Division of Gastroenterology & Hepatology
24 Hour Ambulatory pH Test
What is a 24 Hour Ambulatory pH Test?
Ambulatory 24 hour pH monitoring is a method of recording the amount and degree of acidic stomach contents backing up into the esophagus. The evaluation involves placing a small probe in the esophagus. The probe is connected to a small recording device. A strap is attached to the device to facilitate carrying it for 24 hours. Using a microprocessor, this unit is able to record the pH or acid levels in the esophagus over a 24 hour period. After the probe is in place, the patient will be free to leave the hospital. During this time the patient is encouraged to continue normal activities. Since the unit is small and worn on a strap, the patient is free to go about their usual daily routine. Resuming normal tasks is important so that the doctor can get a realistic picture of what is taking place in the esophagus.
Patients will be asked to return in approximately 24 hours, at which time the pH probe will be removed and the data will be transferred to a computer for analysis.
What preparation is required?
In most cases, the patient should not eat or drink anything for six (6) hours before the test. Since most tests are scheduled in the morning, skipping breakfast is usually sufficient. Patients should inform the staff of allergies to any drugs, especially lidocaine (similar to the anesthetic used by dentists when filling cavities). Before passage of the probe, the nasal lining will be swabbed with lidocaine to numb the nose. The probe is then passed through the nose into the esophagus. Once the probe is in place, patients can breathe, talk and eat with little or no disruption.
When scheduling the test, patients should inform the staff about any medicines they are taking, since some may need to be stopped before the test.
Are there any complications associated with my test?
The 24 hour Ambulatory pH Test is an extremely safe test. We have performed over 3,000 tests with no serious complications. Some patients have a sore throat for a few hours after the completion of the test and the nose may be slightly irritated from the passage of the probe. Occasionally, mild nosebleeds can occur.