Regional Lung Sound Asynchrony in Chronic Obstructive Pulmonary Disease Patients.
BACKGROUND
Regional lung sound distribution in chronic obstructive pulmonary disease (COPD) is reported to be asynchronous. Mathematical analyses using vibration response imaging (VRI), such as left and right lung asynchrony (gap index; GI) and regional lung asynchrony (asynchrony score; AS), are useful measures to evaluate lung sound asynchrony.


OBJECTIVE
The aim of this study was to investigate the association of lung sound asynchrony with pulmonary functions and emphysematous lesions in COPD patients.


METHODS
VRI recordings and pulmonary function tests were performed in 46 stable male COPD patients and in 40 healthy male smokers. Lung sound asynchrony was evaluated using GI, AS of the left and right lung (AS L-R), and AS of the upper and lower lung (AS U-L). In 38 patients, computed tomography taken within 6 months was available and analyzed.


RESULTS
AS L-R and AS U-L were significantly higher in COPD patients than in healthy smokers, with no significant difference in GI. There were no significant correlations with either AS and pulmonary functions, excluding a negative correlation between AS U-L and diffusion capacity. Although there were no significant correlations between both AS and severity of emphysema, significant positive correlations were observed between heterogeneity of emphysematous lesions and AS L-R (ρ = 0.38, p < 0.05) or AS U-L (ρ = 0.51, p < 0.005).


CONCLUSIONS
Regional lung sounds are distributed more asynchronously in COPD patients than in healthy smokers, which correlates with the heterogeneous distribution of emphysematous lesions.
Division of Respiratory Medicine, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan.
Masamichi
M
Mineshita
Hirotaka
H
Kida
Hiroshi
H
Handa
Hiroki
H
Nishine
Naoki
N
Furuya
Takeo
T
Inoue
Shin
S
Matsuoka
Teruomi
T
Miyazawa
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D008448:Maximal Expiratory Flow Rate; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D029424:Pulmonary Disease, Chronic Obstructive / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012129:Respiratory Function Tests; D012135:Respiratory Sounds / Q000503:physiopathology*; D012720:Severity of Illness Index; D014797:Vital Capacity; D055815:Young Adult