single path method under PFC flow rate of Q = 0.75 L/min and gas flow ratio/PFC flow ratio of V/Q = 3, 9, 15, 18, and calculated by the equation (1):
GEP=(difference in PO2 or PCO2 between inlet and outlet of TLV-OX / atmosphere pressure(760mmHg))×bunsen coefficient×Q(1)
The newly developed TLV-OX was shown to be 22.5mL/min, and the previous TLV-OX was 18.9mL/min in V/Q=18. GEP of the newly developed TLV-OX was increased by 15.9% compared with the previous TLV-OX. In conclusion, it was considered that the difference in PCO2 between PFC and blood was kept at a high level by shortening the gas flow length and with an increase of gas inlets. We will optimize TLV-OX design to offer a high GEP using a Multi Objective Genetic Algorithm.