title: Risk score elaboration for mediastinitis after coronary artery bypass grafting.
abstract: BACKGROUND
  The mediastinitis is a serious postoperative complication of cardiac surgery, with an incidence of 0.4 to 5% and mortality between 14 and 47%. Several models were proposed to assess risk of mediastinitis after cardiac surgery. However, most of these models do not evaluate the postoperative morbidity.
  
  
  OBJECTIVE
  This study aims to develop a score risk model to predict the risk of mediastinitis for patients undergoing coronary artery bypass grafting.
  
  
  METHODS
  The study sample included data from 2,809 adult patients undergoing coronary artery bypass grafting between January 1996 and December 2007 at Hospital São Lucas -PUCRS. Logistic regression was used to examine the relationship between risk factors and the development of mediastinitis. Data from 1,889 patients were used to develop the model and its performance was evaluated in the remaining data (n=920). The definitive model was created with the data analysis of 2,809 patients.
  
  
  RESULTS
  The rate of mediastinitis was 3.3%, with mortality of 26.6%. In the multivariate analysis, five variables remained independent predictors of the outcome: chronic obstructive pulmonary disease, obesity, surgical reintervention, blood transfusion and stable angina class IV or unstable. The area under the ROC curve was 0.72 (95% CI, 0.67-0.78) and P = 0.61.
  
  
  CONCLUSIONS
  The risk score was constructed for use in daily practice to calculate the rate of mediastinitis after coronary artery bypass grafting. The score includes routinely collected variables and is simple to use.
authors.affiliation: Postoperative Cardiac Surgery Unit, PUCRS Sao Lucas Hospital, Porto Alegre, Rio Grande do Sul, Brazil. ellenmagedanz@yahoo.com.br
authors.forename: Ellen Hettwer
authors.initials: EH
authors.lastname: Magedanz
authors.forename: Luiz Carlos
authors.initials: LC
authors.lastname: Bodanese
authors.forename: João Carlos Vieira da Costa
authors.initials: JC
authors.lastname: Guaragna
authors.forename: Luciano Cabral
authors.initials: LC
authors.lastname: Albuquerque
authors.forename: Valério
authors.initials: V
authors.lastname: Martins
authors.forename: Silvia Daniela
authors.initials: SD
authors.lastname: Minossi
authors.forename: Jacqueline da Costa Escobar
authors.initials: Jda C
authors.lastname: Piccoli
authors.forename: Marco Antônio
authors.initials: MA
authors.lastname: Goldani
mesh_terms: D001026:Coronary Artery Bypass / Q000009:adverse effects*; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008480:Mediastinitis / Q000209:etiology* / Q000401:mortality / Q000517:prevention & control; D008875:Middle Aged; D018570:Risk Assessment / Q000379:methods