Analysis of Adventitious Sounds in Patients with Diffuse Panbronchiolitis by a Phonopneumogram

Abstract

This study was conducted to clarify the acoustic features of adventitious sounds in patients with DPB (diffuse panbronchiolitis). We analysed the lung sounds by phonopneumography using a soundspectrograph.
Among fourteen patients, crackles were observed in all patients and wheezes in eleven patients. Crackles occurred on early inspiration but no fixed tendency was observed on expiration. Crackles were not affected by posture and were transmitted over a wide area. The average number of crackles per inspiratory phase was 11.6 and per expiratory phase was 9.1. The frequency of the sound was 200Hz to 1, 150Hz. The number and frequency of the crackles in DPB were less than in fibrosing alveolitis. Therefore, crackles in DPB were regarded as coarse crackles. This was confirmed by wave-form analysis using a zero-crossing method.
Wheezes were obtained throughout the respiratory cycle in both inspiratory and expiratory phases and had overtones which were integral multiples of the fundamental frequency. Acoustically, wheezes in DPB resembled those of asthma. Adventitious sounds in DPB may derive from the larger airways.