What is esophageal pH monitoring?
Esophageal pH monitoring is a procedure for measuring the reflux (regurgitation or backwash) of acid from the stomach into the esophagus.
When is esophageal pH monitoring used?
Esophageal pH monitoring is used to diagnose gastro-esophageal reflux (GERD, the regurgitation of acidic, partially digested food contents from the stomach into the esophagus) and to determine the effectiveness of medications that are given to prevent acid reflux.
How is esophageal pH monitoring performed?
Esophageal pH monitoring is performed by passing a thin plastic catheter a sixteenth of an inch in diameter through one nostril, down the back of the throat, and into the esophagus as the patient swallows. The tip of the catheter contains a sensor that senses acid. The sensor is positioned in the esophagus so that it is just above the lower esophageal sphincter, a specialized area of esophageal muscle that lies at the junction of the esophagus and stomach and prevents acid from refluxing back up into the esophagus. In this position the sensor records each reflux of acid. The catheter protruding from the nose is connected to a recorder that registers each reflux of acid. The patient is sent home with the catheter and recorder in place and returns the next day to have them removed. During the 24 hours that the catheter is in place, the patient goes about his or her usual activities, for example, eating, sleeping, and working. Meals, periods of sleep, and symptoms are recorded by the patient in a diary and/or by pushing buttons on the recorder. After the catheter is removed, the recorder is attached to a computer so that the data it has gathered can be downloaded into the computer where it is analyzed and put into graphic form.