Clinical applicability of a methacholine inhalational challenge
J. R. Myers, W. M. Corrao and S. S. Braman
Cough, dyspnea, and chest pain are symptoms common to many cardiopulmonary
diseases. A comprehensive evaluation, including a history, physical
examination, ECG, chest roentgenogram, and pulmonary function studies, will
often yield a specific diagnosis. However, when these symptoms are
intermittent, as they often are in patients with bronchial asthma, the
diagnosis may not be apparent. If asthma is thought to be a diagnostic
possibility, a bronchial inhalation challenge should be used to demonstrate
bronchial hyperreactivity, the hallmark of asthma. The methacholine
chloride inhalation challenge is a simple and useful laboratory test to
diagnose bronchial hyperreactivity. We describe eight patients with a
variety of clinical symptoms to demonstrate the usefulness of this test.
Patients with unexplained respiratory symptoms should be considered for
bronchial inhalation challenge before proceeding to more invasive
diagnostic procedures.