title: General surgical operative duration is associated with increased risk-adjusted infectious complication rates and length of hospital stay.
abstract: BACKGROUND
  Studies of specific procedures have shown increases in infectious complications with operative duration. We hypothesized that operative duration is independently associated with increased risk-adjusted infectious complication (IC) rates in a broad range of general surgical procedures.
  
  
  METHODS
  We queried the American College of Surgeons National Surgical Quality Improvement Program database for general surgical operations performed from 2005 to 2007. ICs (wound infection, sepsis, urinary tract infection, and/or pneumonia) and length of hospital stay (LOS) were evaluated versus operative duration (OD, ie, incision to closure). Multivariable regression adjusted for 38 patient risk variables, operation type and complexity, wound class and intraoperative transfusion. We also analyzed isolated laparoscopic cholecystectomies in patients of American Society of Anesthesiologists class 1 or 2, without intraoperative transfusion and with a clean or clean-contaminated wound class.
  
  
  RESULTS
  In 299,359 operations performed at 173 hospitals, unadjusted IC rates increased linearly with OD at a rate of close to 2.5% per half hour (chi-square test for linear trend, p < 0.001). After adjustment, IC risk increased for each half hour of OD relative to cases lasting <or=1 hour, almost doubling at 2.1 to 2.5 hours (odds ratio = 1.92; 95% CI, 1.82 to 2.03; p < 0.001). In isolated laparoscopic cholecystectomy, IC rates increased linearly with OD (n = 17,018, chi-square test for linear trend, p < 0.001) with rates for 1.1 to 1.5 hour cases (1.4%) doubling those lasting <or=0.5 hour (0.7%). Across all procedures, adjusted LOS increased geometrically with operative duration at a rate of about 6% per half hour (coefficient for natural log transformed LOS = 0.059 per half hour; 95% CI, 0.058 to 0.060; p < 0.001).
  
  
  CONCLUSIONS
  Operative duration is independently associated with increased ICs and LOS after adjustment for procedure and patient risk factors.
authors.affiliation: Department of Surgery, University of Kentucky College of Medicine, Lexington, KY 40536, USA. ldproc0@email.uky.edu
authors.forename: Levi D
authors.initials: LD
authors.lastname: Procter
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Davenport
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Bernard
authors.forename: Joseph B
authors.initials: JB
authors.lastname: Zwischenberger
mesh_terms: D001803:Blood Transfusion / Q000706:statistics & numerical data; D017081:Cholecystectomy, Laparoscopic / Q000706:statistics & numerical data; D013502:General Surgery / Q000145:classification / Q000706:statistics & numerical data*; D006801:Humans; D007432:Intraoperative Period; D007902:Length of Stay / Q000706:statistics & numerical data*; D015999:Multivariate Analysis; D016017:Odds Ratio; D018570:Risk Assessment; D013530:Surgical Wound Infection / Q000453:epidemiology*; D014481:United States