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Validating The Clinical Utility Of Sgaw As A Response Variable In Methacholine Challenge Testing, Jacqueline N. Parker, Allison R. Tzeng, David A. Kaminsky

Larner College of Medicine Fourth Year Advanced Integration Teaching/Scholarly Projects

Introduction: Airway hyperresponsiveness (AHR) is a characteristic feature of asthma diagnosed using the methacholine challenge test (MCT) based on a drop in FEV₁ > 20 % from baseline at a concentration of < 8 mg/mL (provocative concentration 20 denoted PC₂₀). However, there are other physiological responses to methacholine, of which airway resistance—as measured by specific airway conductance, sGaw—has been suggested as an alternative to diagnosing AHR. A positive sGaw is denoted by a drop greater than 40% from baseline at a concentration of < 8 mg/ml (PC₄₀). We sought to determine the clinical utility of sGaw vs FEV₁ in diagnosing AHR and its association with asthma.

Methods: …