Bronchoectatic disease

Bronchoectatic disease is a chronic acquired, and in some cases congenital, disease characterized by a local suppuration (purulent endobronchitis) in irreversibly altered (enlarged, deformed) and functionally inferior bronchi, predominantly in the lower parts of the lungs.

Bronchiectasis is an expansion and destruction of large bronchi caused by chronic infection and inflammation. Common causes are cystic fibrosis, immune disorders and infections, although some cases are probably idiomatic. Symptoms - chronic cough and discharge of purulent sputum; some patients may have fever and shortness of breath. Diagnosis is based on anamnesis and visualization of the process, usually with high-resolution CT, although the standard radiography of the chest can be of diagnostic significance. Treatment, as well as the prevention of exacerbations are carried out using antibiotics, include secretion drainage and monitoring the development of complications such as superinfection and hemoptysis. If possible, the main causes of development of bronchiectasis should be treated.

[1], [2], [3]

Causes of the bronchiectasis

Diffuse bronchiectasis develops in patients with genetic, immune or anatomical defects that cause damage to the respiratory tract. Cystic fibrosis is the most common cause; less frequent genetically determined causes - dyskinesia of cilia and a severe deficit of alpha1-antitrypsin. Hypogammaglobulinemia and immunodeficiency can also cause diffuse damage to the bronchial tree, as do rare airway structure disorders (eg, tracheobronchomegaly [Mounier-Kuhn syndrome], cartilage deficiency [Williams-Campbell Syndrome]). Diffuse bronchiectasis is a rare complication of more frequent diseases such as rheumatoid arthritis, Sjogren's syndrome and allergic bronchopulmonary aspergillosis, probably due to a variety of mechanisms.

Local bronchiectasis develops with untreated pneumonia or obstruction (for example, due to foreign bodies and tumors, external compression or alteration of anatomy after partial resection).

All these conditions worsen airway clearance and immune defense mechanisms, leading to an inability to lead out a secret and predisposing to infection and chronic inflammation. As a result of frequent infection, usually caused by Haemophilus influenzae (35%), Pseudomonas aeruginosa (31%), Moraxella catarrhalis (20%), Staphylococcus aureus (14%), and Streptococcus pneumoniae (13%), the airway is filled with a viscous mucus secret, containing inflammatory mediators and pathogens, and slowly expand, scar and deform. Histologically, bronchial walls are thickened due to edema, inflammation and neovascularization. The destruction of the surrounding interstitium and alveoli causes fibrosis, emphysema or both.

Non-tuberculosis mycobacteria can cause bronchial dilatation, as well as colonize the lungs of patients with bronchiectasias that develop due to other causes.

[4], [5], [6], [7], [8],

Symptoms of the bronchiectasis

The main symptoms of bronchiectasis are a chronic cough, in which a large volume of thick, viscous, purulent sputum can be released. Dyspnea and wheezing are observed frequently. Hemoptysis, which can be massive, occurs due to the formation of new blood vessels in the airways from the bronchial (but not pulmonary) arteries. Subfebrile temperature occurs with exacerbations of the disease, during which the intensity of cough and sputum volume increase. Chronic bronchitis may resemble bronchiectasis on clinical manifestations, but bronchiectasis is characterized by more abundant discharge of purulent sputum daily and typical changes in CT.

Typical symptoms of bronchoectatic disease are bad breath and pathological respiratory sounds, including rattling and wheezing. The terminal phalanges of the fingers can also be thickened.

Symptoms usually develop imperceptibly and repeat more and more often, with years gradually worsening. In severe cases, hypoxemia, pulmonary hypertension and right ventricular failure may occur.

Superinfection caused by multiresistant microorganisms, including non-tuberculosis mycobacteria, should be considered a possible main cause of the onset of symptoms in patients with recurrent exacerbations or worsening rates of external respiration function in the study of lung function.

[9], [10], [11]

Forms

The independence of bronchoectatic disease as a separate nosological form at the present time can be considered proven by the following circumstances. Infectious and inflammatory process with bronchoectatic disease occurs, mainly, within the bronchial tree, and not in the pulmonary parenchyma. In addition, a convincing confirmation is the operation, in which removal of bronchiectasis leads to recovery of patients.

Along with bronchoectatic disease as an independent nosological unit, the pathomorphological substrate of which is the primary bronchiectasis (bronchiectasis), secrete secondary bronchiectasias (bronchiectasis), which are a complication or manifestation of another disease. Most often secondary bronchiectasis occurs with lung abscess, pulmonary tuberculosis, chronic pneumonia. With secondary bronchiectasis, there are usually pathological changes in the respiratory part of the lungs, which distinguishes secondary bronchiectasis from bronchiectasis.

[12], [13], [14]

Diagnostics of the bronchiectasis

Diagnosis is based on anamnesis, physical examination and X-ray examination, starting with chest radiography. Radiographic data suspicious for bronchiectasis include irregular scattered blackouts caused by slimy plugs, a "honeycomb lung" and rings and "tramway rails" caused by thickened, enlarged bronchuses located perpendicularly or along the x-ray, respectively. Radiographic structures may differ depending on the underlying disease: bronchiectasis in cystic fibrosis develops mainly in the upper lobes, while those caused by other causes are more diffuse or predominate in the lower lobes. CT with high resolution is the method of choice for the detection of bronchiectasis. The study is almost 100% sensitive and specific. CT usually reveals bronchial extensions and cysts (sometimes in the form of grape clusters), scattered mucus plugs and airways, which are more than 1.5 times larger in diameter compared to neighboring blood vessels. Extended bronchial tubes of medium caliber can extend almost to the pleura. Atelectasis, consolidation and reduced vascularization are additional nonspecific changes. Differential diagnosis of the enlarged airway includes bronchitis and "traction bronchiectasis" that occur when pulmonary fibrosis stretches the airways and keeps them open.

