Factors influencing the bronchodilator effect of a deep inspiration in asthmatic patients with provoked bronchoconstriction.
We have studied 26 asthmatic patients in whom deep inspiration induced a transient but marked bronchodilatation when carbachol-induced bronchoconstriction was present. Changes in bronchial tone were assessed by specific airway resistance measurements. Bronchodilatation after a slow inspiration (eight subjects) or a 10-second breath-hold at total lung capacity (13 subjects) was significantly less than that observed after either a fast inspiration or no breath-holding period. The magnitude of the bronchodilatation induced by a fast inspiration without breath-holding was directly and significantly related to the magnitude of the carbachol-induced bronchoconstriction in five subjects.
D000328:Adult; D000403:Airway Resistance / Q000187:drug effects; D001249:Asthma / Q000503:physiopathology*; D001985:Bronchial Provocation Tests; D002217:Carbachol / Q000494:pharmacology*; D003251:Constriction, Pathologic / Q000139:chemically induced; D005260:Female; D006801:Humans; D008176:Lung Volume Measurements; D008297:Male; D012119:Respiration
D002217:Carbachol