Epidemiologia de pneumonias associadas à ventilação mecânica por Pseudomonas aeruginosa em pacientes internados na unidade de terapia intensiva de adultos de um hospital universitário brasileiro

Abstract

Ventilator-associated pneumonia (VAP) is the most common nosocomial infection in intensive care units and Pseudomonas aeruginosa is the main agent. The aim of the study was the epidemiology of VAP by Pseudomonas aeruginosa, with emphasis on areas in its endemic and epidemic nature, etiology, mode of transmission, predisposing factors associated environmental sources such as reservoir and prognosis in an intensive care unit mixed adults. The present study was case (patient with VAP due to Pseudomonas aeruginosa) vs control (patients without VAP) in the period September 2008 to August 2009. The diagnosis was made based on clinical, radiological and microbiological (counts 106 CFU / ml in tracheal aspirate). The samples from the hands of health professionals (printing technique), colonization of the oropharynx of patients (swab collection), surfaces (samples marked area) air (exposure of plates) and tap water and drain of sinks (swab collection ) were grown on agar pseudomonas. Isolates were identified by phenotypic tests and profiles of antimicrobial susceptibility were defined through the technique of gel diffusion (CLSI). Pseudomonas aeruginosa is the causative agent predominant in the VAP (38%) in the period of investigation, with a high frequency of multiresistant samples. The independent risk factors for the development of VAP were: tracheostomy, use 03 antimicrobials and prior mucosal colonization of the oropharynx. There was an outbreak during the investigation, caused by strains susceptible and multiresistant to antimicrobials, with evidence of transmission by the hands of health professionals. The hospital mortality in patients with VAP was 36.84%, with worse prognosis (62.50% Vs 18.18%, P 0.05) in those infected with multiresistant strains. The importance of environmental sources, mainly water as a source / reservoir of this microorganism has not been confirmed. Our results suggest that patients colonized in the use of various antimicrobials and the contaminated hands of health care workers were the main epidemiological aspects to be highlighted.