TITLE:
Preoperative Anemia Is Associated with Increased Mortality Following Primary Unilateral Total Joint Arthroplasty
AUTHORS:
Michael D. Herrick, Brian D. Sites, Melissa M. Masaracchia, Wayne E. Moschetti
KEYWORDS:
Anesthesia, Total Joint Arthroplasty, Anemia
JOURNAL NAME:
Open Journal of Anesthesiology,
Vol.6 No.6,
June
9,
2016
ABSTRACT: Background: Total joint arthroplasty is a commonly performed procedure for end-stage osteoarthritis. Preoperative anemia is a well-characterized and potentially modifiable risk factor for morbidity and mortality in non-cardiac surgery. This retrospective cohort study identified the prevalence of anemia in our total joint arthroplasty population and investigated if there was an association with all-cause mortality. Study Design and Methods: Using an electronic medical record, we examined all patients who underwent a primary unilateral total joint arthroplasty at Dartmouth-Hitchcock Medical Center from January 1, 2011 through July 1, 2015. Preoperative anemia thresholds were defined according to the World Health Organization as 12 mg/dl for women and 13 mg/dl for men. Kaplan-Meier survival analyses were performed to examine the relationship between preoperative anemia and all-cause mortality. Cox proportional hazards were calculated for various models adjusting for potential confounders. Results: 439 of the 3247 patients (13.5%) that underwent total joint arthroplasty met the preoperative definition for anemia. 48 patients (1.48%) died during 6470 patient years of follow up, generating an incidence rate of 7.4 deaths per 1000 patient years. The crude hazard ratio for death in anemic patients was 3.42 (95% CI 1.89, 6.82). In multiple models adjusting for various health related confounders, preoperative anemia was associated with a roughly two-fold increase risk of death compared to non-anemic patients. Conclusion: Preoperative anemia is prevalent in our population and it is associated with increased postoperative mortality in total joint arthroplasty patients, even when adjustments are made for significant co-morbidities.