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Esophageal Function Tests

Esophageal function tests

Definition

The esophagus is the muscular tube through which food passes on its way from the mouth to the stomach. The main function of the esophagus is to propel food into the stomach. To ensure that food does not move backwarda condition known as refluxsphincters (constricting ring-shaped muscles) at either end of the esophagus close when the food is not passing through them in a forward direction. Esophageal function tests are used to determine whether the sphincters are working properly.


Purpose

The esophagus has two sets of sphincters at its upper and lower ends. Each of these muscular rings must contract in an exact sequence for swallowing to proceed normally. The upper esophageal sphincter normally stops the contents of the stomach from moving backward into the pharynx and larynx (voice box). The lower esophageal sphincter guards against stomach acid moving upward into the esophagus. The lower sphincter should be tightly closed except to allow food and fluids to enter the stomach.

The three major symptoms occurring with abnormal esophageal function are difficulty with swallowing (dysphagia); heartburn; and chest pain. Doctors perform a variety of tests to evaluate these symptoms. Endoscopy, which is not a test of esophageal function, is often used to determine if the lining of the esophagus has any ulcers, tumors, or areas of narrowing (strictures). Many times, however, endoscopy only shows the doctor if there is an injury to the esophageal lining; it does not always provide information about the cause of the problem. Tests that measure the functioning of the esophagus are sometimes needed in addition to endoscopy. There are three basic types of tests used to assess esophageal function:

  • Manometry. Manometry is used to study the way the muscles of the esophagus contract, and is most useful for investigating dysphagia.
  • Esophageal pH monitoring. This test measures changes in the acidity of the esophagus, and is valuable for evaluating patients with heartburn or gastroesophageal reflux disease (GERD).
  • X-ray studies. This type of imaging study is used to investigate dysphagia, either by using a fluoroscope to follow the progress of a barium mixture during the process of swallowing, or by using radioactive scanning techniques.

Description

Manometry

This study is designed to measure the pressure changes produced by contraction of the muscular portions of the esophagus. An abnormality in the function of any one of the segments of the esophagus can cause difficulty in swallowing (dysphagia). A manometric examination is most useful in evaluating patients when an endoscopy yields normal results.

During manometry, the patient swallows a thin tube carrying a device that senses changes in pressures in the esophagus. Readings are taken at rest and during the process of swallowing. Medications are sometimes given during the study to aid in the diagnosis. The results are then transmitted to recording equipment. Manometry is most useful in identifying diseases that produce disturbances of motility or contractions of the esophagus. In 2003, a solution containing five drops of peppermint oil in 10 mL of water was found to improve the manometric features of diffuse esophageal spasm (DES). The peppermint oil solution eliminated simultaneous esophageal contractions in all patients in the study.


Esophageal pH monitoring

This procedure measures the esophagus' exposure to acid reflux from the stomach. The test is ideal for evaluating recurrent heartburn or gastroesophageal reflux disease (GERD). Excessive acid reflux may produce ulcers, or strictures resulting from healed ulcers, in addition to the symptom of heartburn.

Normally, acid from the stomach washes backward into the esophagus in small amounts for short periods of time. The lower esophageal sphincter usually prevents excessive reflux in patients without disease. Spontaneous contractions that increase esophageal emptying and production of saliva also act to prevent damage to the esophagus.

Researchers have shown that in the esophagus, the presence of acid is damaging only if it lasts over long periods of time. Therefore, esophageal pH monitoring has been designed to monitor the level of acidity over a 24-hour period, usually in the patient's home. In this way, patients are able to maintain their daily routine, document their symptoms, and correlate symptoms with specific activities. During this period, a thin tube with a pH monitor remains in the esophagus to record changes in acidity. After the study, a computer is used to compare the changes with symptoms reported by the patient.

In addition to esophageal pH monitoring, the doctor may perform a Bernstein test (also known as the acid perfusion test) and an acid clearing test. In the Bernstein test, a small quantity of hydrochloric acid (HCl) is directed into the patient's esophagus. If the patient feels pain from the acid, the test is positive for reflux esophagitis. If there is no discomfort, another explanation must be sought for the patient's symptoms. In the acid clearing test, HCl is also directed into the esophagus. This test, however, measures the patient's ability to quickly swallow the acid. If the patient has to swallow more than 10 times to move the acid down the esophagus, he or she has a problem with esophageal motility.

pH monitoring is usually performed before surgery to confirm the diagnosis and to judge the effects of drug therapy. In 2003, studies showed that integrated esophageal and gastric acidity provided better quantitative measures of esophageal dysfunction in GERD than conventional measurements of pH. This finding may suggest better ways to evaluate the effectiveness of different treatments for GERD.


