Diagnosis of bronchial asthma

The study of the function of external respiration in patients with bronchial asthma is mandatory and allows us to objectify the degree of bronchial obstruction, its reversibility and variability (daily and weekly fluctuations), as well as the effectiveness of the treatment.

[1], [2], [3],

Spirography

Spiography - graphical recording of the volume of the lungs during breathing. Characteristic spirographic signs of the violation of bronchial patency in patients with bronchial asthma are the following:

• decrease in the forced vital capacity of the lungs (FVC) and the forced expiratory volume in the first second (FEV1), with FEV being the most sensitive indicator reflecting the degree of bronchial obstruction;
• the decrease in the Tiffno index (ratio FEV1 / ZHEL), as a rule it is less than 75%. With bronchial obstruction, the decrease in FEV is more pronounced than FVC1, so the Tiffno index is always reduced.

The measurement of these feeders should be made 2-3 times and for the true value to take the best value. Obtained absolute values are compared with those that are calculated by special nomograms taking into account the growth, sex, age of the patient. In addition to the aforementioned changes in the spirogram, with exacerbation of bronchial asthma, the residual lung volume and functional residual capacity increase significantly.

With frequent exacerbations of the disease and the development of emphysema, a decrease in the vital capacity of the lungs (LEL) is revealed.

Pneumotachography

Pneumotachography registration in a two-coordinate loop system "flow-volume" - the rate of expiratory air flow in the 25-75% FVC section, i.e. In the middle of an exhalation. This method calculates the peak-to-peak space velocity (PIC), maximum space velocities at 25%, 50%, 75% FVC (MOS25, MOC50, M0C75) and average space velocities of COC25, 75.

According to pneumotachography (loop-volume analysis), it is possible to diagnose a violation of bronchial patency at the level of large, medium or small bronchi. For obstruction mainly at the level of the central airways, large bronchi characterized by a marked decrease in the volume rate of forced expiration in the initial part of the descending branch of the flow / volume curve (PIC and MOS25 in% to proper values are reduced more significantly than MOC50 and MOS75). The peripheral bronchial obstruction observed in bronchial asthma is characterized by a concave character of the exhalation curve and a significant decrease in the maximum space velocity at 50-75% FVC (MOS50, MOS75).

Definition of the FEV1 index Tiffno and pneumotachography with the construction of the "flow-volume" curve is advisable to conduct before and after the application of bronchodilators, as well as to assess the severity of the disease and control the course of bronchial asthma (2 times a year).

Peak fliometry

Pikfluometry is a method of measuring the maximum (peak) air volume velocity during forced exhalation (peak expiratory flow) after a full inspiration.

The peak expiratory flow rate (PEF) is closely correlated with FEV1. Portable individual peak flow meters are currently designed and widely used. Peakflowmetry is performed several times during the day, before and after taking bronchodilators. Mandatory is the measurement of PSV in the morning (immediately after the patient's recovery), then 10-12 hours later (in the evening). Peakflowmetry should be performed by a doctor during the patient's admission, and also daily by the patient himself. This allows us to say about the stability and severity of the course of bronchial asthma, to identify the factors that cause the exacerbation of the disease, the effectiveness of the therapeutic measures.

The normal values of PSV in adults can be determined using a nomogram.

For reliable bronchial asthma, the following changes in PSV are characteristic:

• increase in PSV more than 15% after 15-20 minutes after inhalation of short-acting beta2-stimulants;
• daily fluctuations PSV are 20% or more in patients receiving bronchodilators, and 10% or more in patients without bronchodilator therapy;

Daily fluctuations of PEF are determined by the following formula:

Daily variation of PSV in% (PSV day in%) = PSV max - PSV min / PSV average 100%

• decrease in PSV by 15% or more after exercise or after exposure to other triggers.

