Anatomical diagnostic protocol in evaluating chronic cough with specific reference to gastroesophageal reflux disease.

Using the anatomic, diagnostic protocol, the cause of chronic cough can be determined 88% to 100% of the time, leading to specific therapy with success rates of 84% to 98%. Gastroesophageal reflux disease (GERD), along with postnasal drip syndrome (PNDS) and asthma, is one of the three most common causes of chronic cough in all age groups. When GERD is the cause of chronic cough, there may be no gastrointestinal (GI) symptoms up to 75% of the time, and, in these cases, the term "silent GERD" is used. The most sensitive and specific test for GERD is 24-hour esophageal pH monitoring. In interpreting this test, it is essential not only to evaluate the duration and frequency of the reflux episodes but also to determine the temporal relationship between reflux and cough events. Patients with normal standard reflux parameters still may have reflux diagnosed as the likely cause of cough if a temporal relationship exists. The definitive diagnosis of cough resulting from GERD can only be made if cough goes away with antireflux therapy. When 24-hour esophageal pH monitoring cannot be done, an empiric trial of antireflux medical therapy is appropriate when GERD is a likely cause of chronic cough. It is likely in the following settings: patients with prominent GI symptoms consistent with GERD and/or those with no GI complaints and normal chest x-rays, who are not taking angiotensin-converting enzyme inhibitors and who are not smoking, and in whom asthma and PNDS have been excluded. However, if empiric treatment fails, it cannot be assumed that GERD has been ruled out as a cause of chronic cough; rather, objective investigation for GERD is recommended, because the empiric therapy may not have been intensive enough or it may have failed. In treating patients with chronic cough resulting from GERD, cough has been reported to resolve with medical therapy 70% to 100% of the time. Mean time to recovery may take as long as 161 to 179 days, and patients may not start to get better for 2 to 3 months. In patients who fail to respond to maximal medical therapy, antireflux surgery can be successful.