Abstract
Introduction
Allogeneic blood transfusion (ABT) remains a widely used therapeutic intervention in patients undergoing total knee arthroplasty (TKA). There is mounting evidence that tranexamic acid (TXA), a powerful antifibinolytic, can significantly reduce perioperative blood loss with a concomitant lower ABT rate. In May 2012, TXA intravenous infusion was introduced as standard therapy in all patients undergoing major hip and knee arthroplasty. The TXA protocol included infusing 1 gm prior to incision and 1 gm after lowering the tourniquet. Nadir hemoglobin (Hb) level has been shown to be the single most important predictor of ABT in patients undergoing TKA. It is often used as the main trigger for ABT and in research trials examining restrictive transfusion trials. There is a paucity of information regarding the impact of TXA on Hb levels in patients undergoing primary TKA. The purpose of this retrospective study was to examine the impact of TXA on hemoglobin levels in primary TKA patients.
Methods
Patients undergoing primary single, or bilateral, TKA from a single orthopedic surgeon from the years 2009–2010 before TXA infusion (n=78) were compared to patients undergoing the same operation after TXA was introduced as a therapeutic intervention (n=97). TKA is a very standardized operation that has stayed consistent over the convening years in terms of surgical technique and intra-operative management. The following Hb values were selected for analysis between the two groups: pre-surgical Hb value, immediate post-operative Hb, nadir Hb, and discharge Hb. Paired t-test was used for analysis with p-value set at 0.05. Additional data analysis included: length of stay (LOS) and rate of ABT.
Results
Demographically, the control group was younger compared to the experimental group (60 vs. 64 years). Table 1 shows the difference in the selected Hb values between the two groups.
There was no difference in Hb values going into surgery between the two groups. For all other Hb values, there was a significant difference between the control group and the TXA group throughout the postoperative period. In addition, Hb drift was significantly lower in the TXA group compared to the control group by 0.7 g/dl. ABT rate was 4% for the TXA group and 50% for the control group. The control group had a higher LOS compared to the TXA, 4.9 vs. 4.3 days.
Conclusion
TXA infusion in the intraoperative period is an effective therapeutic intervention for reducing the downward drift of Hb levels throughout the postoperative period in patients undergoing TKA, and in turn, significantly impacts ABT rate and resource utilization.
