Multidrug-Resistant Pseudomonas aeruginosa Ventilator-Associated Pneumonia: The Role of Endotracheal Aspirate Surveillance Cultures

BACKGROUND: Inappropriate antibacterial treatment of ventilator-associated pneumonia (VAP) due to multidrug-resistant (MDR) pathogens is associated with increased mortality. Endotracheal aspirate (ETA) surveillance cultures potentially identify MDR pathogens, particularly MDR Pseudomonas aeruginosa, resulting in improved selection of therapy in patients who subsequently develop VAP. OBJECTIVE: To investigate the role of ETA surveillance cultures in the identification of MDR P aeruginosa in newly intubated adults who subsequently develop VAP. METHODS: Daily ETA surveillance cultures for P aeruginosa were collected in all adults newly intubated for 48 hours or more. Patients with preexisting lung disease or colonization or infection with R aeruginosa were excluded. Risk factors and outcomes of patients newly colonized with MDR P aeruginosa were assessed. RESULTS: Seventy-five patents newly colonized with R aeruginosa were identified. Twenty (27%) of these patients were colonized with a P aeruginosa isolate that was MDR (resistant to 0 classes of antibiotics). Six patients were colonized by an isolate resistant to all tested classes of antibiotics. Forty-five percent of patients colonized with MDR P aeruginosa subsequently developed VAP. Prior receipt of fluoroquinolones was an independent predictor of colonization with MDR P aeruginosa (OR 11.82; 95% CI 2.10 to 66.46; p = 0.005). CONCLUSIONS: Performance of routine surveillance cultures may aid in the early detection of MDR P aeruginosa, improving the initiation of early and appropriate antibiotic therapy for patients who subsequently develop VAP.