Tranexamic acid is effective in reducing perioperative blood loss in a myriad of clinical interventions, including major orthopedic surgery. Despite a large number of clinical studies, the optimal dosing of the drug is not clear. Iwai et al. investigated whether repeat-dose tranexamic acid was more effective compared with single-dose tranexamic acid in patients undergoing total knee replacement surgery. The authors enrolled 78 patients and divided them (not at random) into three groups: one group received 1 gram tranexamic acid during the operation (n = 21), one group received tranexamic acid during and 3 hours after the operation (n = 26), and one group did not receive tranexamic acid (control group, n = 31). Patients who received two doses of tranexamic acid had 300 mL less blood loss than patients who received only one dose of tranexamic acid and 500 mL less blood loss compared to patients not treated with the drug. Allogeneic transfusion was not required in all three groups. The control group was administered a mean of 400 mL blood by autotransfusion, whereas both tranexamic acid groups did not require any transfusion. There were no significant differences in thrombotic and other adverse events between the three groups.

This study again shows the potential of tranexamic acid to reduce perioperative blood losses. However, the practical implications of these results are less clear as the effect on clinically relevant outcomes was not studied. Side/adverse effects of repeated doses of tranexamic acid were not observed. However, the sample size may have been much too small to draw defintive conclusions at this point. Lastly, the nonrandomized study design and the fact that the study was not performed in a double-blind fashion may have introduced selection bias and other confounding variables.

– Marcel Levi