Introduction:
An esophageal impedance test is a diagnostic procedure that involves monitoring for 24 hours to determine the quantity of acidic and non-acidic reflux from the stomach into the esophagus. It allows the doctor to evaluate if the patient's symptoms are associated with gastroesophageal reflux disease (GERD). The esophagus, a muscular tube, functions as a conduit that links the mouth to the stomach, facilitating the transportation of food and liquids to the stomach. The role of the stomach is to digest food, and it is done using the acids present in the stomach called gastric acid or stomach acid.
This acid is secreted naturally by the lining of the stomach, controlled by both nervous systems and hormones. Gastroesophageal reflux disease (GERD) is the term used to describe the condition where stomach contents, including stomach acid, consistently flow back into the esophagus. This can happen because a valve called the lower esophageal sphincter present at the end of the esophagus does not close properly when food enters the stomach. Acid backwash flows back through the esophagus into the throat and mouth, giving a sour taste.
Why Is the Esophageal Impedance Test Performed?
An esophageal 24-hour pH impedance test is done to check for GERD (gastroesophageal reflux disease). GERD can show symptoms like:
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Difficulty in swallowing.
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Heartburn (burning sensation or discomfort in the chest region).
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Voice changes or hoarseness.
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A feeling of a lump in the throat.
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Constant cough or throat clearing.
This test is one of several ways through which the doctor can assess the health problems affecting the esophagus and stomach.
This test is a safer and cost-effective tool that is helpful in testing patients early and providing them with correct therapy to avoid unnecessary treatment and avoid side effects.
How to Prepare for the Esophageal Impedance Test?
The doctor will discuss with the patient their medications and will inform them accordingly when to stop taking them before the test. The doctor will also instruct the patients to stop eating and drinking four hours before the test is scheduled. The patient can return to regular activities as the procedure does not require any sedation or anesthesia. The time taken for the whole procedure is between 10 minutes to 30 minutes.
What Are the Complications of the Esophageal Impedance Test?
The esophageal impedance test is considered a safe and easy procedure. The patients may face some difficulty during the test due to sensitive gag reflexes. The patients might feel some mild and temporary discomfort in the nose and throat from the catheter. Rarely, some patients might have a nosebleed due to the procedure. In extremely rare cases, a tear in the wall of the esophagus, throat, or lung could be noticed because of the procedure.
How Is the Esophageal Impedance Test Performed?
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There is no requirement for anesthesia or sedation during the procedure, so the patient will remain conscious throughout. The patient will receive a local anesthetic in their nose and throat from the doctor to ensure their comfort while inserting the catheter. The distance from the nose to the opening of the stomach will be measured using a manometry catheter.
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After that, one end of the testing catheter (a catheter is a flexible, narrow tube) will be placed into the patient’s nose. It will be swallowed into the esophagus along with the sips of water. The other end of the catheter will be secured to the patient’s cheek and wrapped around the ear, and attached to a small data recorder that the patient will wear at the waist level, held by a strap over the shoulder. The data recorder is about the size of a smartphone. This data recorder collects information from the acid-sensitive tip of the catheter inside the patient’s body.
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The patient can swallow, breathe and talk without any difficulty during the procedure. The placement of the catheter usually takes about ten minutes, but in case the doctor has asked for esophageal manometry (esophageal manometry is a diagnostic test done to identify problems with movement and pressure in the esophagus that may cause problems), the appointment might take little longer.
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The patient is allowed to leave the site after the placement of the catheter, and he or she can do their usual daily activities and can eat and drink normally. The catheter will not cause any problems, and can breathe, eat, drink, and talk while it is in place. The patients will be asked to keep a diary with them to note down the timing of meals and activities done. The patient should also make a note of any symptoms or issues (like heartburn, regurgitation, sore throat, cough, etc.) faced during the experience.
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The patient is advised not to shower, bathe or swim while wearing the data recorder. The patient should be careful when around pets and kids to make sure they do not accidentally come close and pull the catheter out. The patient should go about the daily routine and eat a regular meal so as to get a realistic recording of how much reflux occurs during the usual routine. After 24 hours, the patient has to return to the site to get the catheter removed and to turn in the dairy. Removing the catheter requires less than a minute.
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The doctor downloads the data from the data recorder to see changes in acid levels throughout the day. The patient can expect to receive the test's final results in approximately one week. The doctor uses the data to make a diagnosis and plan the treatment accordingly.
Conclusion:
The esophageal impedance test is a diagnostic test wherein the data is collected for 24 hours. This procedure is the most sensitive tool for assessing gastroesophageal reflux (acidic, weakly acidic, and weakly alkaline), their composition, number of reflux episodes, duration of acid or volume exposure, and number of proximal reflux events. This test is most useful in cases suggestive of gastroesophageal reflux diseases. The esophageal impedance test helps in timely diagnosis and provides correct treatment to the patient.
