title: Nosocomial infections adversely affect the outcomes of patients with serious intraabdominal infections.
abstract: BACKGROUND
  Patients with serious intraabdominal infections (IAI) who subsequently acquire nosocomial infections (NI) have been shown to have adverse outcomes. We evaluated factors that put patients at risk for developing NI and examined the effect of the NI on outcomes.
  
  
  METHODS
  This study was a retrospective review of NI among 168 patients diagnosed with IAI over a seven-year period.
  
  
  RESULTS
  Sixty-six patients (39.3%) developed 98 NI (23 urinary tract, 20 surgical site, 19 pneumonia, 14 bloodstream, 12 recurrent peritonitis, seven intravascular catheter-related, and three enteric). There were 35 males and 31 females. Patients with NI were older (56.0 +/- 18.3 vs. 47.0 +/- 15.6 years, p = 0.001), had a higher admission APACHE II score (10.7 +/- 6.1 vs. 7.5 +/- 5.1 points, p = 0.001), and more often had concomitant medical diagnoses (27.3% vs. 12.7%, OR = 2.57, 95% CI: 1.159-5.69, p = 0.018) than those who did not develop infection. Antimicrobial resistance among the IAI was higher in the NI group (19.7 vs. 5.9%, OR = 3.93, 95% CI: 1.41-10.93, p = 0.006). Patients who developed NI had an increased mortality rate (27.0% vs. 4.0%, OR = 8.87, 95% CI: 2.82-27.86, p < or = 0.0001), longer hospital stay (24.7 +/- 19.5 vs. 11.7 +/- 8.1 days, p < or = 0.0001), required more days of intravenous antibiotics (11.5 +/- 8.0 vs. 7.6 +/- 4.4 days, p < or = 0.0001), and were more likely to be admitted to an intensive care unit (54.5% vs. 25.5%, OR = 3.51, 95% CI: 1.82-6.77, p < or = 0.0001). Multivariate analysis demonstrated that antimicrobial resistance and an APACHE II score of > or = 10 independently predicted the development of a nosocomial infection. Age >/= 50 years, APACHE II score > or = 10, or the presence of a NI independently predicted death.
  
  
  CONCLUSIONS
  The development of NI following treatment of an IAI significantly affects mortality, hospital length of stay, and treatment. Early recognition and treatment of these infections, combined with strategies to prevent NI, may be important to improve outcomes in this patient population.
authors.affiliation: Department of Surgery, MetroHealth Medical Center Campus, Case Western Reserve University, Cleveland, Ohio 44109, USA.
authors.forename: James I
authors.initials: JI
authors.lastname: Merlino
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Yowler
authors.forename: Mark A
authors.initials: MA
authors.lastname: Malangoni
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D015897:Comorbidity; D016001:Confidence Intervals; D016638:Critical Illness; D003428:Cross Infection / Q000175:diagnosis* / Q000453:epidemiology* / Q000628:therapy; D005260:Female; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D015994:Incidence; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010538:Peritonitis / Q000175:diagnosis* / Q000453:epidemiology* / Q000628:therapy; D011336:Probability; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D018805:Sepsis / Q000175:diagnosis* / Q000453:epidemiology* / Q000628:therapy; D012720:Severity of Illness Index; D017678:Sex Distribution; D016019:Survival Analysis