One Dose of Intravenous Tranexamic Acid Is Equivalent to Two Doses in Total Hip and Knee Arthroplasty.

Background: Tranexamic acid (TXA) helps to prevent excessive blood loss during total hip arthroplasty (THA) and total knee arthroplasty (TKA), but the most efficacious dosing protocol has not been ascertained. The purpose of this study was to identify whether 1 dose of intravenous TXA is equivalent to 2 doses for reducing blood loss and transfusion rates following THA and TKA without an increase in complications.
Methods: We identified 1,736 patients who underwent THA (592 who did not receive TXA, 454 who received 1 dose of TXA, and 690 who received 2 doses) and 2,042 patients who underwent TKA (744 who did not receive TXA, 499 who received 1 dose, and 799 who received 2 doses) from 2012 to 2016. The differences among groups with regard to the change in hemoglobin levels, rate of allogeneic blood transfusions, and rate of complications were assessed.
Results: Patients who underwent THA and received 1 dose or 2 doses of TXA had similar drops in the mean hemoglobin levels postoperatively (2.9 g/dL and 3.1 g/dL, respectively; p = 0.197) and both had a smaller drop than the control group (3.6 g/dL; p < 0.001 compared with the 1 and 2-dose groups). These findings were confirmed by a multivariate analysis that controlled for age, sex, and preoperative hemoglobin level. Transfusion was required for 12.5% of the patients who underwent THA without receiving TXA, no patient who received 1 dose, and 0.7% of the patients who received 2 doses. The patients who underwent TKA and received 1 dose or 2 doses of TXA had similar mean drops in the hemoglobin level postoperatively (2.4 g/dL and 2.4 g/dL, respectively; p = 0.891), and both had less of a drop than the control group (2.9 g/dL; p < 0.001 compared with the 1 and 2-dose groups). These findings were also confirmed by a multivariate analysis that controlled for age, sex, and preoperative hemoglobin level. Transfusion was required for 4.3% of the patients who underwent TKA without receiving TXA, 0.4% of those who received 1 dose, and 0.3% of those who received 2 doses. Similar rates of perioperative complications occurred among all groups.
Conclusions: One dose of TXA was as effective as 2 doses for decreasing blood loss and transfusion rates after THA and TKA without an increase in complications.
Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.