Samples using bronchodilators

Bronchodilation tests are used to determine the degree of reversibility of bronchial obstruction. Define the FEV1, the Tiffno index, the flow-volume curve (pneumotachography), and the peak flowmetry before and after using the bronchodilator. The state of bronchial obstruction is judged on the basis of the absolute increase in FEV1 (ΔOPV1isx%) "

ΔFEV1исх% = FEV1dilate (ml) -FEV1исх (ml) / FEV1ххх (ml) х 100%

Notes: FEV1dilat (ml) - the volume of forced expiration in the first second after the application of bronchodilators; FEV1 out (ml) - the volume of forced exhalation in the first second of the initial, before the use of bronchodilators.

X-ray examination of the lungs

Specific changes in X-ray examination of the lungs are not detected. During an attack of bronchial asthma, as well as with frequent exacerbations, signs of emphysema, increased transparency of the lungs, horizontal position of the ribs, widening of the intercostal spaces, low diaphragm position

With infectious-dependent bronchial asthma, an X-ray examination can reveal signs characteristic of chronic bronchitis (see the relevant chapter), pneumosclerosis.

Electrocardiographic study

During an attack of bronchial asthma, signs of increased stress on the myocardium of the right atrium are found: high pointed pins P in leads II, III, aVF, V "V" can rotate the heart around the longitudinal axis in a clockwise direction (right ventricle forward), which is manifested by the appearance of deep teeth S in the thoracic leads, including in the left. After stopping the attack, the indicated ECG changes disappear. In severe bronchial asthma, frequent exacerbations, the chronic pulmonary heart is gradually formed, which is manifested by ECG signs of myocardial hypertrophy of the right atrium and right ventricle.

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

Assessment of the gas composition of arterial blood

Determination of the gas composition of arterial blood allows more objective assessment of the severity of exacerbation of the disease, and is also necessary for asthmatic status. Pronounced bronchial obstruction (FEV1 - 30-40% of that, PSV <100 l / min) is accompanied by hypercapnia, with less pronounced obstruction determined by hypoxemia and hypocapnia.

During severe exacerbation of bronchial asthma, arterial hypoxemia is observed due to ventilation-perfusion disorders.

It is advisable to use the method of pulse oximetry, which makes it possible to determine the saturation of arterial blood with oxygen and to draw a conclusion about the effectiveness of the administration of bronchodilating agents.

[9], [10], [11], [12]

Bronchoscopy

Bronchoscopy is not a routine method of research in bronchial asthma. It is used only if differential diagnosis is necessary, usually with neoplasms of the broncho-pulmonary system.

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

Assessment of the allergic status

Evaluation of the allergic status is performed for the purpose of diagnosing the atopic (allergic) form of bronchial asthma and identifying the so-called causative allergen (the "culprit" allergen) that causes the development and exacerbation of bronchial asthma.

Allergic diagnosis is carried out only in the phase of remission of bronchial asthma, sets of various allergens are applied. The most frequently used skin tests (application, scarification and intradermal methods of using allergens). The magnitude and nature of the developing edema or inflammatory reaction are evaluated. The introduction of the "allergen-culprit" is accompanied by the most pronounced edema, hyperemia, itching. The most sensitive but less specific breakdown is the intradermal administration of the allergen. These tests do not have independent diagnostic value, but taking into account the data of the allergological history and clinical data are of great help in diagnosing bronchial asthma.

With allergic form of bronchial asthma, provocative tests based on the reproduction of allergic reactions by introducing an allergen into the shock organ are also positive. An inhalation provocative test is used, the essence of which is that the patient inhales through the inhaler first a control indifferent solution, and in the absence of reaction to it - solutions of the allergen in a consistently increasing concentration (from the minimum to the one that gives a noticeable reaction in the form of shortness of breath) . Before and after each inhalation of the allergen, a spirogram is recorded, determined by FEV1 and the Tiffno index. The provocative test is considered positive with a decrease in FEV1 and Tiffno index by more than 20% compared to the baseline values. A provocative inhalation test can be carried out only in the phase of remission in a hospital environment, the developed bronchospasm should be immediately stopped by bronchodilators.

