title: Pharyngeal pH alone is not reliable for the detection of pharyngeal reflux events: A study with oesophageal and pharyngeal pH-impedance monitoring.
abstract: BACKGROUND
  Pharyngeal pH probes and pH-impedance catheters have been developed for the diagnosis of laryngo-pharyngeal reflux.
  
  
  OBJECTIVE
  To determine the reliability of pharyngeal pH alone for the detection of pharyngeal reflux events.
  
  
  METHODS
  24-h pH-impedance recordings performed in 45 healthy subjects with a bifurcated probe for detection of pharyngeal and oesophageal reflux events were reviewed. Pharyngeal pH drops to below 4 and 5 were analysed for the simultaneous occurrence of pharyngeal reflux, gastro-oesophageal reflux, and swallows, according to impedance patterns.
  
  
  RESULTS
  Only 7.0% of pharyngeal pH drops to below 5 identified with impedance corresponded to pharyngeal reflux, while 92.6% were related to swallows and 10.2 and 13.3% were associated with proximal and distal gastro-oesophageal reflux events, respectively. Of pharyngeal pH drops to below 4, 13.2% were related to pharyngeal reflux, 87.5% were related to swallows, and 18.1 and 21.5% were associated with proximal and distal gastro-oesophageal reflux events, respectively.
  
  
  CONCLUSIONS
  This study demonstrates that pharyngeal pH alone is not reliable for the detection of pharyngeal reflux and that adding distal oesophageal pH analysis is not helpful. The only reliable analysis should take into account impedance patterns demonstrating the presence of pharyngeal reflux event preceded by a distal and proximal reflux event within the oesophagus.
authors.affiliation: CHU Bordeaux, Bordeaux, France ; Bordeaux Segalen University, Bordeaux, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Desjardin
authors.affiliation: Hospices Civils de Lyon, Lyon, France ; Claude Bernard Lyon 1 University, Lyon, France.
authors.forename: Sabine
authors.initials: S
authors.lastname: Roman
authors.affiliation: CHU Nantes, Nantes, France ; Nantes University, Nantes, France.
authors.forename: Stanislas Bruley
authors.initials: SB
authors.lastname: des Varannes
authors.affiliation: INSERM 0204, Rouen, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Gourcerol
authors.affiliation: Assistance Publique-Hôpitaux de Paris, Colombes, France ; INSERM U987, Boulogne Billancourt, France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Coffin
authors.affiliation: CHU Rennes, Rennes, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Ropert
authors.affiliation: Hospices Civils de Lyon, Lyon, France ; Claude Bernard Lyon 1 University, Lyon, France.
authors.forename: François
authors.initials: F
authors.lastname: Mion
authors.affiliation: CHU Bordeaux, Bordeaux, France ; Bordeaux Segalen University, Bordeaux, France.
authors.forename: Frank
authors.initials: F
authors.lastname: Zerbib
keywords: Gastro-oesophageal reflux; laryngo-pharyngeal reflux; oesophageal impedance; pharyngeal pH