Ana Torres, Mariano Fernández-Fairén,Daniel Hernández Vaquero
Introduction: Tranexamic acid has showed its good results reducing blood loss in total knee arthroplasties. It has also probed being cost-effective (red cell concentrate: 350 euros/ TXA vial 3, 05 euros) but it remains not being clear at what time during the surgery we have to administrate it. In this prospective, randomized study, we have investigated the effects of the use of tranexamic acid before or after inflating the tourniquet on blood loss, transfusion needs and thromboembolic complications after implanting a total knee arthroplasty. 120 patients were selected and assigned randomly in two groups: tranexamic acid employed before inflating (group 1) or just before deflating the tourniquet (Group 2).
Methods and Materials: From May 2011 to May 2012, 80 patients (38 males, 42 females; aged 64-81 years, mean age 69, 2years) underwent to a total knee replacement. All of them had moderate-severe knee osteoarthritis. They were randomized divided into Group1 and Group 2 of 40 patients each. The patients in Group 1 received tranexamic acid (TXA) before inflating the tourniquet and TXA was administered on the patients in Group 25 minutes before deflating the tourniquet. TXA was used in both groups every 8 hours during the first three days postop. Variables under comparison included haemoglobin determinations (pre, postop and fifth days after surgery), drainage blood volume, transfusion requirements and appearance of thromboembolic complications.
Results: The drainage blood loss was 364 ± 186 ml (Group 1) and 413 ± 175 ml (Group 2).The total blood loss was 573 ± 159 ml (Group 1) and 608 ± 132 (Group 2). No statistical significant differences were found in the amount of blood at the drain and on the total blood loss.The haemoglobin values did not showed statistical significant differences between groups before surgery on the postop or 5 days after the surgery. No significant difference in haemoglobin determinations (pre, postop and fifth days after surgery), drainage blood volume, transfusion requirements, deep-vein thrombosis, and pulmonary embolism was detected between the groups. One patient in group 1 received 1 unit of allogenic blood and one patient in group 2 received 3 units. No statistical significant difference was seen.Two patients in group 1 and three patients in group 2 had clinical symptoms of deep vein thrombosis. Only one patient in group 2 presented an eco-Doppler study positive for a lower limb thrombosis.
Conclusions: We conclude that there is no significant difference on blood loss, transfusion requirements and thromboembolic complications after performing a total knee arthroplastywhen thetranexamic acid is employed before inflating or just before releasing the tourniquet.
