Many complications can develop in patients in intensive care. One of these most severe conditions is Mendelssohn syndrome.
What is this pathology?
Mendelssohn’s syndrome most often means obstructive pulmonary disease with damage to the lung tissue (pneumonitis), which develops when gastric juice enters the respiratory tract. This condition was first described in 1946. It is observed in severe patients who have suffered a traumatic brain injury, abdominal surgery (especially on the abdominal organs) and childbirth. In most cases, the culprit of this kind of pathology is anesthesia (due to it there is a relaxation of smooth muscles).
Against the background of relaxed and lost muscle tone, aspiration (getting into the respiratory tract) of the contents of the stomach (usually only gastric juice) occurs. As a result of this, both the
bronchial tree and the lung tissue are affected. The condition is extremely serious, can lead to death if appropriate assistance is not provided. It is worthwhile to understand in more detail why such an unpleasant disease arises and what should be done with it.
Causes
Several diseases can lead to the development of Mendelssohn syndrome. These include:
- Pathologies of the nervous system (severe brain injury, lesion of the glossopharyngeal nerve, increased nervous regulation of the parietal cells of the stomach and motility of the hollow organs of the gastrointestinal tract).
- Digestive tract diseases (hiatal hernia , cardia achalasia).
- Diseases of the respiratory tract (short trachea, fistulas between the esophagus and the respiratory throat).
In addition to these ailments, severe illness can lead to pneumonitis. A considerable influence on the development of aspiration is also exerted by abdominal operations (due to a decrease in the tone of the muscles of the organs and its reduction in the opposite direction of peristalsis waves) and pregnancy (due to displacement of the diaphragm). For example, surgical interventions account for up to 70% of cases.
However, the most common cause of gastric juice into the lower respiratory tract is passive leakage due to the patient's incorrect position and weakness of the cardiac sphincter.
Pathogenesis of aspiration pneumonitis
The disease develops as a result of damage to the lung and bronchial tissue with hydrochloric acid contained in the stomach. Along the way, coagulation necrosis develops (which, again, is due to the action of acid on the mucous membrane of the bronchi). As a result, the secretory ability of the bronchi decreases, which leads to their drying out. In parallel, the acid that has penetrated the lungs causes the development of pneumonitis - aseptic inflammation of the lung tissue. The respiratory surface of the lungs decreases, the production of surfactant decreases. All this leads to an increase in the airiness of the said organ (because of this, 2 forms of pathology are distinguished: asthmatic - with a primary lesion of the bronchi, and obstructive - with a lesion of the lung tissue and the development of obstruction syndrome). The degree is determined by the pH of the gastric juice (the lower it is, the more concentrated the acid, and the stronger the lesion). The most severe changes are observed in the alveoli.
Alveolar manifestations
Very often, when discussing a disease and related symptoms, readers are offered a photo. Diseases like pneumonitis, as a rule, do not differ in any specific external signs. But if you look at the affected area of the tissue through a microscope (which is usually done at autopsy), you can detect certain changes.
As a result of all the above processes and under the influence of gravity, hydrochloric acid sinks into the alveoli. There, due to local effects on the alveolar tissue, the formation of effusion (most often hemorrhagic) occurs. As a result, hemorrhagic pulmonary edema develops.
Under the influence of destruction in the alveoli, prolapse of fibrin is observed, as well as the penetration of blood cells through the basement membrane (in particular, white blood cells and macrophages). As a result of the production of their enzymes, necrosis of the alveolar septa develops, due to which the lung structure is disturbed. In the place where the vessels are located, damage to the endothelium and the formation of microthrombi are observed. All this leads to an increase in the sweating of the fluid through the membranes and the formation of atelectasis. Usually they are the reason that obstructive pulmonary disease develops. If pieces of undigested food or other foreign bodies get into the lungs with acid, such a formation of hemorrhagic edema is combined with the development of a slow granuloma formation reaction around the body. This kind of disease progresses more slowly, but is more difficult.
