Studies on the Pulmonary Physiological Effect of Sympathomimetic Amines in Bronchial Asthma

Abstract

The effects of isoprenaline and orciprenaline, given by pressurized aerosol, on the forced expired volume, arterial blood gas tensions and indices of gas exchange are analysed in a group of 11 asthmatic patients. A small fall in the arterial oxygen tension may occur if the forced expired volume does not increase. This fall may be due to changes in overall lung perfusion or total ventilation in addition to local ventilation/perfusion imbalance. A transient phase of increased alveolar hyperventilation is frequently seen following either drug. This effect appears to be secondary to changes in lung mechanics and dead space ventilation.