X-ray tests

X-ray tests of esophageal function fall into two categories: (1) tests performed with barium and a fluoroscope; and (2) those performed with radioactive materials. Studies performed with fluoroscopy are especially useful in identifying structural abnormalities of the esophagus. Sometimes the patient is given a sandwich or marshmallow coated with barium in order to identify the site of an obstruction. Fluoroscopy can diagnose or provide important information about a number of disorders involving esophageal function, however, including cricopharyngeal achalasia (a swallowing disorder of the throat); decreased or reverse peristalsis; and hiatal hernia.

During fluoroscopy, the radiologist can observe the passage of material through the esophagus in real time, and also make video recordings. These observations are particularly useful when the swallowing symptoms appear to occur mostly in the upper region of the esophagus. The most common cause of difficulty swallowing is a previous stroke, although other diseases of the neuromuscular system (like myasthenia gravis) can produce similar symptoms.

Scans using low-dose radioactive materials are useful because they may demonstrate that food passes more slowly than usual through the esophagus. They can also measure the speed of the bolus' passage. These studies involve swallowing food coated with radioactive material, followed by a nuclear medicine scan. Scans are often used when other methods have failed to make a diagnosis, or if it is necessary to determine the degree of the abnormality.


Preparation

Patients should not eat or drink anything after midnight before an esophageal function test. Many medications affect the esophagus; doses may need to be adjusted or even discontinued prior to testing. Patients must inform their physician of any and all medications they take, including over-the-counter medications and herbal preparations. They must also tell the doctor about any known allergies.


Aftercare

No special care is needed after most esophageal function tests. Patients can usually return to their normal daily activities following almost all of these tests.


Risks

Exposure to x rays, especially in the first three months of a woman's pregnancy, can be harmful to the fetus. Barium swallows may also cause impaction (hardening) of fecal matter. Additionally, although the tubes passed through the esophagus during some of the esophageal function tests are small, and most patients adjust to them quite well, some patients may gag and aspirate (breathe into the lungs rather than passing through the esophagus) some gastric juices.


Normal results

Normal findings include:

  • lower esophageal sphincter pressure ranging from 1020 mm Hg
  • normal peristaltic waves
  • normal size, shape, position, patency and filling of the esophagus
  • negative acid reflux
  • acid clearing in fewer than 10 swallows
  • negative Bernstein test

Manometry is used to diagnose abnormalities related to contraction or relaxation of the various muscular regions of the esophagus. These studies cannot distinguish whether injury to either the muscle or nerves of the esophagus is producing the abnormal resultsonly the final effect on esophageal muscle is identified. The results of this test should be interpreted in light of the patient's entire medical history. For example, there are many diseases that affect the relaxation of the lower esophageal sphincter; one such condition is called achalasia. Achalasia is a frequent finding in individuals with Down's syndrome.

Abnormal results of pH tests can confirm symptoms of heartburn or indicate a cause of chest pain (or rarely, swallowing difficulties). The patient's doctor may want to prescribe or change medications based on these results, or even repeat the test using different doses of medication. As noted above, these studies should be done before surgical treatment of GERD.

X-ray tests can serve to document an abnormality in the esophagus. If the results are negative, other studies may be needed.


Resources

books

Castell, June A., and R. Matthew Gideon. "Esophageal Manometry," in Donald O. Castell and Joel E. Richter, eds., The Esophagus, 3rd ed. Philadelphia, PA: Lippincott, 1999.

Pagana, Kathleen D., and Timothy J. Pagana. Diagnostic Testing and Nursing Implications, 5th ed. St. Louis, MO: Mosby, 1999.

Smout, Andre. "Ambulatory Monitoring of Esophageal pH and Pressure." in Donald O. Castell and Joel E. Richter, eds., The Esophagus, 3rd ed. Philadelphia, PA: Lippincott, 1999.


periodicals

Gardner, J.D., S. Rodriguez-Stanley, and M. Robinson. "Integrated Acidity and the Pathophysiology of Gastroesophageal Reflux Disease." American Journal of Gastroenterology 96, no. 5 (May 2001): 1363-70.

