title: Risk factors for sternal wound infections and application of the STS score in coronary artery bypass graft surgery.
abstract: BACKGROUND
  Sternal wound infection (SWI) after coronary artery bypass graft (CABG) surgery is a major complication. Identifying patients at risk of SWI is essential for the application of preventive measures.
  
  
  OBJECTIVE
  To identify the pre- and intra-operative risk factors, apply the STS risk score and determine the correlation between the risk score and microorganisms isolated from surgical wounds in a Brazilian hospital.
  
  
  METHODS
  This is a retrospective analysis of a database of all CABG surgeries performed in a single institution from 2006 to 2008. Chi-square analysis was used for categorical variables and Student's t-test was used for quantitative variables. Multivariate logistic regression model was used to identify independent risk factors for SWI. P <0.05 was considered significant.
  
  
  RESULTS
  The infection rate was 7.2% (143/1975). The multiple regression analysis found the following risk factors: female gender (OR 2.06; 95%CI 1.40-3.03; P<0.001), BMI>40 kg/m² (OR 6.27, 95%CI 2.53-15.48; P<0.001), diabetes (OR 2.33; 95%CI 1.56-3.49; P<0.001), number of affected coronary arteries (OR 7.78; 95%CI 1.04-57.79; P<0.001) and use of bilateral internal thoracic artery (OR 3.85; 95%CI 2.10-7.07; P<0.001). Infected patients had a mean score of 9, whereas non-infected patients had a mean score of 7 (P<0.001). There was no correlation between microorganisms, scores and risk factors.
  
  
  CONCLUSIONS
  Female gender, diabetes, BMI>40 kg/m², number of affected coronary arteries and use of bilateral internal thoracic artery were associated with a higher risk of infection. The STS risk score can be successfully used and there was no correlation between microorganisms, the score and risk factors at our institution.
authors.affiliation: Institute Dante Pazzanese of Cardiology, São Paulo, SP, Brazil. farskyp@uol.com.br
authors.forename: Pedro Silvio
authors.initials: PS
authors.lastname: Farsky
authors.forename: Humberto
authors.initials: H
authors.lastname: Graner
authors.forename: Pedro
authors.initials: P
authors.lastname: Duccini
authors.forename: Eliana da Cassia
authors.initials: Eda C
authors.lastname: Zandonadi
authors.forename: Vivian Lerner
authors.initials: VL
authors.lastname: Amato
authors.forename: Jaime
authors.initials: J
authors.lastname: Anger
authors.forename: Antonio Flavio de Almeida
authors.initials: AF
authors.lastname: Sanches
authors.forename: Cely Saad
authors.initials: CS
authors.lastname: Abboud
mesh_terms: D015992:Body Mass Index; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D048909:Diabetes Complications; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment / Q000379:methods / Q000592:standards; D013249:Sternum / Q000601:surgery*; D013530:Surgical Wound Infection / Q000453:epidemiology / Q000382:microbiology*