Evaluation of 96-Hour pH Monitoring with the Bravo Wireless System in 60 Patients

Abstract

Introduction: Ambulatory 24-hour pH monitoring with a nasal catheter is currently the gold standard for measuring esophageal pH. The Bravo pH system is a catheter-free pH system which allows for monitoring of esophageal pH for more than 24-hour. The test normally last 48 hours (hs). Aims & Methods: The aim of this study was to determine the feasibility of performing extended (beyond 48 hs) pH monitoring using the Bravo system. From January to October 2005, 60 patients (pts), (32 women and 28 men, 23-62 years, mean age 44), were evaluated at our center for a recording period of 96 hs. For all pts the pH capsule was positioned transorally under direct endoscopic visualization at 6 cm from the GE junction. After the first 48 hs of recording, the pts returned to our outpatients' clinic where the data relating to the first two days of recording were uploaded into the computer. Then the recording was reprogrammed for another 48 hs. The pts then returned again at the end of this second 48 hs period and we compared the results obtained from the first and the second two days of recording. Results: In 27 of the 60 pts the capsule became detached from the esophageal mucosa before the end of the 96 hs period. The other 32 (53.3%) pts completed the study for the entire 96 hs. In those 27 pts where the capsule became detached prior to completing the entire 96 hs test, the recording of the first 48 hs was excellent and therefore perfectly suitable for diagnostic purposes. In 20 of the 32 pts who completed the full 96 hs of recording, the results from the two 48 hs periods were identical: 13 pts who experienced reflux in the first two days with a pathological DeMeester score also experienced reflux in the third and fourth days; 7 pts exhibited no relevant reflux during the entire recording period and therefore had a normal DeMeester. 12 (37,5%) of the 32 patients exhibited normal acid contact time during the first two days of recording while in the last two days they experienced reflux. Conclusion: Our study suggests that pH monitoring can be effectively extended beyond 48 hs in the majority of pts. Further testing beyond this period increases the diagnostic confidence for GERD. Prolonged studies (beyond 48 hs) identify subset of pts (28% in our study) that show cyclic pH fluctuations.