Mujica, V.R., R. S. Mudipalli, and S. S. Rao. "Pathophysiology of Chest Pain in Patients with Nutcracker Esophagus." American Journal of Gastroenterology 96, no.5 (May 2001): 1371-7.

Pimentel, M., G. G. Bonorris, E. J. Chow, and H. C. Lin. "Peppermint Oil Improves the Manometric Findings in Diffuse Esophageal Spasm." Journal of Clinical Gastroenterology 33, no.1 (July 2001): 27-31.

Zarate, N., F. Mearin, A. Hidalgo, and J. R. Malagelada. "Prospective Evaluation of Esophageal Motor Dysfunction in Down's Syndrome." American Journal of Gastroenterology 96, no. 6 (June 2001): 1718-24.


organizations

American Society for Gastrointestinal Endoscopy (ASGE). Thirteen Elm Street, Manchester, MA 01944-1314. (978) 526-8330. <http://www.asge.org>.

Illinois Nurses AssociationAdvanced Practices Registered Nurses (APRNs) Statistics. 105 W. Adams, Suite 2101, Chicago, IL 60603. <www.illinoisnurses.org/aprn.html>.

Society for Gastroenterology Nurses and Associates (SGNA). 401 North Michigan Avenue, Chicago, IL 60611-4267. (800) 245-7462. <www.sgna.org>.


Maggie Boleyn, RN, BSN Lee Shratter, MD

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Esophageal Function Tests

Esophageal Function Tests

Definition

The esophagus is the swallowing tube through which food passes on its way from the mouth to the stomach. The main function of this organ is to propel food down into the stomach. There is also a mechanism to prevent food from coming back up or "refluxing" from the stomach into the esophagus. Esophageal function tests are used to determine if these processes are normal or abnormal.

Purpose

The esophagus is a long, muscular tube that also has two muscles (or sphincters) at the top and bottom. All of these muscular areas must contract in an exact sequence for swallowing to proceed normally. There are three main symptoms that occur when esophageal function is abnormal: difficulty with swallowing (dysphagia), heartburn, and chest pain.

Doctors perform a variety of tests to evaluate these symptoms. Endoscopy, which is not a test of esophageal function, is often used to determine if the lining of the esophagus has any ulcers, tumors, or areas of narrowing (strictures). Many times, however, endoscopy only shows the doctor if there is injury to the esophageal lining, and the procedure gives no information about the cause of the problem.

Therefore, in addition to endoscopy, several studies are available that measure esophageal function. There are three basic types of tests used to assess esophageal function:

  • Manometry is used to study the way the muscles of the esophagus contract, and is most useful for the investigation of difficulty with swallowing.
  • Esophageal pH monitoring measures changes in esophageal acidity, and is valuable for evaluating patients with heartburn or gastroesophageal reflux disease (GERD).
  • X-ray studies investigate swallowing difficulties. They either follow the progress of barium during swallowing using a fluoroscope, or they use radioactive scanning techniques.

Precautions

Pregnant patients undergoing x-ray exams should carefully review the risks and benefits with their doctors. Most x-ray exams of the gastrointestinal tract do not involve radiation levels that are harmful to the unborn baby.

Description

Manometry

This study is designed to measure the pressure changes produced by contraction of the muscular portions of the esophagus. An abnormality in the function of any one of the segments of the swallowing tube causes difficulty in swallowing. Doctors call this symptom dysphagia. This exam is most useful in evaluating those patients whose endoscopy is negative.

During manometry, the patient swallows a thin tube carrying a device that senses changes in pressures in the esophagus. Readings are taken at rest and during swallowing. Medications are sometimes given during the study to help in the diagnosis. The results are then transmitted to recording equipment. Manometry can best identify diseases that produce disturbances of motility or contractions of the esophagus.

ESOPHAGEAL PH MONITORING. This procedure involves measuring the esophagus' exposure to acid that has "refluxed" from the stomach. The test is ideal for evaluating recurring heartburn or GERD. Too much acid produces not only heartburn, but also ulcers that can bleed or produce areas of narrowing (strictures) when they heal.

