Abstract
Tranexamic acid (TXA) is an effective medication to limit blood loss and transfusion requirements in association with contemporary total joint arthroplasty. TXA is in a class of medications termed anti-fibrinolytics due to their action to limit the breakdown of clot that has already been formed. It is useful to note that TXA does not promote the formation of clot, it simply limits the breakdown of already established clot. A recent systematic review and meta-analysis of randomised clinical trials of TXA use in total hip replacement demonstrated: 1) a substantial reduction in the proportion of patients who required transfusion and 2) no increase in DVT or PE. Similarly a recent Cochrane Database systematic review assessed Anti-fibrinolytic Use for Minimising Perioperative Blood Transfusion and found tranexamic acid to be effective in reducing blood loss during and after surgery and to be free of serious adverse effects. The typical dose of TXA in cardiac surgery has been 10–20 mg/kg as an IV bolus given over 10–20 minutes followed by continuous infusion of 1 mg/kg/hour for 8 hours. In orthopaedic surgery varying doses have been used over time. A pragmatic dosing approach for Total Knee and Total Hip patients has been used at the Mayo Clinic over the past 10 years: 1 gram IV over 10 minutes prior to incision (delivered at same time as pre-op antibiotics) followed by 1 gram IV over 10 minutes at the time wound closure is initiated. Infusion rates greater than 100 mg/minute have been associated with hypotension and thus the recommendation for 1 gram over 10 minutes. A recent review of 1500 TKA patients at Mayo Clinic revealed a very low prevalence of clinically symptomatic DVT and PE when tranexamic acid was used with 3 different thromboembolic prophylaxis regimens (aspirin and foot pumps; coumadin; low molecular weight heparin). The safety of TXA for patients with coronary stents has not been fully clarified.
