Dust bronchitis is an occupational disease of the respiratory tract that occurs with prolonged inhalation of industrial dust and leads to atrophic and sclerotic changes in the wall of the trachea and bronchi. The main clinical manifestations include cough, shortness of breath, bronchial obstruction syndrome. To confirm the diagnosis, the connection of bronchitis with professional activity is established, spirometry is performed, methods of radiation diagnostics, bronchoscopy are used. Conservative treatment with bronchodilators and expectorants, corticosteroid hormones is carried out. In case of exacerbations, antibiotics are prescribed.
ICD 10
J42 J64
Meaning
Dust bronchitis occurs in people who have long-term contact with inorganic and organic dust. It is one of the most common occupational diseases. Chronic bronchitis, classified as dust, develops in 15-80% of coal and iron ore miners; in 20% of metallurgists, foundry workers, as well as workers engaged in the production of cement and other building mixes. Inhalation of dust leads to pathology in 10-30% of workers in mills, woodworking, textile and some agricultural enterprises. The risk of developing bronchitis increases in direct proportion to professional experience. Signs of the disease appear on average after 7-10 years from the start of work in harmful conditions.
Causes of dust bronchitis
The occurrence of occupational chronic bronchitis is caused by prolonged regular exposure to a number of harmful factors. The main reason is solid dust particles of medium size (5-10 microns). The damaging agent is the dust itself, as well as its toxic chemical components and allergens present. The dust that provokes the development of the disease happens:
Organic. It is most often formed during the extraction and processing of coal. The composition of the inhaled aerosol depends on the fossil deposit and the production technologies used. Mercury, arsenic, lead and other harmful chemical components are present as impurities. Often the cause of the disease is wool, flour, peat and other types of organic dust.
Inorganic. It is formed during the extraction and processing of minerals and metals. It is present in the air of workshops of metallurgical and machine-building enterprises. It is the main harmful factor in the production of cement. In high concentrations, it has toxic and irritating properties.
Tobacco smoking plays an important role in the occurrence of the disease. Tobacco smoke independently causes damage to the bronchial wall. Together with the harmful effects of dust, the inflammatory process develops more often and faster. Additional causal factors of the appearance of pathology of the respiratory system are hypothermia or overheating of the body, increased humidity in the room, acute and chronic diseases of the respiratory tract. Many patients have a genetic predisposition to lung diseases.
Pathogenesis
When the dust aerosol is inhaled, the barrier functions of the respiratory system are activated. There is an increase in the work of the mucociliary apparatus and increased secretory activity of mucus-producing cells and glands. Over time, with prolonged exposure to dust particles on the respiratory organs, the cilia of the ciliated epithelium atrophy, the epithelium itself is replaced by a multilayer flat one. The function of removing bronchial secretions is disrupted. There is a change in the composition of sputum. The secret becomes more viscous and stagnates in the lumen of the respiratory tract. Excess sputum and irritating dust components cause coughing. The presence of sensitizing agents in the composition of the pollutant provokes episodes of bronchospasm.
The muscular membrane of the bronchus initially hypertrophs, then acquires atrophic changes. The wall of the tracheobronchial tree is remodeled. All its layers are affected, the normal tissue is replaced by a connective tissue that is not capable of stretching. This process causes even greater stagnation of sputum and leads to obturation of the bronchial lumen, the appearance of emphysema. The bronchial wall is overgrown, bronchiectasis is formed.
Classification
Dust bronchitis is classified by etiological factor. The irritating, toxic and allergic properties of the pollutant components are taken into account. Episodes of remission and exacerbation alternate during bronchitis. During the exacerbation, there are phases of aggression, expanded inflammation and resolution. Depending on the pathomophological endoscopic changes, there are catarrhal, catarrhal-atrophic and catarrhal-sclerosing forms of dust inflammation of the bronchi. The disease can occur in asthmatic and obstructive variants. Specialists in the field of pulmonology and occupational pathology distinguish the following stages of the course of the pathological process:
- Stage I. It is characterized by long periods of remission. Exacerbations occur no more than 2 times during the year. The function of external respiration is not impaired, or there are minor deviations from normal indicators. Oxygen saturation of the blood is within normal limits.
- Stage II. Clinical manifestations of the disease are expressed. Periods of exacerbation are protracted, last more than 3 weeks, occur more often 2-3 times a year. Spirometry reveals significant decreases in the main indicators (LEL, FEV1, MVL) compared with normal values. Blood oxygenation is 85-94%.
- Stage III. Remission periods are short. There is diffuse emphysema of the lungs, pneumosclerotic and bronchiectatic changes, pulmonary heart failure. There are sharp violations of the function of external respiration, a significant decrease in VEL. The oxygen content in arterial blood is below 80-85%.
Symptoms of dust bronchitis
Clinical manifestations of bronchial pathology depend on the stage of the process and the nature of the pollutant. It is difficult to suspect dust bronchitis at the initial stage of development. Its rare exacerbations are manifested by a dry or productive cough. Occur more often in the cold season. Sometimes they are accompanied by shortness of breath during physical exertion or attacks of shortness of breath. Body temperature rarely rises. The symptoms of general malaise are weakly expressed. The exacerbation of the pathological process is mistaken for an acute respiratory infection. Contact with the harmful production factor does not stop, and the disease takes a steadily progressive course.
