Value of bronchial challenge in scuba diving candidates

Bronchial challenges were effected with carbachol in 76 subjects who were c andidates for a scuba diving group. Bronchial reactivity was assessed throu gh airway resistance and forced expiratory volume in 1 sec (FEV1) measureme nts. Medical interrogation had revealed symptoms of recent (RA) or ancient (AA) asthma, or allergic rhinitis (AL). Nearly half of the subjects (47%) p resented bronchial hyperresponsiveness (BHR), which was much more frequent in the RA group, but whose strength did not depend on clinical presentation . Prevalence of BHR was fairly high (36%) in the AL group. BHR constituted a contraindication to scuba diving because it may promote pulmonary barotra uma.