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Community-acquired polymicrobial pneumonia in the intensive care unit: aetiology and prognosis

Catia Cillóniz1, Santiago Ewig, Miquel Ferrer

  • 1Department of Pneumology, Institut Clinic del Tórax, Hospital Clinic of Barcelona-Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona-SGR 911-Ciber de Enfermedades Respiratorias, Villarroel 170, Barcelona 08036, Spain.

Critical Care (London, England)
|September 15, 2011
PubMed
Abstract

Insights

Polymicrobial pneumonia is common in ICU patients and increases the risk of incorrect initial antibiotic treatment. This inappropriate treatment, not the polymicrobial infection itself, independently predicts higher hospital mortality in severe community-acquired pneumonia.

Area of Science:

  • Infectious Diseases
  • Critical Care Medicine
  • Microbiology

Background:

  • Polymicrobial etiology in community-acquired pneumonia (CAP) admitted to the ICU is understudied.
  • Understanding its prevalence and impact is crucial for patient outcomes.

Purpose of the Study:

  • To determine the prevalence of polymicrobial etiology in severe CAP patients in the ICU.
  • To describe the clinical characteristics and outcomes associated with polymicrobial CAP.
  • To identify predictors of polymicrobial etiology and mortality.

Main Methods:

  • Prospective observational study of 362 adult CAP patients admitted to the ICU.
  • Etiology was established in 196 patients.
  • Analysis of pathogen identification, clinical data, and mortality.

Main Results:

  • Polymicrobial infection was found in 11% of cases (20% of those with defined etiology).
  • Streptococcus pneumoniae, respiratory viruses, and Pseudomonas aeruginosa were common pathogens.
  • Inappropriate antimicrobial treatment was more frequent in polymicrobial cases (39% vs. 10%) and predicted mortality (aOR=10.79).

Conclusions:

  • Polymicrobial pneumonia is frequent in ICU patients.
  • It is a significant risk factor for inappropriate initial antimicrobial therapy.
  • Inappropriate treatment, not polymicrobial etiology itself, independently predicts hospital mortality.

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