A comprehensive study of oxygenator gas transfer efficiency and thrombosis risk

Abstract

To investigate the effects of clinical modalities and configurations on oxygenator pressure loss (ΔP), oxygen transfer ability and thrombosis risk and to find out the optimal oxygenator configuration. Modified partial pressure of oxygen (PO2) and a newly proposed thrombosis risk model (constructed from platelets, coagulation factors, hemostatic proteins, and blood stagnation) were used for this study. Oxygen transport and thrombosis risk assessment experiments were used for validation. Both simulation and experimental results indicate that when oxygenator operates at low flow rates with low-pressure loss and high PO2, they produced thrombin concentrations and increased thrombosis risk. For the same membrane fiber region, variations in the oxygenator external structure did not affect PO2 and thrombin production. For the ΔP and thrombosis risk, square oxygenators > round oxygenators, single-inlet oxygenators > multiple-inlet oxygenators, and lower inlet and lower outlet oxygenators > center inlet and center outlet oxygenators. The oxygenator high thrombosis risk region was identified as the blood-to-blood/border impingement region. A study of 81 oxygenator inlet and outlet combinations found that the inlet and outlet locations had little effect on ΔP and PO2. Oxygenator thrombosis risk was the lowest when using a center inlet and an upper/lower outlet configuration. The accuracy of the thrombosis risk model was validated. The oxygenator operation mode had a significant effect on ΔP, PO2, and thrombosis risk. Changes in the oxygenator external configuration had a significant impact on thrombosis. The lowest thrombosis risk was found in the center inlet and upper/lower outlet round oxygenator configuration.