Diagnostics & Testing


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The 48-Hour Bravo Esophageal pH Test

What is an esophageal pH test?

An esophageal pH test measures and records the pH in your esophagus to determine if you have gastroesophageal reflux disease (GERD). The test can also be done to determine the effectiveness of medications or surgical treatment for GERD.

A valve called the lower esophageal sphincter (LES) controls the passage of food from the esophagus to the stomach when you swallow. It remains tightly closed except when you swallow food. When this muscle fails to close or opens spontaneously, the acid, bile and food contents of the stomach can travel backward into the esophagus. The esophageal pH test measures how often stomach contents reflux into the lower esophagus and how much acid the reflux contains.

How does the Bravo esophageal pH test work?

A small capsule, about the size of a gel cap, is temporarily attached to the wall of the esophagus during esophagoscopy. The capsule measures pH levels in the esophagus and transmits readings via a small radio transmitter in the capsule.

The transmitter sends signals to the receiver (about the size of a pager) worn on your belt or waistband. The receiver has several buttons on it that you will press to record symptoms of GERD, such as heartburn. The nurse will tell you what symptoms to record. You will be asked to maintain a diary to record certain events such as when you start and stop eating and drinking, when you lie down, and when you get back up. This will be explained by the nurse.

How do I prepare for the Bravo esophageal pH test?

Let your doctor know if you have an implanted cardiac device such as a pacemaker or implantable cardiac defibrillator (ICD), a history of bleeding problems, dilated blood vessels, and any other previously known problems with your esophagus.

Medication Guidelines
  • 7 days before the monitoring period, do not take proton pump inhibitors: omeprazole (Prilosec), lansoprazole (Prevacid), rabeprazole (Aciphex), pantoprazole (Protonix), esomeprazole (Nexium).
  • 2 days (48 hours) before the monitoring period, do not take the H2 blockers: ranitidine (Zantac), cimetidine (Tagamet),  famotidine (Pepcid), nizatidine (Axid); or the promotility drug metoclopramide (Reglan)
  • 6 hours before the monitoring period, do not take antacids (such as Alka-Seltzer, Gaviscon, Maalox, Milk of Magnesia, Mylanta, Phillips, Riopan, Tums, or any other brands).
  • 4 to 6 hours before your appointment do not eat or drink.

Please note: Occasionally, your doctor might want you to continue taking a certain medicine during the monitoring period to determine if it is effective.

Once the test has begun, what do I need to know and do?

  • Activity — Follow your usual daily routine. Do not reduce or change your activities during the monitoring period. Doing so can make the monitoring results less useful. Note: do not get the receiver wet. It is not waterproof.
  • Eating — Eat your regular meals at the usual times. If you do not eat during the monitoring period, your stomach will not produce acid as usual, and the test results will not be accurate. Eat at least two meals a day. Eat foods that tend to increase your symptoms (without making yourself miserable). Avoid snacking. Do not suck on hard candy or lozenges, and do not chew gum during the monitoring period.
  • Lying down — Remain upright throughout the day. Do not lie down until you go to bed (unless napping or lying down during the day are part of your daily routine).
  • Medicines — Continue to follow your doctor’s advice regarding medicines to avoid during the monitoring period.
  • Recording symptoms — Press the appropriate button on the receiver when symptoms occur (as discussed with the nurse).
  • Recording events — Record the time you start and stop eating and drinking (anything other than plain water). Record the time you lie down (even if just resting) and when you get back up. The nurse will explain how to record this information.
  • Unusual symptoms or side effects —  If you think you might be experiencing any unusual symptoms or side effects, call your doctor.

You will return the receiver and diary when the monitoring period is over.

The information on the receiver will be downloaded to a computer. The results as well your diary will be reviewed and analyzed.

After the test is completed

  • Resume your normal diet and medications.
  • Your doctor will discuss the results of the test with you during your next scheduled appointment.
  • Normal activities — such as swallowing, eating, and drinking — will cause the disposable pH capsule to detach and pass through the digestive tract in an average of 7 to 10 days.
  • No MRI (magnetic resonance imaging) tests should be performed for 30 days following capsule insertion.

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