Effect of a previous deep inspiration on airway resistance in man

We measured airway resistance and thoracic gas volume by the body plethysmograph technique, and transpulmonary pressure in seven healthy, adult subjects, before and after induction of bronchoconstriction. A deep inspiration never altered airway resistance, measured at functional residual capacity in the control state, but always reduced it for 1—2 min when bronchoconstriction was present. Discrepancies in data published on airway resistance may be due to use of methods which require a deep inspiration, or to occurrence of a spontaneous deep inspiration shortly before the test. Submitted on January 13, 1961