Chronic cough due to chronic bronchitis: ACCP evidence-based clinical practice guidelines.
BACKGROUND: Chronic bronchitis is a disease of the bronchi that is manifested by cough and sputum expectoration occurring on most days for at least 3 months of the year and for at least 2 consecutive years when other respiratory or cardiac causes for the chronic productive cough are excluded. The disease is caused by an interaction between noxious inhaled agents (eg, cigarette smoke, industrial pollutants, and other environmental pollutants) and host factors (eg, genetic and respiratory infections) that results in chronic inflammation in the walls and lumen of the airways. As the disease advances, progressive airflow limitation occurs, usually in association with pathologic changes of emphysema. This condition is called COPD. When a stable patient experiences a sudden clinical deterioration with increased sputum volume, sputum purulence, and/or worsening of shortness of breath, this is referred to as an acute exacerbation of chronic bronchitis as long as conditions other than acute tracheobronchitis are ruled out. The purpose of this review is to present the evidence for the diagnosis and treatment of cough due to chronic bronchitis, and to make recommendations that will be useful for clinical practice. METHODS: Recommendations for this section of the review were obtained from data using a National Library of Medicine (PubMed) search dating back to 1950, performed in August 2004, of the literature published in the English language. The search was limited to human studies, using the search terms "cough," "chronic bronchitis," and "COPD." RESULTS: The most effective way to reduce or eliminate cough in patients with chronic bronchitis and persistent exposure to respiratory irritants, such as personal tobacco use, passive smoke exposure, and workplace hazards is avoidance. Therapy with a short-acting inhaled beta-agonist, inhaled ipratropium bromide, and oral theophylline, and a combined regimen of inhaled long-acting beta-agonist and an inhaled corticosteroid may improve cough in patients with chronic bronchitis, but there is no proven benefit for the use of prophylactic antibiotics, oral corticosteroids, expectorants, postural drainage, or chest physiotherapy. For the treatment of an acute exacerbation of chronic bronchitis, there is evidence that inhaled bronchodilators, oral antibiotics, and oral corticosteroids (or in severe cases IV corticosteroids) are useful, but their effects on cough have not been systematically evaluated. Therapy with expectorants, postural drainage, chest physiotherapy, and theophylline is not recommended. Central cough suppressants such as codeine and dextromethorphan are recommended for short-term symptomatic relief of coughing. CONCLUSIONS: Chronic bronchitis due to cigarette smoking or other exposures to inhaled noxious agents is one of the most common causes of chronic cough in the general population. The most effective way to eliminate cough is the avoidance of all respiratory irritants. When cough persists despite the removal of these inciting agents, there are effective agents to reduce or eliminate cough.