title: First agreement analysis and day-to-day comparison of pharyngeal pH monitoring with pH/impedance monitoring in patients with suspected laryngopharyngeal reflux.
abstract: OBJECTIVE
  Diagnosis of laryngopharyngeal reflux (LPR) is still challenging. Recently a diagnostic device for pH values in the aerosolized environment of the pharynx has been introduced (Dx-pH). We evaluated results of Dx-pH with objective criteria of pH/impedance monitoring (MII) and subjective reflux scoring systems and assessed day-to-day variability.
  
  
  METHODS
  This study makes use of a prospective single-center trial. Thirty patients with suspected LPR were analyzed. Upper endoscopic examination, manometry, phoniatric examination, and reflux scores were assessed. Dx-pH was performed on two consecutive days, first in combination with MII and second as single measurement. Thereafter, proton pump inhibitor (PPI) trial was performed. Patients were interviewed about symptom relief after 3 months.
  
  
  RESULTS
  There were considerable differences between MII and results on Dx-pH: day 1 (agreement 11 out of 30, kappa 0.137) and day 2 (agreement 14 out of 30, kappa 0.036). Statistically significant differences were detected correlating all single reflux episodes (n = 453) of Dx-pH with MII and vice versa. Furthermore acidic reflux episodes did not result in pH drops of the pharynx. There was a fair agreement between Dx-pH measurements on subsequent days. After follow-up, 3 out of 18 patients with pathological Dx-pH results reported positive response to PPIs, in contrast to 5 out of 6 patients with pathological MII.
  
  
  CONCLUSIONS
  According to our data, acid pharyngeal pH levels detected with Dx-pH are not related to GERD and acid esophageal reflux episodes do not result in pharyngeal pH alterations. Hence, present etiology of LPR needs to be reconsidered since neither mixed nor gas reflux events result in pharyngeal pH alteration. Other acid-producing or retaining factors should be taken into account.
authors.affiliation: Medical Department, Klinikum rechts der Isar, Technical University of Munich, II, Munich, Germany. valentin.becker@gmx.de
authors.forename: Valentin
authors.initials: V
authors.lastname: Becker
authors.forename: Simone
authors.initials: S
authors.lastname: Graf
authors.forename: Christoph
authors.initials: C
authors.lastname: Schlag
authors.forename: Tibor
authors.initials: T
authors.lastname: Schuster
authors.forename: Hubertus
authors.initials: H
authors.lastname: Feussner
authors.forename: Roland M
authors.initials: RM
authors.lastname: Schmid
authors.forename: Monther
authors.initials: M
authors.lastname: Bajbouj
mesh_terms: D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D004305:Dose-Response Relationship, Drug; D017097:Electric Impedance; D050782:Esophageal pH Monitoring; D004945:Esophagoscopy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006863:Hydrogen-Ion Concentration; D057045:Laryngopharyngeal Reflux / Q000175:diagnosis* / Q000188:drug therapy / Q000378:metabolism; D008297:Male; D008365:Manometry; D008875:Middle Aged; D010614:Pharynx / Q000378:metabolism / Q000503:physiopathology*; D011312:Pressure; D011446:Prospective Studies; D054328:Proton Pump Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use; D012372:ROC Curve; D012720:Severity of Illness Index; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D054328:Proton Pump Inhibitors