[Spirometric modifications induced by bronchography. Effects of Salbutamol]

Bronchography enables an appreciation of the morphology and dynamics of the bronchi inaccessible to the fibroscope. However, this examination may aggravate pulmonary function in patients with chronic airflow obstruction. We have studied the effects of bronchography on forced expiration in order to identify and quantify possible spirometric changes. Thus spirometric tests were done at different times during the examination (V.C., F.E.V., flow-volume curves): before and after anaesthetizing the upper airways with xylocaine, after the introduction of contrast to the bronchi and finally after a Salbutamol aerosol. Spirometric values were unaffected by anaesthesia of the upper airways. On the other hand, the introduction of contrast led to a clear and constant fall in maximum expiratory flow, associated with a fall in forced vital capacity. These changes could not be reversed either after inhalation of Salbutamol or sub-cutaneous Terbutaline. The mechanisms producing the spirometric changes which we report does not seem to involve either the adrenergic system or the irritant receptors. Bronchial obstruction produced by the contrast does not alone appear to explain the changes induced by bronchography. Other mechanisms, not yet identified, probably contribute to the decrease in maximum expiratory flow.