90 Lung ultrasound in pediatric asthma patients: A pilot study characterizing findings at baseline stat

Abstract

Abstract Primary Subject area Emergency Medicine - Paediatric Background Unlike the lung ultrasound (LU) findings of pneumonia, bronchiolitis, pleural effusions and pneumothorax, which have all been well described, the sonographic pattern of asthma remains unclear. Previous pediatric studies have shown that pediatric patients with acute asthma exacerbations had positive LU findings. It is also unclear whether these findings were the result of acute infections associated with the exacerbation or if the findings would be present at baseline, outside an exacerbation in an asthmatic patient. Objectives The primary objective of this study is to characterize lung ultrasound (LU) findings in stable asthma pediatric patients presenting in a tertiary care asthma or respiratory clinic. Design/Methods Eligible patients >6 years of age, underwent a LU by the study sonographer between December 19, 2017 to June 25, 2019, during their regular follow up visit at the pulmonology clinic or scheduled pulmonary function test. Patients were defined as asthmatic if they had a positive methacholine challenge test (MCT) or spirometry at the day of the visit or in the past. Patients were excluded if they had an upper respiratory tract infection in the past 4 weeks, or had any other known pulmonary diseases. Baseline demographic and asthma severity (ISAAC score, ACQ-7) questionnaires were filled out by the patients, following which they underwent a LU by a novice sonographer using a 6-zone protocol. A blinded expert sonographer interpreted the images offline. A positive LU was defined as presence of more than 3 B-lines, consolidation (<1cm or >1cm), absent lung slide, and/or presence of pleural fluid. Results Fifty-two patients were enrolled in the study and 19.2% (CI 8.31-30.15) of the asthma patients had positive LU findings. The positive LU findings were diverse including B-lines (80%), small consolidation (80%), pleural line anomalies (10%). Positive LU findings were not correlated to any demographic value. Conclusion In our study, 19.2% of asthma patients at baseline have a positive LU. Lung consolidations larger than 1 cm were rarely seen. There were no significant differences between demographic data in asthmatic patients with positive compared to those with negative LUS. This positive LU scan rate is in keeping with a prior study on LU in pediatrics.