Day-to-day variability in acid reflux patterns using the BRAVO pH monitoring system

J Clin Gastroenterol. 2006 Jan;40(1):20-4. doi: 10.1097/01.mcg.0000190753.25750.0e.


Background & goals: The wireless pH monitoring system such as the BRAVO pH system is a significant advancement in the evaluation of patients with gastroesophageal reflux because of its potentially better tolerability and the ability to record data over a 48-hour period. The aim of our study was to evaluate safety, performance, tolerability, and day-to-day variability in acid reflux patterns using the BRAVO pH system.

Methods: A total of 90 consecutive patients (48 men and 42 women) with persistent reflux symptoms underwent BRAVO pH capsule placement from October 2002 to August 2003 at a tertiary care hospital. The BRAVO pH capsule was deployed 6 cm proximal to the squamocolumnar junction under endoscopic guidance. The pH recordings over 48 hours were obtained after uploading data to a computer from the pager-like device that recorded pH signals from the BRAVO pH capsule.

Results: Successful pH data over 48 hours was obtained in 90% of patients. Nearly two thirds of patients experienced a variety of symptoms ranging from a foreign body sensation to chest discomfort or pain. Four patients had severe chest pain, 3 of whom required endoscopic removal of the BRAVO pH capsule. In 74.4% of patients, number of reflux events as well as time (%) pH<4 correlated from the first 24-hour period to the second 24-hour period. However, in 28% of patients, no predictable pattern of (%) time pH<4 in the supine position was reproduced from one 24-hour period to the next 24-hour period.

Conclusions: The BRAVO pH system appears a safe and effective method of recording esophageal acid exposure. It is an acceptable alternative for patients who are unwilling or unable to tolerate nasopharyngeal catheter-based pH studies, and it has a potential advantage of the 2-day recording period.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Capsules
  • Esophageal pH Monitoring / instrumentation*
  • Female
  • Gastroesophageal Reflux / diagnosis*
  • Humans
  • Male
  • Middle Aged
  • Monitoring, Ambulatory / instrumentation*
  • Patient Satisfaction
  • Regression Analysis


  • Capsules