Clinical significance of polymicrobial versus monomicrobial bacteremia involving Pseudomonas aeruginosa

The objective of this study was to examine the clinical significance of pol ymicrobial bacteremia involving Pseudomonas aeruginosa. Two hundred forty-e ight episodes of Pseudomonas aeruginosa bacteremia, 43 of which were polymi crobic, were studied prospectively over a 6-year period, Three sets of bloo d cultures were obtained for each patient. Positive results for all three b lood cultures were found more frequently in patients with polymicrobial inf ection, who were older than those with monomicrobial infection. Patients wi th polymicrobial bacteremia also were worse clinically and developed shock more frequently. Crude mortality was higher in patients with polymicrobial infection. A multivariate analysis revealed three variables significantly a nd independently associated with polymicrobial Pseudomonas aeruginosa bacte remia: higher age, poor clinical status of the patient, and positive result s for all blood cultures obtained.