Regular ArticleDuration of Postoperative Fibrinolysis after Total Hip or Knee Replacement: A Laboratory Follow-up Study

IntroductionHyperfibrinolysis is observed during and immediately after major orthopedic surgery. The kinetics and duration of this phase should be defined to adjust the duration of antifibrinolytic treatment with tranexamic acid (TXA).ObjectiveWe aimed to quantify the duration of postoperative fibrinolysis and to assess the biological impact of TXA administration.Materials and MethodsFourteen patients undergoing total hip replacement (THR) and 10 patients undergoing total knee replacement (TKR) with tourniquet were included in an observational, prospective, single-center study. Among these patients, 7 THR patients and 5 TKR patients received TXA (15 mg/kg IV intraoperatively, followed by continuous infusion of 15 mg/kg/h until end of surgery, then every 4 hours until 16 ± 2 hours after surgery). D-dimers, euglobulin lysis time (ELT), and thrombin generation time (TGT) were measured prior to surgery as well as 6, 18 and 24 hours (H) after.ResultsNo significant difference in ELT was observed between the groups. In contrast, D-dimers significantly increased postoperatively in patients not treated with TXA (p < 0.001), while such an increase was prevented in patients receiving TXA, as measured at H0, H6, H18 and H24 after THR, and at H6 and H18 after TKR (p < 0.001). No significant between-group change in TGT, was observed (peak thrombin and endogenous thrombin potential) all along the study.ConclusionThis study shows that fibrinolysis peaked 6 hours after end of surgery and maintained about 18 hours after surgery, as evidenced by an increase in D-dimers. When administered for up to 16 ± 2 hours after surgery, TXA reduced postoperative fibrinolysis.