Infect Chemother.  2006 Apr;38(2):61-69.

Clinical Identifiers and Pathogenic Significance of Pseudomonas aeruginosa Bacteremia, in Comparison with Klebsiella pneumoniae and Enterobacter species

• Kang CI
• Kim SH
• Bang JW
• Kim HB
• Kim NJ
• Kim EC
• Oh MD
• Choe KW

Abstract

BACKGROUND: To identify specific risk factors for Pseudomonas aeruginosa and evaluate the relationship between the mortality rate and P. aeruginosa bacteraemia in bloodstream infections, we compared the clinical features and outcomes of patients with P. aeruginosa bacteremia with the patients with Klebsiella pneumoniae or Enterobacter bacteremia.
MATERIALS AND METHODS
A total of 190 patients with P. aeruginosa bacteremia were identified from January 1998 to December 2002 and included in this retrospective analysis. During the same period, 377 patients with K. pneumoniae bacteremia and 183 patients with Enterobacter bacteremia were identified and compared with those with P. aeruginosa bacteremia.
RESULTS
Factors associated with P. aeruginosa bacteremia in the multivariate analysis included pneumonia, soft tissue infection, nosocomial acquisition, neutropenia, and prior invasive procedure (All P<0.05). The 30-day mortality rate was 37.9% (72/190) in patients with P. aeruginosa bacteremia, 24.1% (91/377) in those with K. pneumoniae, and 25.7% (47/183) in those with Enterobacter bacteremia (P<0.001). However, in the analysis including patients who had received appropriate initial antimicrobial therapy (n=552), the mortality rate of P. aeruginosa bacteremia was not significantly higher than that of non-pseudomonas bacteremia (28.6% [18/63] vs. 22.5% [110/489]; P=0.282). Inappropriate initial antimicrobial therapy was found to be one of the significant independent predictors of mortality. P. aeruginosa bacteremia as a risk factor for mortality did not reach statistical significance (OR, 1.30; 95% CI, 0.73-2.32; P=0.371), after adjusting for underlying illness and adequacy of antimicrobial therapy.
CONCLUSION
An initial empirical antimicrobial coverage of P. aeruginosa should be seriously considered in patients with pneumonia, soft tissue infection, neutropenia, and prior invasive procedure, when gram-negative sepsis was suspected in nosocomial infection.

Keyword

Pseudomonas aeruginosa; Gram-Negative Bacterial Infections; Bacteremia; Treatment Outcome; Risk Factor

MeSH Terms

Bacteremia*
Cross Infection
Enterobacter*
Gram-Negative Bacterial Infections
Humans
Klebsiella pneumoniae*
Klebsiella*
Mortality
Multivariate Analysis
Neutropenia
Pneumonia
Pseudomonas aeruginosa*
Pseudomonas*
Retrospective Studies
Risk Factors
Sepsis
Soft Tissue Infections
Treatment Outcome