title: The effect of spinal anesthesia on blood transfusion rate in total joint arthroplasty.
abstract: BACKGROUND
  Total joint arthroplasty (TJA) patients often receive allogeneic blood transfusion. The use of regional anesthesia (RA) is thought to protect against the need for blood transfusion, but many randomized trials of RA in TJA have not reached this conclusion unanimously. We sought to describe the effect of RA on allogeneic transfusion in a large retrospective TJA series.
  
  
  METHODS
  We examined data from all TJAs performed in Edmonton, Alberta, in the year 2000 (n = 1875) and used logistic regression modelling to determine the relation between the use of RA and allogeneic transfusion.
  
  
  RESULTS
  Twenty-eight percent of TJA subjects received an allogeneic transfusion. Transfusion was independently associated with increasing age, decreasing body mass, decreasing preoperative hemoglobin, female sex, increased comorbidity and prolonged operative time. After controlling for these factors, we found that the use of RA (in the form of spinal anesthesia) compared with general anesthesia reduced the odds ratio (OR) for transfusion to 0.729 (95% confidence interval [CI] 0.559-0.949). This represents the combination of a strong relation between RA and transfusion prevention in hip arthroplasty (OR 0.646, 95% CI 0.443-0.944) and a nonsignificant relation in knee arthroplasty (OR 0.825, 95% CI 0.564-1.208).
  
  
  CONCLUSIONS
  The use of spinal anesthesia protects against allogeneic transfusion in arthroplasty of the hip but not the knee. This is consistent with what is known about the hemodynamic consequences of spinal anesthesia.
authors.affiliation: Department of Anesthesiology and Pain Medicine, University of Alberta, Edmonton. srashiq@ualberta.ca
authors.forename: Saifudin
authors.initials: S
authors.lastname: Rashiq
authors.forename: Barry A
authors.initials: BA
authors.lastname: Finegan
mesh_terms: D000367:Age Factors; D000368:Aged; D000765:Anesthesia, Conduction; D000768:Anesthesia, General; D019644:Arthroplasty, Replacement, Hip; D019645:Arthroplasty, Replacement, Knee; D001803:Blood Transfusion / Q000706:statistics & numerical data*; D001835:Body Weight; D015897:Comorbidity; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D016015:Logistic Models; D008297:Male; D012086:Reoperation; D012189:Retrospective Studies; D012737:Sex Factors; D014184:Transplantation, Homologous
chemical_list: D006454:Hemoglobins