Gastroesophageal reflux disease

Gastroesophageal reflux is the backflow of gastric contents into the esophagus. The esophagus is a muscular tube that carries food from the throat to the stomach. Food is carried along the esophagus by peristalsis (waves of contraction and relaxation of its muscular walls). The part of the esophagus closest to the stomach acts as a sphincter (circular muscle that is capable of opening and closing). During peristalsis, the lower esophageal sphincter relaxes, allowing food to enter the stomach. In the resting state, this sphincter is closed. This prevents reflux (backflow) of stomach contents into the esophagus.

Reflux is considered abnormal when it produces symptoms and/or changes that result in disease to the lining of the esophagus.

Reflux resulting in symptoms usually involves an underlying dysfunction of the lower esophageal sphincter although not all lower esophageal dysfunction results in symptoms.

Reflux is often found in association with hiatal hernia. The lower esophagus and upper part of the stomach normally lie below the diaphragm, in the abdomen. With hiatal hernia, they slide through an enlarged hiatus (opening) in the chest cavity. This results in sphincter dysfunction partially by altering the gastroesophageal angle. Reflux is also promoted by anything that increases abdominal pressure. It may occur if there is incompetence of the lower esophageal sphincter, or in association with pregnancy or obesity or certain medications and alcohol and caffeine.

The above factors increase the esophageal exposure to gastric juice. Gastric juice contains hydrochloric acid and pepsin (a protein digesting enzyme); bile and pancreatic enzymes may also be present. Excessive exposure to these substances may result in inflammation (reflux esophagitis).

History: The most common symptom of gastroesophageal reflux is "heartburn" (a burning pain in the lower chest usually below the sternum). The pain may range from mild to severe and may mimic heart attack (myocardial infarction). However, gastroesophageal reflux is not related to the heart.The pain typically occurs thirty to sixty minutes after eating and is often precipitated by other common symptoms of reflux. These include water brash (a reflexive increase in salivation) and regurgitation (backward flow of stomach contents into the mouth). Aspiration (inhalation) of regurgitated material can occur, especially during sleep. This may result in respiratory symptoms such as hoarseness, wheezing, cough and difficulty breathing. Difficulty swallowing (dysphagia) is often a symptom of complicated reflux disease. Painful swallowing (odynophagia) is usually a symptom of inflammation of the esophagus, or of an ulcer.

Physical exam: The diagnosis is usually suspected from the history. However, in some individuals it may be necessary to rule out a cardiac source of pain (myocardial infarction, angina pectoris, as well as other gastrointestinal disease).

Tests: If there is any question about the diagnosis, the health care provider may order an upper Gastrointestinal (GI) x-ray, and/or an endoscopy (procedure to visualize the affected area). An upper GI series (contrast x-ray of the upper GI tract) will detect ulcers of the esophagus, stomach, or duodenum (part of the small intestine). For those whose symptoms are not typical, special studies may be required to make the diagnosis. The simplest of these tests is the Bernstein acid perfusion test. In this test, a specific concentration of hydrochloric acid is instilled into the esophagus. If the individual's pain is reproduced by this procedure and relieved by instillation of saline solution, it is an indication that acid reflux is the cause of the pain. The Bernstein test may be done along with motility studies (also referred to as esophageal manometry). Manometry (pressure measurement) may demonstrate an abnormally low lower esophageal pressure, or may show impaired peristalsis in the lower esophagus. In some cases, ambulatory pH monitoring may be helpful. By continuously monitoring the pH (degree of acidity) of the esophagus for up to 24 hours, the persons daily pattern of reflux and its relationship to the occurrence of symptoms can be documented. Radioisotope scans are sometimes done to demonstrate reflux. A reflux scan is less sensitive than 24-hour pH monitoring; however, it can help document aspiration (inhalation of regurgitated material).

Treatment of symptomatic reflux may be considered in several phases. Phase I consists of general measures, phase II is medical treatment, and phase III is surgical intervention.

In phase I, measures that decrease abdominal pressure are helpful. In overweight people, weight loss may make a difference. Tight clothing and belts should be avoided. Meals should be small and frequent. Raising the head of the bed or using more then one pillow when reclining may allow gravity to help relieve symptoms. Avoidance of reclining for at least two hours after meals is recommended. Avoiding substances that may increase symptoms is best. Examples of such substances include alcohol, tobacco, caffeine, acidic foods and drink (such as citrus, tomatoes), fats, chocolates, and peppermint. Medications the individual is taking should be reviewed. Certain medications (such as anticholinergic drug and calcium channel blockers) can decrease lower esophageal sphincter tone. Others (potassium supplements, certain antibiotics) may be irritating to the esophagus. Antacids may be helpful when taken after meals and at bedtime. They have an acid neutralizing effect; however, this effect is not long-term.

If the above measures are unsuccessful in controlling symptoms, histamine (H2) antagonists are introduced in phase II treatment. By blocking histamine receptors, these medications decrease the secretion of gastric acid. If the response is incomplete, cholinergic drugs or other motility promoting agents may be added. These medications increase esophageal and gastric motility, increase lower esophageal sphincter tone, and promote gastric emptying. Mucosal protective agents may also be tried.

Most individuals, particularly those with uncomplicated disease respond well to phase I or II therapy. Complications generally require phase II. If severe reflux esophagitis is present, a proton pump inhibitor medication may be tried. This new type of medication directly blocks the secretion of acid (hydrogen ions or protons) by the stomach. This type of medication often produces complete healing in four to eight weeks; however, most have reoccurrence after the drug is discontinued. Currently, proton pump inhibitors are approved for short- term use only.

Antireflux surgery is phase III and is indicated when symptoms persist or recur despite conservative treatment. If a hiatal hernia is present, it is reduced. That is, the stomach and esophagus are returned to their normal position in the abdominal cavity, and the hiatal opening is secured with sutures. A procedure (fundoplication) may be indicated to create a high pressure area in the lower esophagus, preventing reflux.