Aspiration pneumonia.

The primary problems that predispose to aspiration pneumonia include a reduced level of consciousness, dysphagia, periodontal disease, and mechanical interference that is related to the insertion of various tubes into the respiratory or gastrointestinal tracts. The bacterial flora involved include the indigenous oral flora (among which anaerobes predominate) and, in the hospital or a similar setting, nosocomially acquired pathogens such as Staphylococcus aureus and various aerobic and facultative gram-negative bacilli that may colonize patients. Specific etiologic diagnosis is difficult. The most useful materials for reliable anaerobic and aerobic culture are pleural fluid, transtracheal aspirates, and secretions obtained with a protected bronchial brush and during bronchoalveolar lavage. Special care must be taken to avoid normal and colonizing flora and to keep anaerobes viable. Aside from the drainage of empyemas, the primary therapy for aspiration pneumonia involves antimicrobial agents. A number of options are available; the most appropriate mode of therapy depends on the nature of the infecting flora and the severity of the illness.