General article
Within-breath changes of airway calibre in patients with airflow obstruction by continuous measurement of respiratory impedance

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Abstract

We bench-tested a commercially available instrument for measuring respiratory impedance (Siregnost FD5: Siemens) and found that resistance (R) and phase changes were accurately recorded in models. In a single human subject, total respiratory resistance (R1) was closely comparable to resistance measured by the Mead—Whittenberger technique. The derived continuous variable (Ros) was similar to R at <4 cmH2O·litres−1·sec, but underestimated R at higher values. Ros was highly correlated with airways resistance by body plethysmography (Raw), but with a low slope and high intercept (Ros=1.38+0.59 Raw: r=0.89).

Because of turbulence, both in model larynxes and in normal subjects, Ros tends to rise with increases in flow in either direction. Ros also tends to fall as lung volume rises, and vice versa, reflecting cyclic changes in airway calibre. We devised indices of expiratory narrowing of airways from the maximum flow-volume loop, and the plethysmographic alveolar pressure-flow loop, and compared them with the slope of the relation between Ros and lung volume during tidal breathing, in nine normal subjects and 16 patients with airflow obstruction.

Twelve of the 16 patients, all with abnormal flow-volume loops, had high Ros-volume slopes, demonstrating excessive expiratory narrowing even during tidal breathing. We found no patients with normal inspiratory Ros together with an abnormal Ros - volume slope. Thus unstressed inspiratory calibre was never dissociated front airways narrowing on expiration.

References (17)

  • J.H. Alpers et al.

    Significance of a looped appearance of the flow: alveolar pressure relationship of the lungs as examined by the whole body plethysmograph

    Clin. Sci.

    (1967)
  • T. Brancatisano et al.

    Respiratory movements of the vocal cords

    J. appl. Physiol.: Resp. Environ. Exercise Physiol.

    (1983)
  • A.G. Cutillo et al.

    Mechanical behaviour of the respiratory system as a function of frequency in health and disease

    Bull. Eur. Physiopathol. Resp.

    (1983)
  • S.V. Dawson et al.

    Wave-speed limitation on expiratory flow—a unifying concept

    J. appl. Physiol.: Resp. Environ. Exercise Physiol.

    (1979)
  • A.B. DuBois et al.

    A new method for measuring airways resistance in man using a body plethysmograph: values in normal subjects and in patients with respiratory disease

    J. clin. Invest.

    (1956)
  • A.B. DuBois et al.

    Oscillation mechanics of lungs and chest in man

    J. appl. Physiol.

    (1956)
  • M. Franetzki et al.

    A direct- display oscillation method for measurement of respiratory impedance

    J. appl. Physiol.: Resp. Environ. Exercise Physiol.

    (1979)
  • A.F. Gelb et al.

    Mechanisms limiting airflow in bullous lung disease

    Am. Rev. resp. Dis.

    (1973)
There are more references available in the full text version of this article.

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