pH monitoring of stomach acid

The procedure known as pH monitoring measures how often stomach acid enters the esophagus from the stomach. It also measures how long the acid stays in the esophagus. Your doctor might order this test if you report having heartburn or to check for gastroesophageal reflux (GERD) or a hiatal hernia. You also might have pH monitoring to see if medication to treat your GERD is working to reduce acid levels in your esophagus.

Types of pH monitoring

There are two types of pH monitoring:

• Ambulatory pH monitoring, when your doctor or nurse (RN) passes a thin tube (catheter) through your nose to your esophagus. The tube is left in place for 24 hours. Monitoring sensors in the tube measures acid levels in your esophagus. A small recorder is attached to the part of the tube that sticks out of your nose. You wear this equipment at home on your belt around your waist and keep a record (diary) of your activities and any symptoms you have. A nurse (RN) removes the tube the next day and reviews the results.
• Esophagogastroduodenoscopy (EGD) with Bravo: A capsule about the size of a large vitamin that contains a monitoring device is placed in your esophagus during upper GI endoscopy. You wear a recorder about the size of a pager on a belt that can be placed over your shoulder. The information from the capsule is transmitted to the recorder, which you return to your doctor. The capsule collects data for 2 or 3 days and then falls off and is passed through your stool. It can be flushed down the toilet. EGD with Bravo, also called catheter-free wireless capsule pH monitoring, allows you to go to work and enjoy other activities without a catheter in your nose. The device and diary should be returned after 48 hours or when indicated by staff.

What to expect with pH monitoring

If you need Ambulatory pH monitoring, you will be asked not to eat, drink or smoke before your procedure. You also might need to avoid certain medications. Your nurse (RN) puts pain-relieving (numbing) medication in your nose to make you more comfortable, then places a thin, flexible tube (catheter) through your nose and down your esophagus. You’ll be asked to drink a little water to be sure the tube is in place. The bit of the tube that sticks out of your nose will be taped to the side of your face. A small recorder is attached to the part of the tube that sticks out of your nose.

The whole procedure takes 15 to 30 minutes.

You’ll wear this equipment at home and keep a record of your activities and any symptoms you have. Your doctor or nurse will explain how to record your activities on the recorder.

If you have Bravo pH monitoring, you will be asked not to eat, drink or smoke before your procedure. You also might need to avoid certain medications. You’ll be sedated and any discomfort should be minor. Your doctor may numb your throat with a gargle before placing the endoscope in your mouth.

The endoscopy procedure takes less than 30 minutes, then you’ll be monitored for 30 minutes to one hour, after which you can have someone pick you up and drive you home. You might need to rest the remainder of the day, but you can usually resume normal activities the next day. You might notice a sore throat or abdominal bloating for a day or two.

Your nurse will explain how to record your activities on the recorder and explain any special instructions.