MECHANICAL IMPEDANCE OF THE CHEST IN SMOKERS AND NON-SMOKERS

  • 1 January 1981
    • journal article
    • research article
    • Vol. 17  (1) , 93-105
Abstract
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 resistance and its frequency dependence, compliance, inertance and resonant frequency of the respiratory system were computed using the assumption of a 2nd order linear system. 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 resistance was significantly increased at all frequencies. It was normal in a number of subjects with abnormally low maximal expiratory flows. Unlike maximal flow, forced oscillations indices were not correlated to tobacco consumption expressed in pack-years. Impedance measurements of breathing air may not be especially useful for early detection of airway abnormalities.