The importance of aprotinin and pentoxifylline in preventing leukocyte sequestration and lung injury caused by protamine at the end of cardiopulmonary bypass surgery

Background: Protamine has adverse effects on pulmonary gas exchange during the postoperative period. The objective of this study was to investigate the importance of aprotinin and pentoxifylline in preventing the leukocyte sequestration and lung injury caused by protamine administered after the termination of cardiopulmonary bypass (CPB). Methods: Participants (n = 39) were allocated into three groups at the termination of CPB: Group 1, (control group, n = 16); Group 2 (aprotinin group, n = 12), who received protamine + aprotinin (15 000 IU/kg); and Group 3 (Pentoxifylline group, n = 11), who received protamine + pentoxifylline (10 mg/kg). Leukocyte counts in pulmonary and radial arteries were determined after the termination of CPB and before any drug was given (t(1)), and 5 minutes (t(2)), 2 hours (t(3)), 6 hours (t(4)) and 12 hours (t(s)) after the administration of protamine. Alveolar-arterial O-2 gradient (A-aO(2)) and dynamic pulmonary compliance were measured at t(1), t(2) and t(3). Results: In the control group, an increase in pulmonary leukocyte sequestration was observed 5 minutes and 2 hours after protamine administration, after which this difference disappeared. No significant degree of pulmonary sequestration was detected in any measurements after protamine was administered in the aprotinin and pentoxifylline (PTX) groups. Dynamic lung compliance was 50.1, 45.2 and 47.2 ml/cm H2O in the control group, 49.2, 61.1 and 56.3 ml/ cm H2O in the aprotinin group, and 49.5, 54.5 and 50.4 ml/cm H2O in the PTX group. The A-aO(2) gradient was 212.2, 263.3 and 254.3 mmHg in the control group, 209.4, 257.1 and 217.3 mmHg in the aprotinin group, and 211.3, 260.8 and 219.2 mmHg in the PTX group. Conclusion: Aprotinin and PTX treatments have favourable effects on lung function by reducing protamine-induced leukocyte sequestration into lungs at the end of CPB.