Dust bronchitis

Dust bronchitis is a disease of the bronchi, in which their diffuse damage occurs not because of an infection, but as a result of mechanical or chemical impact on the mucous membranes of the bronchial tree of dust particles that are in the inhaled air. This disease is classified as professional and has a chronic form.

Professional dust bronchitis is most often diagnosed in miners in coal mines and ore quarries, in workers in the metallurgical and chemical industries, and in construction materials manufacturing plants, where production processes involve crushing materials and the release of large amounts of solid particles into the atmosphere. Work in textile, flour milling, and woodworking plants is characterized by increased dustiness.

This disease has two etiological varieties: dust bronchitis and toxic-dust bronchitis (in the presence of various toxic components in the dust).

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Causes of dust bronchitis

So, as is evident from the name of the disease, the cause of dust bronchitis is dust, that is, solid microscopic particles of various origins. The pathophysiological mechanism of bronchial damage is as follows. When inhaling air, dust particles through the nasopharynx and larynx enter the system of tubular air branches of the trachea - the bronchi. The functional task of the bronchi is not only to supply air to the lungs and remove the gas mixture from the respiratory system, but also to clean the inhaled air.

The walls of the bronchi are covered with a mucous membrane consisting of ciliated epithelium, and in a deeper layer there are glands that produce mucus. Dust particles settle on the cilia and villi of the epithelium, are enveloped in mucus and are removed by contraction of the muscular plate of the bronchi - when a person coughs (and coughs up phlegm).

When the dust content in the air exceeds the physiological capabilities of the bronchi, the dust settles on the cilia of the epithelium, reducing or completely blocking their contractions. This leads to dystrophy and sloughing of entire sections of the ciliated epithelium and a functional disorder of the bronchi. At the same time, the mucus that accumulates in the lumens of the bronchi becomes thicker and constantly irritates the nerve endings of the reflex zones of the bronchi. As a result, a cough occurs.

Significant damage to the bronchial mucosa prevents the timely removal of mucus, and it begins to close their lumens. In clinical medicine, this is called obstruction or obstruction of the bronchi and is often detected in such a disease as chronic dust bronchitis.

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Symptoms of dust bronchitis

There is no clear classification of this pathology, but based on typical signs of varying degrees of bronchial damage, specialists distinguish three degrees of chronic dust bronchitis.

Symptoms of dust bronchitis of the first (mild) degree:

• suffer from attacks of dry cough (there is very little sputum, it is difficult to cough it up);
• 1-2 times a year there are exacerbations of prolonged periods of cough;
• Shortness of breath may occur with significant physical exertion;
• During auscultation of the bronchi using a phonendoscope, harsher breathing and, at times, dry wheezing are heard.

Symptoms of dust bronchitis of the second (moderate) degree:

• constantly recurring long bouts of coughing, accompanied by minor secretion of sputum;
• shortness of breath during normal physical activity;
• a feeling of difficulty breathing and attacks of suffocation are possible;
• listening to breathing records its rigidity and weakening, as well as the presence of wheezing in the lower part of the lungs;
• increased frequency of exacerbations up to 3-4 times during the year;
• during an exacerbation, the volume of sputum increases (there may be a small amount of pus present);
• changes in respiratory function with a reduction in forced expiratory volume to 70-80%;
• X-ray examination reveals moderate changes in the pattern of the lower parts of the lungs, pathological thickening of the bronchial walls, swelling of their mucous membrane, as well as diffuse expansion of the air spaces of the distal bronchioles, which is characteristic of pulmonary emphysema;
• signs of pulmonary heart disease (enlargement and dilation of the right chambers of the heart).

