Pharyngoesophageal pH monitoring.

Pharyngeal acid reflux events may be significant in the pathogenesis of various supraesophageal manifestations of gastroesophageal reflux disease. Intragroup variation and an extensive overlap among subject groups and normal controls make proximal esophageal 24-hour pH monitoring studies unreliable for the diagnosis of pharyngeal reflux. However, the clinical value of pharyngeal pH monitoring still remains uncertain. A 24-hour pharyngeal pH monitoring study has shown that at least some pharyngeal reflux events occur in most healthy subjects, mainly in the upright position. Based on these data, values for the upper limits of normal for total pharyngeal acid exposure time and pharyngeal acid events have been determined. This study provides clinicians with reference values for physiologic pharyngeal reflux, but the parameters of abnormal pharyngeal reflux events are still unknown. More research is needed before this practice can become part of the routine evaluation of patients with pharyngeal, laryngeal, respiratory, or ear, nose, and throat symptoms or disorders.