Ace the CPFT Challenge 2026 – Breathe Easy with Pulmonary Success!

The methacholine challenge test is primarily utilized to diagnose asthma by assessing airway responsiveness. In this test, methacholine, which is a bronchoconstrictor, is inhaled to evaluate how sensitive the airways are. If the patient has asthma, exposure to methacholine will lead to bronchoconstriction resulting in decreased airflow, which is measurable through spirometry. This test helps determine whether the patient has hyperreactive airways characteristic of asthma, making it a critical tool in the diagnostic process.

In contrast, the other options do not accurately reflect the primary application of the methacholine challenge test. Lung cancer assessment typically involves imaging techniques and biopsies rather than a bronchial reactivity test. Measuring static lung volumes is instead done through techniques like spirometry or plethysmography, which focus on lung capacity rather than the reactivity of the airways. Lastly, evaluating respiratory infections would rely on clinical assessments and laboratory tests rather than a methacholine challenge aimed at bronchial response. Thus, the role of the methacholine challenge is distinctly aligned with diagnosing asthma through the evaluation of airway responsiveness.