Symptoms of dust bronchitis of the third (severe) degree

• the cough becomes persistent and productive (with phlegm);
• shortness of breath occurs not only with minimal physical exertion, but also at rest;
• significant changes in the pattern of the root and lower parts of the lungs;
• asthmatic syndrome and signs of perifocal pneumonia (focal non-inflammatory lung lesion) appear;
• diffuse pulmonary emphysema syndrome with obstruction (narrowing or complete obstruction of individual sections of the bronchial tree) is expressed;
• periods of exacerbation are frequent and last a long time;
• respiratory function is significantly impaired (forced expiratory volume is reduced to 50% or less), decreased oxygen content in the blood (hypoxemia) to 85%;
• clear signs of decompensated pulmonary heart disease appear (rapid fatigue, increased sleepiness, hyperhidrosis, pulsation in the upper abdomen, a feeling of pressure in the chest, swelling of the jugular veins).

Symptoms of toxic dust bronchitis

Toxic dust bronchitis - as a type of professional dust bronchitis - is complicated by the fact that the inhaled air, in addition to dust, contains toxic substances such as formaldehyde, sulfur compounds, chlorinated hydrocarbons, ethylene glycol, nitrites, metal oxides, etc. When they come into contact with the mucous membrane of the bronchi, they cause irritation and inflammation.

Symptoms of toxic-dust bronchitis are expressed not only in coughing fits, but also in the form of increased body temperature, pus in sputum, changes in the biochemical composition of the blood. During the inflammation of the bronchial mucosa, their walls are subject to deformation, the lumens narrow, scars may appear, disrupting the passage of air into the lungs.

Diagnosis of dust bronchitis

Diagnosis of chronic dust bronchitis is based on a complete anamnesis, taking into account all patient complaints and the nature of their professional activities. The following examination methods are used:

• general blood and urine analysis;
• biochemical and bacteriological analysis of sputum;
• chest x-ray (bronchi and lungs in two projections, during exhalation and inhalation);
• spirography (vital capacity of the lungs is determined and graphically recorded);
• spirometry (forced expiratory volume is determined);
• oximetry (determines the level of oxygen saturation in the blood);
• capnography (determines the pressure of carbon dioxide in the air filling the alveoli of the lungs);
• pneumotachography (determines the degree of bronchial resistance and elasticity of lung tissue);
• electromyography (determines the bioelectrical activity of the respiratory muscles);
• bronchography (with contrast agent);
• CT and MRI of the lungs.

In the process of diagnosing dust bronchitis, it is necessary to exclude other pathologies of the respiratory system, in particular, chronic pneumonia, pulmonary tuberculosis, malignant neoplasm (sarcoidosis, lymphogranulomatosis), diffuse fibrosing alveolitis, bronchiectatic disease, etc. Therefore, differential diagnosis of dust bronchitis is very important. For this purpose, bronchoscopy is performed with simultaneous transbronchial biopsy of lung tissue and their histological examination, as well as puncture of the lymph nodes located at the roots of the lungs.

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Treatment of dust bronchitis

It should be noted that the treatment of dust bronchitis is long-term and, first of all, is aimed at restoring the patency of the bronchi and relieving their spasms.

Drug therapy for this disease involves taking medications to facilitate the secretion of sputum, that is, expectorants based on thermopsis herb, coltsfoot leaves, marshmallow root or licorice - in the form of ready-made syrups, mixtures or home-made decoctions.

To improve expectoration in chronic dust bronchitis, doctors prescribe alkaline inhalations: 3 g of sodium bicarbonate and 1 g of sodium tetraborate and sodium chloride per 100 ml of distilled or boiled water. Inhalations should be done several times a day (15-20 ml per procedure).

For the same purpose, the following drugs are used: Acetylcysteine, Bisolvon, Ambroxol (Lazolvan), etc. Acetylcysteine (synonyms - ACC, Broncholysin, Mukobene, Tussikom, Fluimucil, etc.) is prescribed at 0.2 g three times a day (or 0.6 g once). Side effects in the form of nausea and vomiting, tinnitus and urticaria are possible. Contraindicated in severe bronchospasm, liver disease, kidney disease, adrenal dysfunction, gastric ulcer and duodenal ulcer in the acute stage, during pregnancy.

