Assessment of severity of ICU-acquired pneumonia and association with etiology

Marta Di Pasquale, Miquel Ferrer, Mariano Esperatti, Ernesto Crisafulli, Valeria Giunta, Gianluigi Li Bassi, Mariano Rinaudo, Francesco Blasi, Michael Niederman, Antoni Torres

Research output: Contribution to journalArticlepeer-review


OBJECTIVES:: We evaluated the association between severity of illness and microbial etiology of ICU-acquired pneumonia to define if severity should be used to guide empiric antibiotic choices. DESIGN:: Prospective observational study. SETTING:: ICUs of a university hospital. PATIENTS:: Three hundredy forty-three consecutive patients with ICU-acquired pneumonia clustered, according to the presence of multidrug resistant pathogens. INTERVENTIONS:: None. MEASUREMENTS AND MAIN RESULTS:: Two hundred eight patients had ventilator-associated pneumonia and 135 had nonventilator ICU-acquired pneumonia. We determined etiology in 217 patients (63%). The most frequent pathogens were Pseudomonas aeruginosa, Enterobacteriaceae, and methicillin-sensitive and methicillin-resistant Staphylococcus aureus. Fifty-eight patients (17%) had a multidrug-resistant causative agent. Except for a longer ICU stay and a higher rate of microbial persistence at the end of the treatment in the multidrug-resistant group, no differences were found in clinical and inflammatory characteristics, severity criteria, and mortality or survival between patients with and without multidrug-resistant pathogens, even after adjusting for potential confounders. Patients with higher severity scores (Acute Physiology and Chronic Health Evaluation II and Sepsis-related Organ Failure Assessment) and septic shock at onset of pneumonia had significantly lower 28- and 90-day survival and higher systemic inflammatory response. The results were similar when only patients with microbial diagnosis were considered, as well as when stratified into ventilator-associated pneumonia and nonventilator ICU-acquired pneumonia. CONCLUSIONS:: In patients with ICU-acquired pneumonia, severity of illness seems not to affect etiology. Risk factors for multidrug resistant, but not severity of illness, should be taken into account in selecting empiric antimicrobial treatment.

Original languageEnglish
Pages (from-to)303-312
Number of pages10
JournalCritical Care Medicine
Issue number2
Publication statusPublished - Feb 2014


  • Intensive Care Unit
  • Microbiology
  • Nosocomial Infection
  • Severity Of Illness
  • Ventilator-Acquired Pneumonia

ASJC Scopus subject areas

  • Critical Care and Intensive Care Medicine
  • Medicine(all)


Dive into the research topics of 'Assessment of severity of ICU-acquired pneumonia and association with etiology'. Together they form a unique fingerprint.

Cite this