Effects of cold air hyperpnea in patients with chronic obstructive lung disease.

In 26 well-characterized, stable patients with chronic obstructive pulmonary disease (COPD), we measured changes in forced expiratory volume in one second (FEV1) induced by isocapnic hyperpnea of subfreezing dry air. The patients had a mean FEV1 of 1.21 L(38% predicted); 13 of 26 increased their FEV1 by at least 20% in response to inhaled beta agonists, and 11 of 18 subjects tested demonstrated at least a 30% increase in FEV1 with oral administration of corticosteroids. Only 6 of 26 patients responded to cold air hyperpnea with a 20% decrease in FEV1. Cold air response was not related to baseline FEV1 or to the level of hyperpnea attained. Though responses to inhaled beta agonists and systemic steroids were correlated, neither correlated with cold air responses. We conclude that in COPD airway reactivity is not nonspecific but depends on the agent used to elicit airway responses.