The aim of this study was to evaluate the significance of pH monitoring at two levels, hypopharynx and esophagus in gastroesophageal reflux.

29 patients with pathological gastroesophageal reflux were classified into two groups: Group I had recurrent respiratory symptoms and Group II had not recurrent respiratory symptoms. The ambulatory pH monitoring was performed at the hypopharynx and the esophagus simultaneously with two channel catheter for 18~24 hr. The pathological reflux was defined when the percent of time that pH was below 4.0 exceeding the 95th percentile of normal value. Hypopharyngeal reflux was defined as the pharyngeal pH drops below 4.

39 patients were performed pH monitoring at the level of hypopharynx and esophagus for 24 hours. Among 7 patients with chronic respiratory symptom, 6 patients (85.7%) have pathological esophageal reflux. Among 32 patients without chronic respiratory symptom, 23 patients (71.8%) have pathological esophageal reflux. Thus 29 out of 39 patients (74%) have pathological esophageal reflux. In the Group I, all parameters except the longest episode showed significant differences between hypopharyngeal and esophageal pH monitoring. None of parameters showed significant differences between group I and II in the pharyngeal pH monitoring.

Regardless of presence of respiratory symptoms, the pH monitoring at the pharyngeal level in patients with gastroesophageal reflux did not showed any differences compared with the esophageal pH monitoring. Therefore we may reconsider the usefulness of hypopharyngeal pH monitoring in patients with chronic respiratory symptoms.