title: Prolonged ambulatory oesophageal pH and pressure recording in healthy adults in Singapore.
abstract: OBJECTIVE
  Data on prolonged ambulatory oesophageal pH and pressure monitoring in normal subjects in the East are limited. This study aimed to define the normal characteristics of ambulatory oesophageal pH and motility among healthy adults in Singapore.
  
  
  METHODS
  Prolonged ambulatory oesophageal pH and pressure recording was performed on 10 healthy volunteers using a one-channel pH probe, a two channel pressure probe, a portable digital data recorder and a computerised data analysis system. The median (range) number of episodes with pH < 4 and the percentage of total time with pH < 4 were 24% (4%-56%) and 3.0% (0.2%-4.0%) respectively. They were greater in the upright than supine positions.
  
  
  RESULTS
  The median percentages of peristaltic and simultaneous contractions were 65.8%-80.5% and 10.6%-12.7% respectively. The frequency, amplitude and duration of peristaltic contractions were greater during mealtimes than between meals in the upright position.
  
  
  CONCLUSIONS
  This study provides the first data on prolonged ambulatory oesophageal pH and manometry in healthy Singaporean adults.
authors.affiliation: Department of Medicine, National University Hospital, Singapore.
authors.forename: K Y
authors.initials: KY
authors.lastname: Ho
authors.forename: J Y
authors.initials: JY
authors.lastname: Kang
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D016001:Confidence Intervals; D004947:Esophagus / Q000502:physiology*; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008365:Manometry; D018670:Monitoring, Ambulatory; D010528:Peristalsis / Q000502:physiology; D011187:Posture; D011312:Pressure; D012815:Signal Processing, Computer-Assisted; D012846:Singapore; D018709:Statistics, Nonparametric