Bronchial asthma is a chronic lung disease based on the increased sensitivity of the bronchi to various stimuli (in particular, allergens). In response to the action of these stimuli, a narrowing (obstruction) of the bronchi develops. This process is due to several reasons: an increase in the tone of the bronchi, excess discharge into the lumen of the bronchi and their inflammation. In asthma, seizures most often occur sporadically, for example after contact with an irritant. In severe asthma, bronchial obstruction often persists between attacks.
One of the most dangerous complications of asthma is asthmatic status – a life-threatening attack that is not amenable to conventional treatment. Such patients need immediate hospitalization in the intensive care unit.
Bronchial asthma is a very common disease, it affects about 5% of the population. The prevalence of asthma is even higher in children. Bronchial asthma in adults is a chronic disease that requires constant treatment under the guidance of a specialist.
Heredity plays an important role in the occurrence of asthma: if one of the parents suffers from asthma, then the probability that it will occur in a child is almost 50%, if both — 65%.
Types of asthma
Many patients with asthma develop antibodies to one or more allergens. This form is called allergic bronchial asthma. It is often combined with skin diseases (neurodermatitis) and allergic rhinitis. Allergic asthma is also called exogenous asthma, as opposed to endogenous bronchial asthma, which caused neither by the susceptibility to allergies nor environmental allergens play a role.
Allergic asthma usually develops in children and young people. The most common allergens include pollen, mold fungi, cockroaches, house dust and the epidermis (outer skin layer) of animals, especially cats.
Food allergens cause asthma much less frequently than airborne, but some foods and dietary supplements can provoke severe attacks. Often, patients with bronchial asthma have reflux esophagitis (throwing the acidic contents of the ventricle back into the esophagus), and its treatment can reduce the severity of bronchial asthma.
In bronchial asthma, the sensitivity of the respiratory tract to a variety of irritants, including cold air, perfumery, smoke. A choking attack can cause severe physical exertion and rapid, excessive breathing (caused by laughter or crying).
Medicines cause about 10% of asthma attacks. The most common type of drug asthma is aspirin asthma. Intolerance to aspirin and other nonsteroidal anti-inflammatory drugs usually develops in 20-30 years.
An attack of asthma can be provoked by beta-blockers (propranolol, metoprolol, timolol), including those that are part of eye drops.
Symptoms
The main symptoms are shortness of breath (feeling of suffocation, lack of air), coughing, wheezing.
Dyspnea periodically increases or decreases. It often increases at night, and it may become clear that it appeared after an acute respiratory illness (cold) or inhalation of an irritating substance. Although with obstruction of the bronchi, airflow resistance increases as you exhale, patients usually complain of difficulty breathing (which is caused by respiratory muscle fatigue).
Cough is sometimes the only complaint. The use of bronchodilators helps to confirm the diagnosis. The appearance of sputum cough during an attack foreshadows its end. An asthma attack usually develops within 10-30 minutes after contact with an allergen or irritant.
Diagnostics
- The main method of diagnosing bronchial asthma is spirometry (a study of the function of external respiration). The patient makes a forced (amplified) exhalation into the apparatus, and it calculates the basic parameters of breathing. The main ones include the forced expiratory volume in 1 second and peak volume velocity. Spirometry almost certainly includes a study of the reaction to bronchodilators: for this, the patient is given several (usually four) breaths of salbutamol or another quick-acting bronchodilator and re-spirometry is performed. Spirometry should also be carried out to monitor the progress of asthma treatment: it is necessary to focus not only on the presence or absence of complaints against the background of treatment but also on the objective indicators that spirometry gives. There are simple devices (peak fluorometers) for independent use by patients with asthma;
- Lung function may be normal during the interictal period; sometimes provocative tests are carried out in these cases, usually with methacholine. A negative methaquine test excludes bronchial asthma, but a positive one does not confirm this diagnosis. The methacholine test is positive in many healthy people; it may be positive, for example, within a few months after a respiratory viral infection;
- Chest X-ray is required for severe attacks, as it allows to reveal hidden complications that require immediate treatment.
Treatment
Treatment is prescribed in accordance with the severity and duration of the disease. The course of bronchial asthma is impossible to predict, and its treatment requires an individual approach to each patient. The frequency of hospitalizations is lower among those patients who are carefully monitored and who use drugs correctly.
The form of anti-asthma drugs may be different: inhalers are widely used. The advantage of inhalation in comparison with oral and parenteral (intravenous) routes of administration is that a higher concentration of the drug gets in the lungs, and the number of side effects is minimal.
Inhaled beta-adrenostimulators, including salbutamol, terbutaline, bitolterol and pirbuterol are also widely used. These drugs last longer than their predecessors and less likely to cause cardiovascular complications. The longest effect has salmeterol. It can be used for the prevention of night attacks. However, the effect of salmeterol develops slowly and the drug is not suitable for the treatment of seizures.
There is a fear that addiction is developing to adrenostimulants. Although this process is reproduced in an experiment on laboratory animals, the clinical significance of addiction is not yet clear. In any case, the patient’s need for more frequent use of the drug should prompt the patient to contact their doctor immediately, as it can be a sign of asthma transition to a more severe form and the need for additional treatment. Previously, inhaled adrenergic stimulants were recommended to be used regularly (for example, 2 breaths 4 times a day), but due to frequent cardiovascular complications and addiction at the present time, they can be used more rarely, as well as when needed.
Inhaled glucocorticoids are widely used in bronchial asthma. They are designed to achieve the maximum local effect with minimal absorption and minimal complications. They can be used to cancel glucocorticoids after prolonged use, to reduce dependence on adrenostimulators and reduce the frequency of attacks during physical exertion. Candida stomatitis can be eliminated or prevented if you thoroughly rinse your mouth after inhaling the drug. Bear in mind that inhaled glucocorticoids do not give a quick effect. They must be regularly used for several weeks or even several months (to achieve the maximum effect).
Methylxanthines (theophylline, aminophylline) are currently almost never used for the treatment of bronchial asthma.
Leukotriene antagonists – drugs that block leukotriene receptors (zafirlukast, montelukast), as a rule, are used for mild or moderate asthma, usually in combination with other drugs.
Inhalation M-anticholinergics (for example, ipratropium bromide) are used mainly for chronic obstructive bronchitis, but in some cases – for bronchial asthma.
If bronchial asthma is caused by allergies to ticks and certain types of pollen, desensitization may help, although it is most effective in allergic rhinitis.