Impulse oscillometry and free-running tests for diagnosing asthma and monitoring lung function in young children

Janne Burman,Leo Pekka Malmberg,Sami Remes,Tuomas Jartti,Anna S Pelkonen,Mika J Mäkelä

doi:10.1016/j.anai.2021.03.030

Abstract

BackgroundSeparating individuals with viral-induced wheezing from those with asthma is challenging, and there are no guidelines for children under 6 years of age. Impulse oscillometry, however, is feasible in 4-year-old children. ObjectiveTo explore the use of impulse oscillometry in diagnosing and monitoring asthma in young children and evaluating treatment response to inhaled corticosteroid (ICS). MethodsA total of 42 children (median age 5.3 years, range 4.0-7.9 years) with physician-diagnosed asthma and lability in oscillometry were followed for 6 months after initiation of ICS treatment. All children performed the 6-minute free-running test and impulse oscillometry at 3 time points. After the baseline, they attended a second visit when they had achieved good asthma control and a third visit approximately 60 days after the second visit. A positive ICS response was defined as having greater than 19 points in asthma control test and no hyperreactivity on the third visit. ResultsIn total, 38 of 42 children responded to ICS treatment. Exercise-induced increases of resistance at 5 Hz decreased after ICS treatment (61% vs 18% vs 13.5%, P < .001), and running distance during the 6-minute test was lengthened (800 m vs 850 m vs 850 m, P = .001). Significant improvements in childhood asthma control scores occurred between the baseline and subsequent visits (21 vs 24 vs 24, P < .001) and acute physicians’ visits for respiratory symptoms (1, (0–6) vs 0, (0–2), P = .001). Similar profiles were observed in children without aeroallergen sensitization and among those under 5 years of age. ConclusionImpulse oscillometry is a useful tool in diagnosing asthma and monitoring lung function in young children.

Highlights

The prevalence of childhood asthma varies in European birth cohorts, possibly at least to some extent owing to lack of universal consensus guidelines on diagnosing early childhood asthma.[1]
We evaluated the feasibility of impulse oscillometry together with clinical assessment in the evaluation of inhaled corticosteroid (ICS) treatment responses in Finnish preschool children aged 4 to 7 years
More than 90% of all children responded to ICS treatment in terms of improving Childhood Asthma Control Test (C-ACT) scores, decreasing acute physicians’ visits, and decreasing exercise-induced bronchoconstriction (EIB), measured as the resistance change at 5 Hz after exercise

Summary

Introduction

The prevalence of childhood asthma varies in European birth cohorts, possibly at least to some extent owing to lack of universal consensus guidelines on diagnosing early childhood asthma.[1]. Impulse oscillometry is a noninvasive lung function tool that only requires passive patient cooperation with normal breathing by a mouthpiece. It uses externally applied pressure signals and their resultant flows to determine resistance and reactance, the components of respiratory impedance. All children performed the 6-minute free-running test and impulse oscillometry at 3 time points After the baseline, they attended a second visit when they had achieved good asthma control and a third visit approximately 60 days after the second visit. Exercise-induced increases of resistance at 5 Hz decreased after ICS treatment (61% vs 18% vs 13.5%, P < .001), and running distance during the 6-minute test was lengthened (800 m vs 850 m vs 850 m, P = .001).

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Conclusion