title: Failure to Redose Antibiotic Prophylaxis in Long Surgery Increases Risk of Surgical Site Infection.
abstract: BACKGROUND
  Antibiotic prophylaxis is a key component of the prevention of surgical site infection (SSI). Failure to manage antibiotic prophylaxis effectively may increase the risk of SSI. This study aimed to examine the effects of antibiotic prophylaxis on SSI risk.
  
  
  METHODS
  A retrospective cohort study was conducted among patients having general surgery between May 2012 and June 2015 at the University of Washington Medical Center. Peri-operative data extracted from hospital databases included patient and operation characteristics, intra-operative medication and fluid administration, and survival outcome. The effects of antibiotic prophylaxis and potential factors on SSI risk were estimated using multiple logistic regression and were expressed as risk ratios (RRs).
  
  
  RESULTS
  A total of 4,078 patients were eligible for analysis. Of these, 180 had an SSI. Mortality rates within and after 30 days were 0.8% and 0.3%, respectively. Improper antibiotic redosing increased the risk of SSI (RR 4.61; 95% confidence interval [CI] 1.33-15.91). Other risk factors were in-patient status (RR 4.05; 95% CI 1.69-9.66), smoking (RR 1.63; 95% CI 1.03-2.55), emergency surgery (RR 1.97; 95% CI 1.26-3.08), colectomy (RR 3.31; 95% CI 1.19-9.23), pancreatectomy (RR 4.52; 95% CI 1.53-13.39), proctectomy (RR 5.02; 95% CI 1.72-14.67), small bowel surgery (RR 6.16; 95% CI 2.13-17.79), intra-operative blood transfusion >500 mL (RR 2.76; 95% CI 1.45-5.26), and multiple procedures (RR 1.40; 95% CI 1.01-1.95).
  
  
  CONCLUSIONS
  These data demonstrate that failure to redose prophylactic antibiotic during long operations increases the risk of SSI. Strengthening a collaborative surgical quality improvement program may help to eradicate this risk.
authors.affiliation: 1 Division of Nursing Science, Faculty of Nursing, Chiang Mai University , Chiang Mai, Thailand .|2 Department of Biobehavioral Nursing and Health Systems, School of Nursing, University of Washington , Seattle, Washington.
authors.forename: Nongyao
authors.initials: N
authors.lastname: Kasatpibal
authors.affiliation: 2 Department of Biobehavioral Nursing and Health Systems, School of Nursing, University of Washington , Seattle, Washington.
authors.forename: Joanne D
authors.initials: JD
authors.lastname: Whitney
authors.affiliation: 3 Department of Surgery, University of Washington , Seattle, Washington.
authors.forename: E Patchen
authors.initials: EP
authors.lastname: Dellinger
authors.affiliation: 4 Department of Anesthesiology and Pain Medicine, University of Washington , Seattle, Washington.
authors.forename: Bala G
authors.initials: BG
authors.lastname: Nair
authors.affiliation: 5 Department of Psychosocial Nursing and Community Health, School of Nursing, University of Washington , Seattle, Washington.
authors.forename: Kenneth C
authors.initials: KC
authors.lastname: Pike
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use; D019072:Antibiotic Prophylaxis / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D013530:Surgical Wound Infection / Q000188:drug therapy* / Q000453:epidemiology* / Q000401:mortality / Q000517:prevention & control
chemical_list: D000900:Anti-Bacterial Agents
keywords: antibiotic prophylaxis; surgical site infection