title: Comparison of an oropharyngeal pH probe and a standard dual pH probe for diagnosis of laryngopharyngeal reflux.
abstract: OBJECTIVE
  We compared the ability of an oropharyngeal (OP) aerosol-detecting pH probe and a standard dual pH probe in measuring laryngopharyngeal reflux (LPR).
  
  
  METHODS
  Fifteen subjects with LPR symptoms had 24-hour simultaneous placement of the OP probe and a standard dual pH probe. Acid exposure was defined as a 10% pH decrease below baseline for the OP probe or a pH of less than 4 at the upper esophageal sphincter (UES) probe of the dual pH probe.
  
  
  RESULTS
  The mean duration of acid exposure was 650 seconds (SD, 619) or 0.75% of the total time for the OP probe and 438 seconds (SD, 511) or 0.51% of the total time for the UES probe. When we excluded meals and sleep, the mean duration of acid exposure was 271 seconds (SD, 356) or 0.31% of the total time for the OP probe and 271 seconds (SD, 359) or 0.31% of the total time for the UES probe. The correlation coefficient (R) between the two probes for measurement of the duration of acid exposure was 0.50 (p < 0.05). When we excluded meals and the supine position, the R was notably higher, at 0.95 (p < 0.0001).
  
  
  CONCLUSIONS
  The OP probe reliably documented LPR events when meals and sleep were eliminated and was better tolerated than the standard dual probe.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of Washington, Seattle, Washington, USA.
authors.forename: Justin S
authors.initials: JS
authors.lastname: Golub
authors.forename: Michael M
authors.initials: MM
authors.lastname: Johns
authors.forename: Jae H
authors.initials: JH
authors.lastname: Lim
authors.forename: John M
authors.initials: JM
authors.lastname: DelGaudio
authors.forename: Adam M
authors.initials: AM
authors.lastname: Klein
mesh_terms: D005764:Gastroesophageal Reflux / Q000175:diagnosis* / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009960:Oropharynx / Q000378:metabolism* / Q000473:pathology*; D012720:Severity of Illness Index; D013997:Time Factors