Tranexamic Acid Reduces Transfusion Rates in Obese Patients Undergoing Total Joint Arthroplasty

While tranexamic acid (TXA) has been well shown to reduce blood loss after joint replacement surgery, little is known regarding its effectiveness in obese patients. The aim of this study was to evaluate the effect of TXA changes in hematocrit and hemoglobin levels as well as incidence of packed red blood cell (pRBC) transfusions in obese patients undergoing total joint arthroplasty (TJA).

Between January 2014 and May 2015, 420 consecutive primary joint replacements were performed by two surgeons at our institution. One-hundred-fifty-seven patients (total hip arthroplasty [THA]=29; total knee arthroplasty [TKA]=128) were obese with a body mass index (BMI) greater than or equal to 30 kg/m2. Medical records were reviewed and identified that TXA was utilized in 85 (54.1%) arthroplasties (study group) and was compared to a consecutive series of 72 (45.9%) TJAs (control group). TXA was given intravenously (IV) in two doses: (1) one gram prior to incision and (2) one gram at the time of femoral preparation in THA or prior to cementation in TKA. Changes in hemoglobin and hematocrit levels, number of pRBC transfusions, and occurrence of thrombolytic events were recorded.

The changes in hematocrit (7.2% vs. 8.1%) and hemoglobin levels (3.0 g/dl vs. 3.3 g/dl) were less in the group that received TXA than the control group, albeit not significantly (p=0.100 and p=0.278, respectively). Within the control group, 26 (36.1%) patients required a pRBC transfusion with a mean of 2.0 units per patient (range:1-5); whereas, only eight (9.4%) patients with TXA required a mean of 1.6 units per patient (range: 1-2). The use of TXA significantly reduced the incidence of pRBC transfusions, especially in TKA (p<0.001). Sub-analyses revealed that transfusion rates were even more significantly reduced by TXA in obesity type II and III. Two pulmonary emboli were reported in the group that did not receive TXA; whereas, no thrombolytic events were reported in the group that did receive TXA.

Utilization of TXA significantly reduced the rate of pRBC transfusions in obese patients.