title: Characteristics and clinical relevance of proximal esophageal pH monitoring.
abstract: OBJECTIVE
  It is well established that various ENT disorders and symptoms may be a manifestation of gastroesophageal reflux disease (GERD). Measuring proximal esophageal acid exposure might be useful in the evaluation of patients with suspected reflux-related ENT manifestations, but the limited available data are conflicting. The aim of the present study was to study the determinants of proximal esophageal acid exposure (PR) and to evaluate the clinical usefulness of ambulatory proximal pH monitoring.
  
  
  METHODS
  Twenty healthy controls and 346 patients with suspected reflux disease underwent typical and atypical GERD symptom assessment, endoscopy, esophageal manometry and ambulatory combined dual esophageal pH, and Bilitec duodeno-gastro-esophageal reflux exposure (DGER) monitoring. The presence of pathological PR and its relation to symptom pattern and distal esophageal acid exposure (DR) and DGER exposure were analyzed.
  
  
  RESULTS
  Fifty-seven patients (16%) had pathological PR. Demographic characteristics, symptom pattern, and manometric findings did not differ in patients with normal or pathological PR. Patients with pathological PR had significantly higher DR and DGER. The multivariate analysis identified only pathological DR as an independent risk factor for the presence of pathological PR (odds ratio 4.515, 95% CI 2.48-8.23, p < 0.0001). Only 20 patients (6%) had pathological proximal reflux without pathological distal acid reflux.
  
  
  CONCLUSIONS
  The findings of the present article do not support routine proximal esophageal pH monitoring as a clinical tool: PR does not differentiate patients with typical or atypical GERD manifestations and depends mainly on DR.
authors.affiliation: Department of Medicine, Division of Gastroenterology, University Hospitals Leuven, Belgium.
authors.forename: Mike
authors.initials: M
authors.lastname: Cool
authors.forename: Johan
authors.initials: J
authors.lastname: Poelmans
authors.forename: Louw
authors.initials: L
authors.lastname: Feenstra
authors.forename: Jan
authors.initials: J
authors.lastname: Tack
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D004945:Esophagoscopy; D004947:Esophagus / Q000378:metabolism*; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D016015:Logistic Models; D008297:Male; D008365:Manometry; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000379:methods*