Yoeri Bemelmans

Tranexamic acid in hip and knee arthroplasty 33 3 Introduction Since the introduction of tranexamic acid (TXA) usage in primary hip- and knee arthroplasty procedures, perioperative blood loss is reduced with a decreased incidence of allogenic blood transfusions [1,7,15,27,30]. TXA is a synthetic analogue of the amino acid lysine that reduces blood loss by inhibiting the degradation of fibrin and disintegration of blood clots. Perioperative allogenic blood transfusions are strongly related to increased risk of surgical site infection and deep venous thrombosis [14,17]. Therefore, it is of paramount importance to prevent blood transfusions. Standardized perioperative protocols are used without an increased risk of perioperative thrombo- embolic events (e.g. deep venous thrombosis/pulmonary embolism) [8,9,10,19]. Given these benefits, a perioperative TXA protocol is increasingly implemented and used in primary hip and knee arthroplasty. Different perioperative protocols exist on type of administration, frequency of administration, dosage and timing of administration. TXA can be administered orally, intravenously or topical, with equal safety and efficacy in terms of postoperative blood transfusions and (low) adverse events (AE) rates [2,3,8,10,11,19,21,28,29]. To maximise the effect of TXA and minimise AE rates, perioperative protocols are needed with substantial clinical evidence. The aim of this study was to evaluate the incidence of perioperative allogenic blood transfusions after the implementation of a combined low-dose oral and intravenous TXA protocol for elective hip and knee arthroplasty. Patients andmethods This retrospective cohort studyevaluates the incidenceof allogenicblood transfusions in patients who have been operated on primary total hip (THA), unicompartimental (UKA) - and total knee arthroplasty (TKA). All data was obtained from the hospital transfusion and surgery registration. To evaluate possible inclusion in this study, the complete database of surgeries performed between June 2014 and June 2019 were screened. All primary unilateral THA, UKA and TKA patients were included. Arthroplasty surgeries related to complications, revision or trauma were excluded from analysis. Selection of patients is presented in figure 1. Pre-, peri, and postoperative protocols All patientswere operatedwith the use of standardized perioperative protocols regarding fast-track or outpatient surgery (e.g. multimodal pain management, mobilisation <24hrs after surgery, no drain/urinary catheter) [22]. In UKA procedures, tourniquet was used. Only in knee arthroplasty patients, local infiltration analgesia was used. Patients were