Gastroesophageal reflux disease (GERD) - Diagnosis

The main diagnostic methods for gastroesophageal reflux disease are X-ray examination of the esophagus, esophagoscopy, radioactive technetium scintigraphy, manometric examination of the esophageal sphincters, and daily monitoring of intraesophageal pH. Prolonged intraesophageal pH monitoring is of great value in atypical forms of gastroesophageal reflux disease (to verify non-cardiac chest pain, chronic cough, and suspected pulmonary aspiration of gastric contents); in case of refractoriness of the treatment; and in preparing the patient for antireflux surgery.

Methods of diagnosis of gastroesophageal reflux disease

Research methods	Possibilities of the method
24-hour pH monitoring in the lower third of the esophagus.	Determines the number and duration of pH<4 and >7 episodes in the esophagus, their relationship with subjective symptoms, food intake, body position, smoking, and medication. Allows for individual selection of therapy and monitoring of drug effectiveness.
X-ray examination of the esophagus.	Detects esophageal hernia, erosions, ulcers, esophageal strictures.
Endoscopic examination of the esophagus.	Reveals inflammatory changes in the esophagus, erosions, ulcers, esophageal strictures, Barrett's esophagus.
Esophageal scintigraphy with radioactive technetium (10 ml of egg white with Tc11, the patient swallows every 20 seconds, and an image is taken in a halochamber every second for 4 minutes).	Allows to assess esophageal clearance (isotope delay of more than 10 minutes indicates a slowdown in esophageal clearance).
Manometric study of the esophageal sphincters.	Allows to detect changes in the tone of the esophageal sphincters. Norm according to DeMeester: Basal pressure of the LES 14.3-34.5 mm Hg. The total length of the LES is not less than 4 cm. The length of the abdominal part of the lower esophageal sphincter is not less than 2 cm.

Additional methods include bilimetry and the omeprazole test, the Bernstein test, the Stepenko test, the standard acid reflux test, the study of esophageal clearance, the methylene blue test, the study of proteolytic intraesophageal activity using the V.N. Gorshkov method, and conducting pulmonary function tests after intraesophageal perfusion of hydrochloric acid.

When conducting an X-ray examination to detect gastroesophageal reflux, the patient must drink a contrast suspension with barium sulfate, after which the patient is examined in a horizontal position or in the Trendelenburg position. A number of additional methodological techniques are used to increase intra-abdominal pressure (Valsalva and Müller, Weinstein, etc.). In the presence of gastroesophageal reflux, barium again enters the esophagus. Often, signs of esophagitis are detected during fluoroscopy: expansion of the lumen of the esophagus, restructuring of the relief of the mucous membrane of the esophagus, unevenness of the outlines, weakening of peristalsis. The X-ray method is especially valuable for detecting a hernia of the esophageal opening of the diaphragm.

Diagnosis of hernia of the esophageal opening of the diaphragm includes direct and indirect signs. A direct sign is the detection of a hernial sac in the mediastinum, the main radiological symptoms of which are: accumulation of contrast agent in the esophagus above the diaphragm with a horizontal barium level, the presence of a wide communication between the supradiaphragmatic part of the esophagus and the stomach, the presence of characteristic folds of the gastric mucosa in the area of the esophageal-gastric junction, displacement of part or all of the anatomical cardia above the diaphragmatic opening. Indirect signs include: absence or reduction of the gas bubble in the stomach, its detection above the diaphragm, smoothing of the angle of His, fan-shaped arrangement of folds of the gastric mucosa in the esophageal opening of the diaphragm (3-4 folds), lengthening or shortening of the thoracic esophagus. In doubtful cases, it is advisable to use pharmacoradiography - artificial hypotension with atropine, which allows detecting even small GERD.

Additional diagnostic methods for gastroesophageal reflux disease

The presence of gastroesophageal reflux can be determined using probing with methylene blue. A dye is introduced into the patient's stomach through a thin gastric tube (3 drops of a 2% solution of methylene blue per 300 ml of boiled water), then the tube is washed with a saline solution, pulled slightly proximal to the cardia, and the contents of the esophagus are aspirated with a syringe. The test is considered positive if the contents of the esophagus are colored blue.

A standard acid reflux test is also used to detect gastroesophageal reflux. 300 ml of 0.1 M hydrochloric acid is injected into the patient's stomach and the pH is recorded using a pH probe located 5 cm above the lower esophageal sphincter while performing maneuvers aimed at increasing intra-abdominal pressure: deep breathing, coughing, Müller and Valsalva maneuvers in four positions (lying on the back, on the right and left side, lying with the head down 20°). The test is positive if a decrease in the pH of the esophagus is recorded in at least three positions.

During the acid perfusion test or Bernstein and Baker test, the patient is in a sitting position. The probe is inserted through the nose into the middle part of the esophagus (30 cm from the wings of the nose). 15 ml of 0.1 M hydrochloric acid is administered at a rate of 100-200 drops per 1 min. The test is considered positive if heartburn, chest pain occur and subside after the introduction of a saline solution. For reliability, the test is repeated twice. The sensitivity and specificity of this test are about 80%.

More physiological is the Stepenko test, in which instead of hydrochloric acid the patient is injected with his own gastric juice.

Laboratory research

There are no pathognomonic laboratory signs for GERD.

Recommended laboratory tests: complete blood count, blood type, Rh factor.

Instrumental research

Mandatory instrumental studies

Single:

• esophagogastroduodenoscopy - allows to differentiate between non-erosive reflux disease and reflux esophagitis, to identify the presence of complications;
• biopsy of the esophageal mucosa in complicated cases of GERD: ulcers, strictures, Barrett's esophagus;
• X-ray examination of the chest, esophagus and stomach.

Research conducted in dynamics:

• esophagogastroduodenoscopy (may not be performed in case of non-erosive reflux disease);
• biopsy of the esophageal mucosa in complicated cases of GERD: ulcers, strictures, Barrett's esophagus;

Additional laboratory and instrumental research methods

Single:

• 24-hour intraesophageal pH-metry: increase in the total reflux time (pH less than 4.0 more than 5% during the day) and the duration of the reflux episode (more than 5 min). The method allows to evaluate the pH in the esophagus and stomach, the effectiveness of drugs; the value of the method is especially high in the presence of extraesophageal manifestations and the absence of the effect of therapy.
• Intraesophageal manometry is performed to assess the functioning of the lower gastrointestinal sphincter (LES) and the motor function of the esophagus.
• Ultrasound examination of the abdominal organs - with GERD unchanged, is performed to identify concomitant pathology of the abdominal organs.
• Electrocardiographic examination, bicycle ergometry - used for differential diagnosis with coronary heart disease, no changes are detected with GERD.
• Proton pump inhibitor test - relief of clinical symptoms (heartburn) while taking proton pump inhibitors.

Differential diagnostics

With a typical clinical picture of the disease, differential diagnosis is usually not difficult. In the presence of extraesophageal symptoms, it should be differentiated from ischemic heart disease, bronchopulmonary pathology (bronchial asthma, etc.). For differential diagnosis of gastroesophageal reflux disease with esophagitis of other etiology, a histological examination of biopsy specimens is performed.

Indications for consultation with other specialists

The patient should be referred for consultation to specialists if the diagnosis is uncertain, if there are atypical or extraesophageal symptoms, or if complications are suspected (esophageal stricture, esophageal ulcer, bleeding, Barrett's esophagus). A consultation with a cardiologist (for example, if there is chest pain that does not subside with proton pump inhibitors), a pulmonologist, or an otolaryngologist may be necessary.

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