[Clinical comparative studies on effect of tranexamic acid on blood loss associated with total knee arthroplasty]

To investigate an effect of tranexamic acid on blood loss associated with total knee arthroplasty (TKA).

From June 2005 to June 2006, 102 patients (43 males, 59 females; aged 59-77 years, averaged 68 years) underwent TKA. Of the 102 patients, 59 had osteoarthritis, 23 had rheumatoid arthritis, and 20 had traumatic arthritis. The illness course ranged from 2 to 12 years. They were randomized divided into Group A and Group B of 51 patients each. The patients in Group A received tranexamic acid, and the patients in Group B received an equal volume of normal saline. In Group A, 1 g of tranexamic acid dissolved in 250 ml of normal saline was intravenously infused before deflation of the tourniquet; another intravenous administration of the same drug of the same dosage was given 3 hours later. In Group B, only 250 ml of normal saline was infused intravenously. The amounts of blood loss and blood transfusion during operation and after operation in all the 102 patients were recorded. They were also observed for whether they had deep vein thrombosis. D-dimeride, fibrinogen, prothrombin time, and activated partial thromboplastin time were also examined before operation, during operation (deflation of the tourniquet), and 3 hours after operation.

The blood loss was 256 +/- 149 ml in Group A and 306 +/- 214 ml in Group B during operation; there was no significant difference between the two groups (P > 0.05). The postoperative drainage volume was 478 +/- 172 ml in Group A and 814 +/- 156 ml in Group B, and the total blood loss was 559 +/- 159 ml in Group A and 1208 +/- 243 ml in Group B; there were significant differences between the two groups (P < 0.05). The averaged amount of blood transfusion was 556 +/- 174 ml in Group A and 1024 +/- 278 ml in Group B; there was a significant difference between the two groups (P < 0. 05). The postoperative hemoglobin concentration was higher in Group A than that in Group B (1.0-1.1 g/dL vs. 0.6-0.8 g/dL). The postoperative follow-up for 6-12 months revealed that no deep vein thrombosis was found in both lower limbs of the patients by the color Doppler ultrasonography. The level of D-dimeride was significantly higher 3 hours after operation than before operation (0.92 +/- 0.56 mg/L vs. 0.35 +/- 0.13 mg/L in Group A; 1.32 +/- 0.79 mg/L vs. 0.37 +/- 0.21 mg/L in Group B) (P < 0.05). The D-dimeride level 3 hours after operation was significantly higher in Group B than in Group A (P < 0.05). There were no significant differences in the levels of fibrinogen, prothrombin time,.and activated partial thromboplastin time between the two groups (P > 0.05).

During and after the TKA operation, a short-term use of tranexamic acid can significantly decrease blood loss and blood transfusion with no increasing risk for venous thrombosis.