Chronic bronchitis: an overview of information

Chronic bronchitis is a diffuse progressive inflammation of the bronchi that is not associated with local or generalized lung damage and manifests itself as a cough. Chronic is called a bronchitis, in which productive cough, not associated with any other disease (eg, tuberculosis, bronchus tumor, etc.), lasts at least 3 months per year for 3 consecutive years.

Chronic bronchitis is a disease characterized by chronic diffuse inflammation of the bronchial mucosa, restructuring of its epithelial structures, hypersecretion and increased viscosity of the bronchial secretion, a violation of the protective cleansing function of the bronchi and a permanent or recurring cough with separation of sputum, not associated with other diseases of the bronchopulmonary system. Chronic inflammation of the bronchial mucosa is caused by prolonged irritation of the airways with volatile pollutants of domestic or industrial nature (most often tobacco smoke) and / or a virus-bacterial infection.

The above definition of chronic bronchitis is of fundamental importance, since, firstly, it makes it possible to clearly identify and diagnose chronic bronchitis as an independent nosological form and, secondly, forces the therapist to conduct differential diagnosis with pulmonary diseases accompanied by sputum cough (pneumonia, tuberculosis and etc.).

[1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12]

Epidemiology

Epidemiology of chronic bronchitis

Chronic bronchitis is a widespread disease and occurs in 3-8% of the adult population. According to A. N. Kokosov (1999), the prevalence of chronic bronchitis in Russia is 16%.

Most pulmonologists offer to allocate primary and secondary chronic bronchitis.

Under primary chronic bronchitis is understood as chronic bronchitis as an independent disease, not associated with any other bronchopulmonary pathology or lesion of other organs and systems. At the primary chronic bronchitis there is a diffuse lesion of the bronchial tree.

Secondary chronic bronchitis is etiologically associated with chronic inflammatory diseases of the nose, paranasal sinuses; with chronic limited inflammatory lung diseases (chronic pneumonia, chronic abscess); with endured pulmonary tuberculosis; with severe heart diseases, flowing with stagnant phenomena in a small circle; with chronic renal failure and other diseases. Usually secondary chronic bronchitis is less common locally - diffuse.

Chronic bronchitis is the most common disease of the bronchopulmonary system. In the US, for example, only chronic obstructive bronchitis (COPD), i.e. The most prognostically unfavorable form of chronic bronchitis, affects about 6% of men and 3% of women, in the UK - 4% of men and 2% of women. In people over 55, the prevalence of this disease is about 10%. The proportion of chronic bronchitis in the general structure of respiratory diseases of non-tuberculosis nature reaches now more than 30%.

Depending on the nature of the course, the severity of the pathological process in the bronchi and the features of the clinical picture of the disease, there are two main forms of chronic bronchitis:

1. Chronic simple (non-obstructive) bronchitis (CHB) is a disease characterized by the lesion of predominantly proximal (large and medium) bronchi and a relatively favorable clinical course and prognosis. The main clinical manifestation of chronic non-obstructive bronchitis is a persistent or intermittent cough with sputum separation. Signs of unexpressed bronchial obstruction occur only during periods of exacerbation or at the latest stages of the disease.
2. Chronic obstructive bronchitis (COB) is a disease characterized by deeper degenerative-inflammatory and sclerotic changes not only in the proximal but also in the distal sections of the airways. The clinical course of this form of chronic bronchitis, as a rule, is unfavorable and characterized by a prolonged cough, gradually and steadily increasing dyspnea, a decrease in exercise tolerance. Sometimes, chronic obstructive bronchitis reveals signs of local bronchial involvement (bronchiectasis, cicatricial changes in the bronchus wall, pneumosclerosis).

The main distinguishing feature of chronic obstructive bronchitis is an early lesion of the respiratory parts of the lungs, manifested as signs of respiratory failure, slowly progressing in parallel with the increase in the degree of bronchial obstruction. It is believed that in chronic obstructive bronchitis, the annual decrease in GEL is more than 50 ml per year, whereas in chronic obstructive bronchitis less than 30 ml per year.

