Impedance Probe Test, Adult-Why am I having this test?
An impedance probe test is a procedure to measure the amount of acid in the tube that connects the mouth to the stomach (esophagus). The test shows the levels of stomach acids and liquids in your esophagus over a 24-hour period. This helps to diagnose gastroesophageal reflux disease (GERD). The test may also be called esophageal impedance pH monitoring or 24-hour esophageal pH test.
You may need an impedance probe test if you have symptoms of GERD, including:
- Difficult or painful swallowing.
- The feeling of having a lump in the throat.
- A bitter taste in the mouth.
- Bad breath.
- Having a large amount of saliva.
- Having an upset or bloated stomach.
- Chest pain.
- Shortness of breath or wheezing.
- Ongoing (chronic) cough or a night-time cough.
- Wearing away of tooth enamel.
- Weight loss.
Your health care provider may order an impedance probe test if medicines and lifestyle changes have not eased your symptoms.
What is being tested?
- You will be given one or more of the following:
- A medicine to help you relax (sedative).
- A medicine to numb your nose and throat (local anesthetic).
- A long, thin tube will be put into your nostril, down your throat, and into your esophagus. The tube has a small probe attached to one end and a monitor attached to the other end. This tube will be taped to your cheek.
- This tube will stay in place for 24 hours. It measures the acid in your esophagus while you eat, drink, and sleep.
- You may stay in the hospital for monitoring during this test. Or, you may be able to go home and return in 24 hours to have the tube removed. If you go home during the test, ask your health care provider what activities are safe for you.
- During the test, you may be asked to write down:
- What you eat and drink, and how much.
- The times of day that you eat and drink.
- Any symptoms of reflux that you have.
How do I prepare for this test?
- Follow instructions from your health care provider about how to prepare for this test. Ask whether there are any eating or drinking restrictions.
- Take over-the-counter and prescription medicines only as told by your health care provider.
- Know that the tube may be a little uncomfortable and you may gag when the tube is inserted.
- Plan to have someone drive you home from the hospital or clinic because you must not drive for 24 hours if you are given a sedative.
What do the results mean?
The results of this test show:
- How much stomach acid is in your esophagus.
- Whether a level of acid that is higher than normal could be causing your symptoms.
Your health care provider will explain what the test results mean for you. A level of acid in the esophagus that is higher than normal can mean that you may have:
- Barrett esophagus.
- Inflammation of the esophagus (esophagitis).
- Abnormalities in muscle tone in the bottom of the esophagus.
It is up to you to get your test results. Ask your health care provider, or the department performing the test, when the results will be ready.
Talk with your health care provider to discuss your results, treatment options, and if necessary, the need for more tests. Talk with your health care provider if you have any questions about your results.