To provide physicians and their patients with information on the management of cough manifested both as a defense mechanism and as a symptom of diseases, such as asthma, gastroesophageal reflux disease (GERD) or bronchogenic carcinoma, the American College of Chest Physicians (ACCP) convened a panel of experts and published their recommendations in a supplement to the August 1998 issue of Chest. Richard S. Irwin, M.D., University of Massachusetts Medical School, served as chair of the panel that developed the statement. The ACCP statement, endorsed by the American and Canadian Thoracic Societies, can also be obtained by calling the ACCP at 847-498-1400 or 800-343-2227. A modified version is available for the general public.
The statement is divided into five chapters: an introduction, a discussion of cough as a defense mechanism, a discussion of cough as a symptom, guidelines for evaluating cough and pharmacologic treatment. The following information has been summarized from the 48-page document:
Cough is one of the most common reasons for which patients see their physician. The annual cost of treating cough in the United States, including the cost of nonprescription medications, is over $1 billion.
The two categories of cough are acute (lasting less than three weeks) and chronic (lasting three to eight weeks or longer). These categories are not mutually exclusive. Acute cough is almost always caused by the common cold. The most common causes of chronic cough in nonsmokers in all age groups are postnasal drip syndrome from upper respiratory tract conditions, asthma and GERD. In these patients, the cough can manifiest as dry or productive. Less common causes of chronic cough include chronic bronchitis, bronchiectasis, postinfectious cough, bronchogenic carcinoma, cough induced by use of angiotensin-converting enzyme inhibitors, psychogenic cough and habit cough, and chronic interstitial pulmonary disease. The most common causes of cough in children are asthma, upper and lower respiratory tract infections and GERD. Less common but important causes of chronic cough in young children include congenital anomalies, heart disease, foreign bodies, aspiration and environmental factors.
The cause of chronic cough can be determined in most patients; specific therapy will usually be successful if chronic cough is systematically evaluated. The ACCP guidelines discuss when it is sufficient to take only a personal history and do a physical examination and when more expensive tests are needed for a diagnosis. Guidelines and algorithms for evaluating acute and chronic cough in immunocompetent and immunocompromised adults, and for evaluating cough in children, are presented in the report. The algorithm for evaluating chronic cough in immunocompetent adults is included in this report (see page 698). One section of the ACCP statement provides detailed guidance for using this algorithm.
According to the statement, pharmacologic treatment of cough is either antitussive (to prevent, control or eliminate cough) or protussive (to make cough more effective). Antitussive therapy is indicated when cough serves no useful function such as clearing the airways. The two kinds of antitussive therapy are specific and nonspecific. Specific antitussive therapy is directed at the etiology or mechanism causing cough (e.g., cigarette smoking). Nonspecific antitussive therapy is directed at the symptom and is prescribed to control cough.
Because of the high probability of being able to determine the causes of cough and prescribe specific treatment, there is a limited role for nonspecific antitussive therapy. The ACCP committee recommends that nonspecific antitussive therapy be prescribed only when specific therapy cannot be given because the cause is not known or because specific theapy has not had a chance to work or will not work (e.g., inoperable lung cancer). Protussive therapy is indicated when cough performs a useful function and needs to be encouraged (e.g., in patients with cystic fibrosis).