[Mechanical impedance of the chest in smokers and non-smokers (author's transl)].
Mechanical impedance of the respiratory system was measured at 5, 10, 15 and 20 Hz in 47 healthy non-smokers, 20 ex-smokers and 51 current smokers. Besides the resistance and its frequency dependence, the compliance, the inertance and the resonant frequency of the respiratory system were computed using the assumption of a second order linear system. The data were normalized for sex, age and body height on the basis of correlations observed in non-smokers. No significant difference was found in ex-smokers. In smokers the resistance was significantly increased at all frequencies. However, it was normal in a number of subjects with abnormally low maximal expiratory flows. unlike maximal flows, forced oscillations indices were not correlated to tobacco consumption expressed in pack-years. The results do not indicate that impedance measurements breathing air may be specially useful for early detection of airway abnormalities.
D000328:Adult; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000502:physiology* / Q000503:physiopathology; D008170:Lung Compliance; D008297:Male; D008450:Maximal Midexpiratory Flow Rate; D010992:Plethysmography, Impedance; D012907:Smoking
Impédance mécanique thoraco-pulmonaire chez des sujets femeurs et non-femeurs.