Polymicrobial bacteraemias in ICU patients. Impact on outcome

Abstract number: P1439

Sancho S., Zaragoza R., Camarena J., Artero A., González R., Nogueira J.

Introduction: The aims of this study were to know the epidemiological and clinical features of polymicrobial bacteremias in UCI patients and to know their impact on mortality.

Methods: From January 2000 to Juny 2009 all clinically significant bacteremias in a teaching hospital were collected. Clinical and microbiological characteristics were recorded. Polymicrobial bacteremia was defined when two or more microorganisms were isolated in the same blood culture. Multivariate analysis was used to determine the differences between polymicrobial and monomicrobial bacteremias and to analyse the factors associated to related mortality to infection, using the SPSS package (13.0).

Results: Among 293 ICU-bacteremias, 45 (15.3%) were polymicrobial. The mean age of patients was 61.9 SD 14 years. Bacteremia was hospital-acquired in 93.3% of these cases. 26.7% developed septic shock and 57.8% severe sepsis. The main sources of bacteremia were: respiratory (31.1%), catheter (17.7%) and abdominal foci (13.3%). The microorganisms most frequently isolated were: Acinetobacter baumannii (35.5%), Enterococcus spp (24.4%) and Pseudomonas aeruginosa (22.2%). Empirical antimicrobial treatment was inadequate in 28.9% of these cases. The global mortality rate was 53.3% and the related mortality 22.2%. The isolation of Enterococcus spp. in blood culture was the only factor associated with polymicrobial bacteremias (p = 0.037; OR = 7.06; 95% CI: 1.12–44.51). The factors associated with related mortality were: S. aureus (p = 0.004; OR = 10.06; 95% CI: 2.07–48.94), the presence of septic shock (p = 0.0001; OR = 9.80; 95% CI: 3.01–31.89), the APACHE II during bacteremia (p = 0.0001; OR = 1.21; 95% CI: 1.11–1.31), and inadequate empirical antimicrobial treatment (p = 0.018; OR = 4.24; 95% CI: 1.28–14.11) but not polymicrobial bacteremias.

Conclusions: Polymicrobial bacteremias had a high prevalence in the ICU, were hospital-acquired, and their main sources of infection were repiratory and abdominal. Enterococcus spp were the unique microorganism associated with polymicrobial bacteremias. Although the rate of inadequate empirical antimicrobial treatment was high, mortality rates were not higher in polymicrobial bacteremias than in the group with monomicrobial bacteremias.

Session Details

Date: 10/04/2010
Time: 00:00-00:00
Session name: Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases
Location: Vienna, Austria, 10 - 13 April 2010
Presentation type:
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