Wireless oesophageal pH monitoring: feasibility, safety and normal values in healthy subjects

Scand J Gastroenterol. 2005 Jul;40(7):768-74. doi: 10.1080/00365520510023602.


Objective: A new wireless technique for oesophageal pH monitoring has recently been introduced (Bravo). To implement this technique in clinical practice, values of normal oesophageal acid exposure need to be defined in a large age- and gender-matched healthy population. The aims of this study were to investigate the feasibility and safety of the wireless technique and to establish normal values for oesophageal acid exposure.

Materials and methods: Fifty-seven asymptomatic subjects underwent upper gastrointestinal endoscopy with transoral placement of a radio-transmitting capsule 6 cm above the squamocolumnar junction. Oesophageal acid exposure was monitored via a portable receiver during 48 h.

Results: Seven men were excluded from the study: capsule dysfunction in 1 and oesophagitis in 6. Fifty subjects (25 M, 25 F, median age 42 years) were included in the study. The radio-transmitting capsule was successfully attached to the oesophageal mucosa in all cases and there were no complications. During pH monitoring 2 capsules were prematurely detached after 32 and 36 h, respectively. The median percentage time with oesophageal pH of less than 4 was 0.7% on day 1 and 1.0% on day 2 (p = 0.033) and the 95th percentile for the 48-h recordings was 4.4%.

Conclusions: Ambulatory pH monitoring using the Bravo system is feasible and appears to be safe. This is the first study to establish normal values for oesophageal acid exposure in a large age- and gender-matched healthy population and offers a basis for the use of the wireless technique in clinical practice.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cohort Studies
  • Esophagoscopy / methods*
  • Esophagus / physiology*
  • Feasibility Studies
  • Female
  • Gastroesophageal Reflux / diagnosis
  • Humans
  • Hydrogen-Ion Concentration*
  • Male
  • Middle Aged
  • Monitoring, Physiologic / instrumentation*
  • Reference Values
  • Risk Factors
  • Sensitivity and Specificity
  • Time Factors