161. INTRODUCTION OF A USER-FRIENDLY DOSE OF TRANEXAMIC ACID IN PRIMARY ARTHROPLASTY PATIENTS

Abstract

Purpose: Multiple studies have demonstrated the efficacy of Tranexamic Acid (TA) in reducing blood loss and red blood cell transfusion in patients undergoing primary total hip (THA) or knee (TKA) arthroplasty. However, the dosing schedules of either an initial bolus followed by a 6–12 hour infusion or multiple intravenous bolus doses are not ‘user-friendly’ for regular application. The purpose of this study was to assess the efficacy and acceptance of a single dose protocol for the use of TA in primary THA or TKA.

Method: We selected a single dosing schedule of 20mg/kg TA given either prior to skin incision for THA or approximately ten minutes prior to tourniquet release for TKA. The hospital pharmacy supplied the TA rounded off to the nearest 5kg/100mg in a 100ml mini-bag. In March 2008, we introduced the routine use of TA to all patients undergoing primary THA or TKA at our institution. Mini-bags were pre-ordered at the time of the preoperative clinic visit and delivered to the pre-surgical preparation area on day of surgery. One month after implementation of this protocol we compared blood loss, transfusion rates, and hemoglobin at discharge between the patients operated on from April 1 to June 30, 2007 (when this protocol was not in place) to those from April 1 to June 30, 2008. No other routine patient care practices were altered during this time period.

Results: We found a significant reduction in the decrease in hemoglobin from 2007 compared to 2008 for both THA and TKA (46g/L to 39g/L, and 45g/L to 36g/L, respectively), which led to both a reduction in transfusion rates (13.5% to 3.6%, and 13.1% to 2.0%, respectively) and higher hemoglobin levels at discharge. All patients received the TA as ordered.

Conclusion: Dosing and timing of TA is critical to maximize its antifibrinolytic effect. Our weight increment dose protocol led to minimal dose variability, facilitated pharmacy drug preparation, and minimized wastage. This simple ‘user-friendly’ protocol was found to reduce the decrease in hemoglobin and transfusion rates, demonstrating similar efficacy to other more complex dosing schedules. This protocol was well received and accepted by surgeons, anesthesiologists, pharmacy, and nursing staff.