Hiba Saleem

almost 4 years ago

A methacholine challenge test is a type of bronchoprovocation test used to help diagnose asthma. Methacholine is a bronchoconstrictor. The patient is made to inhale methacholine and spirometry is performed before and after every dose of inhaled methacholine to measure the amount of airway constriction. A methacholine challenge test is considered positive if methacholine causes the FEV1 to drop by 20% or more compared to the baseline.