Lung ultrasound in bronchiolitis

Abstract

Background: Bronchiolitis is the most common acute viral infection of the lower respiratory tract in infants. Clinical severity is associated with different risk factors; however, no clinical, laboratory, or radiological findings are able to predict the course of the disease in full-term infants. Lung ultrasound (LUS) is a valid technique for the diagnosis and evaluation of pediatric respiratory diseases.

Aims: The aim of our study was to correlate an LUS score with a clinical score, to describe lung ultrasound findings in cases and controls, and to compare LUS findings with chest X-ray (CXR) in infants hospitalized with bronchiolitis.

Methods: We conducted a single-center, longitudinal, prospective study on 92 infants. Sixty-three out of 92 infants were hospitalized for acute bronchiolitis (cases) and twenty-nine out of 92 for diseases not involving the respiratory system (controls). All patients with bronchiolitis underwent a clinical evaluation with the assignment of a clinical severity score and performed lung ultrasound with the assignment of an LUS score. Twenty-three out of 63 infants with bronchiolitis underwent also a CXR for clinical indications. Control infants performed only LUS.

Results: In infants with bronchiolitis LUS score showed a positive correlation with the clinical score (r = .62, p < .001) and the length of hospitalization (r = .42; p < .001). The need of oxygen therapy was more frequent in the patients with higher LUS score (p < .001). LUS findings observed in the cases were the presence of B-lines, subpleural consolidations, and abnormalities of the pleural line. No LUS alterations were observed in the controls. In patients who performed LUS and CXR, we found a correlation between the presence of abnormalities of the pleural line with LUS and the presence of air trapping with CXR (r = .55; p = .007).

Keywords: bronchiolitis; infant; lung; ultrasound.