Lung sound analysis in a patient with vocal cord dysfunction and bronchial asthma

摘要

Objective. Vocal cord dysfunction (VCD) is a condition characterized by adduction of the vocal cords, resulting in narrowing or even closure of the glottis during inspiration. This can cause wheezing that originates at the site of narrowing. Some patients have both VCD and asthma. In such cases, an acute episode of VCD can be difficult to differentiate from that of asthma. We tested the usefulness of lung sound analysis (LSA) in such a condition. Methods. We performed an LSA in a patient with asthma and coexisting VCD diagnosed using laryngoscopy. Results and conclusion. The LSA during an acute VCD episode revealed monophonic continuous adventitious sounds that were distributed symmetrically over both lung fields. The time domain analysis revealed that the adventitious sounds originated in the neck. These LSA findings clearly indicated that the acute episode was not due to asthma but due to VCD. This case illustrates that the LSA may be a useful tool to differentiate between an acute episode of asthma and that of VCD.