Does leucocyte depletion during cardiopulmonary bypass improve oxygenation indices in patients with mild lung dysfunction?

Background. Leucocyte-depleting arterial line filters have not dramatically improved lung function after cardiopulmonary bypass (CPB), but patients with pre-existing lung dysfunction may benefit from their use. Methods. We randomized 32 patients with mild lung dysfunction having elective first-time coronary revascularization to either a leucocyte depleting or a standard 40-mm arterial line filter during CPB. The alveolar arterial oxygenation index was calculated before and 5 min after CPB, then at 1, 2, 4, 8, and 18 h after surgery. Time to extubation on the ITU was recorded. Preoperative, immediate postoperative, and 24 h postoperative chest x-rays were scored for extravascular lung water. Results. Postoperative alveolar–arterial oxygenation indices were better in the patients who received leucocyte depletion during CPB (1.65±0.96 in the study group vs 2.90±1.72 in the control group, P