title: Ambulatory combined pH, bile and manometric monitoring of the oesophagus in asymptomatic healthy volunteers.
abstract: BACKGROUND
  With the development of sophisticated equipment ambulatory studies of oesophageal motor function, pH and bilirubin have gained in popularity. The aim of the study was to present reference values for combined 24 h pH, bilirubin and manometric measurements of the oesophagus.
  
  
  METHODS
  Twenty-six (15 male) healthy volunteers without symptoms of gastro-oesophageal reflux underwent a 24-h ambulatory oesophageal combined three-channel pressure, acid and bilirubin detection.
  
  
  RESULTS
  The subjects were studied for a median of 20 h (16-22). The median per cent time with pH < 4 for the whole measured time was 3.1 (0.8-14; 5 and 95 percentiles). Bile was detected for a median of 0.05% (0.0-8.5; 5 and 95 percentiles) of the time. Eighty-one per cent of the contractions were peristaltic, 55% of which were complete. Of these, 53% had a pressure over 30 mmHg at all three pressure points, giving an efficient peristalsis in a median of 29% (13-46; 5 and 95 percentiles) of all registered contractile patterns. No difference between the genders could be observed.
  
  
  CONCLUSIONS
  This study provides normative data for ambulatory oesophageal manometry, pH and bilirubin studies that can be used for comparing with patients with disease.
authors.affiliation: Division of Surgery, Karolinska Institute Danderyd Hospital, Stockholm, Sweden. jacob.freedman@kir.ds.sll.se
authors.forename: Jacob
authors.initials: J
authors.lastname: Freedman
authors.forename: Madeleine
authors.initials: M
authors.lastname: Lindqvist
authors.forename: Anders
authors.initials: A
authors.lastname: Melcher
authors.forename: Lars
authors.initials: L
authors.lastname: Granström
authors.forename: Erik
authors.initials: E
authors.lastname: Näslund
mesh_terms: D000328:Adult; D000368:Aged; D001646:Bile / Q000737:chemistry*; D002404:Catheterization / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D004947:Esophagus / Q000737:chemistry* / Q000502:physiology*; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008365:Manometry / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D011312:Pressure; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity