gastrointestinal disorders
Ambulatory pH Monitoring
Introduction
Ambulatory 24-hour esophageal pH monitoring with or without intraluminal Impedance Planimetry is currently the most common test for quantifying To document excessive acid or nonacid reflux To correlate symptoms with reflux episodes To identify candidates for antireflux surgery To evaluate the effectiveness of medical or surgical treatments Ambulatory pH monitoring can be done when the patient is on or off proton pump inhibitor (PPI) therapy. When monitoring is done while the patient is off PPI therapy, the diagnosis of gastroesophageal reflux disease can be confirmed or excluded. If monitoring is done while the patient is off PPI therapy and no acidic pH is found in the stomach, the diagnosis of achlorhydria is confirmed. When monitoring is done while the patient is on PPI therapy, the adequacy of gastric acid suppression and the presence of esophageal acid exposure in patients who have been referred for testing because PPI therapy failed can be determined. Tests may use a transnasal continuous reflux-monitoring catheter or a wireless pH-monitoring device that is endoscopically attached to the distal esophagus. Complications are very rare. Patients must have nothing by mouth (npo) after midnight but are free to eat as usual after the monitoring device is placed. 