Thus, the clinical evaluation of patients with chronic bronchitis requires mandatory isolation of the two main forms of the disease. In addition, it is important to diagnose the course of the disease (exacerbation, remission), the nature of inflammation of the bronchial mucosa (catarrhal, mucopurulent, purulent), the severity of the disease, the presence of complications (respiratory failure, compensated or depleted chronic pulmonary heart, etc.) .

Below is the simplest and most accessible classification of chronic bronchitis.

[13], [14], [15], [16], [17], [18], [19]

Causes of the chronic bronchitis

The cause of chronic bronchitis

The disease is associated with prolonged irritation of the bronchi with various harmful factors (smoking, inhalation of air polluted by dust, smoke, carbon oxide, sulfur dioxide, nitrogen oxides and other chemical compounds) and recurrent respiratory infection (respiratory viruses, Pfeiffer's rod, pneumococcus), less likely to occur cystic fibrosis, and alpha-1 antitrypsin insufficiency. Predisposing factors are chronic inflammatory and suppuration in the lungs, upper respiratory tract, decreased resistance of the organism, hereditary predisposition to respiratory diseases.

What causes chronic bronchitis?

Pathogenesis

Pathological anatomy and pathogenesis

Hypertrophy and hyperfunction of the bronchial glands, increased mucus secretion, a relative decrease in serous secretion, a change in the secretion, a significant increase in acidic mucopolysaccharides in it, which increases the viscosity of phlegm. Under these conditions, the ciliated epithelium does not provide cleansing of the bronchial tree and the normal update of the entire secretion layer; the emptying of the bronchi with this condition of mucociliary clearance occurs only with coughing. Such conditions for the mucociliary apparatus are disastrous: dystrophy and atrophy of the ciliated epithelium occur. At the same time, the glandular apparatus that produces lysozyme and other antibacterial protectors undergoes the same degeneration. In these conditions, a bronchogenic infection develops, the activity and relapses of which largely depend on the local immunity of the bronchi and the development of secondary immune deficiency.

In the pathogenesis of the disease, spasm, edema, fibrotic changes in the bronchial wall with stenosis of its lumen or its obliteration are important. Obstruction of small bronchi leads to overstretching of the alveoli on expiration and violation of the elastic structures of the alveolar walls, as well as to the appearance of hyperventilated and completely non-ventilated zones functioning as an arteriovenous shunt. Due to the fact that the blood passing through these alveoli is not enriched with oxygen, arterial hypoxemia develops. In response to alveolar hypoxia, a spasm of the arterioles of the lungs occurs with an increase in total pulmonary-arterial resistance; there is precapillary pulmonary hypertension. Chronic hypoxemia leads to polycythemia and increased blood viscosity, accompanied by metabolic acidosis, which further strengthens vasoconstriction in the small circulation.

In large bronchi, surface infiltration develops, in medium and small bronchi, and also in bronchioles, this infiltration can be profound with the development of erosion, ulceration and the formation of meso- and panbronchitis. The phase of remission is characterized by a reduction in inflammation in general, a significant decrease in the amount of exudate, proliferation of connective tissue and epithelium, especially in case of ulceration of the mucosa. The final phase of the chronic inflammatory process in the bronchi is sclerosis of their walls, atrophy of glands, muscles, elastic fibers, cartilage. Perhaps irreversible stenosis of the lumen of the bronchus or its expansion to the formation of bronchiectasises.

Chronic bronchitis - Pathogenesis

Symptoms of the chronic bronchitis

Symptoms and clinical course of chronic bronchitis

The onset of the disease is gradual. The first symptom is a morning cough with the separation of mucous sputum. Gradually cough begins to occur at night and in the afternoon, intensifying, as in chronic bronchitis, when inhaled cold raw or hot dry air. The amount of sputum increases, it becomes mucopurulent and purulent. Appears and progresses shortness of breath, first with physical exertion, and then at rest.

In the clinical course of chronic bronchitis four stages are distinguished: catarrhal, purulent, obstructive and purulent-obstructive. The third stage is characterized by emphysema and bronchial asthma, for the fourth stage - purulent complications (bronchoectatic disease).