Clinical manifestations of pathology
How to determine that the patient has aspiration pneumonitis? A specific “photo of the disease” can be represented as follows:
- First of all, the clinic will be determined by the direct effect of acid on the mucous membrane. There is a clinical picture of acute and severe respiratory failure - bronchospasm, increasing cyanosis, respiratory failure.
- From the cardiovascular system, tachycardia, a drop in blood pressure, are observed. In some cases, cardiac arrest or rhythm failure occurs. Along the way, cardiac output decreases and pressure in the pulmonary arteries increases. Due to impaired gas exchange, respiratory and metabolic alkalosis develops. The larger the volume of lung tissue affected, the worse the condition of the patient and the more difficult it will be to cure.
- Typically, signs of damage and respiratory failure appear on the 2nd day, less often - later. Sometimes the symptoms can be erased, and functional disorders may not occur at all.
Diagnostics
The identification of Mendelssohn’s syndrome is not an easy task, since pathology usually develops in debilitated patients, and not always, as was said above, the clinical picture can take place. First of all, the presence of respiratory failure (shortness of breath, wheezing, cyanosis) should be determined. These symptoms cannot always be detected in patients on mechanical ventilation. The most accurate method for diagnosing Mendelssohn syndrome is radiography, or fluorography of the lungs.
The picture shows the presence of effusion in the lungs, an increase in their airiness. In some cases, the bronchial contrast is enhanced (normally on the radiograph in a direct projection the bronchi are not visible, and they can be identified only if lateral pictures are taken). If the patient is undergoing fluorography with a suspicion of this syndrome, then, due to the development of necrosis, the tubular branches of the trachea will be visible on a direct radiograph.
Suction Syndrome Treatment
If aspiration of gastric contents has nevertheless occurred, treatment should be started immediately. First of all, it is necessary to exclude repeated ingress of acid into the lower respiratory tract. To do this (if the condition of the patient allows), you need to raise the head of his bed. Immediately it is necessary to establish ventilation in the lungs and ensure good blood oxygenation. As a rule, mechanical ventilation is prescribed under intermittent positive pressure and hyperbaric oxygen saturation of the blood (use of mechanical ventilation systems, monitoring of the gas composition of the blood). All this will prevent the development of acidosis.
To reduce the volume of damage to the lung tissue, glucocorticosteroids are prescribed intravenously and their small dose is intrabronchial. Hormones allow you to stop the spread of the process and limit it. For the purpose of prevention, antibiotics are prescribed (usually cephalosporins and macrolides). Sympathomimetics should also be taken (in order to reduce the secretion in the bronchi and lungs).
Syndrome Complications
With timely treatment of complications, as a rule, it is possible to avoid. If you are late, the aspiration syndrome can lead to dangerous and undesirable consequences.
Often after a disease, if it occurred with a disruption of the rhythm, there may subsequently be atrial fibrillation or a permanent form of ventricular fibrillation. If it cannot be stopped, but the patient does not complain, you can leave the patient under the supervision of only a local therapist.
Another complication is the development of lung atelectasis, or chronic obstruction. In this case, the stabilization process will be quite long, and the emphasis is usually on relieving symptoms, since this disease is incurable.
The most serious complication of pneumonitis is death. Especially often it takes place in cases when the aspiration syndrome in newborns develops.
Prevention and prognosis of the disease
To prevent the development of aspiration pneumonia, a set of certain measures is required. First of all, all patients and women in labor who are shown intervention under general anesthesia should empty their stomach and intestines. Thanks to this, the main factor in the development of pneumonitis is eliminated.
Before anesthesia, it is recommended to undergo fluorography in order to exclude the content of gastric juice in the respiratory tract. Intubation of the patient must be carried out even when the patient is conscious. They lay the person so that the upper body is slightly raised. This is achieved by regulating the head of the bed or operating table (while eliminating the possibility of passive leakage of the contents of the digestive system into the respiratory tract).
Subject to the observance of the intubation technique and proper preparation of the patient for surgery, the risk of developing Mendelssohn syndrome is minimal.
The prognosis for this disease is as follows: up to 56 percent of patients with advanced pneumonitis of the respiratory tract usually die. If treatment measures were started in a timely manner, the risk of complications and death is reduced to zero.