title: Postoperative anemia and early functional outcomes after fast-track hip arthroplasty: a prospective cohort study.
abstract: BACKGROUND
  Postoperative anemia is prevalent in fast-track hip arthroplasty (THA) where patients are mobilized and discharged early, but whether anemia impairs functional recovery after discharge has not been adequately evaluated previously. This study aimed to evaluate whether postoperative anemia influenced recovery of mobility and quality of life (Qol) during the first 2 weeks after discharge from THA.
  
  
  METHODS
  This was a prospective observational study in 122 THA patients more than 65 years of age. Mobility and Qol were assessed pre- and postoperatively by the 6-minute walk test (6MWT; primary outcome), the timed up-and-go test, and the FACT-anemia subscale. Twenty-four-hour mobility at home was assessed by activity monitoring on Days 1 to 6 after discharge. Hemoglobin (Hb) at discharge (HbD) and the Hb decrease from preoperatively (ΔHb) were compared to mobility and Qol the first 2 weeks after discharge using bivariate and multivariate linear regression.
  
  
  RESULTS
  Mean (±SD) HbD and ΔHb values were 11.1 (±1.4) and 2.8 (±1.2) g/dL and correlated weakly to 6MWT 2 weeks after discharge (r = 0.23 and r = -0.20 respectively; p < 0.05) but HbD levels were not correlated to other mobility or Qol measures. After adjustment for preoperative patient-related factors, HbD explained 6% (95% confidence interval, 0%-9%; p < 0.05) of the variation in 6MWT recovery.
  
  
  CONCLUSIONS
  Despite a weak, but significant, correlation between postoperative Hb and the recovery of 6MWT, all other mobility and Qol measures were not influenced by postoperative Hb. Thus, moderate postoperative anemia has limited impact on early postdischarge functional recovery after fast-track THA.
authors.affiliation: Section of Surgical Pathophysiology, Rigshospitalet, Copenhagen University Hospital.|Lundbeck Foundation Centre for Fast-Track Hip and Knee Arthroplasty, Cophenhagen, Denmark.
authors.forename: Øivind
authors.initials: Ø
authors.lastname: Jans
authors.affiliation: Physical Medicine & Rehabilitation Research-Copenhagen (PMR-C), Department of Physical Therapy, Clinical Research Centre, and Department of Orthopedic Surgery, Hvidovre Hospital, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Thomas
authors.initials: T
authors.lastname: Bandholm
authors.affiliation: Section of Surgical Pathophysiology, Rigshospitalet, Copenhagen University Hospital.
authors.forename: Sorel
authors.initials: S
authors.lastname: Kurbegovic
authors.affiliation: Department of Orthopedic Surgery, Gentofte Hospital, Gentofte, Denmark.
authors.forename: Søren
authors.initials: S
authors.lastname: Solgaard
authors.affiliation: Department of Orthopedic Surgery, Vejle Sygehus, Vejle, Denmark.
authors.forename: Per
authors.initials: P
authors.lastname: Kjaersgaard-Andersen
authors.affiliation: Section for Transfusion Medicine, Rigshospitalet.
authors.forename: Pär I
authors.initials: PI
authors.lastname: Johansson
authors.affiliation: Section of Surgical Pathophysiology, Rigshospitalet, Copenhagen University Hospital.|Lundbeck Foundation Centre for Fast-Track Hip and Knee Arthroplasty, Cophenhagen, Denmark.
authors.forename: Henrik
authors.initials: H
authors.lastname: Kehlet
mesh_terms: D000368:Aged; D000740:Anemia / Q000453:epidemiology* / Q000209:etiology; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000379:methods / Q000534:rehabilitation; D016063:Blood Loss, Surgical / Q000706:statistics & numerical data; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008991:Monitoring, Physiologic; D011183:Postoperative Complications / Q000453:epidemiology*; D011184:Postoperative Period; D020127:Recovery of Function / Q000502:physiology*; D016138:Walking