Abstract
Introduction
Tranexamic acid is an inhibitor of fibrinolysis that blocks the lysine-binding site of plasminogen to fibrin, and thereby decreases blood loss in patients undergoing surgery.
Aims and objectives
A prospective, randomized, double-blind study was done on 100 patients undergoing primary cemented Unilateral Total Knee Arthroplasty to determine the effect of tranexamic acid on intra- and postoperative blood losses and on the transfusions requirements.
Material and Methods
100 patients undergoing unilateral cemented total knee Arthroplasty for osteoarthritis were enrolled for the study. All total knee replacement was done under combined spinal epidural anaesthesia with the use of tourniquet.
100 patients were randomized to tranexamic acid (15 mg/kg) given as a bolus intravenous injection or placebo (normal saline) given intravenously, 15 minutes before the release of tourniquiet.
The blood loss (at removal of the drain 24 hours after the operation) and the number of blood transfusions required were recorded. The patients were screened for deep venous thrombosis with bilateral compression Ultrasonography using Colour Doppler imaging on the tenth postoperative day. The Hemoglobin level was measured preoperatively and on the 3rd postoperative day. The D-dimer levels were measured preoperatively and 24 hrs postoperatively.
Results
Patients receiving tranexamic acid had a mean postoperative blood loss of 175 ml(range, 130–310ml) versus 330 ml (range, 210–460ml) (p value<0.05), and a total need for 3 blood transfusions versus 15. Only 3 out 50 patients in tranexamic acid group required blood transfusion whereas 12 out of 50 patients in the placebo group required transfusion.
In the group receiving placebo the mean fall in hemoglobin was 2.1g/dl (range, 1.5–3.2) and in the group treated with tranexamic acid 1.3 g/dl (0.9–2) (p<0.05). At 24 hrs postoperatively, mean plasma D-dimer concentration in the Tranexamic group was half of that in the control group. No patient in either group had any evidence of deep vein thrombosis on bilateral compression Ultrasonography using Colour Doppler imaging done on the tenth postoperative day.
Conclusion
Tranexamic acid 15 mg/kg given as a single bolus dose reduces blood loss, and transfusion requirements in unilateral primary cemented total kneearthroplasty without any increased risk of thrombus formation.
