Sensory-Mechanical Responses to High-Dose Methacholine Bronchoprovocation: The Modulating Effects of Deep Inspirations

The physiologic variables distinguishing classic asthma (CA), cough variant asthma (CVA), and methacholine (MCh)-induced cough with normal airway sensitivity (COUGH) are incompletely understood. Defining the range of normal responses associated with deep inspirations (DIs) during high-dose MCh is crucial to understand the clinical relevance of COUGH with respect to CA and CVA. The purpose of this study is to characterize responses to DI in healthy normal individuals (without asthma, chronic cough or asymptomatic airway hyperresponsiveness) during high-dose MCh and compare with responses in CA, CVA and COUGH.