Pneumonia syndromes: a clinical approach in the elderly.

Important in the pathogenesis of pneumonia in the elderly patient are chronic diseases, including diabetes mellitus, coronary artery disease, congestive heart failure, chronic obstructive pulmonary disease, and cerebrovascular disease. Also vital are the changes that take place in the immune system and mucociliary clearance mechanisms of the lung. The clinician should be aware of these risk factors, especially since the mortality rate of lower respiratory infections approaches 40% in these elderly patients. Treatment guidelines are included.