Bronchoconstriction induced by repeated forced vital capacity manoeuvres.

An asthmatic atopic patient who developed bronchoconstriction during repeated forced vital capacity manoeuvres and after exercise is reported. Since increases in total airway and upper segment resistances and drop in FEV1 and Vmax 50 were induced, it is considered that bronchoconstriction involved most of the airways. Partial prevention of this effect could be demonstrated after inhalation of an adrenergic bronchidilator or disodium cromoglycate. Atropine completely prevented the flow response but did not alter the total airway resistance increase. Bronchoconstriction is interpreted as partially related to mast cell disruption and cholinergically mediated stimuli.