Bronchial asthma is a chronic non-infectious disease of the respiratory tract of an inflammatory nature. An attack of bronchial asthma often develops after precursors and is characterized by a short, sharp breath and a noisy prolonged exhalation. It is usually accompanied by a cough with viscous phlegm and loud wheezing sounds. Diagnostic methods include the assessment of spirometry data, peak flowmetry, allergy tests, clinical and immunological blood tests. In treatment, aerosol beta-adrenergic agonists, m-anticholinergics, ASIT are used; in severe forms of the disease, glucocorticosteroids are used.
Over the past two decades, the incidence of bronchial asthma (BA) has increased, and today there are about 300 million asthmatics in the world. This is one of the most common chronic diseases to which all people are susceptible, regardless of gender and age. The mortality rate among patients with bronchial asthma is quite high. The fact that in the past twenty years the incidence of bronchial asthma in children constantly growing makes bronchial asthma not just a disease, but a social problem, to combat which maximum efforts are directed. Despite the complexity, bronchial asthma responds well to treatment, thanks to which you can achieve persistent and long-term remission. Constant control over their condition allows patients to completely prevent the onset of asthma attacks, reduce or eliminate the intake of drugs for stopping attacks, as well as lead an active lifestyle. This helps to maintain lung function and completely eliminate the risk of complications.
Causes of Asthma
The most dangerous provoking factors for the development of bronchial asthma are exogenous allergens, laboratory tests for which confirm a high level of sensitivity in BA patients and in those at risk. The most common allergens are household allergens – house and book dust, food for aquarium fish and animal dander, plant allergens and food allergens, also called nutritional allergens. In 20-40% of patients with bronchial asthma, a similar reaction to drugs is revealed, and in 2% the disease is obtained as a result of work in hazardous industries or, for example, in perfumery stores.
Infectious factors are also an important link in the etiopathogenesis of bronchial asthma, since microorganisms, their metabolic products can act as allergens, causing sensitization of the body. In addition, constant contact with the infection maintains the inflammatory process of the bronchial tree in the active phase, which increases the body’s sensitivity to exogenous allergens. The so-called haptenic allergens, that is, allergens of a non-protein structure, entering the human body and binding with its proteins also provoke allergic attacks and increase the likelihood of AD. Factors such as hypothermia, aggravated heredity and stressful conditions also occupy one of the important places in the etiology of bronchial asthma.
Pathogenesis of Bronchial Asthma
Chronic inflammatory processes in the respiratory organs lead to their hyperactivity, as a result of which, upon contact with allergens or irritants, bronchial obstruction instantly develops, which limits the air flow rate and causes suffocation. Asthma attacks are observed with different frequency, but even in the stage of remission, the inflammatory process in the airways persists. At the heart of the violation of the patency of the air flow in bronchial asthma are the following components: obstruction of the airways due to spasms of the smooth muscles of the bronchi or due to edema of their mucous membrane; blockage of the bronchi with secretion of the submucous glands of the respiratory tract due to their hyperfunction; replacement of the muscle tissue of the bronchi with the connective tissue during a long course of the disease, which causes sclerotic changes in the wall of the bronchi.
At the heart of the changes in the bronchi is sensitization of the body, when antibodies are produced during allergic reactions of an immediate type, proceeding in the form of anaphylaxis, and when the allergen is re-encountered, an instant release of histamine occurs, which leads to edema of the bronchial mucosa and hypersecretion of the glands. Immunocomplex allergic reactions and delayed sensitivity reactions proceed similarly, but with less severe symptoms. An increased amount of calcium ions in human blood has recently also been considered a predisposing factor, since an excess of calcium can provoke spasms, including spasms of the bronchial muscles.
In the pathological examination of the dead during an attack of suffocation, there is a complete or partial blockage of the bronchi with viscous thick mucus and emphysematous expansion of the lungs due to difficult exhalation. Tissue microscopy most often has a similar picture – it is a thickened muscle layer, hypertrophied bronchial glands, infiltrative bronchial walls with desquamation of the epithelium.
Classification of Asthma
BA is subdivided according to etiology, severity of the course, level of control and other parameters. Allergic (including occupational asthma ), non-allergic (including aspirin asthma ), unspecified, mixed bronchial asthma are distinguished by origin . According to the severity, the following forms of AD are distinguished:
- Intermittent (episodic). Symptoms occur less than once a week, and exacerbations are rare and short.
- Persistent (constant flow). Divided into 3 degrees:
- mild – symptoms occur from 1 time per week to 1 time per month
- average – daily seizure frequency
- severe – symptoms persist almost constantly.
During asthma, exacerbations and remission (unstable or stable) are isolated. Whenever possible, control over AD seizures can be controlled, partially controlled and uncontrolled. A complete diagnosis of a patient with bronchial asthma includes all of the above characteristics. For example, “Bronchial asthma of non-allergic origin, intermittent, controlled, in the stage of stable remission.”
Bronchial asthma symptoms
The asthma attack in bronchial asthma is divided into three periods: the precursor period, the peak period and the period of reverse development. The period of precursors is most pronounced in patients with an infectious-allergic nature of BA, it is manifested by vasomotor reactions from the nasopharynx organs (abundant watery discharge, incessant sneezing). The second period (it can start suddenly) is characterized by a feeling of tightness in the chest, which does not allow breathing freely. The inhalation becomes sharp and short, and the exhalation, on the contrary, becomes long and noisy. Breathing is accompanied by loud wheezing, a cough with viscous, difficult to expectorate sputum appears, which makes breathing arrhythmic.
