Ventilator-associated pulmonary infection: the germ theory of disease remains viable.

Pulmonary infection complicating mechanical ventilation is a major problem in critical care. The key issues surrounding care of patients suspected of having this disease are 1) appropriate diagnostic criteria; 2) when antibiotic therapy should be started; and 3) what constitutes adequate antibiotic therapy. Current data support use of quantitative cultures obtained by either bronchoscopic or blind catheter lavage or mini-brushing. Antibiotic therapy should be guided by duration of hospitalization prior to presumed infection and local predominating nosocomial organisms and their microbial resistance patterns. The key issue with timing of therapy now centers around early termination of therapy if quantitative cultures are negative.