methacholine challenge test(redirected from Metacholine challenge test)
methacholine challenge test
a test that involves the inhalation of increasing concentrations of methacholine, a potent bronchoconstrictor, in patients with possible bronchial hyperreactivity; usually performed when a diagnosis of asthma or bronchospastic lung disease is not clinically obvious.
methacholine challenge test(mĕth″ă-kō′lĭn)
A test for airway hyperresponsiveness, e.g., asthma or occupational asthma, in which a person is given various dilutions of the drug methacholine hydrochloride to inhale, after which spirometric measurements are taken. Decreases in the forced expiratory volume in the first second of expiration of 20% or more or decreases in specific conductance of 35% or more are indicative of airway hyper-responsiveness.