Is bronchoalveolar lavage with quantitative cultures a useful tool for diagnosing ventilator-associated pneumonia?

The results of a recently published Canadian study suggest that bronchoalveolar lavage and endotracheal aspiration are associated with similar clinical outcomes and similar overall use of antibiotics in critically ill patients with suspected ventilator-associated pneumonia (VAP). The study, however, does not provide convincing information on the best strategy to diagnose VAP, to accurately choose initial treatment and to exclude VAP in order to avoid administering antibiotics to patients without bacterial infection. In fact, this trial has several limitations or drawbacks: patients at risk for developing VAP due to Pseudomonas aeruginosa or methicillin-resistant Staphylococcus aureus were excluded, far from the real-life scenario; a significant number of patients were receiving recent antimicrobial therapy at the time of sampling, with, consequently, difficult-to-interpret culture results; randomization of included patients for initial treatment – meropenem plus ciprofloxacin or meropenem alone – resulted in a high rate of inappropriate initial empirical therapy due to the absence of customization to local epidemiology; and the initial decision to treat and the re-evaluation at day 3 were, in fact, based on clinical judgment and not on direct examination and quantitative culture results. In summary, because antimicrobial treatment was initiated in all suspected patients and was rarely withheld in patients with negative cultures, the study does not suggest an appropriate strategy for improving the use of antibiotics in intensive care unit patients. Such a strategy has two requirements: immediate administration of adequate therapy in patients with true VAP, and avoidance of administering antibiotics in patients without bacterial infection.