Ulinastatin, a urinary trypsin inhibitor, is widely used to treat acute systemic inflammatory disorders. However, the effects of ulinastatin, especially on the potential for hemostasis, have not been fully elucidated. This study examined whether ulinastatin had any beneficial effects on blood loss and blood transfusion requirements in patients undergoing major orthopedic surgery.

Eighty patients, aged 18 to 75 years, scheduled for major orthopedic surgery were enrolled in this study and were divided into the ulinastatin (n = 40) and control (n = 40) groups. Following the induction of general anesthesia, and immediately before the surgical incision, the patients in the ulinastatin group were given 5,000 units/kg of ulinastatin, which were mixed in 100 ml normal saline intravenously over 30 min, while those in the control group received the same volume of normal saline. The amounts of blood loss, infused fluid, and transfused blood products were measured throughout the study period. Blood samples for coagulation parameters were obtained before inducing anesthesia (T1), at the end of surgery (T2), and 12 h after surgery (T3).

The amounts of blood loss and infused fluid during surgery were not significantly different between the two groups. However, 12 h postoperative blood loss was significantly less in the ulinastatin group than in the control group (255.0 ± 133.2 ml VS. 395.4 ± 338.4 ml, P < 0.05).

Our data suggest that a single infusion of ulinastatin in major orthopedic surgery is associated with decreased blood loss in the early postoperative period.