1 Literature Review Peter R. McNally, DO, FACP, FACG Lone Tree, Colorado

2 Four-day Bravo pH capsule monitoring with and without proton pump inhibitor therapy. Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:

3 Introduction Ambulatory pH testing is considered the most objective means of diagnosing gastroesophageal reflux disease (GERD). Ambulatory pH testing is considered the most objective means of diagnosing gastroesophageal reflux disease (GERD). Limitations of conventional catheter-based pH testing include patient tolerance, potential for catheter migration, and limitation of “usual” patient physiologic and dietary activity. Limitations of conventional catheter-based pH testing include patient tolerance, potential for catheter migration, and limitation of “usual” patient physiologic and dietary activity. The Bravo wireless pH capsule (Medtronic, Shoreview, MN) has overcome these barriers and has the additional advantage of allowing for 48 + hour recording periods. The Bravo wireless pH capsule (Medtronic, Shoreview, MN) has overcome these barriers and has the additional advantage of allowing for 48 + hour recording periods. Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:

4 Study Purpose Ambulatory pH testing is often used to guide the management of reflux symptoms that do not respond to proton pump inhibitor (PPI) therapy and to evaluate the contribution of acid reflux to atypical reflux symptoms (chest pain, cough, hoarseness, throat tightness and asthma). Ambulatory pH testing is often used to guide the management of reflux symptoms that do not respond to proton pump inhibitor (PPI) therapy and to evaluate the contribution of acid reflux to atypical reflux symptoms (chest pain, cough, hoarseness, throat tightness and asthma). Controversy exists on whether such clinical studies should be conducted on or off PPI. This pilot study aimed to evaluate the feasibility of 4- day pH recordings using a single Bravo pH capsule, encompassing the pre and intra- treatment periods with PPI. Controversy exists on whether such clinical studies should be conducted on or off PPI. This pilot study aimed to evaluate the feasibility of 4- day pH recordings using a single Bravo pH capsule, encompassing the pre and intra- treatment periods with PPI. Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:

5 Study Design 18 patients with variety of symptoms to include refractory GERD, chest pain, or chronic cough were included in the study. 18 patients with variety of symptoms to include refractory GERD, chest pain, or chronic cough were included in the study. Using two separate receivers calibrated to a single Bravo pH capsule -- 4 day monitoring. Using two separate receivers calibrated to a single Bravo pH capsule -- 4 day monitoring. Rabeprazole was administered on days 2- 4 of the study (20 mg orally twice daily). Rabeprazole was administered on days 2- 4 of the study (20 mg orally twice daily). Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:

6 Study Measurements % time pH < 4 per 24 hrs % time pH < 4 per 24 hrs Symptom index score Symptom index score Correlation symptoms & acid reflux Correlation symptoms & acid reflux Effect of Rabebrazole on acid reflux events Day 2, 3, 4. Effect of Rabebrazole on acid reflux events Day 2, 3, 4. Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:

7 Results Bravo pH capsule functioned for 4 days in 16 of 18 (89%) patients (capsule detachment at day-2 in one patient and day-3 in another). Bravo pH capsule functioned for 4 days in 16 of 18 (89%) patients (capsule detachment at day-2 in one patient and day-3 in another). 9 of 16 (53%) of patients had acid exposure exceeding 4% on day-1. 9 of 16 (53%) of patients had acid exposure exceeding 4% on day-1. Patients showed significant and progressive reductions in acid exposure on days 2-4 of the recording period. Patients showed significant and progressive reductions in acid exposure on days 2-4 of the recording period. Six of 7 (87%) patients with abnormal acid reflux exposure on day-1, normalized by day-3. Six of 7 (87%) patients with abnormal acid reflux exposure on day-1, normalized by day-3. Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:

8 Results 7 pts with chest pain 7 pts with chest pain – 1/7 had >50% correlation acid events and pain 3 pts with chronic cough 3 pts with chronic cough – 0/3 had correlation with acid events and cough 7 pts with refractory heartburn 7 pts with refractory heartburn – 1/7 patients failed to normalize acid exposure after 4 days of Rabebrazole Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:

9 Conclusions Prolonged esophageal pH recording using the Bravo pH system is feasible. Prolonged esophageal pH recording using the Bravo pH system is feasible. Prolonged pH recording will allow for testing both off and on a therapeutic trial of PPI. Prolonged pH recording will allow for testing both off and on a therapeutic trial of PPI. Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3:

10 Reviewer Comments We can anticipate more studies using this prolonged pH capsule testing among patients with: Persistent GERD symptoms despite use of PPI Atypical GERD (chest pain, asthma, hoarseness, globus) Severe erosive GERD Barrett’s esophagus Recurrent Peptic stricture Hirano I, Zhang Q, Pandolfino JE, and Kahrilas PJ. Clinical Gastroenterology and Hepatology 2005;3: