DIAGNOSING VENTILATOR-ASSOCIATED PNEUMONIA - THE ROLE OF BRONCHOSCOPY

Objective: To discuss the two diagnostic procedures used most frequent ly to obtain uncontaminated loner airway secretions during bronchoscop y. Design: This article reviews the contributing risk factors of venti lator-associated pneumonia (VAP) and the recent studies that have asse ssed the usefulness of the protected specimen brush (PSB) and bronchoa lveolar lavage (BAL) in the nonimmunocompromised host. Results: A prom pt, accurate diagnosis of VAP, including specific identification of th e bacterial pathogen, remains a common challenge in the intensive-care unit. Standard clinical criteria are of suboptimal specificity for ma king decisions, including selecting antibiotic therapy. Bronchoscopic techniques of lung secretion sampling can be used in the intensive-car e unit in an effort to overcome the effects of oropharyngeal contamina tion. The PSB and BAL, used appropriately, can help intensive-care cli nicians formulate specific antimicrobial therapy. Evaluation of intrac ellular bacteria obtained by BAL has been reported to be useful in gui ding empiric antibiotic therapy while the final results of cultures ob tained with the PSB are pending. Prior antibiotic therapy, however, ma y confound the interpretation and clinical utility of results. Conclus ion: Currently, for a patient taking antibiotic therapy, no reliable t echnique nor quantitative culture threshold exists to help in diagnosi ng suspected VAP or in guiding antibiotic therapy. If the clinical sit uation allows, antibiotic therapy should be discontinued for 48 hours; then, the PSB, BAL, protected BAL, or endobronchial aspiration should be used. These contemporary modalities, however, necessitate further clinical trials before widespread use is warranted.