Abstract

This study aims at investigating whether the development of Ventilator-Associated Pneumonia (VAP) episodes caused by Multidrug-Resistant (MDR) Pseudomonas aeruginosaor other microorganisms (Staphylococcus aureus and other bacilli) were related to different risk factors. A 1-year retrospective case-control study was conducted in surgical-clinical Intensive Care Unit (ICU). Inclusion criteria were VAP cases (n = 66) caused by MDR P. aeruginosa (Group P, n = 31) compared with those caused by other microorganisms (Group C, n = 35). Altogether, the VAP incidence rate of 21.11 per 1, 000 ventilation days was high and compatible with ICUs in developing countries. Most of VAP cases (92.4%) were identified as late-onset pneumonia with 5 early-onset cases associated with Methicillin-SusceptibleStaphylococcus aureus (MSSA). In a logistic regression analysis, Group P was independently associated with four variables: presence of three or more invasive devices; use of three or more antibiotics; use of aminoglycosides; and absence of immunocompromise. Empirical antibiotic therapy was inadequate in 48.4% of the VAP cases caused by MDR P. aeruginosa with crude mortality rate (46.7%) higher than in those which patients received adequate antibiotics (18.7%). The findings to show that there were no outcome differences between the groups regarding critical care unit survival, but there were significant differences between pathogens groups regarding risk factors.

Key words: Nosocomial infection, risk factors, epidemiologic study.