Esophageal pH and Manometry
When Heartburn Isn't Simple
Our digestive system is a good example of how we usually take our bodies for granted. As long as everything is working well, we never give it a thought. One problem that often cannot be ignored, however, is acid reflux from the stomach backing up into the esophagus. Almost all adults occasionally experience mild heartburn that a simple dose of antacid will quickly relieve. But when attacks of heartburn are frequent and severe, they can become serious. Also known as gastroesophageal reflux disease (GERD), severe heartburn is usually caused by a weakness in the protective "valve" that lies between the bottom of your esophagus and your stomach - the lower esophageal sphincter.
A Weakened Valve
When you eat, your stomach starts making powerful hydrochloric acid to help digest your food. Your esophagus, or "food pipe," has no special lining to protect it from stomach acid - instead you have a one-way valve, the Lower Esophageal Sphincter (LES). Located at the point where the esophagus joins the stomach, the LES valve acts like a tiny "trapdoor." Normally, the door is closed. When you swallow, this tiny door opens to allow the passage of food into the stomach, but then quickly closes again to prevent backward flow.
If the LES valve is weak, reflux of stomach contents into the esophagus occurs. Even a little acid from the stomach can irritate the delicate lining of the esophagus causing severe inflammation and painful symptoms. Often this malfunction of the LES is associated with a hiatal hernia - a partial slippage of the stomach from the abdomen up into the chest cavity.
Like Waves on a Beach
Another important action of the esophagus is peristalsis. Although it seems like a simple organ, the esophagus is not a just a hollow tube. The wall of the esophagus is made of muscle fibers that contract whenever you swallow. Like waves on a beach, these rhythmic waves of peristalsis sweep food down the esophagus and into your stomach. When these waves are weak or disorganized, difficulty swallowing can occur. When the waves are too strong, chest pains may occur.
Surgery for GERD
Most cases of acid reflux respond to lifestyle changes and prescription medication. But, some patients, especially the younger ones, may have some reservations about taking prescription drugs every day for the rest of their lives. In others, the symptoms are so severe that medications do not totally control the problem.
In these cases, surgical recontruction of the LES valve may be necessary. In the past, surgery for GERD often meant a major surgical incision, a long hospital stay, and up to 6 weeks of recovery. Now a newer "bandaid" technique using a laparoscope has raised interest in surgical treatment for severe reflux disease.
Called "Laparoscopic Nissen Repair," this new procedure uses several mini-incisions and allows a shorter hospital stay and recovery period making surgery a better option for selected patients. Before surgery is considered, it is important that the diagnosis of GERD be firmly established. In addition to your doctor's history and physical exam, and x-rays or "scope" tests, two additional tests are often performed to be certain that surgery is the best treatment - esophageal manometry and pH testing.
Manometry is the recording of muscle pressures within an organ. Esophageal manometry is a test that allows your doctor to evaluate the strength and coordination of the waves of peristalsis in your esophagus as well as the strength of the LES valve at the end of it.
The equipment for esophageal manometry consists of a thin tube with pressure sensors along its wall. When this tube is positioned in the esophagus, these sensors measure the pressure as the esophagus squeezes. These pressure measurements are recorded and analyzed in a computer. Your doctor can then evaluate the wave pattern to determine if it is normal or abnormal. If the waves are weak or the LES valve strong, surgery may not be the right answer.
Esophagal pH Testing
pH is the measure of acidity or alkalinity. Most people are familiar with pH tests done on soil or swimming pools. An esophageal pH test measures how often the stomach acid refluxs up into the lower esophagus. The equipment for esophageal pH testing consists of a thin flexible tube with a pH probe on the end. The tubing is gently inserted through the nose and into the esophagus. It is attached to a portable recorder that is carried at the waist. Over a period of about 24 hours, the acid level in the lower esophagus is constantly measured and recorded on the tape recorder. When the patient experiences symptoms of reflux or chest pain, a button is pushed on the recorder. This marks the time to see how the symptoms relate to the acidity levels measured by the probe. The recording is then summarized by a computer and then evaluated by your doctor.
Preparation for these studies is very simple. You should not eat or drink any food or liquids for about 8 hours before the exam. Small sips of water are OK. Antacid tablets are permissible until the night before the test.
Certain medications can interfere with these tests. You should review with your doctor all medications that you are taking to determine which should and should not be taken before these tests. In general, the following medications should be stopped at least 72 hours before testing. However, do not stop taking any medications without first consulting with your doctor.
During The Test
- Caffeine (coffee, tea, cola, chocolate)
- Alcohol (beer, wine, liquor)
- Tagamet, Axid, Zantac, Pepcid, cimetidine
- Prilosec, Prevacid
- Propulsid, Reglan (metoclopramide)
- Donnatal, Librax, Levsin
- Urecholine (bethanechol)
- Erythromycin, E-mycin
- Nitroglycerin, Isordil
- Calcium Channel Blockers Procardia, Adalat, Calan, Cardizem, etc
- Beta-Blockers Corgard, Inderal, Lopressor, Tenormin, etc
Esophageal Manometry takes about an hour. The thin soft tubing is gently passed through the nose, or occasionally the mouth. Upon swallowing, the tip of the tube is positioned in the esophagus. There may be some mild gagging at this point, but quickly passes. You will be asked to swallow saliva (called a dry swallow) or sips of water (called a wet swallow) while various pressure recordings are made. The tube is then withdrawn.
Often, the Esophageal pH study can be done the same day of the Manometry. It takes about 10 minutes to insert another thin flexible tube through the nose and position it in the lower esophagus just above the LES. This tubing which contains the pH probe is wrapped around your ear and is taped to your nose and face. It is attached to the waist recorder and you may immediately resume normal activities and diet. You will have to wear this tubing taped to your face for 24 hours so you may wish to plan any social commitments accordingly. To protect the recorder, you may not take a shower or tub bath during the test period. You will be asked to return the following day at which time the recorder and tubing are removed.
Benefits and Side Effects
The primary benefit is that your doctor can have clear documentation of how your esophagus musle works and the degree and duration of significant acid reflux. While other examinations are used to study the esophagus, there is nothing else that provides this particular information.
Generally, there are no serious problems associated with Esophageal Manometry and pH Testing. Once the tube is in place, it is usually well tolerated. Occasionally, a mild sore throat may occur which resolves when the tube is removed.
Esophageal Manometry and ph Testing are not much fun. But they are important methods of determining the severity of acid reflux and the appropriateness of medical or surgical therapy. They can also be helpful in cases of unexplained chest pain and difficulty in swallowing. With this information, a more effective treatment plan can be prescribed.