Airway responsiveness and chronic airway obstruction

Mechanisms of bronchial hyperreactivity in cystic fibrosis

We studied 14 patients with cystic fibrosis (CF) who had evidence of bronchial hyperreactivity on a standardized histamine challenge. Patients had a histamine challenge on the first day. Then they were pretreated with either 0.25 mg ipratropium bromide or 0.5 mg fenoterol hydrobromide on 2 separate days, and the histamine challenge was repeated. Baseline forced expiratory volume in 1 sec was similar on the 3 days; however, there was a small but significant (P less than 0.05) improvement after fenoterol. Mean PC20 on the control day was 1.50 mg/ml, which increased significantly after pretreatment with ipratropium (2.88 mg/ml, P less than 0.01) and fenoterol (3.64 mg/ml, P less than 0.005), indicating protection against histamine-induced bronchial hyperreactivity. The six CF patients with "coexistent asthma," as defined by recurrent episodes of wheezing responsive clinically to bronchodilator therapy, had no significant protection from ipratropium, whereas the eight "nonasthmatic" CF patients were protected by both ipratropium and fenoterol. We postulate that at least two mechanisms contribute to histamine-induced bronchial hyperreactivity in patients with CF, one related to vagally mediated reflex bronchoconstriction and another that acts independently of this mechanism.

Future trends in the management of asthma and chronic obstructive pulmonary disease

The strategic approach to the management of asthma and reversible chronic obstructive pulmonary disease employs the use of bronchodilators, corticosteroids, and other agents. A stepped therapeutic approach based upon inhaled beta agonists, long-acting oral methylxanthines and practical steroid strategies is valuable for most patients with reversible asthma and a considerable number of patients with advanced chronic obstructive pulmonary disease. The goals of therapy are a complete or acceptable relief of symptoms and the achievement of the highest possible level of human function, maximal improvement in airflow, and minimal or no side effects from the pharmacologic agents used. The response to therapy from each agent should be carefully assessed by objective measurements of one-second forced expiratory volume and forced vital capacity using simple, practical spirometers. Future trends in asthma therapy include new inflammatory mediator blockers, combined pharmacologic strategies, and other new agents. Future trends in chronic obstructive pulmonary disease include the early identification and intervention with drugs that could reduce or minimize nonspecific bronchial hyperreactivity.

Chronic bronchial disease of the cat

This discussion of chronic bronchial disease in the cat includes a discussion of the functional anatomy and physiology of the feline lung, the immunologic aspects of the disease, the role of infections, and particulate aerosols and noxious gases in the etiology and clinical course of feline asthma and chronic bronchitis, and the pathology and diagnosis of chronic bronchitis.