What Should Define Preoperative Anemia in Primary THA?

Journal Article (Journal Article)

BACKGROUND: The use of tranexamic acid (TXA) in THA decreases the risk of transfusion after surgery. However, nearly 10% of patients still undergo a transfusion, which has been independently associated with an increased risk of complications. Preoperative anemia has been proven to be a strong predictor of transfusion after THA, but the ideal "cutoff" values in today's population that maximize sensitivity and specificity to predict transfusion have yet to be established. QUESTIONS/PURPOSES: (1) Which preoperative factors are associated with postoperative transfusion in the setting of TXA use? (2) If preoperative hemoglobin (Hgb) remains associated with transfusion, what are the best-supported preoperative Hgb cutoff values associated with increased transfusion after THA? METHODS: A retrospective chart analysis was performed from January 1, 2013, to January 1, 2015, on 558 primary THAs that met prespecified inclusion criteria. A multivariable logistic regression analysis model was used to identify independent factors associated with transfusion. Area under the receiver-operator curve (AUC) was used to determine the best-supported preoperative Hgb cut point across all participants, as well as adjusted by sex and TXA use. Overall, 60 patients with a blood transfusion were included and compared with 498 control subjects (11% risk of transfusion). RESULTS: After controlling for potential confounding variables such as age, sex, American Society of Anesthesiologist score, intravenous TXA (IV TXA) use, and preoperative Hgb, we found that patients with lower preoperative Hgb (g/dL per 1-unit decrease, odds ratio [OR], 2.6; 95% CI, 2.0-3.5; p < 0.001), female sex (vs male, OR, 4.2; 95% CI, 1.7-10.3; p = 0.002), and those unable to receive IV TXA (topical TXA/no TXA, OR, 13.5; 95% CI, 6.3-28.6; p < 0.001) were more likely to receive a transfusion. Of these, preoperative Hgb was found to be the variable most highly associated with transfusion (AUC, 0.876). A preoperative Hgb cutoff value of 12.6 g/dL maximized the AUC (0.876) for predicting transfusion across all patients unadjusted for baseline characteristics (sensitivity = 83, specificity = 84) with values of 12.5 g/dL (sensitivity = 85, specificity = 77) and 13.5 g/dL (sensitivity = 92, specificity = 77) for women and men, respectively. CONCLUSIONS: The 1968 WHO definitions of anemia (preoperative Hgb < 13 g/dL for men and < 12 g/dL for women) used currently may underestimate patients at risk of transfusion after THA today. Further studies are needed to see if blood conservation referral decreases the risk of transfusion with preoperative treatment of anemia. LEVEL OF EVIDENCE: Level III, therapeutic study.

Full Text

Duke Authors

Cited Authors

  • Klement, MR; Peres-Da-Silva, A; Nickel, BT; Green, CL; Wellman, SS; Attarian, DE; Bolognesi, MP; Seyler, TM

Published Date

  • November 2017

Published In

Volume / Issue

  • 475 / 11

Start / End Page

  • 2683 - 2691

PubMed ID

  • 28786087

Pubmed Central ID

  • PMC5638743

Electronic International Standard Serial Number (EISSN)

  • 1528-1132

Digital Object Identifier (DOI)

  • 10.1007/s11999-017-5469-4


  • eng

Conference Location

  • United States