Despite recommendations by the American Academy of Pediatrics against routine imaging in acute bronchiolitis, chest radiography (CXR) is often performed during admission for bronchiolitis. There have been no studies in the United States that have identified clinical predictors of imaging results. By identifying such predictors, the use of CXR in a subgroup of patients with bronchiolitis could be reduced.
We conducted a retrospective cohort study involving electronic chart review of patients 024 months of age hospitalized for bronchiolitis, as determined by ICD9 codes, in an inner city tertiary care children’s hospital. Patients with known comorbid conditions that could increase their risk of pneumonia were excluded. Demographic, clinical, microbiologic, and radiologic data were extracted using Clinical Looking Glass. Chisquare test was used to compare patients with benign CXR (normal or consistent with viral infection) to those with pathologic CXR (focal infiltrate, consolidation, opacity, pneumonia, or other abnormal findings). Data were analyzed with SPSS software.
A total of 526 patients between January 2007 and December 2008 met inclusion criteria. Mean age on admission was 6.5 months, and mean length of stay was 3.57 days. CXR was performed on 357 patients (68%), of which 85 (24%) were pathologic. Elevated white blood cell count (WBC) was seen in 6 of these 85 (7%) compared to 31 of 238 patients (13%) with benign CXR (p = 0.241); 34 patients had no WBC recorded. Fever was present on initial evaluation in 51 of 84 patients (61%) with pathologic CXR compared to 123 of 264 patients (47%) with benign CXR (p = 0.024); nine patients had no preadmission vital signs recorded. When analyzed in combination, 4 of 80 patients (5%) with pathologic CXR had both elevated WBC count and fever, compared with 15 of 248 patients (6%) with benign CXR (p = 0.741).
Leukocytosis and fever are commonly used clinical predictors of bacterial pneumonia. In the setting of acute viral bronchiolitis, WBC does not appear to be predictive of imaging results, while fever on initial evaluation does appear to have an association with pathologic imaging. When analyzed together the association is no longer apparent. Further investigation into additional predictors of imaging results in acute bronchiolitis is warranted.
To cite this abstract:Azzarone G, Nazif J, Esteban N, Biller R, Liewehr S. Chest Radiographs and Bronchiolitis: Can Imaging Results Be Predicted?. Abstract published at Hospital Medicine 2012, April 1-4, San Diego, Calif. Abstract 97567. Journal of Hospital Medicine. 2012; 7 (suppl 2). https://www.shmabstracts.com/abstract/chest-radiographs-and-bronchiolitis-can-imaging-results-be-predicted/. Accessed July 21, 2019.