Pneumonias acquired from others. 2. Radiographic findings, treatment.

Although patterns found on the chest film of a patient suspected to have pneumonia are usually nonspecific by themselves, they are useful in eliminating or narrowing diagnostic possibilities. For example, a miliary pattern suggests miliary tuberculosis, but it may also be caused by several noninfectious diseases (table 1). Other clues, such as the presence or absence of fever, must also be considered to arrive at a likely diagnosis. Cavitary lesions, bilateral hilar adenopathy, pleural effusions, and pulmonary nodules are other findings that are commonly seen on the chest film of these patients. Possible infectious and noninfectious causes are listed in tables 2 through 5. Antimicrobial therapy that is appropriate, free from side effects, and cost-effective must be chosen. The frequency of administration of a drug can make a great difference in the total cost of treatment, since hospitals charge for each intravenous dose. The clinician should consider which drug is effective against the infective organism and also the least expensive to administer (table 6).