THE EFFECT OF ANTISPASMODIC DRUGS ON THE ENDOMURAL BRONCHIAL (OR "SQUEEZE") PRESSURES IN BRONCHITIS AND ASTHMA1 2
Journal/Book: Reprinted fron THE AMERICAN REVIEW OF REBPIRATORY DISEASES Vol. 93 No. 5 May 1969 Printed in U.S.A.. 1969;
Abstract: 1 From the Departments of Respiratory Diseases and of Medical Physics University of Edinburgh Edinburgh Scotland. 2 Supported by the British Medical Research Council and the Royal Victoria Hospital Tuberculosis Trust. SUMMARY The effects of antispasmodic drugs an the endomural bronchial (balloon) pressure excursion and the corresponding esophageal pressure excursion were observed in 21 patients (6 with chronic asthma 15 with chronic bronchitis). In most of the asthmatics and some of the bronchitics administration of an antispasmodic drug resulted in a proportionately greater fall of endomural bronchial pressure excursion than of the esophageal pressure excursion suggesting relaxation of "dynamic" tone. In addition a fall of the end-expiratory balloon pressure trace was observed in all 13 patients in whom it was possible to make a valid Observation suggesting that the antispasmodics also relaxed "static" bronchial tone. The results are in keeping with the hypothesis that in asthmatics an increase in bronchial muscle tone may be the major factor in the airway obstruction. Increased bronchial muscle tone appeared to play a less important role in patients with chronic bronchitis although there was a good deal of variation from patient to patient. . . .