title: Association between elevated pre-operative glycosylated hemoglobin and post-operative infections after non-emergent surgery.
abstract: BACKGROUND
  A chronic state of impaired glucose metabolism affects multiple components of the immune system, possibly leading to an increased incidence of post-operative infections. Such infections increase morbidity, length of stay, and overall cost. This study evaluates the correlation between elevated pre-operative glycosylated hemoglobin (HbA1c) and post-operative infections.
  
  
  METHODS
  Adult patients undergoing non-emergent procedures across all surgical subspecialties from January 2010 to July 2014 had a preoperative HbA1c measured as part of their routine pre-surgical assessment. 2200 patient charts (1100 < 6.5% HbA1c and1100 ≥ 6.5% HbA1c) were reviewed for evidence of post-operative infection (superficial surgical site infection, deep wound/surgical space abscess, pneumonia, and/or urinary tract infection as defined by Centers for Disease Control criteria) within 30 days of surgery.
  
  
  RESULTS
  Patients with HbA1c < 6.5% and those with HbA1c ≥ 6.5% showed no statistically significant difference in overall infection rate (3.8% in the HbA1c < 6.5% group vs. 4.5% in the HbA1c ≥ 6.5% group, p = 0.39). Both linear regression and multivariate analysis did not identify HbA1c as an individual predictor of infection. Elevated HbA1c was, however, predictive of significantly increased risk of post-operative infection when associated with increased age (≥81 years of age) or dirty wounds.
  
  
  CONCLUSIONS
  The risk factors of post-operative infection are multiple and likely synergistic. While pre-operative HbA1c level is not independently associated with risk of post-operative infection, there are scenarios and patient subgroups where pre-operative HbA1c is useful in predicting an increased risk of infectious complications in the post-operative period.
authors: Department of Surgery, Mount Sinai Beth Israel, United States; Department of Surgery, Icahn School of Medicine at Mount Sinai, United States.
authors: Joseph M
authors: JM
authors: Blankush
authors: Department of Surgery, Mount Sinai Beth Israel, United States; Department of Surgery, Icahn School of Medicine at Mount Sinai, United States.
authors: I Michael
authors: IM
authors: Leitman
authors: Department of Surgery, Mount Sinai Beth Israel, United States; Department of Surgery, Icahn School of Medicine at Mount Sinai, United States.
authors: Aron
authors: A
authors: Soleiman
authors: Department of Surgery, Mount Sinai Beth Israel, United States; Department of Surgery, Icahn School of Medicine at Mount Sinai, United States.
authors: Trung
authors: T
authors: Tran
keywords: Complication; Glycosylated hemoglobin; Hyperglycemia; Infections; Surgery