Detection and definition of abnormal paediatric breath sounds using digital stethoscopes compared to standard auscultation.

Introduction/Aim: The audio characteristics of abnormal paediatric breath sounds are not well-defined and digital techniques to capture them have not been widely investigated. Our study aimed to define the audiological features of abnormal paediatric breath sounds objectively and compare the ability of digital stethoscopes to detect them against auscultation using standard bell-and-diaphragm stethoscopes. Method(s): Twenty children with normal breath sounds, generalized wheeze or crackles, and some with a diagnosis of cystic fibrosis were auscultated by a paediatric consultant and digitally recorded using both the LittmanTM 3200 Digital Electronic Stethoscope and a ClinicloudTM Digital Stethoscope. We used spectrographic analysis and recording playback to detect abnormal breath sounds and define their audio waveform characteristics. Result(s): Digital stethoscopes were more sensitive than standard auscultation in detecting wheeze in our study. Patients with clinicallydescribed wheeze had periodic waveform segments of increased intensity and frequency compared to background breath sounds, mostly spanning expiration for a period of 0.03-1.2 seconds at frequencies of 100-1050Hz, and occasionally spanning shorter inspiratory segments. Recordings of patients with crackles revealed brief (6-20 millisecond) discontinuous sounds with a distinguishing waveform identifiable within them. Conclusion(s): Digital breath sound analysis may be more sensitive than manual auscultation in detecting breath sound abnormalities in children, with potential applications for improved diagnosis, data sharing and disease monitoring. Further research and development is needed.