The Bernstein test is used to simulate the symptoms of heartburn, a burning sensation in the chest. The test is designed to reproduce the symptoms experienced when acid refluxes up into the esophagus from the stomach. It is also known as the acid perfusion test.
Today, the Bernstein test is rarely used. Doctors prefer to use other tests for acid reflux-related symptoms, such as the 24-hour esophageal pH test.
The esophagus extends from your lower throat to your stomach. At the end of the esophagus is a muscular valve or sphincter called the lower esophageal sphincter. It is responsible for opening to let food and saliva pass from the esophagus to the stomach. It is only open for a few seconds and then it closes. This closure keeps stomach contents from creeping back up into your esophagus.
Heartburn occurs when the valve doesn’t stay closed properly. A malfunction of the muscular valve or the lower esophageal sphincter can be due to an abnormally weak muscle or an abnormal relaxation of the valve or sphincter muscle. Either abnormality can cause acid in your stomach to move upwards into the esophagus, causing a burning sensation in your chest.
The Bernstein test is typically used to diagnose gastroesophageal reflux disease (GERD).
It is used with other tests to check the function of the sphincter at the end of the esophagus to help determine the cause of recurring heartburn. It can also rule out heartburn as a cause of your symptoms.
The test will be performed in a laboratory or hospital. You should not eat or drink anything eight hours before the test.
To begin the test, a thin tube is lubricated and inserted in your nostril. It is then gently slid down the back of your throat and into your esophagus. A nasogastric tube is guided by way of the nose into the stomach. Once the tube is in place, a mild hydrochloric acid solution will be sent down the tube. It will be followed by a saline solution. This procedure may be repeated several times.
You will be asked if you feel a burning sensation or other discomfort during the test. You will not be told which solution is being administered at what time. The point of the test is to determine the cause of your pain.
The salt solution typically causes no pain. The acid solution may cause pain if your esophagus has been damaged by stomach acid. The Bernstein test may cause gagging or vomiting. However, it doesn’t cause any lasting damage. The hydrochloric acid solution used in the test is very mild.
After the test, your doctor will review your results. If your pain coincided with the hydrochloric acid, you may have GERD. Typically, more testing is needed to make an accurate diagnosis. Such testing could include:
- continuous (24-hour) esophageal pH monitoring(to test for acidity of stomach contents)
- barium swallow (to look for radiologic evidence of damage in the esophagus)
- endoscopy of your esophagus, stomach, and small intestine (direct visualization of the upper digestive tract)
- esophageal manometry (to look for motility problems of the esophagus)