title: The proximal probe in esophageal pH monitoring: development of a normative database.
abstract: Healthy volunteers without symptoms of either gastroesophageal reflux or laryngopharyngeal reflux and without abnormalities on laryngologic examination were recruited for esophageal pH monitoring. Thirty subjects underwent ambulatory 24-hour double-channel pH probe monitoring to establish normative data for the upper probe, which was positioned just above the upper esophageal sphincter. Data were analyzed excluding meal periods plus 2 minutes of postprandial time. The mean, standard deviation, median, and 95th percentile were calculated for various reflux parameters for the following intervals: total study duration, upright time, supine time, and postprandial time. Normal subjects display physiologic reflux above the upper esophageal sphincter (median one event, 95th percentile 6.9 events), and 80.4% of these events occur in the upright position. The reflux area index (RAI) appears to be the most useful parameter to measure laryngopharyngeal reflux severity.
authors.affiliation: Texas Voice Center/Van Lawrence Voice Institute, Department of Otorhinolarvngology and Communicative Sciences Baylor College of Medicine, Houston 77030, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Vincent
authors.forename: J D
authors.initials: JD
authors.lastname: Garrett
authors.forename: S L
authors.initials: SL
authors.lastname: Radionoff
authors.forename: L A
authors.initials: LA
authors.lastname: Reussner
authors.forename: C R
authors.initials: CR
authors.lastname: Stasney
mesh_terms: D000293:Adolescent; D000328:Adult; D019992:Databases as Topic; D004943:Esophagogastric Junction / Q000502:physiology; D004947:Esophagus / Q000502:physiology*; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D012016:Reference Values; D012720:Severity of Illness Index