Ambulatory esophageal and hypopharyngeal pH monitoring in patients with hoarseness.

Ten patients referred by an otolaryngologist for ambulatory esophageal pH monitoring for suspected reflux-induced hoarseness were monitored with a dual ambulatory pH system in which probes were simultaneously placed 5 cm above the lower esophageal sphincter and 2 cm above the upper esophageal sphincter (laryngeal inlet). All were nonsmokers. Hypopharyngeal reflux (pH drop less than 4 in upper electrode preceded by pH drop less than 4 in esophageal electrode) was conclusively demonstrated in 7 of 10 patients. Three of these seven patients had normal frequency and duration of esophageal reflux and would have been classified as normal, yet demonstrated acid reflux into the hypopharynx. As a group, these patients were high frequency, short duration, upright refluxers. Combined hypopharyngeal and esophageal pH monitoring is useful in the diagnosis of reflux-induced hoarseness.