At stage II of the disease, the cough becomes permanent. Mucous sputum coughs up with difficulty. With the asthmatic variant of bronchitis, episodes of dry painful cough occur more in the evening and morning hours, attacks of suffocation. The patient complains of heaviness in the chest. There is shortness of breath with a small load – fast walking, climbing stairs. Usually there is difficulty exhaling. Exacerbations occur more often, become protracted. When a secondary infection is attached, fever appears, sputum becomes purulent, yellow-green.
As the pathology of the respiratory tract progresses further, shortness of breath increases. Its appearance is provoked by the slightest physical exertion – slow walking, changing the position of the body. The feeling of lack of air becomes constant. The patient is concerned about frequent unproductive cough. Palpitations, cardiac arrhythmias, aching and compressive pains in the heart area, a feeling of heaviness in the right hypochondrium are added. I am worried about pronounced general weakness, a feeling of constant fatigue, increased sweating.
Complications
Bronchitis detected at an early stage, with the exclusion of contact with a damaging agent and timely treatment initiated, proceeds relatively favorably, progresses slowly. Complications of dusty occupational pathology appear at the II–III stages of the course of the disease. Emphysema of the lungs occurs early, further aggravating expiratory dyspnea. Bronchiectasis, being an endogenous source of infection, is complicated by the development of pneumonia. Respiratory failure gradually joins in. Stagnation in the small circle of blood circulation leads to the formation of a severe disabling pathology – a chronic pulmonary heart disease.
Diagnostics
Diagnostic search is carried out by a professional pathologist with the involvement of pulmonologists. The length of professional activity, the nature of harmfulness, the incidence of chronic bronchitis in the workplace are specified. When examined in the later stages of the disease, cyanosis of the lips and terminal phalanges of the fingers or diffuse cyanosis is observed. The chest often acquires a barrel-shaped emphysematous form. To clarify the diagnosis , the following are performed:
- Physical examination. At the beginning of the disease, physical data are scarce. During the period of exacerbation, a few dry wheezes can be heard against the background of hard breathing. Later, the number of whistling and buzzing wheezes increases. Breathing becomes weakened, rapid. A palpitation joins, a feeling of interruptions in the work of the heart.
- Functional diagnostics. With spirometry, gradually progressive violations of respiratory function of a mixed (restrictive-obstructive) type are observed. The electrocardiogram shows signs of overload, and later hypertrophy of the right parts of the heart, tachycardia, extrasystole.
- Visualization techniques. With bronchitis in the initial form, radiological changes are usually absent. Later, there is an increase and deformation of the vascular pattern, signs of emphysema, pneumosclerosis. CT and MRI of the chest can detect the presence of bronchoctases and differentiate dust bronchitis with other pathology of the respiratory system.
- Laboratory tests. With the course of the pathological process, peripheral blood parameters change. At the last stage of the disease, symptomatic erythrocytosis, slowing of ESR is observed. Sputum examination by various methods makes it possible to determine the microbial composition and identify the presence of bacterial resistance to antibiotics, as well as to exclude pulmonary tuberculosis.
To clarify the degree of respiratory insufficiency, blood oxygenation is determined. In order to make a differential diagnosis with oncological pathology and clarify the level of damage to the bronchial wall, bronchoscopy with biopsy is performed. To exclude bronchial asthma, the patient is examined by an allergist. If necessary, pre-tests are carried out, the level of general and specific immunoglobulin E is determined. A patient with suspected dust bronchitis needs to consult an oncologist, a pulmonologist and a phthisiologist.
Treatment for dust bronchitis
The main therapeutic and preventive measure after diagnosis is the cessation of contact with dust. The patient is recommended to change jobs. A smoker should give up smoking. Conservative pathogenetic treatment is being carried out. Drugs are prescribed for a long time. The following groups of medicines are used:
- Expectorants and bronchodilators. At the beginning of the disease, expectorant drugs are mainly used. Medications of reflex action and mucolytics are prescribed. At later stages, M-cholinergic blockers or their combinations with beta-adrenomimetics, methylxanthines of short and prolonged action are added to treatment.
- Corticosteroid hormones. Inhalation, oral and parenteral forms of drugs are used. Inhaled corticosteroids are selected individually, it is possible to use combinations with bronchodilators. Parenteral and oral forms are prescribed in short courses for the relief of obstructive syndrome.
- Antibiotics and cardiac remedies. The use of antibiotics is indicated during the period of infectious exacerbation, when the course of the disease is complicated by bronchopneumonia. They are prescribed taking into account the sensitivity of the microflora. Cardiac remedies are used to treat pulmonary heart disease and symptomatic hypertension. It is preferable to use calcium antagonists and cardiac glycosides.
Immunomodulators, vitamins, adaptogens are prescribed for general strengthening purposes. Physiotherapy procedures on the chest, physical therapy, massage are shown. If necessary, a sanitization bronchoscopy is performed. Severe respiratory insufficiency is an indication for prolonged oxygen therapy through an oxygen concentrator.
Prognosis and prevention
Dust bronchitis is a chronic progressive disease. With the timely exclusion of inhalation of industrial dust, the prognosis is favorable. A late-diagnosed disease complicated by respiratory insufficiency, chronic pulmonary heart leads to disability of the patient. Death can occur from severe pneumonia, pulmonary heart failure.
Collective and individual means of protection are used for primary prevention. Preliminary (before employment) and regular preventive (for workers in hazardous production) medical examinations are carried out. Secondary prevention is reduced to rational employment. It is recommended to avoid contact with respiratory infection, to be vaccinated against influenza.