Effect of Hemoperfusion Using Polymyxin B-immobilized Fibers on Acute Lung Injury in a Rat Sepsis Model

Direct hemoperfusion using polymyxin B-immobilized column (PMX-DHP) is recognized as an effective treatment for septic shock. However, whether its efficacy is limited to cardiovascular dysfunction remains unknown. Therefore, we planned to examine the effects of PMX-DHP in an acute lung injury model. [Materials and methods] Rats were assigned to either PMX-DHP group or control group (n= 7 in each). A lung injury was created by the intratracheal instillation of LPS. In PMX-DHP group, an arteriovenous extracorporeal circuit using PMX column was applied for three hours. The same procedure using a dummy column was applied in control group. The lung microcirculation was observed, and adherent leukocytes, RBC velocity, and the arterial PaO2 were calculated. Pathological changes and the wet/dry weight ratio of the lungs were examined. [Results] Adherent leukocytes and platelets to the lung venules were recognized at 3 hours, and their numbers increased over time. Treatment with PMX-DHP significantly suppressed these events and helped maintenance of the blood flow and PaO2 levels. The lung edema and the histologic damages were also suppressed. [Conclusions] PMX-DHP improved the microcirculation by suppressing leukocyte and platelet adhesion. PMX-DHP had beneficial effects in a model for acute lung injury.