title: Epidemiology and outcome of major postoperative infections following cardiac surgery: risk factors and impact of pathogen type.
abstract: BACKGROUND
  Major postoperative infections (MPIs) are poorly understood complications of cardiac surgery. We examined the epidemiology, microbiology, and outcome of MPIs occurring after cardiac surgery.
  
  
  METHODS
  The study cohort was drawn from the Society of Thoracic Surgeon National Cardiac Database and comprised adults who underwent cardiac surgery at 5 tertiary hospitals between 2000 and 2004. We studied the incidence, microbiology, and risk factors of MPI (bloodstream or chest wound infections within 30 days after surgery), as well as 30-day mortality. We used multivariate regression analyses to evaluate the risk of MPI and mortality.
  
  
  RESULTS
  MPI was identified in 341 of 10,522 patients (3.2%). Staphylococci were found in 52.5% of these patients, gram-negative bacilli (GNB) in 24.3%, and other pathogens in 23.2%. High body mass index, previous coronary bypass surgery, emergency surgery, renal impairment, immunosuppression, cardiac failure, and peripheral/cerebrovascular disease were associated with the development of MPI. Median postoperative duration of hospitalization (15 days vs 6 days) and mortality (8.5% vs 2.2%) were higher in patients with MPIs. Compared with uninfected individuals, odds of mortality were higher in patients with S aureus MPIs (adjusted odds ratio, 3.7) and GNB MPIs (adjusted odds ratio, 3.0).
  
  
  CONCLUSIONS
  Staphylococci accounted for the majority of MPIs after cardiac surgery. Mortality was higher in patients with Staphylococcus aureus- and GNB-related MPIs than in patients with MPIs caused by other pathogens and uninfected patients. Preventive strategies should target likely pathogens and high-risk patients undergoing cardiac surgery.
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA. chen@duke.edu
authors.forename: Luke F
authors.initials: LF
authors.lastname: Chen
authors.forename: Jean Marie
authors.initials: JM
authors.lastname: Arduino
authors.forename: Shubin
authors.initials: S
authors.lastname: Sheng
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Muhlbaier
authors.forename: Zeina A
authors.initials: ZA
authors.lastname: Kanafani
authors.forename: Anthony D
authors.initials: AD
authors.lastname: Harris
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Fraser
authors.forename: Keith
authors.initials: K
authors.lastname: Allen
authors.forename: G Ralph
authors.initials: GR
authors.lastname: Corey
authors.forename: Vance G
authors.initials: VG
authors.lastname: Fowler
mesh_terms: D000368:Aged; D001419:Bacteria / Q000145:classification / Q000302:isolation & purification; D001424:Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology / Q000401:mortality; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D018805:Sepsis / Q000453:epidemiology* / Q000382:microbiology / Q000401:mortality; D013530:Surgical Wound Infection / Q000453:epidemiology* / Q000382:microbiology / Q000401:mortality; D016019:Survival Analysis; D013903:Thoracic Surgery