Impact of Obesity on Tranexamic Acid Efficacy in Adult Patients With Major Bleeding

Tranexamic acid (TXA) is an antifibrinolytic used for prophylaxis and treatment of acute bleeding. Although fixed dosing is often used in practice, weight-based dosing is sometimes used in the operating room (OR). The efficacy and safety of fixed-dose TXA is not well established in patients with above average weight or body mass index.

To characterize the efficacy and safety of intravenous TXA in obese patients with major bleeding.

This was a retrospective review of 165 patients receiving fixed-dose TXA for acute bleeding outside the OR. Blood product administration (BPA) before and after TXA was collected, along with demographic and bleed-related information. Thrombotic events were the major safety end point. A prespecified subgroup analysis was conducted in patients weighing at least 100 kg compared with a lower weight. Logistic regression was performed to determine whether an association exists between body weight and blood product requirement after TXA administration.

In the 24 hours after TXA, patients received an average of 4.17 units of blood product. Patients weighing at least 100 kg averaged 4.04 total units, compared with 4.19 units in the lower weight group (P = 0.603). Administration of individual blood products did not differ between groups, and thrombotic events were similar. Regression analysis did not associate weight with total BPA.

In patients receiving fixed-dose TXA, weight does not appear to alter blood product requirements or rates of adverse thrombotic events. These data support continued use of fixed-dose TXA for treatment of acute major bleeding in obese patients.