Abstract
Introduction
We examined the effect on blood loss of two standardised intravenous bolus doses of 500 mg of Tranexamic Acid, a fibrinolytic inhibitor that reduces blood loss following Knee Arthroplasty (KA).
Materials and Methods
Our study included one hundred consecutive patients undergoing primary cemented KA, who received two standarised bolus doses of 500 mg of Tranexamic Acid. The first dose was administered at induction to anaesthetic and the second dose was administered just before the closure. Data, which included Haemoglobin (Hb), Haematocrit (Hct), Length of Hospital Stay (LOS) and complications, was collected prospectively by an independent observer. Routine blood tests were done on the 1st or 2nd post-operative day.
Results
Out of 100 patients aged from 49 to 92 years old (mean age of 69 years), 39 were male and 48 underwent a right KA. The mean LOS was 4.73 days with a standard deviation (SD) of 3.07 days. The mean drop of Hb was 2.04 g/dl (15.5%) with a SD of 0.89 g/dl (6.2%). The mean drop of Hct was 0.096 (16.7%) with a SD of 0.325 (10.0%).
Only 2 patients had developed symptoms of anaemia and were transfused with 2 units of red blood cells each. Ultrasound scan was used to investigate patients with possible Deep Venous Thrombosis (DVT). Indications were calf pain and swelling of the lower limb. 10 patients were investigated, out of which in only 3 patients the diagnosis of DVT was confirmed, whereas in 2 patients DVT could not be excluded because of obesity.
Conclusions
We believe that the use of two standardised intravenous bolus doses of 500 mg of Tranexamic Acid reduces peri-operative blood loss, reducing the need for transfusion, without increasing the risk of thromboembolic complications.
