Surgeries
Preoperative Tranexamic Acid, Tourniquet Use, and Recorded Intraoperative Blood Loss in Total Knee Arthroplasty
By Sandra Elizabeth Castillo-Sánchez, Martha A. Sánchez-Rodrı́guez, Andrea Lara Salazar and 8 others.
Abstract
Background
Anesthesiologist-estimated blood loss is a frequent outcome in retrospective blood-conservation studies, but whether it captures the effect of tranexamic acid (TXA) in total knee arthroplasty (TKA) is unknown.
Methods
This retrospective cohort study included primary unilateral TKAs in patients aged 40–75 years (2024–2025) at a public hospital in Mexico. The primary outcome, intraoperative blood loss recorded on the anesthesia record, was analyzed with linear regression including a TXA × tourniquet interaction and prespecified confounders. Predictors of TXA use and recording patterns were examined.
Results
Of 343 patients, 125 (36.4%) received 1 g intravenous TXA and 233 (67.9%) had a tourniquet. TXA was not associated with recorded blood loss without a tourniquet (adjusted difference +15 mL; 95% CI −73 to 103) or with one (+24 mL; −18 to 65), whereas the tourniquet was associated with −349 mL (−405 to −293). Clinical and organizational variables did not predict TXA use (optimism-corrected AUC 0.54). Without a tourniquet, 95.5% of values were multiples of 50 mL; with a tourniquet, 0 mL was recorded less often after TXA (adjusted OR 0.43; 0.23–0.80).