VENTILATOR-ASSOCIATED BACTERIAL PNEUMONIA - CHALLENGES IN DIAGNOSIS, TREATMENT, AND PREVENTION

Ventilator-associated pneumonia (VAP) is a common infection in intensi ve care unit patients that results in high mortality and morbidity and increased duration of hospital stay. Clinical diagnostic methods are sensitive, but lack specificity. Quantitative analysis of specimens fr om the lower respiratory tract increases specificity. Bacteria causing VAP may originate from the patient's endogenous flora, other patients or hospital personnel, or from environmental sources. Aspiration or d irect inoculation are the major routes of bacterial entry into the low er respiratory tract. The bacterial inoculum and host response in the lung are important factors for pathogenesis. Late-onset nosocomial pne umonia is often caused by Pseudomonas aeruginosa, Acinetobacter specie s, and Staphylococcus aureus. Streptococcus pneumoniae and Haemophilus influenzae, however, are the more common pathogens in early-onset dis ease. Oropharyngeal and gastric colonization with bacteria, cross-infe ction, as well as the indiscriminate use of antibiotics or invasive de vices substantially increase the risk of VAP. An understanding of the epidemiology and pathogenesis of VAP, along with implementation of app ropriate preventive measures, are needed to decrease the incidence, mo rbidity, and mortality associated with VAP.