Blood-conserving and therapeutic efficacy of intravenous tranexamic acid at different time points in primary total knee arthroplasty with tourniquet application: a randomized controlled trial

Abstract

Objective To investigate the effect of the first dose of tranexamic acid received intravenously before tourniquet compression and release in total knee arthroplasty (TKA) on perioperative blood loss and therapeutic efficacy of patients. Methods In this double-blind trial, 90 patients undergoing primary TKA were randomized into 2 groups: the patients in group A was received intravenous tranexamic acid (TXA) 10 minutes before tourniquet compression (20 mg/kg) and 3, 6 and 24 hours later (10 mg/kg), and the patients in Group B was treated the same as Group A but received intravenous TXA before tourniquet release. The primary outcomes were the change of blood loss, hemoglobin and hematocrit. Secondary outcomes included operation and tourniquet time, blood transfusion rate, subcutaneous petechiae and circumferential changes of the operated limb, visual analog scale (VAS), hospital for special surgery (HSS) score, length of stay (LOS) postoperatively, complications and patient satisfaction. Results No statistically significant differences were found between the 2 groups with regard to age, gender, weight, BMI, Kellgren-Lawrence class, preoperative blood volume, preoperative laboratory values, operation and tourniquet time, transfusion rate, knee circumference, preoperative HSS, VAS. There was no significant difference in intraoperative blood loss (IBL) (52.71 ml vs. 63.44 ml, P= 0.07), hidden blood loss (HBL) (91.39 ml vs. 119.90, P= 0.40) and total blood loss (TBL) (144.1 ml vs. 183.3 ml, P= 0.72) between groups A and B. Hemoglobin, hematocrit and red blood cell count (RBC) dropped to a low point on postoperative day 3 and then rebounded, returning to normal levels on day 21, and the trend of change between the 2 groups was no statistically significant difference. There was no significant difference in subcutaneous ecchymosis, knee swelling, HSS, VAS, LOS postoperatively, complication rate and patient satisfaction. Conclusion There was no significant difference in total perioperative blood loss, knee swelling, subcutaneous bruising and petechiae, knee function, complication rate and satisfaction between the intravenous tranexamic acid before tourniquet compression and release in primary total knee arthroplasty. However, the trend towards better reduction of perioperative blood loss, as reflected by changes in blood loss and h ematocrit, may be related to the role of the effective blood concentration formed in the operative area before tourniquet pressurization. Although it is not possible to conclude that better hemostasis can be achieved by administration before tourniquet compression, we believes that 10 minutes before tourniquet compression is a more recommendable option when conditions permit, and that the second postoperative dose should be dripped intravenously 3 hours after the first dose to ensure effective plasma concentrations.