The diagnosis is established using fnbrrobronhoscopy, in which the endobronchial manifestations of the inflammatory process (catarrhal, purulent, atrophic, hypertrophic, hemorrhagic, fibrous-ulcerative endobronchitis) and its severity (but only to the level of subsegmental bronchus) are visually assessed. Bronchoscopy allows the biopsy of the mucous membrane and histological methods to clarify the nature of its morphological changes, as well as to reveal tracheobronchial hypotonic dyskinesia (an increase in the mobility of the walls of the trachea and bronchi during breathing, until the expiratory collapse of the tracheal wall and the main bronchi - as in laryngomalation, only with the opposite sign ) and a static retraction (change in configuration and a decrease in the lumen of the trachea and bronchus), which can complicate chronic bronchitis and be one of the causes of bronchial obstruction. However, in chronic bronchitis, the main pathological changes occur in the smaller bronchi, therefore broncho- and radiography is used to diagnose this disease.

Chronic bronchitis - Symptoms

Forms

Classification of chronic bronchitis

Form of chronic bronchitis:

• simple (non-obstructive);
• obstructive.

Clinical-laboratory and morphological characteristics:

• catarrhal;
• mucopurulent or purulent.

Phase of the disease:

• exacerbation;
• clinical remission.

Degree of severity:

• light - FEV1 more than 70%;
• Average - FEV1 in the range from 50 to 69%;
• heavy - FEV1 less than 50% of the proper value.

Complications of chronic bronchitis:

• emphysema of the lungs;
• respiratory failure (chronic, acute, acute on the background of chronic);
• bronchiectasis;
• secondary pulmonary arterial hypertension;
• pulmonary heart (compensated and decompensated).

This classification takes into account the recommendations of the European Respiratory Society, in which the severity of chronic bronchitis is estimated by the reduction in FEV1 compared with the proper values. It is also necessary to distinguish between primary chronic bronchitis - an independent nosological form, and secondary bronchitis, as one of the manifestations (syndrome) of other diseases (for example, tuberculosis). In addition, when formulating the diagnosis of chronic bronchitis in the phase of exacerbation, it is advisable to indicate a possible causative agent of bronchopulmonary infection, although in broad clinical practice this approach has not yet become widespread.

Chronic bronchitis - Classification

[20], [21], [22], [23], [24], [25]

Differential diagnosis

Differential diagnosis of chronic bronchitis

Chronic bronchitis is differentiated from bronchial asthma, tuberculosis and lung cancer. From bronchial asthma, chronic bronchitis is characterized first of all by the absence of asthma attacks, while obstructive bronchitis is characterized by persistent cough and shortness of breath. There are other, laboratory methods for differential diagnosis of these diseases, for example, sputum microscopy.

Chronic bronchitis - Diagnosis

[26], [27], [28], [29], [30], [31], [32], [33], [34], [35]

Treatment of the chronic bronchitis

Treatment of chronic bronchitis

Treatment of chronic bronchitis in most cases is done on an outpatient basis and is in the competence of a bronchologist or pulmonologist. Sputum preparations of reflex action (infusion of thermopsis, alteic root, leaves of mother-and-stepmother, plantain), mucolytics and cysteine derivatives are used to improve sputum removal. Proteolytic enzymes (trypsin, chymotrypsin, chymopsy) reduce the viscosity of phlegm, but now they are rarely used in connection with the threat of hemoptysis and the development of allergic reactions, bronchospasm. Preferred for this is acetylcysteine, which has the ability to rapidly dilute sputum, including purulent. It is also advisable to use such mucoregulators as bromhexyl and ambroxol, which improve bronchial drainage. In the presence of symptoms of bronchial obstruction and insufficiency of bronchial drainage, broncho dilators are added - cholinoblockers (atrovent in aerosol) or beta-adrenomimetics (salbutamol, berotek), long-acting theophylline preparations (retafil, teopek, etc.).

Chronic bronchitis - Treatment

With the appearance of purulent sputum, signs of intoxication, leukocytosis, increased ESR, chronic bronchitis should be treated with the use of antimicrobial therapy (aminopenicillins in combination with beta-lactamase inhibitors, macrolides, fluoroquinolines, etc.) with courses sufficient to suppress infection activity of 7-14 days .