Systemic leukocyte filtration during cardiopulmonary bypass

Cardiopulmonary bypass (CPB) induces a whole body inflammatory response leading to postoperative lung dysfunction. Activated leukocytes may play a role in the pathogenesis of pulmonary dysfunction. We evaluated postoperative lung function after the use of leukocyte-depleting filters incorporated in the extracorporeal circuit during CPB.From November 1997 to March 2000, 40 patients underwent isolated coronary artery bypass grafting. Patients were randomly allocated to the leukocyte-depletion group (group F, 20 patients) or to the control group (group C, 20 patients).There was no significant difference between the two groups with respect to age, sex, weight, height, body surface area, haemoglobin and haematocrit levels, preoperative left ventricular ejection fraction, cooling temperature, aortic crossclamping and CBP duration. Blood samples were drawn preoperatively, at aortic declamping, 60 min after CPB, after arriving at the intensive care unit (ICU) and 24 h after the operation. We analysed blood cell count, elastase, interleukin-8 (IL-8) and tumour necrosis factor (TNF-α) levels and continuous monitoring of arterial blood gases in the intensive care unit (ICU).The analysis of total circulating white blood cells (WBCs) showed a significant reduction of WBCs in both groups soon after aortic declamping [from the right atrium: 6.4 109/l ± 1.4×109/l in group F vs 10.3 ± 1.8×109/l in group C (p