Is tranexamic acid effective on hidden blood loss in patients during total knee arthroplasty?

OBJECTIVES: This study aims to investigate if tranexamic acid (TXA) reduces both visible and hidden blood loss in patients undergoing total knee arthroplasty (TKA). PATIENTS AND METHODS: A total of 128 female patients (mean age 68.9±5.8 years; range, 55 to 80 years) who underwent TKA and were admitted between January 2010 and January 2020 were included in this retrospective study. Only patients who had primary unilateral knee arthroplasty with a cemented posterior cruciate ligament substituting implant were included. Patients were divided into two groups according to TXA administration in the perioperative period. Group 1 consisted of patients who did not receive TXA (n=69), while Group 2 consisted of patients who received TXA (n=59). The effect of TXA on visible and hidden blood loss, amount of erythrocyte suspension transfusions, postoperative early wound complications, and the relationship between the volume of hidden blood loss and drainage volume were detected. RESULTS: There was no statistically significant difference between the groups in terms of age, body mass index, operation side, preoperative hematocrit (HCT) values, and total blood volume. Postoperative HCT values were statistically higher in Group 2. Fifty-four units of erythrocyte suspension transfusion were required in Group 1, while six units were required in Group 2 (p<0.001). Early wound complication was determined in 10 patients in Group 1 and only in one patient in Group 2 (p=0.011). Intraoperative blood loss, postoperative drainage volume, hidden blood loss, and total blood loss values were significantly lower in Group 2 (p=0.001). In all patients, there was a significant positive correlation between the postoperative drainage volume and the hidden blood loss volume (r=0.532, p=0.001). CONCLUSION: The use of TXA in patients undergoing TKA reduces postoperative bleeding (visible and hidden blood loss), blood transfusion needs, and early wound complications. In addition, drainage volume in postoperative 24 hours can be used to estimate the amount of hidden blood loss in early postoperative period.