Bronchial asthma is a disease caused by bronchial hypersensitivity to different irritants/triggers (in particular, allergens). In response to the action of these stimuli, a narrowing (obstruction) of the bronchi takes place. This process appears due to several reasons: an increase in the bronchial tone, excess bronchial secretion into the lumen and their inflammation. In asthma, seizures most often occur sporadically, for example, after contact with an irritant. In a severe form of asthma, bronchial obstruction often persists between seizures.
One of the most severe complications of bronchial asthma is status asthmaticus. It is a life-threatening attack that is not respondable to conventional therapy. Such patients need immediate hospitalization in the intensive care unit.
Bronchial asthma is a very common disease. It affects about 5% of the population. Among children, the prevalence of asthma is even higher, in many cases in children it passes while growing. Bronchial asthma in adults is a chronic disease that requires constant treatment under healthcare supervision.
An important role in the occurrence of asthma is played by heredity: if one of the parents suffers from asthma, then the probability it will damage 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 (runny nose). Allergic bronchial asthma is also called exogenous, as opposed to endogenous bronchial asthma, in the development of which neither predisposition to allergies, nor allergens from the environment play a role.
Allergic bronchial asthma usually develops in childhood and young adulthood. The most common allergens include pollen, molds, cockroaches, house dust, and the epidermis (outer skin layer) of animals, especially cats.
Food allergens are much less likely to cause asthma than airborne ones, but some foods and nutritional supplements can cause severe attacks. Often in patients with bronchial asthma, reflux esophagitis is detected, its treatment can reduce bronchial asthma severity.
In bronchial asthma, respiratory tract sensitivity to a number of irritants is increased, including cold air, perfumes, smoke. Seizure attacks can trigger heavy physical exertion and rapid, excessive breathing.
Medications cause about 10% of bronchial asthma attacks. The most common type of drug causing asthma is aspirin-induced asthma. Intolerance to aspirin and other non-steroidal anti-inflammatory drugs usually develops in 20-30 years.
Beta-blockers (propranolol, metoprolol, timolol), including those that are part of eye drops, can provoke a bronchial asthma attack.
The main symptoms of bronchial asthma are shortness of breath (sensation of suffocation, lack of air), cough, wheezing. Shortness of breath periodically increases and decreases. Often it intensifies at night, and it may turn out that it appeared after an acute respiratory disease (cold) or inhalation of any irritating substance. Although resistance to air flow increases during exhalation in the case of bronchial obstruction, patients usually complain of difficulty breathing (due to fatigue of the respiratory muscles).
Coughing is sometimes the only symptom, then the disappearance or weakening of it after the appointment of asthma inhalers (agents that expand the bronchi) helps to confirm the diagnosis. The appearance of cough with sputum during an attack warns about its end. An asthma attack usually develops within 10-30 minutes after contact with an allergen or trigger.
The main diagnostic method for bronchial asthma is spirometry (a study of external respiration function). The patient makes a forced exhalation into the device. The device calculates the basic parameters of respiration. The main ones include forced expiratory volume in 1 second and peak volumetric velocity. Spirometry always includes a study of the reaction to bronchodilators. For this, the patient is given several (usually four) breaths of salbutamol or another rapid-acting bronchodilator and spirometry is repeated.
Spirometry must be carried out to monitor the progress of asthma treatment. It is necessary to focus not only on the presence or absence of complaints during treatment, but also on objective indicators that spirometry gives. There are simple devices (pick-ups) for independent use by patients with asthma.
In the attack-free interval, lung function may be normal. Sometimes, in these cases, provocative tests are performed, usually with methacholine. A negative test with methacholine excludes bronchial asthma, but a positive test does not yet confirm this diagnosis. The methacholine test is positive in many healthy people; it can be positive, for example, for several months after a respiratory viral infection.
Watch the video about how spirometry procedure is conducted:
Chest x-ray is required for severe attacks, as it reveals hidden complications that require immediate treatment.
Treatment is prescribed in accordance with the severity and duration of the disease. The course of bronchial asthma is impossible to predict. Its treatment requires an individual approach. It was shown that the frequency of hospitalizations is lower among those patients who are carefully monitored and trained to use drugs correctly.
The form of anti-asthma drugs’ application can be different: inhalers (individual and compressor – the so-called nebulizers) and turbuhalers (for inhalation of powdered drugs) are widely used. The advantage of inhaled administration in comparison with the oral and parenteral (intravenous) routes of administration is that a higher concentration of the drug is achieved in the lungs, the number of side effects is minimal. Sometimes it is advisable to prescribe the drug precisely orally since this route of administration allow the drug to reach those areas of the lungs.
Inhaled beta-adrenostimulants are widely used, including salbutamol, terbutaline, bitolterol and pirbuterol. These drugs last longer than their predecessors, and less commonly cause cardiovascular complications. Salmeterol has the longest action. It can be used to prevent night attacks. However, the effect of salmeterol develops slowly, the drug is not suitable for the treatment of seizures.
There is a supposition that addiction develops to adrenostimulants. Although this process is reproduced as an experiment on laboratory animals, the clinical significance of addiction is not yet clearly examined. In any case, the patient’s need for more frequent use of the drug. In any case, the patient should consult his doctor immediately, as it may be a sign of asthma becoming more severe and the need for additional treatment.
Methylxanthines (theophylline, aminophylline) are currently almost not used for bronchial asthma treatment.
Leukotriene antagonists – drugs that block leukotriene receptors, as a rule, are used for mild or moderate asthma, usually in combination with other drugs.
Inhaled M-anticholinergics (for example, ipratropium bromide) are used mainly in chronic obstructive bronchitis, but in some cases, in bronchial asthma, as well.
Tags: bronchial asthma, bronchospasm, respiratory disease