Normally, acid refluxes into the esophagus in only small amounts for short periods of time. A muscle called the lower esophageal sphincter prevents excessive reflux. Spontaneous contractions that increase esophageal emptying and production of saliva are other important protective mechanisms.

"pH" is the scientific term that tells just how acidic or alkaline a substance is. Researchers have shown that in the esophagus, the presence of acid is damaging only if it persists for prolonged periods. Therefore, the test has been designed to monitor the level of acidity over 24 hours, usually in the home. In this way, patients maintain their daily routine, documenting their symptoms, and at what point in their activities they occurred. During this period, a thin tube with a pH monitor remains in the esophagus to record changes. After the study, a computer is used to compare changes in acidity with symptoms reported by the patient.

Surgery is an effective and long-lasting treatment for symptoms of recurrent reflux and is the choice of many patients and doctors. pH monitoring is usually performed before surgery to confirm the diagnosis and to judge the effects of drug therapy.

X-RAY TESTS. These fall into two categories: (1) those done with the use of barium and a fluoroscope; and (2) those performed with radioactive materials.

Studies performed with fluoroscopy are of greatest value in identifying a structural abnormality of the esophagus. Although this is not truly an esophageal function test, it does allow doctors to consider other diagnostic possibilities. Often a sandwich or marsh-mallow coated with barium is used to identify the site of an obstruction.

During fluoroscopy, the radiologist can observe the passage of material through the esophagus in real time, and video recordings can also be done. This is particularly useful when the swallowing symptoms appear to involve mainly the upper region of the esophagus. The most common cause of swallowing difficulties is a previous stroke, although other diseases of the neuromuscular system (like myasthenia gravis) can produce the same symptoms.

Scans using low-dose radioactive materials are useful because they are able not only to demonstrate that food passes through the esophagus more slowly than normal, but also how slow. These studies involve swallowing food coated with material that is followed by a nuclear medicine scanner. Scans are best used when other methods have failed to make a diagnosis, or if it is necessary to determine the degree of the abnormality. As of 1997, scans mainly served as research tools.

Preparation

Patients should not eat or drink for several hours before the exam. Many medications affect the esophagus; doses sometimes need to be adjusted or even stopped for a while. Patients must inform doctors of all medications taken, including over-the-counter medications (purchased without a doctor's prescription), and any known allergies.

Aftercare

For most of these studies, no special care is needed after the procedure. Patients can often go about normal daily activities following any of these tests. One exception is for those who undergo an x-ray exam with the use of barium. This can have a constipating effect and patients should ask about using a mild laxative later on.

Risks

Exposure of a fetus to x rays, especially in the first three months, is a potential risk.

Other studies of esophageal function are essentially free of any significant risk. The tubes passed during these procedures are small, and most patients adjust to them quite well. However, since medications cannot be used to relax patients, some may not tolerate the exam.

Abnormal results

Manometry is used to diagnose abnormalities related to contraction or relaxation of the various muscular regions of the esophagus. These studies cannot distinguish whether injury to either the muscle or nerves of the esophagus is producing the abnormal results. Only the final effect on esophageal muscle is identified. Results should be interpreted in light of the patient's entire medical history.

For example, there are many diseases that cause poor relaxation of the lower esophageal sphincter. When no cause is found, the disease is called achalasia.

Abnormal results of pH tests can confirm symptoms of heartburn or indicate a cause of chest pain (or rarely, swallowing difficulties). Doctors may want to start or change medications based on these results, or even repeat the test using different doses of medication. As noted above, these studies are indicated before surgical treatment of GERD.

X-ray tests can only serve to document an abnormality, and they are far from perfect. If they are negative, then other studies are often needed.

Resources

PERIODICALS

Mittal, Ravinder K., and David H. Balaban. "The Esophagogastric Junction." New England Journal of Medicine 336 (27 Mar. 1997): 924-932.

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"Esophageal Function Tests." Gale Encyclopedia of Medicine, 3rd ed.. . Encyclopedia.com. 18 Dec. 2017 <http://www.encyclopedia.com>.

"Esophageal Function Tests." Gale Encyclopedia of Medicine, 3rd ed.. . Encyclopedia.com. (December 18, 2017). http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/esophageal-function-tests-0

"Esophageal Function Tests." Gale Encyclopedia of Medicine, 3rd ed.. . Retrieved December 18, 2017 from Encyclopedia.com: http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/esophageal-function-tests-0