The effect of tranexamic acid on blood coagulation in primary total hip arthroplasty using rotational thromboelastometry: a randomized controlled trial.

Background: Tranexamic acid (TXA), is commonly administered prophylactically to reduce blood loss in patients undergoing total hip arthroplasty (THA). However, its effect has never been studied. We hypothesized that no difference exists in the degree of fibrinolysis and blood loss between patients receiving prophylactic TXA and placebo.

Methods: This double-blinded randomized-controlled trial included 50 patients undergoing primary THA in 2021-2023. Clinicaltrials.gov (NCT03897621). Rotational-thromboelastometry (ROTEM) were performed to test blood coagulability using non citrated whole blood (NATEM) and blood treated with TXA (T-APTEM). The intervention group received TXA intravenously. The placebo group received 0.9% sodium chloride solution. The primary outcome measure was to quantitate the degree of fibrinolysis measured by maximum lysis (ML) demonstrated by ROTEM variables. Fibrinolysis was defined as ML (maximum lysis) > 15% within 1 h of testing.

Findings: Blood coagulability tested by ROTEM was within the normal range in all patients, and no difference was found between the TXA group and placebo group.NATEM and T-APTEM variables were similar in both groups and no patient developed fibrinolysis during the entire perioperative phases. At baseline, T-APTEM, compared with NATEM, showed shorter CT (746 ± 265 vs. 991 ± 237 p < 0.05) and greater ML (1.9 ± 2.2 vs. 0.8 ± 1, p < 0.05), suggesting some degree of acceleration of coagulation. Postoperatively, blood coagulability showed a tendency of acceleration with shorter CT (689 ± 188 vs. 828 ± 163, p < 0.05) and CFT (258 ± 101 vs. 293 ± 87 p < 0.05) and increased A10 (41 ± 9 vs. 38 ± 8, p < 0.05). Clinical outcomes, including blood loss, hematologic variables, and coagulation profile were similar between the two groups.

Interpretation: Normal range of blood coagulability in all patients, no significant differences between NATEM and T-APTEM variables, and similar clinical outcome between the two groups suggest that there is no definitive medical indication for TXA administration in patients undergoing THA without a preexisting fibrinolytic condition. Monitoring blood coagulability using ROTEM may be useful in guiding selective administration of TXA in high-risk patients.

Funding: Department of Anesthesiology funding, Thomas Jefferson University Hospital. Support was provided solely from institutional and/or departmental sources.