RCT: Single IV Dose of TXA Is Safe, Effective for TKA
Along the spectrum of early and late adopters in medicine, most orthopaedic surgeons fall in the middle. They wait for science to prove the efficacy and safety of an innovation, carefully review the published studies regarding that innovation, and adopt it if it will improve their patients’ outcomes.
In the December 4, 2019 issue of JBJS, Jules-Elysee et al. compare tranexamic acid (TXA) administered intravenously (IV) versus topically in a double-blinded, randomized controlled trial (RCT) of patients undergoing primary total knee arthroplasty (TKA). Level-I evidence is rare in the orthopaedic literature, so when a well-performed RCT comes out, we should closely evaluate its findings.
A potent antifibrinolytic, TXA has been shown in multiple studies to decrease blood loss associated with major orthopaedic procedures. However, there are persistent (but not necessarily evidence-based) concerns about its potential to cause thrombogenic complications, and the safest and most effective route of TXA administration remains an open question.
In this study, the IV group received TXA once before tourniquet inflation and again 3 hours later, along with a topical placebo given 5 minutes before tourniquet release. The topical group received an IV placebo at the same time intervals as the IV group, along with TXA delivered topically in the wound prior to tourniquet release. The authors found lower systemic levels of plasmin-anti-plasmin (PAP, a measure of fibrinolysis) in both groups 1 hour after tourniquet release, but PAP levels remained significantly lower in the IV group (indicating higher antifibrinolytic activity) 4 hours after tourniquet release, which was likely related to the second IV dose of TXA.
The authors also found no between-group difference in systemic or wound levels of prothrombin fragment 1.2 (PF1.2, a marker of thrombin generation), indicating there was no increase in thrombogenicity in the IV group. Interestingly, Jules-Elysee also found that the IV group had significantly higher hemoglobin and hematocrit levels 1 and 2 days after surgery, and those patients had a significantly shorter hospital stay.
Finding no major between-group differences in the mechanism of action, coagulation, or fibrinolytic profile, the authors concluded that a single IV dose of TXA may be the most simple protocol for hospitals to adopt if they are still concerned about TXA safety. Perhaps these Level-I findings will help some of the late adopters get over their fears about the safety of IV TXA.
Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media