During an attack, the patient’s position is forced, he usually tries to take a sitting position with the body tilted forward, and find a fulcrum or rests with his elbows on his knees. The face becomes puffy, and during exhalation, the cervical veins swell. Depending on the severity of the attack, the involvement of muscles can be observed, which helps to overcome the resistance on exhalation. In the period of reverse development, a gradual discharge of sputum begins, the number of wheezing decreases, and the attack of suffocation gradually fades away.
Manifestations in which the presence of bronchial asthma can be suspected.
- high-pitched wheezing rales on exhalation, especially in children.
- recurrent episodes of wheezing, shortness of breath, tightness in the chest, and cough that gets worse at night.
- seasonality of deterioration of health from the respiratory system
- the presence of eczema, allergic diseases in history.
- deterioration or the onset of symptoms upon contact with allergens, taking medications, upon contact with smoke, with sudden changes in ambient temperature, acute respiratory infections, physical exertion and emotional stress.
- frequent colds “descending” in the lower respiratory tract.
- improvement after taking antihistamines and anti-asthma drugs.
Depending on the severity and intensity of asthma attacks, bronchial asthma can be complicated by emphysema of the lungs and the subsequent attachment of secondary cardiopulmonary insufficiency . An overdose of beta-adrenostimulants or a rapid decrease in the dosage of glucocorticosteroids, as well as contact with a massive dose of an allergen, can lead to status asthma , when asthma attacks follow one after another and are almost impossible to stop. Status asthmaticus can be fatal.
The diagnosis is usually made by a pulmonary clinician based on complaints and the presence of characteristic symptoms. All other research methods are aimed at establishing the severity and etiology of the disease. With percussion, the sound is clear boxed due to the hyper-airiness of the lungs, the mobility of the lungs is sharply limited, and their boundaries are shifted down. During auscultation over the lungs, vesicular breathing is heard, weakened with a prolonged expiration and with a large number of dry wheezing. Due to the increase in lung volume, the point of absolute dullness of the heart decreases, the heart sounds are muffled with an accent of the second tone over the pulmonary artery. From instrumental studies:
- Spirometry . Spirography helps to assess the degree of bronchial obstruction, to find out the variability and reversibility of the obstruction, as well as to confirm the diagnosis. In BA, forced expiration after inhalation with a bronchodilator increases by 12% (200 ml) and more in 1 second. But to obtain more accurate information, spirometry should be performed several times.
- Peak flowmetry . Measurement of peak expiratory activity (PSV) allows monitoring the patient’s condition by comparing the indicators with those obtained earlier. An increase in PSV after inhalation of a bronchodilator by 20% or more from PSV to inhalation clearly indicates the presence of bronchial asthma.
Additional diagnostics include allergen tests, ECGs, bronchoscopy, and chest x-rays . Laboratory blood tests are of great importance in confirming the allergic nature of bronchial asthma, as well as monitoring the effectiveness of treatment.
- Blood test . Changes in the OAC – eosinophilia and a slight increase in ESR – are determined only during an exacerbation. A blood gas assessment is needed during an attack to assess the severity of DN. A biochemical blood test is not the main diagnostic method, since the changes are of a general nature and such studies are prescribed to monitor the patient’s condition during an exacerbation.
- General sputum analysis . Microscopy in sputum can reveal a large number of eosinophils, Charcot-Leiden crystals (shiny transparent crystals that form after the destruction of eosinophils and have the shape of rhombuses or octahedrons), Kurshman spirals (formed due to small spastic contractions of the bronchi and look like casts of transparent mucus in the form of spirals). Neutral leukocytes can be found in patients with infectious-dependent bronchial asthma in the stage of an active inflammatory process. The release of Creole bodies during an attack is also noted – these are rounded formations consisting of epithelial cells.
- Study of the immune status . In bronchial asthma, the number and activity of T-suppressors decreases sharply, and the amount of immunoglobulins in the blood increases. The use of tests to determine the amount of immunoglobulins E is important if allergy tests are not possible.
Treatment of bronchial asthma
Since bronchial asthma is a chronic disease, regardless of the frequency of attacks, the fundamental point in therapy is to exclude contact with possible allergens, adherence to elimination diets and rational employment. If it is possible to identify an allergen, then specific hyposensitizing therapy helps to reduce the body’s response to it.
For the relief of asthma attacks, beta-adrenomimetics are used in the form of an aerosol in order to quickly increase the lumen of the bronchi and improve the outflow of sputum. These are fenoterol hydrobromide, salbutamol, orciprenaline. The dose in each case is selected individually. Preparations of the m-anticholinergic group – aerosols of ipratropium bromide and its combination with fenoterol – also relieve attacks well.
Xanthine derivatives are very popular among patients with bronchial asthma. They are prescribed to prevent asthma attacks in the form of prolonged-release tablets. In the past few years, drugs that inhibit the degranulation of mast cells have had a positive effect in the treatment of bronchial asthma. These are ketotifen, sodium cromoglycate and calcium ion antagonists.
In the treatment of severe forms of asthma, hormonal therapy is used, almost a quarter of patients need glucocorticosteroids, 15-20 mg of Prednisolone is taken in the morning along with antacids that protect the gastric mucosa. In a hospital setting, hormonal drugs can be administered in the form of injections. The peculiarity of the treatment of bronchial asthma is that it is necessary to use drugs in the minimum effective dose and to achieve an even greater reduction in dosages. For better sputum discharge, expectorant and mucolytic drugs are indicated.
Forecast and prevention
The course of bronchial asthma consists of a series of exacerbations and remissions, with timely detection, a stable and long-term remission can be achieved, the prognosis depends to a greater extent on how carefully the patient treats his health and observes the doctor’s prescriptions. The prevention of bronchial asthma is of great importance, which consists in the sanitation of foci of chronic infection, the fight against smoking, as well as in minimizing contact with allergens. This is especially important for people who are at risk or have a history of family history.