title: Hypopharyngeal and distal esophageal pH monitoring in children with gastroesophageal reflux and respiratory symptoms.
abstract: OBJECTIVE
  Fundoplication is frequently required for gastroesophageal reflux (GER)-related respiratory disease. Correlation between esophageal pH data and respiratory symptoms is poor but may be improved by monitoring hypopharyngeal pH. Reflux to the hypopharynx is underestimated by salivary bicarbonate. The aim of this study was to determine if hypopharyngeal pH monitoring using pH 4 and pH 5 as reflux thresholds could predict children with reflux-related respiratory disease.
  
  
  METHODS
  One hundred five children aged 4 months to 12 years underwent esophageal and hypopharyngeal pH monitoring. Hypopharyngeal pH data were analyzed using pH 4 and pH 5 as reflux thresholds. pH data from 4 groups were compared: group A, control group, no GER, no respiratory symptoms (n = 20); group B, respiratory symptoms, no GER (n = 16); group C, GER, no respiratory symptoms (n = 26); and group D, both GER and respiratory symptoms (n = 37).
  
  
  RESULTS
  Comparing groups C and D, there was no significant difference in hypopharyngeal pH data. Using pH 5 as the reflux threshold, children in group B refluxed to the hypopharynx significantly more frequently than controls. This was most evident in children with wheeze.
  
  
  CONCLUSIONS
  Hypopharyngeal pH monitoring does not differentiate children with GER and respiratory symptoms from those with GER alone and is therefore of doubtful value in diagnosing recurrent aspiration.
authors.affiliation: Department of Paediatric Surgery, Royal Belfast Hospital for Sick Children, Belfast BT12 6BE, Northern Ireland.
authors.forename: Raghu N
authors.initials: RN
authors.lastname: Ramaiah
authors.forename: Michael
authors.initials: M
authors.lastname: Stevenson
authors.forename: William A
authors.initials: WA
authors.lastname: McCallion
mesh_terms: D002648:Child; D002675:Child, Preschool; D050782:Esophageal pH Monitoring; D005764:Gastroesophageal Reflux / Q000150:complications* / Q000378:metabolism*; D006801:Humans; D007013:Hypopharynx / Q000378:metabolism*; D007223:Infant; D012120:Respiration Disorders / Q000209:etiology* / Q000378:metabolism*; D012720:Severity of Illness Index