title: Duration of postoperative fibrinolysis after total hip or knee replacement: a laboratory follow-up study.
abstract: BACKGROUND
  Hyperfibrinolysis 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).
  
  
  OBJECTIVE
  We aimed to quantify the duration of postoperative fibrinolysis and to assess the biological impact of TXA administration.
  
  
  METHODS
  Fourteen 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 (15mg/kg IV intraoperatively, followed by continuous infusion of 15mg/kg/h until end of surgery, then every 4hours until 16±2hours after surgery). D-dimers, euglobulin lysis time (ELT), and thrombin generation time (TGT) were measured prior to surgery as well as 6, 18 and 24hours (H) after.
  
  
  RESULTS
  No 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.
  
  
  CONCLUSIONS
  This study shows that fibrinolysis peaked 6hours after end of surgery and maintained about 18hours after surgery, as evidenced by an increase in D-dimers. When administered for up to 16±2hours after surgery, TXA reduced postoperative fibrinolysis.
authors.affiliation: Cochin-Hôtel Dieu University Hospital, Assistance Publique - Hôpitaux de Paris, Université Paris Descartes, France. antonia.blanie@bct.aphp.fr
authors.forename: Antonia
authors.initials: A
authors.lastname: Blanié
authors.forename: Lorenn
authors.initials: L
authors.lastname: Bellamy
authors.forename: Yara
authors.initials: Y
authors.lastname: Rhayem
authors.forename: Claire
authors.initials: C
authors.lastname: Flaujac
authors.forename: Charles Marc
authors.initials: CM
authors.lastname: Samama
authors.forename: Michaela
authors.initials: M
authors.lastname: Fontenay
authors.forename: Nadia
authors.initials: N
authors.lastname: Rosencher
mesh_terms: D000368:Aged; D000933:Antifibrinolytic Agents / Q000008:administration & dosage*; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects; D015415:Biomarkers / Q000097:blood; D004334:Drug Administration Schedule; D005260:Female; D063285:Fibrin Clot Lysis Time; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism; D005342:Fibrinolysis / Q000187:drug effects*; D005500:Follow-Up Studies; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D010297:Paris; D011182:Postoperative Care; D019106:Postoperative Hemorrhage / Q000097:blood / Q000517:prevention & control*; D011446:Prospective Studies; D013917:Thrombin / Q000378:metabolism; D013997:Time Factors; D014148:Tranexamic Acid / Q000008:administration & dosage*; D016896:Treatment Outcome
chemical_list: D000933:Antifibrinolytic Agents; D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D; D014148:Tranexamic Acid; D013917:Thrombin