Chronic cough with a history of excessive sputum production. The spectrum and frequency of causes, key components of the diagnostic evaluation, and outcome of specific therapy
Department of Medicine, Division of Pulmonary, Allergy & Critical Care
Adolescent; Adult; Aged; Aged, 80 and over; Chi-Square Distribution; Chronic Disease; Combined Modality Therapy; Cough; Diagnosis, Differential; Female; Humans; Male; Middle Aged; Prospective Studies; Remission Induction; Respiratory Function Tests; Sputum; Treatment Outcome
Life Sciences | Medicine and Health Sciences
STUDY OBJECTIVE: To determine (1) the spectrum and frequency of causes of chronic cough with a history of excessive sputum production (CCS) and (2) the response of these causes to specific therapy. STUDY DESIGN: Prospective study utilizing the anatomic diagnostic protocol originally developed to diagnose chronic cough. PATIENTS: Seventy-one immunocompetent adults who complained of expectoration of greater than 30 mL of sputum per day. LOCATION: University hospital pulmonary outpatient clinic. RESULTS: Patients were seen an average of 4.2 times over 4.6 months before a specific diagnosis was made. The cause of CCS was determined in 97%. It was due to one cause in 38%, 2 in 36%, and three in 26%. Postnasal drip syndrome (PNDS) was a cause 40% of the time, asthma 24%, gastroesophageal reflux disease (GERD) 15%, bronchitis 11%, bronchiectasis 4%, left ventricular failure 3%, and miscellaneous causes 3%. Among patients with a normal chest radiograph who were nonsmokers and not taking an angiotensin converting enzyme inhibitor; CCS was due to PNDS, or asthma, or GERD, or all three in 100% of cases. Chest radiograph, methacholine inhalation challenge, 24-h esophageal pH monitoring, bronchoscopy, and spirometry with bronchodilator each had a sensitivity and negative predictive value of 100%. Chest radiograph and barium swallow had positive predictive values of only 38% and 30%, respectively. CONCLUSIONS: (1) The anatomic diagnostic protocol for cough is also valid for CCS; (2) the major causes of chronic excessive sputum production and chronic cough are so similar that CCS should be considered a form of chronic cough; (3) the evaluation of CCS is more complicated and takes longer than the evaluation of chronic cough; (4) the major strength of the laboratory diagnostic protocol is that it reliably rules out conditions; (5) the outcome of specific therapy is almost always successful; and (6) the term "bronchorrhea" can be misleading if it is applied to excessive sputum production before a specific diagnosis of its source is made since the most common cause of excessive sputum that is expectorated (PNDS) is a disorder of the upper respiratory tract. Therefore, nonspecific therapies theoretically aimed at reducing mucus production in the lower respiratory tract are not likely to be helpful.
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Citation: Chest. 1995 Oct;108(4):991-7.
Smyrnios, Nicholas A.; Irwin, Richard S.; and Curley, Frederick J., "Chronic cough with a history of excessive sputum production. The spectrum and frequency of causes, key components of the diagnostic evaluation, and outcome of specific therapy" (1995). Open Access Articles. 432.