Abstract
Background
Tranexamic acid (TXA) is a lysine analog that has been shown to reduce intra-operative blood loss in total joint replacements. Effect of TXA in morbid obese patients has not been established. The aim of this study was to evaluate the effect of TXA on change of haematocrit (HCT) and packed RBC (PRBC) blood transfusion rate in our institution, especially in morbid obese patients.
Methods
Between January 2014 and December 2014, 216 primary and revision hip and knee arthroplasty were identified from our prospective institutional database. All cases were performed by two adult reconstruction specialists. All primary total hip arthroplasties (THA) were non-cemented and all primary total knee arthroplasties (TKA) were cemented with similar implant and technique. Use of TXA in our institution was initiated on August of 2014. TXA was given intravenously (IV) as one gram prior to incision and one gram at the time of femoral preparation in THA or cementation in TKA, not exceeding 10mg/kg. In cases where IV TXA was contraindicated, topical was used. We analyzed pre- and post-operative hematocrit and transfusion rate. Criteria for transfusion was HCT < 25 or Hb < 9. 72 patients (33%) were considered morbid obese with body mass index (BMI) ≥ 35.
Results
In the non-TXA group, 50 out of 126 cases (40%) were transfused (17 THA, 25 TKA, 5 revision THA, 3 revision TKA), ranging from 1–5 PRBC. In the TXA group, 13 out of 90 cases (14%) were transfused (3 THA, 8 TKA, 2 revision THA), ranging 1–2 PRBC. This difference was statistically significant (p=0.0001).
The overall drop in the TXA group HCT was 5.9 ± 3.9, as compared to 9.8 ± 4.3 in the non-TXA groups, which was statistically significant (p=0.0001).
The mean pre- and post-operative HCT was 37.4 ± 4.3 and 28.2 ± 3 in the transfused patients without TXA. The average drop in HCT was 9.3 ± 4.3. The mean pre- and post-operative HCT was 34.3 ± 4.1 and 27.4 ± 1.9 in the transfused patients without TXA. The average drop in HCT was 7.3 ± 2.9.
In the morbid obese patients, 45 did not receive TXA, 17 had transfusion with average drop in HCT of 9.6 ± 3.9; 29 received TXA and 2 had transfusion with average drop in HCT of 5.9 ± 3.1. There transfusion and drop in HCT was significantly less for morbid obese patients that received TXA (p=0.0001).
Discussion and Conclusions
Since initiating TXA in our institution, the overall transfusion rate in both primary and revision arthroplasty cases have dramatically declined (26%). This was more evident in morbidly obese patients. In cases that needed transfusion with TXA, only one or two PRBC was given, which was a drastic improvement.
