Electrogastrography is a modern technique that allows you to explore the motor ability of a person’s stomach without probing. Conventional diagnostic methods, involving the need to swallow a probe, often lead the subjects into horror. Although sounding cannot be called painful, there is very little pleasant in such a procedure. EGG uses the data of the biopotentials of the stomach, recorded through the front wall of the abdominal cavity with a special device - an electrogastrograph. Thanks to this method, without resorting to invasive diagnosis, the attending physician can obtain data on the presence of digestive disorders.
How the stomach works in the human body
The gastrointestinal tract is a complex system consisting of many components. Each of its elements carries out its own unique functions, and in general the entire digestive tract is responsible for processing food entering the body, absorbing nutrients from it, removing the processed product - feces. At the same time, the process of food processing begins even in the oral cavity, and then through the esophagus a lump of chewed food gets into the stomach.
The stomach is a hollow organ located in the upper part of the abdominal cavity, between the esophagus and the duodenum. Anatomically, its structure is represented by four departments - the input (cardiac), arch, middle part (body), pyloric (antral) department. In the antrum is the pyloric sphincter.
The oblong shape of the organ has two bends - small and large. Small bend facing the liver, large - to the spleen. Outside, the organ is covered with a serous membrane, and its walls consist of three layers of tissue - muscle, submucous and mucous.
The gastric mucosa contains special digestive glands that produce the enzyme - pepsin, and an aggressive fluid - hydrochloric acid.
In addition, the antrum contains cells that produce mucus that covers the inner lining of the stomach. The main function of this mucus is protective. It is thanks to her that gastric juice cannot digest the internal mucous layer of an organ.
In the digestive system of the human body, the stomach performs several functions:
The motility of the stomach implies peristaltic contractions of the muscle tissue of the organ, which contribute to the advancement of the food lump in the gastric cavity towards the intestines. Also, due to reductions, food is partially chopped.
Secretory function means that the glands of the stomach are capable of secreting special enzymes and fluid to digest the food lump.
The excretory or excretory function of the stomach is activated in cases where intoxication processes occur in the body. In this case, toxic products can be released through the mucous membrane of the stomach into the cavity of the organ.
The bulk of the beneficial nutrients are absorbed in the intestines. The walls of the stomach in some quantities absorb:
The essence of the electrogastrography method, for which an examination is prescribed
Any disturbances in the contractile activity of the stomach and intestines, disorders of coordination of peristalsis can provoke or be the result of some pathological processes. Assessing the degree of violation helps to identify the severity of the patient's condition, as well as the prognosis of the course of the disease.
Stomach electrography refers to techniques for assessing the motor function of an organ, which use data characterizing the electrical activity of these organs. Such techniques are based on the relationship of contractile and electrical activity of the gastrointestinal tract.
In medicine, there are two types of electrogastrography:
The first type of procedure involves the placement of fixing electrodes directly on the walls of the organ, so it is rarely used. The second type of EGG implies that the electrodes are fixed on the anterior abdominal wall, that is, on the skin of the abdomen.
The goals of the appointment of gastric EGG are:
- the need to establish a primary or approve an existing diagnosis;
- study of organ motility disorders;
- preoperative preparation;
- the need to differentiate mechanical and functional disorders;
- selection and development of treatment tactics;
- quality control and effectiveness of the treatment.
Indications and contraindications for gastrogastrography of the stomach
The basis for the appointment of a diagnostic procedure is the presence of a stomach disease. In this case, the attending physician must determine the state of the peristalsis of the organ, as well as the features of its reaction to various medications.
Among the indications for the implementation of electrodiagnostics:
- stomach ulcer;
- small bowel disease;
- the presence of adhesions in the abdominal cavity;
- refluxes: deviations in the work of the so-called transition zones;
- diagnosis of bowel obstruction;
- suspected postoperative intestinal paresis.
What contraindications does the procedure involve? Due to its painlessness and harmlessness, the EGG of the stomach has practically no contraindications. If the examinee has a pacemaker, electronic devices, implants or shunts installed, this should be reported to the attending physician in advance.
Preparation requirements and procedure technique
All preparatory measures before electrogastrography are aimed at cleansing the stomach and intestines. For these purposes, 2-3 days before it, as part of the preparation of the patient, he is introduced a regimen of a non-slag diet. To reduce the level of gas formation in the digestive tract, the following are excluded from the diet:
- fresh fruits and vegetables;
- bread, especially black bread;
- milk and dairy products;
- alcoholic and carbonated drinks;
- fatty varieties of fish and meat.
