Breath sound analysis could predict the length of symptomatic days of wheezy children

Abstract

Background: Breath sound analysis is one of the methods for examining the characteristics of recorded respiratory sounds. This approach may allow physicians to evaluate an abnormal breath sound precisely. To determine the usefulness of this approach to predict the length of symptomatic days of wheezy children, we evaluate the frequency spectrum of recorded breath sounds. Methods: We enrolled the subjects who were admitted with wheezy bronchitis or bronchial asthma. Breath sounds were recorded by electro stethoscope (Litmann Electronic Stethoscope Model 4100). We examined the relationship between wheezy sound frequency spectrum and the length of symptomatic days. Recorded sounds were analyzed using the sound analysis software (Litmann, version 1.0). Results: Eighteen subjects were enrolled in this study (median age, 2.9 y). The median length of symptomatic days were 6.0 days (IQR:1.0 to 10.0). Polyphonic wheezy subjects in an inspiration phase had more long symptomatic periods than monophonic wheezy subjects (r = 0.47, p = 0.04). A maximum value frequency detected at expiration phase were negatively correlated with the length of symptomatic days (r = -0.47, p = 0.049). Conclusions: Breath sound frequency analysis may be a useful objective method for determining the severity of wheezy symptom. Breath sound recording was easy to perform for children without harmful event, and this method could perform precise analysis of wheezy sounds.