48 Hour BRAVO (Wireless) Esophageal pH Monitoring Improves Symptom Correlation as Compared to 24 Hour Studies Alone

Abstract

Background: Historical ambulatory pH monitoring systems for the evaluation of GERD have been catheter-based and uncomfortable for patients, commonly limiting both their diet and activities. These studies may also underestimate the amount of reflux a patient has in a routine day. Compared to conventional catheter based pH monitoring systems, wireless (Bravo) pH monitoring is better tolerated by patients and allows for an increased duration of pH recording. Currently, there is lack of data regarding the optimal duration of wireless studies and concern that day 1 results are not typical of a patient's routine lifestyle given the effects of sedation. Few studies have evaluated the merits of 24 versus 48 hour wireless pH monitoring. Aims: The aims of this study were: 1)To identify differences in reflux parameters between day 1 and day 2 as measured by wireless pH monitoring and 2)To assess the effect of 48 hour studies on the number of reflux episodes and symptom correlation as compared to 24 hour studies. Methods: A retrospective chart review of 124 consecutive patients who underwent 48 hour wireless esophageal pH monitoring studies. All patients underwent EGD using IV conscious sedation prior to wireless capsule placement. Acid reflux variables [including total reflux time, number of reflux episodes, and total percent time of pH 95 was significantly higher at 48 hrs vs 24 hrs for both heartburn and regurgitation (31% vs 22%, p=0.003 and 21% vs 13%, p= 0.005). As expected, 48 hour testing also captured a significantly higher number of reflux episodes as compared to 24 hour results alone (97 vs 47, p 95 for typical symptoms of GERD. Prolonged recording of patient symptoms and/or sedation effects may account for the better symptom correlation. Although there were no statistical differences seen in this study between 24 and 48 hour studies for total percent time pH <4, 48 hr studies captured significantly more reflux episodes as compared to 24 hr monitoring alone. These results suggest that patients undergoing wireless pH monitoring should have 48 hour studies performed as standard of practice.