Abstract
Although continuing antithrombotic therapy is desirable to prevent perioperative cardiovascular and cerebrovascular diseases, perioperative blood loss remains a concern in patients undergoing total knee arthroplasty. The purpose of this study was to assess the impact of continuing chronic antithrombotic therapy on blood loss and major bleeding events. METHODS: We classified 201 consecutive patients undergoing total knee arthroplasty into 2 groups: (1) patients taking antiplatelet agents, vitamin K antagonists, and/or direct oral anticoagulants, referred to as the continuing antithrombotic therapy group (n = 32); and (2) patients not receiving these agents, referred to as the no antithrombotic therapy group (n = 169). During the study period, antithrombotic agents were continued perioperatively in all patients receiving antithrombotic therapy. Surgical procedures were performed without the use of a pneumatic tourniquet or drain. Screening for deep vein thrombosis was routinely performed before and after total knee arthroplasty. The total perioperative blood loss was calculated from blood volume and change in hemoglobin from preoperatively to postoperative days 1, 3, and 7. RESULTS: The perioperative blood loss after total knee arthroplasty did not differ significantly between the continuing antithrombotic therapy group and the no antithrombotic therapy group at 1 day postoperatively (448 ± 213 compared with 495 ± 345 mL [95% confidence interval (CI) of the difference, -172 to 77 mL]; p = 0.45), 3 days postoperatively (841 ± 308 compared with 826 ± 328 mL [95% CI, -108 to 139 mL]; p = 0.81), and 7 days postoperatively (855 ± 313 compared with 861 ± 245 mL [95% CI, -122 to 108 mL]; p = 0.91). No patients in the continuing antithrombotic therapy group and 2 patients (1.2%) in the no antithrombotic therapy group had allogeneic blood transfusion (p = 1). No major bleeding events occurred in the continuing antithrombotic therapy group. CONCLUSIONS: Perioperative blood loss in patients continuing chronic antithrombotic therapy during total knee arthroplasty was not significantly different from that in patients receiving no chronic antithrombotic therapy. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.