Abstract
Multiple studies have shown tranexamic acid (TXA) to reduce blood loss and transfusion
rates in patients undergoing total knee arthroplasty (TKA). Accordingly, TXA has become
a routine blood conservation agent for TKA. In contrast, ε-aminocaproic acid (EACA),
a similar acting antifibrinolytic to TXA, has been less frequently used. This study
evaluated whether EACA is as efficacious as TXA in reducing postoperative blood transfusion
rates and compared the cost per surgery between agents. A multicenter retrospective
chart review of elective unilateral TKA from April 2012 through December 2014 was
performed. Five hospitals within a health care system participated. Data collected
included age, gender, severity of illness score, use of antifibrinolytic and dose,
red blood cell (RBC) transfusions and the number of units, and preadmission and discharge
hemoglobin (Hb). Dosing of the antifibrinolytic differed based on the agent used,
5 or 10 g (based on weight) for EACA versus 1 g for TXA. The institutional acquisition
cost of each antifibrinolytic was obtained and averaged over the study period. Of
2,922 primary unilateral TKA cases, 820 patients received EACA, 610 patients received
TXA, and 1,492 patients received no antifibrinolytic (control group). Compared with
the control group both EACA and TXA groups had significantly fewer patients transfused
(EACA 2.8% [p < 0.0001], TXA 3.2% [p < 0.0001] vs. control 10.8%) and lower mean RBC units transfused per patient (EACA
0.05 units/patient [pt] [p < 0.0001], TXA 0.05 units/pt [p < 0.0001] vs. control 0.19 units/pt]. There was no difference in mean RBC units transfused
per patient, percentage of patients transfused, and discharge Hb levels between the
EACA and TXA groups (p = 0.822, 0.236, and 0.322, respectively). Medication acquisition cost for EACA averaged
$2.23 per surgery compared with TXA at $39.58 per surgery. Administration of EACA
or TXA significantly decreased postoperative transfusion rates compared with no antifibrinolytic
therapy. Utilization of EACA for unilateral TKA proved to be comparable to TXA in
all studied aspects at a lower cost. The level of evidence for the study is Level
3.
Keywords
total knee arthroplasty - total joint arthroplasty - tranexamic acid - ε-aminocaproic
acid - blood transfusion
