It has been shown that pneumonia resolves two to four times more slowly in patients 50 years or older than in younger patients. Bronchoscopic evaluation is recommended in patients with slow-resolving infection. Therefore, it is useful to know what clinical and radiographic courses to expect of pneumonia in the elderly. In this study, El Solh and colleagues attempted to define the effect of comorbidity, functional status, and microbial pathogens on the radiographic resolution of this disease in elderly patients.

All patients 70 years or older who were hospitalized for community-acquired pneumonia were eligible for inclusion in the study. Additional inclusion criteria were the presence of new infiltrates on admission chest radiography, temperature of 38°C (100.4°F) or higher or less than 35°C (95.0°F), lower respiratory symptoms, positive sputum and blood cultures, or positive serology for atypical infection. Chest radiographs were taken at admission and every three weeks up to 12 weeks or until radiographic abnormalities had resolved.

Ninety-seven patients were identified for enrollment. Of these, 74 entered the study with at least an initial and a follow-up radiograph, and 64 completed the study. Approximately one-third of the patients had complete radiographic clearance by three weeks, and two-thirds had complete radiographic clearance by nine weeks. Fifty-six patients (76 percent) had complete clearance at 12 weeks, with eight (11 percent) having persistent abnormalities.

Body temperature and total white blood cell count returned to normal in all patients within three weeks of antimicrobial therapy despite the presence of residual radiographic abnormalities. Factors that independently influenced resolution were comorbidity and multilobar disease, with significantly longer delays in patients with a higher comorbidity index and those with multilobar disease. Radiographic clearance also was slower in patients with documented bacteremia and with nonbacteremic enteric gram-negative pneumonias.

The authors conclude that radiographic resolution in elderly patients admitted to the hospital for pneumonia is influenced significantly by multilobar involvement and comorbidities. These results cannot necessarily be applied to outpatients. The authors suggest that a waiting period of 12 to 14 weeks may be necessary before deciding that the pneumonia is nonresolving, at which point further investigation may be necessary to look for an alternate etiology that would account for the abnormalities.