title: Patterns of laryngopharyngeal and gastroesophageal reflux.
abstract: OBJECTIVE
  Double-probe, 24-hour pH monitoring remains the 'gold standard' for the diagnosis of laryngopharyngeal reflux disease, even though there is no consensus on how to interpret the data collected.
  
  
  METHODS
  Tetra-probe, 24-hour pH monitoring was performed in 56 patients with suspected laryngopharyngeal reflux, in order to investigate patterns of laryngopharyngeal and gastroesophageal reflux.
  
  
  RESULTS
  The number of reflux episodes and the total and percentage time periods spent with pH < 4.0 were correlated with the distance of the probe from the lower oesophageal sphincter. The number of reflux episodes and the total and percentage time periods with pH < 4.0 were greater when patients were upright (i.e. during the daytime). There were few laryngopharyngeal reflux events recorded for pH levels of <4.0; however, there were a significant number of laryngopharyngeal reflux events recorded for pH levels of <5.0, a level capable of causing laryngopharyngeal reflux disease. When a pH level of <5.0 was used, the number, total time and percentage time of laryngopharyngeal reflux episodes was greater during the supine period (i.e. during sleeping) in a quarter of the cases, compared with results when a pH of <4.0 was used.
  
  
  CONCLUSIONS
  It is valid to use a pH level of 5.0 as indicative of laryngopharyngeal reflux in the hypopharynx.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Kurume University School of Medicine, Kurume, Japan. kimisato@oct-net.ne.jp
authors.forename: K
authors.initials: K
authors.lastname: Sato
authors.forename: H
authors.initials: H
authors.lastname: Umeno
authors.forename: S
authors.initials: S
authors.lastname: Chitose
authors.forename: T
authors.initials: T
authors.lastname: Nakashima
mesh_terms: D050782:Esophageal pH Monitoring; D005744:Gastric Acid / Q000378:metabolism; D005745:Gastric Acidity Determination; D005764:Gastroesophageal Reflux / Q000175:diagnosis*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D057045:Laryngopharyngeal Reflux / Q000175:diagnosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013997:Time Factors