Abstract
Background: MostGraph, an instrument used for measuring respiratory resistance and reactance by forced oscillation methods, has recently been developed in Japan. Although the reference values of respiratory resistance and reactance in childhood had been reported, the ranges of these values vary. Respiratory resistance and reactance depend on the frequency of the impulse used in children; therefore, there is a need to evaluate the changes in these values in each patient. Objective: The aim of this study was to evaluate the correlation between the changes in Mostgraph parameters and those in the spirometric assessments in medicated asthmatic children. Subjects and Methods: 63 patients with asthma, between 6 to 17 years of age, were evaluated by MostGraph and spirometry. We evaluated the correlations between the changes in Mostgraph parameters and those in the spirometry by Spearman coefficient statistical analysis. Results: The difference of average R5 correlated with ⩒50 (ρ=-0.501, p<0.001) and FEF25-75 (ρ=-0.472, p<0.001). The difference of inspiratory R5 correlated mostly with that in ⩒50 (ρ=-0.524, p<0.001). The ratio of change in inspiratory R5 correlated with that in ⩒50 (ρ=-0.515, p<0.001). The correlations between the changes in MostGraph parameters and those in the spirometry at expiratory phase did not differ from those at inspiratory phase. Conclusion: MostGraph could detect the different changes that occurred in the peripheral respiratory tracts. Future studies should aim to assess the manner in which MostGraph can be best utilized for the management of asthma.