To document the initial function and subsequent monitoring of the progression of the disease, lung function tests should be performed. Bronchiectasis is associated with airflow restriction (reduced forced expiratory volumes in 1 s [FEV1], forced vital capacity [FVC] and FEV / FVC); FEV can improve in response to bronchodilators such as beta-agonists. The lung volume and diffusion ability of carbon monoxide (DLCo) can be reduced.

Studies aimed at diagnosing the main cause include sputum analysis with staining and bacteriological examination of cultures of bacteria, mycobacteria (Mycobacterium avium complex and mycobacterium tuberculosis) and fungal (Aspergillus) infection. Mycobacterial superinfection is diagnosed with repeatedly cultivated atypical mycobacteria (with a large number of colonies) and detection of granulomas on a biopsy with parallel x-ray signs of the disease. Additional studies may include the study of sweat chloride for the diagnosis of cystic fibrosis, which should be performed even in older patients; rheumatoid factor and other serological tests to exclude systemic diseases of connective tissue; Immunoglobulins, including subclasses of IgG, to document some immunodeficiencies; tests for aspergillous precipitin, IgE and eosinophilia to exclude allergic bronchopulmonary aspergillosis and alpha 1 antitrypsin to document its deficiency. When clinical manifestations suggest dyskinesia of cilia (in the presence of diseases of the sinuses and bronchiectasis of the middle and lower lobes with or without infertility), a biopsy of the nasal or bronchial epithelium should be performed and the biopsy specimen should be examined by transmission electron microscopy for the presence of a pathological structure of the cilia. A less invasive alternative is the study of sperm motility. The diagnosis of ciliary dyskinesia should be established with caution, an experienced physician trained in specialized methods, since nonspecific structural defects may be present in 10% of cilia in healthy patients and in patients with lung diseases; infection can cause transient dyskinesia; ciliated ultrastructure can be normal in patients with primary ciliary dyskinesia syndromes characterized by the pathological function of cilia.

Bronchoscopy is prescribed when anatomical disturbances or compression are suspected from the outside.

[15], [16], [17], [18], [19], [20],

Treatment of the bronchiectasis

Treatment includes prevention of exacerbations, treatment of underlying causes, intensive treatment of exacerbations and monitoring of complications.

There is no consensus on the best approach to preventing or limiting exacerbations. Daily prophylaxis with oral antibiotics is suggested (for example, ciprofloxacin 500 mg twice a day) and, in patients with cystic fibrosis, colonized with P. Aeruginosa, inhaled tobramycin (300 mg twice a day for a month in a month). In addition, in patients with diffuse bronchiectasis, due to other causes, aerosol gentamicin (40 mg twice daily) can be effective.

As with any chronic lung disease, patients are recommended to be vaccinated against influenza and pneumococcal annually .

Different techniques can promote secretion clearance, including postural drainage and percussion of the chest, devices that provide positive exhalation pressure, intrapulmonary percussion fans, pneumatic vests and autogenous drainage (breathing techniques that help move the secret from the peripheral to the central respiratory tract). Mucolytic (rhDNa3a) has shown clinical efficacy in patients with cystic fibrosis. Patients should test respiratory techniques under the guidance of a respiratory specialist and select and apply the technique that is most effective; no other methods of choice are justified.

Additional treatment for bronchiectasis depends on the underlying cause. Allergic bronchopulmonary aspergillosis is treated with glucocorticoids and, possibly, in combination with azolid antifungal agents. Patients with immunoglobulin deficiency should receive replacement therapy. Patients with a deficiency of alpha-1 antitrypsin should also receive substitution therapy.

Treatment of exacerbations of bronchiectasis is carried out with antibiotics that are effective against H. Influenzae, P. Aeruginosa, M. Catarrhalis. Aureus and S. Pneumoniae (for example, ciprofloxacin 400 mg intravenously 2-3 times, then 500 mg orally 2 times a day or levofloxacin 750-500 mg intravenously, then orally once a day for 7-14 days). Azithromycin 500 mg once a week is effective in bronchiectasis caused by cystic fibrosis, but it is unclear whether macrolides are effective in other nosological forms. Antibiotic therapy should be accompanied by an increased impact on the clearance of sputum from the respiratory tract.

Control of acute complications includes treatment of mycobacterial superinfection and bleeding.

Empirically prescribed regimen in the treatment of M. Avium complex may include the simultaneous administration of several (not less than three) drugs: clarithromycin orally 500 mg twice a day or azithromycin 250-500 mg once a day; rifampicin 600 mg orally once a day or rifabutin 300 mg orally once a day and ethambutol 25 mg / kg orally once a day (2 months), then continue at 15 mg / kg once a day. All drugs should be taken for a long time (up to 12 months), until sputum cultures are negative. There is rarely a need for surgical resection, but can be considered when antibiotic therapy is ineffective and bronchiectasis is of a rather limited nature.

Massive bleeding is usually treated with bronchial embolization of the artery along with antibiotic therapy for exacerbations.

Prevention

Prevention of bronchiectasis requires timely detection and treatment of underlying causes. Unfortunately, most patients seek medical help only when the disease is fully formed bronchiectatic disease.

[21], [22], [23],

Forecast

In general, in 80% of patients who do not further deteriorate lung function due to isolated bronchiectasis, bronchiectasis has a good prognosis. However, patients with cystic fibrosis have an average life expectancy of 32 years, and most patients periodically experience exacerbations.

[24], [25]