On the evening before the examination, the patient can take a laxative drug or make a cleansing enema. Dinner should be light.
In the morning before the procedure, it is forbidden to eat and drink, since it is carried out strictly on an empty stomach.
The total duration of gastric EGG is about 40-50 minutes. The examinee is placed on a couch, in a supine position. Special sensitive electrodes are fixed on the legs and stomach.
The location of the active conductor is determined radiographically - it is located at the intersection of the pyloric part of the stomach and the middle of the abdomen. The second electrode is placed on the right foot.
After the doctor receives data recorded on an empty stomach, a food sample is taken. The patient takes 150 grams of bread, drinks it with a glass of tea with sugar, takes a sip of a suspension of barium sulfate.
The sensors display a broken line with a certain size and frequency of the teeth on the device’s screen. These teeth are a reflection of biocurrents arising from contractile activity of the muscle tissue of the stomach.
The apparatuses with which the procedure is carried out (electrogastrographs) make it possible to register on the surface of the body fluctuations of biocurrents corresponding to the rhythm of gastric motility.
Due to the fact that the frequency bandwidth has a narrow range, the device selectively records precisely synchronized vibrations with contractions of the stomach.
Before the fixation begins and after its completion, the diagnostician sets up a potential calibration.
Features of the interpretation of the indications of the electrogastrograph
There are normal indicators of electrical vibrations of the biocurrents of the digestive tract, with which the result is compared. The EGG standards of the stomach are presented by such indications of the amplitude of the curve:
- colon: 0.01-0.03 Hz;
- the body of the stomach: 0.03-0.07 Hz;
- ileum: 0.07-0.13 Hz;
- jejunum: 0.13-0.18 Hz;
- duodenum: 0.18-0.25 Hz.
Medical scientists L.G. Krasilnikov and B.I. Fishson-Ryssom determined three types of EGG curves in healthy people: the normokinetic curve has an amplitude of 0.2-0.4 mV, and the hyperkinetic curve has an amplitude exceeding 0.4 mV. The hypokinetic curve is recorded with an amplitude below 0.2 mV.
Any pathological processes in the stomach and neighboring organs that affect the ability of the stomach to contract are displayed on the electrogastrogram as characteristic changes, for example, a change in the rhythm of contractile movements, a violation of the amplitude of the teeth on the curve.
In addition, EGG gives the doctor the opportunity to determine the effect of various drugs and substances on the motor function of an organ. So, the introduction of 2-5 grams of sodium bicarbonate to the patient is shown by an increase in the amplitude of electro-vibrations. Hydrochloric acid has the property of inhibiting contractions of the stomach, so the amplitude of electrical vibrations decreases.
Atropine, administered to patients with a healthy stomach and with peptic ulcer, also reduces the amplitude of the oscillations of the curve, while morphine increases it. At the same time, the effect of morphine and atropine in patients is expressed much longer than in healthy ones.
According to the results of electrogastrography, the doctor-diagnostician can detect the normal frequency of contractions (2-4 cycles per minute), or the presence of motor impairment.
Bradigastria is diagnosed if the subject has hypotonic congestion - the frequency of contractions is less than 2 cycles per minute. Tachigastria is characterized by hypertonicity, when 4 to 10 cycles of contractions are recorded per minute in a patient.
The data obtained are made out by the diagnostician in a medical report. The document, together with the fixed images of the curves, is issued to the patient, who then passes them to his attending physician. According to the conclusion of the diagnostician, the doctor will be able to determine the diagnosis of a particular patient, develop treatment tactics for him, select drug therapy, and, if necessary, prescribe other types of diagnostic procedures.
Electrogastrography is a safe and completely painless way to examine the functional abilities of the stomach. This diagnostic method does not require compliance with complex training measures and has no contraindications. It can be administered to children, adults, pregnant and lactating women. By examining the results of EGG, the doctor can establish deviations in the digestive tract associated with an upset stomach motility.
Specialty: infectious disease specialist, gastroenterologist, pulmonologist.
Total length of service: 35 years.
Education: 1975-1982, 1MI, San Gig, highest qualification, infectious diseases doctor.
Science degree: doctor of the highest category, candidate of medical sciences.
- Infectious diseases.
- Parasitic diseases.
- Emergency conditions.