Modified Low-Flow Ultrafiltration Ameliorates Hemodynamics and Early Graft Function and Reduces Blood Loss in Living-Donor Lobar Lung Transplantation

Background: This study analyzed the clinical application of modified low-flow ultrafiltration (MUF) to minimize cardiopulmonary bypass (CPB)-related adverse effects in patients undergoing living-donor lobar lung transplantation (LDLLT). Method: The study enrolled 33 consecutive patients who underwent LDLLT from 1999 to 2004: 8 patients underwent conventional CPB without MUF (control group), and 15 underwent arteriovenous MUF (MUF-treated group). Hemodynamics, graft function, blood loss and blood transfusion requirements, and clinical outcomes were analyzed. Results: There was a significant increase in systolic blood pressure and a decrease in pulmonary to systemic pressure ratio in the MUF-treated group (p < 0.05). No hemodynamic changes occurred in the control group. MUF resulted in significant improvements in arterial oxygen tension/fraction of inspired oxygen ratio (PaO₂/FiO_2; 411 ± 107 vs 272 ± 107 mm Hg, p < 0.05) and the alveolar-arterial oxygen difference (a-aDO₂; 158 ± 84 vs 315 ± 127 mm Hg, p < 0.05) at 15 minutes after CPB. There were no differences in PaO₂/FiO₂ and A-aDO₂ between the groups beyond 6 hours post-operatively. Post-operative blood loss and blood transfusion requirements were lower in the MUF-treated group than in the control group (p < 0.05). There were no differences in survival, duration of ventilation, intensive care unit stay, and hospital stay between the groups. Conclusions: The low-flow MUF brought improved hemodynamics and gas exchange capacity of transplanted grafts and lowered post-operative blood loss and blood transfusion requirement. This strategy may minimize CPB-related adverse effects in patients undergoing LDLLT.