Bisolvon tablets (synonyms: Bromhexine, Solvin, Flegamine) 0.008 g are prescribed 8 mg 2 times a day to thin sputum. The drug can cause nausea and vomiting, as well as dyspeptic symptoms and exacerbation of peptic ulcer. And the drug Ambroxol (synonyms: Lazolvan, Bronchopront, Fluixol, Mucovent, Secretil, Viscomcil, etc.) is taken to reduce the viscosity of sputum and its better removal from the bronchi - one tablet (30 mg) no more than three times a day (during meals). Among its undesirable, but possible effects, nausea and vomiting are indicated.

To relieve bronchial spasms in occupational dust bronchitis, bronchodilators such as Teopec and Terbutaline are used.

The drug Teopec (analogues - Theophylline, Teostat, Teotard, Retafil, Asmolept, Spophyllin, Euphyllong) not only expands the bronchial lumen and reduces the tension of the respiratory muscles, but also activates the function of the ciliated epithelium of the bronchi. The dosage is determined by the doctor strictly individually, and the standard dose is: the first 1-2 days - half a tablet (0.15 g) 1-2 times a day (after meals, with an interval of 12 hours between doses); then 0.2-0.3 g twice a day. The course of treatment can last up to three months. Teopec is not prescribed for hyperthyroidism, myocardial infarction, heart rhythm disturbances, epilepsy. Its side effects include: dizziness, headache, nausea, vomiting, abdominal pain, tachycardia, anxiety, sleep and appetite disorders.

Terbutaline (synonyms - Brikanil, Arubendol, Spiranil, Terbasmin, Terbutol, Tergil, etc.) belongs to the group of selective beta2-adrenergic agonists. It is produced in tablets of 2.5 mg. Doctors prescribe one tablet twice a day. Contraindications to the use of this drug are dysfunction of the thyroid gland, tachycardia, infectious diseases of the uterus, chronic pyelitis. And possible side effects are manifested in the form of palpitations and tremors.

M-cholinergic receptor blockers expand the lumen of the bronchi. For example, Ipratropium bromide (synonyms - Atrovent, Vagos, Itrop, Arutropid, Normosecretol), produced in the form of an aerosol for inhalation, is recommended by doctors for the treatment and prevention of respiratory failure in chronic dust bronchitis - 1-2 doses (1 dose - 0.02 mg) three times a day. However, this drug causes dry mouth and increases the viscosity of sputum. It should be used with caution in case of increased intraocular pressure (glaucoma) and obstruction of the urinary tract in pathologies of the prostate gland.

Treatment of dust bronchitis is carried out using special breathing exercises, increased oxygen pressure in pressure chambers (hyperbaric oxygenation method). Positive effects are provided by such physiotherapeutic procedures as electrophoresis with calcium chloride solution (on the chest), UHF currents and decimeter waves (on the area of the lung roots), as well as short-wave diathermy on the area between the shoulder blades.

Prevention of dust bronchitis

The main prevention of dust bronchitis is the use of personal protective equipment (respiratory masks, petal masks, etc.) in dust-hazardous industries. And the mandatory presence of supply and exhaust ventilation and other means of collective protection of workers in production facilities.

It is necessary to undergo preventive medical examinations on time, as required for personnel of such enterprises and industries.

Prognosis for dust bronchitis

It should be borne in mind that dust bronchitis is a very serious disease that is fraught with irreversible negative consequences. As it develops from stage to stage, the threat of pulmonary heart disease makes the prognosis of dust bronchitis very pessimistic. After all, as the size of the right ventricle of the heart increases and changes in the large vessels of the pulmonary circulation occur, dystrophic and even necrotic processes occur in the tissues of the heart muscle. Dust bronchitis of the third degree threatens loss of ability to work and disability.

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