Bravo® pH Test: How Wireless Esophageal pH Monitoring Works

What is the Bravo® pH Monitoring System?

Bravo esophageal pH monitoring is a minimally-invasive test used to measure acidity (pH) inside the esophagus, usually over a period of between 48 and 96 hours. Tracking acidity inside the esophagus with the Bravo pH test is useful in diagnosing, monitoring and assessing treatments related to acid reflux and gastroesophageal reflux disease (GERD).

GERD is a chronic condition caused by acid being repeatedly regurgitated into the esophagus (AKA acid reflux). This is usually due to a problem with the Lower Esophageal Sphincter (LES), which is a muscular, donut-shaped valve between the bottom of the esophagus and the stomach. Over time, acid exposure caused by backwash of stomach contents into the throat and mouth can damage the lining of the esophagus.

How does the Bravo pH Test Work?

The Bravo pH test measures levels of stomach acid in the esophagus, utilizing a small, wireless monitoring capsule approximately the size of a standard gel cap. This device is temporarily attached to the lining of the patient’s esophagus using a instrument called an endoscope.

The Bravo pH monitoring capsule contains a battery, an acid sensor and a transmitter, which the capsule uses to wirelessly communicate data to an outside receiver. 

Once the pH capsule is placed inside the esophagus and activated, the sensor in the capsule is used to monitor for acid levels that might be associated with GERD, usually for between 48 to 96 hours. The transmitter wirelessly sends this information to a small receiver that’s kept near the patient’s body or worn on the belt. The data is collected and stored for later study by specialists.

How is Bravo Esophageal pH Monitoring Performed?

Positioning of the Bravo pH test capsule is usually performed while the patient is under sedation. Placement is usually done an outpatient procedure. Because of the anesthesia, you will likely need someone to drive you home afterward.

During the procedure, a doctor uses a long, thin instrument called an endoscope to attach the wireless pH capsule to the lower part of the esophagus. Essentially a miniature data collection and transmission device, the capsule contains a sensor that measures acid levels in the esophagus over an extended period — usually between 48-96 hours — wirelessly transmitting this data to a receiver kept close to the body. 

Unless directed by their doctor, a patient can and should carry out their normal activities while utilizing the Bravo pH monitoring system, including eating and drinking what the patient normally would. The pH capsule will not be damaged or dislodged by these activities, and your physician will want to see how acid levels in the esophagus change as your go about your day-to-day activities and diet.

During the testing period, you’ll likely be asked to keep a diary that includes the time you eat or drink, what you had to eat or drink, periods spent lying down, the time of any symptoms you might experience and more. Entries in this diary will later be cross-checked against acid events in your test results to identify patterns that might be helpful in treating or managing your condition.

Once the testing period is over, the Bravo capsule detaches from the esophagus — usually within four to 10 days. From there, the Bravo® test capsule is designed to harmlessly pass through the digestive tract and leave the body in a bowel movement. The capsule is flushable and disposable, so once it passes through the digestive system, retrieval is not required.  

How is Traditional Esophageal pH Monitoring Different from Bravo pH monitoring?

The Bravo pH monitoring system is different from traditional methods because it works wirelessly, transmitting data from inside the esophagus to a receiver worn on the belt or kept close to the body.

Traditional esophageal pH monitoring uses a thin wire that connects the acid sensor to a data collection device outside the body. This wire — called a lead — is usually passed up the nose and down the throat into the lower esophagus. The lead is then left in place during testing, usually for up to 24 hours.

Because the Bravo pH capsule is wireless, testing is much more comfortable for patients. The Bravo® system also usually collects data for a longer period of time than traditional pH monitoring — 48-96 hours vs. 24 hours — giving physicians more information about acid intrusion into the esophagus and why it might be occurring.

What Conditions Can Bravo Esophageal pH Monitoring Diagnose?

Bravo esophageal pH monitoring is primarily used to diagnose and manage gastroesophageal reflux disease (GERD), a chronic condition in which stomach acid flows back into the esophagus.

This backflow of acid can cause symptoms like heartburn and chest pain. If GERD is left untreated long enough, it can damage the lining of the esophagus, increasing the patient’s risk of esophageal cancer and other conditions, including Barrett’s Esophagus. Bravo pH monitoring can help doctors assess the severity of GERD, and whether treatments to stop acid reflux into the esophagus are working.

What is Gastroesophageal Reflux Disease (GERD)?

Bravo esophageal pH monitoring is primarily used in the diagnosis and treatment of Gastroesophageal reflux disease (GERD), which is a disorder in which the acid and stomach contents are frequently regurgitated into the throat and mouth. Take our 5-minute GERD assessment to understand your symptoms and to see if treatment is recommended.

The symptoms of GERD are different for every patient. However, the most common symptom is frequently-recurring heartburn, which can cause a burning sensation in the upper abdomen, usually after eating. The symptoms of GERD may become worse after you lie down. 

Other symptoms of GERD include: 

  • Recurring nausea
  • Chest pain
  • Trouble swallowing, or pain when swallowing
  • Chronic cough
  • Having a hoarse speaking voice or recurring sore throat 
  • Feeling like there’s a “lump in your throat”
  • New or more frequent asthma attacks 

Who is a Good Candidate for Bravo Esophageal pH Monitoring?

Your Hoag doctor can help you understand if you are a good candidate for Bravo Esophageal pH monitoring. Learn more about our Hoag Foregut Digestive Team of experts. In general, those with pacemakers, implanted defibrillators or neurostimulators are not good candidates for Bravo esophageal pH monitoring, as the device can potentially interfere with the function of these devices. You should also avoid having Magnetic Resonance Imaging (MRI) scans during monitoring and for at least 30 days after the Bravo pH test. 

Other conditions which may cause issues during Bravo pH monitoring include:

  • Esophageal narrowing
  • Active inflammation or obstruction in the esophagus
  • Having previously had esophageal surgery
  • A history of uncontrolled bleeding episodes
  • Difficulty swallowing (AKA dysphagia)
  • Having enlarged blood vessels in the esophagus (AKA esophageal varices)

Anyone with these conditions should inform their doctor before taking a Bravo esophageal pH test. should consult their doctor before taking the test.