IMPLEMENTATION OF BRONCHOSCOPIC TECHNIQUES IN THE DIAGNOSIS OF VENTILATOR-ASSOCIATED PNEUMONIA TO REDUCE ANTIBIOTIC USE

In intensive care units, a large proportion of antibiotics are prescri bed for presumed episodes of ventilator-associated pneumonia (VAP). VA P is usually diagnosed on a combination of clinical, radiographic, and microbiologic criteria with a high sensitivity but low specificity fo r VAP. As a result, patients may receive antibiotics unnecessarily. Sp ecificity can be increased by the addition of quantitative cultures of samples of protected specimen brush (PSB) and bronchoalveolar lavage (BAL) to the diagnostic criteria. We prospectively analyzed the effect s of implementation of PSB and BAL in the diagnosis of VAP on antibiot ic prescription. PSB and/or BAL were performed in patients who fulfill ed the clinical, radiographic, and microbiologic criteria for VAP. Bas ed on quantitative cultures of PSB and/or BAL, patients were categoriz ed into three groups: VAP microbiologically proven (Group 1; n = 72); clinical suspicion of VAP not confirmed microbiologically (Group 2; n = 66); and patients in whom bronchoscopy could not be performed (Group 3; n = 17). In Group 1, antibiotic therapy was instituted empirically in 40 patients (56%) (Group la) and after obtaining culture results i n the other 32 patients (Group Ib). Adjustment of therapy, based on cu lture results, occurred in 14 (35%) patients in Group la. In Group 2, empiric therapy was instituted in 34 (52%) patients (Group 2a) and dis continued within 48 h in 17 of them (50%). In Group 3, 17 (100%) patie nts were treated with antibiotics. Among the 66 patients in whom a cli nical suspicion of VAP was not confirmed, only 18 (27%) were treated w ith antibiotics, and antibiotic therapy was withheld in 48 (35%) of 13 8 patients who underwent bronchoscopy. Withholding of antibiotic thera py had no negative effect on the recurrence of a clinical suspicion of VAP or on mortality rates. We conclude that addition of bronchoscopic techniques to the criteria for VAP may help to reduce antibiotic use. However, the definite benefits and cost-effectiveness of these techni ques should be analyzed in a randomized study.