Ulinastatin Improves Postoperative Oxygenation After Cardiopulmonary Bypass

Inclusion Criteria: * patients who underwent aortic repair or replacement under moderate hypothermic CPB Exclusion Criteria: * Preoperative: \< 19 years old, \> 85 years old, emergency operation, reoperation, left ventricular ejection fraction \< 50%, arrhythmia, ischaemic myocardial disease, uncontrollable hypertension or hypotension, pericardial disease, pre-existing hepatic dysfunction, pre-existing renal dysfunction or underlying lung disease. * Intraoperative: intraoperative application of an intra-aortic balloon pump, administration of steroids or tranexamic acid, and transfusion of fresh frozen plasma or platelet concentrates during CPB. * Postoperative: reoperation for surgical correction of intractable postoperative bleeding within 2 hours after the end of surgery and transfusion of any banked blood products.