Differences in responsiveness to hyperventilation and methacholine in asthma and chronic bronchitis.

In a previous study on 27 patients with chronic bronchitis we found that only three developed bronchoconstriction in response to hyperventilation of cold, dry air despite an increased responsiveness to methacholine inhalation. We therefore investigated bronchial responsiveness to hyperventilation with cold, dry air and methacholine in 27 patients with stable asthma who had a similar range of baseline FEV1 values but who developed …