title: Blood transfusion is associated with increased risk of perioperative complications and prolonged hospital duration of stay among patients undergoing amputation.
abstract: OBJECTIVE
  We evaluated the outcomes of patients undergoing major lower-extremity amputation who received packed red blood cell transfusion.
  
  
  METHODS
  Using the dataset of the National Surgical Quality Improvement Program (2005-2011), we examined 5,739 above-knee and 6,725 below-knee amputations. Patients were stratified by perioperative (preoperative, intraoperative, or postoperative) blood transfusion. Outcomes included perioperative mortality, myocardial infarction (MI), thromboembolism, and duration of stay (DOS) at the hospital. Adjusted comparisons of outcomes between transfused and not-transfused patients were performed by matching the 2 groups for age, smoking, diabetes, renal failure, coronary artery disease, classification of the American Society of Anesthesiologists, functional status, and procedure type. Multivariable logistic and gamma regression were used to examine associations between transfusion and outcomes.
  
  
  RESULTS
  Of the 12,464 amputations in the study cohort 2,133 (17%) required transfusion. The majority of the cases were performed for critical limb ischemia (8,205 amputations; 66%) and the overall 30-days mortality was 9%. In both crude and matched cohorts, although perioperative mortality and cardiac complication rates were similar, transfusion was associated with a greater incidence of pneumonia (crude: 6.1% vs 3%, P < .001; matched: 5.9% vs 3.7%, P < .001), thromboembolism (2.5% vs 1.6%, P = .003; 2.5% vs 1.4%, P = .002) and longer DOS (18 ± 19 vs 13.6 ± 14.3 days, P < .001; 17.8 ± 18.4 vs 14.2 ± 14.5 days, P < .001). Multivariable adjustment for confounding variables in the crude cohort demonstrated that transfusion was independently associated with a greater odds of perioperative pneumonia (odds ratio [OR]:1.6; 95% confidence interval [CI]:1.3-2; P < .001), thromboembolism (OR 1.3, 95% CI 1.0-1.9, P = .09) and longer DOS (mean ratio: 1.1; 95% CI 1.1-1.6; P = .006).
  
  
  CONCLUSIONS
  Among patients who had major lower-extremity amputation, perioperative transfusion independently predicted greater risks for perioperative pneumonia, thromboembolism, and prolonged hospital DOS.
authors.affiliation: Louisiana State University Health Shreveport, Shreveport, LA. Electronic address: ttan1@lsuhsc.edu.
authors.forename: Tze-Woei
authors.initials: TW
authors.lastname: Tan
authors.affiliation: Boston University Medical Center, Boston, MA.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Eslami
authors.affiliation: Boston University Medical Center, Boston, MA.
authors.forename: Denis
authors.initials: D
authors.lastname: Rybin
authors.affiliation: Boston University Medical Center, Boston, MA.
authors.forename: Gheorghe
authors.initials: G
authors.lastname: Doros
authors.affiliation: Louisiana State University Health Shreveport, Shreveport, LA.
authors.forename: Wayne W
authors.initials: WW
authors.lastname: Zhang
authors.affiliation: Boston University Medical Center, Boston, MA.
authors.forename: Alik
authors.initials: A
authors.lastname: Farber
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000671:Amputation, Surgical / Q000401:mortality; D000674:Amputees / Q000706:statistics & numerical data*; D015331:Cohort Studies; D017707:Erythrocyte Transfusion / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data*; D035002:Lower Extremity / Q000601:surgery*; D008297:Male; D009203:Myocardial Infarction / Q000453:epidemiology; D011014:Pneumonia / Q000453:epidemiology; D011183:Postoperative Complications / Q000453:epidemiology*; D012044:Regression Analysis; D012189:Retrospective Studies; D012307:Risk Factors; D013923:Thromboembolism / Q000453:epidemiology; D016896:Treatment Outcome