Lung ultrasound findings in asymptomatic healthy children with asthma.

BACKGROUND: Lung ultrasound (LUS) has been shown to be an effective tool to rapidly diagnose certain causes of pediatric respiratory distress. However, very little is known about LUS findings in pediatric asthma. OBJECTIVES: The primary objective of this study was to characterize LUS findings in a cohort of pediatric patients with a definitive diagnosis of asthma, outside of an asthma exacerbation. METHODS: Eligible patients, aged 6-17 years old and diagnosed with asthma, underwent LUS during an outpatient visit. LUS was conducted using a six-zone scanning protocol. Presence of a LUS artifact was defined by one or more of the following: ≥3 B-lines per intercostal space, pulmonary consolidation, and/or pleural abnormality. Images were interpreted by an expert sonographer blinded to patient clinical characteristics. RESULTS: Fifty-two patients were included. 10/52 (19.2%) patients demonstrated the presence of LUS artifacts: 8 with ≥3 B-lines, 1 with consolidation >1 cm, and 7 with subpleural consolidations <1 cm, 1 with a pleural line abnormality. Artifacts were seen in the right anterior and lateral zones in 60% of participants and were limited to 1-2 intercostal space(s) within one lung zone in all participants. No association was found between presence of LUS artifacts and asthma control or severity. CONCLUSION: To our knowledge, this is the first report of LUS findings in outpatient pediatric asthma. LUS artifacts in asthmatic children can be seen outside of acute exacerbations. Such baseline findings need to be taken into consideration when using LUS for the acute evaluation of a pediatric patient with asthma.

Characterizing pediatric lung ultrasound findings during a chemically induced bronchospasm.

BACKGROUND: Lung ultrasound (LUS) has been shown to be a useful clinical tool in pediatrics, but very little is known about the LUS findings of asthma in children. OBJECTIVES: The primary objective was to characterize LUS findings of pediatric patients before and after a chemically induced bronchospasm. The secondary objective was to evaluate the effect of bronchodilators on LUS findings. METHODS: Eligible children 6-17 years old presenting for a methacholine challenge test (MCT) in a pediatric respiratory clinic were recruited. Patients with viral symptoms were excluded. A six-zone LUS protocol was performed before and after the MCT, and after bronchodilator administration; video recordings were analysed by an expert blinded to the patient characteristics and MCT results. RESULTS: Forty-four patients were included in the study. Five patients had positive LUS findings at baseline. Nine patients out of 29 (31%) had new-onset positive LUS following a reactive MCT. There was a significant association between having a chemically induced bronchospasm and a positive LUS post-MCT (odds ratio [95% confidence interval]: 5.3 [1.0-27.7]; p = 0.05). Among patients who developed positive LUS findings post-MCT, four out of nine returned to having a negative LUS postbronchodilator administration. CONCLUSIONS: This is the first known report of an association between LUS findings and bronchospasm in pediatric patients. It is also the first documentation of resolution of LUS findings postbronchodilator administration. Most LUS findings observed were small and limited to a few intercostal spaces. Further research is required to quantify these findings and evaluate the effect of salbutamol on LUS.