Patterns of resolution of chest radiograph abnormalities in adults hospitalized with severe community-acquired pneumonia

Abstract

Background. Timing of follow-up chest radiographs for patients with severe community-acquired pneumonia (CAP) is difficult, because little is known about the time to resolution of chest radiograph abnormalities and its correlation with clinical findings. To provide recommendations for short-term, in-hospital chest radiograph followup, we studied the rate of resolution of chest radiograph abnormalities in relation to clinical cure, evaluated predictors for delayed resolution, and determined the influence of deterioration of radiographic findings during follow-up on prognosis. Methods. A total of 288 patients who were hospitalized because of severe CAP were followed up for 28 days in a prospective multicenter study. Clinical data and scores for clinical improvement at day 7 and clinical cure at day 28 were obtained. Chest radiographs were obtained at hospital admission and at days 7 and 28. Resolution and deterioration of chest radiograph findings were determined. Results. At day 7, 57 (25%) of the patients had resolution of chest radiograph abnormalities, whereas 127 (56%) had clinical improvement (mean difference, 31%; 95% confidence interval, 25%-37%). At day 28, 103 (53%) of the patients had resolution of chest radiograph abnormalities, and 152 (78%) had clinical cure (mean difference, 25%; 95% confidence interval, 19%-31%). Delayed resolution of radiograph abnormalities was independently associated with multilobar disease (odds ratio, 2.87; P ≤ .01); dullness to percussion at physical examination (odds ratio, 6.94; P ≤ .001); high C-reactive protein level, defined as 1200 mg/L (odds ratio, 4.24; P ≤ .01); and high respiratory rate at admission, defined as 125 breaths/min (odds ratio, 2.42; P ≤ .03). There were no significant differences in outcome at day 28 between patients with and patients without deterioration of chest radiograph findings during the follow-up period (P > .09). Conclusions. Routine short-term follow-up chest radiographs (obtained <28 days after hospital admission) of hospitalized patients with severe CAP seem to provide no additional clinical value. © 2007 by the Infectious Diseases Society of America. All rights reserved.