[18], [19], [20], [21], [22]

Laboratory diagnostics of bronchial asthma

The data of laboratory studies are of great importance in confirming the diagnosis of bronchial asthma (primarily allergic form), assessing the severity and effectiveness of treatment. The most characteristic are the following changes in laboratory indicators:

• The general analysis of blood - eosinophilia, moderate increase in ESR in the period of exacerbation of bronchial asthma;
• The general analysis of sputum is a lot of eosinophils, the Charcot-Leiden crystals are determined (shiny transparent crystals in the form of rhombic or octahedra, formed with the destruction of eosinophils); Kurshman spirals (molds of transparent mucus in the form of spirals, are molds of small spastic-reduced bronchi); In patients with infectious-dependent bronchial asthma with a pronounced activity of the inflammatory process, neutral leukocytes are found in large numbers. In some patients during the attack of bronchial asthma, "Creole calves" are revealed - rounded formations, consisting of epithelial cells;
• Biochemical blood analysis - it is possible to increase the level of alpha2 and gamma globulins, sialic acids, seromucoid, fibrin, haptoglobulin (especially in infectious-dependent bronchial asthma);
• Immunological studies include an increase in the amount of immunoglobulins in the blood, a decrease in the number and activity of T suppressors (more typical of atonic asthma). With the help of a radioimmunosorbent test in atopic bronchial asthma, an increase in the amount of IgE is determined. The use of this test is especially important when it is not possible to conduct allergological testing (skin and provocative samples).

Clinical diagnosis of asthma

Diagnosis of bronchial asthma is facilitated by using the following diagnostic criteria:

• attacks of suffocation with difficulty exhaling, accompanied by dry rales over the entire surface of the lungs, which can be heard even from a distance (distant dry rales);
• equivalents of a typical attack of bronchial asthma: paroxysmal cough at night, disturbing sleep; resurgent wheezing; difficulty breathing or feeling tight in the chest; the appearance of cough, wheezing, or wheezing at a certain time of the year, in contact with certain agents (animals, tobacco smoke, perfume products, exhaust gases, etc.) or after physical exertion;
• the detection of an obstructive type of respiratory failure in the study of parameters of the function of external respiration (decrease in FEV1 of the Tiffno index, peak expiratory flow rate, maximum volumetric expiratory flow rate at the level of 50-75% FVC-MOS50, MOS75 in the analysis of the "flow-volume" loop;
• daily variability of peak expiratory flow rate (20% or more in patients receiving bronchodilators, 10% or more without bronchodilators);
• disappearance or significant relief of breathing and an increase in FEV1 by 20% or more after the application of bronchodilators;
• the presence of a biological marker of bronchial asthma - a high level of nitrogen oxide (NO) in the exhaled air.

Diagnosis of clinical and pathogenetic variants of bronchial asthma according to GB Fedoseev (1996) is presented below.

[23], [24], [25], [26], [27]

Diagnostic criteria for atopic bronchial asthma

1. Allergic anamnesis. Hereditary predisposition: detection of the nearest relatives of bronchial asthma or other allergic diseases. Allergic constitution: development of allergic diseases (exudative diathesis in childhood, allergic rhinitis, urticaria, Quincke edema, neurodermatitis) in the patient at different periods of life (except asthma). Pollen allergy: the association of exacerbations of bronchial asthma with the season of flowering of grasses, shrubs, trees, the appearance of attacks of suffocation in the forest, field. Dust allergy: to house dust (allergens of fluff, feather, pet hair, human epidermis, Dermatophagoides mite); deterioration of breathing during apartment cleaning, work with books, papers; improvement of well-being at work or changing the situation. Food allergies are associated with certain foods (strawberries, honey, crabs, chocolate, potatoes, milk, eggs, fish, citrus fruits, etc.), exacerbations are often accompanied by recurrent urticaria, migraine, constipation; in the anamnesis the communication of attacks of a dyspnea with the use in writing of the specified products. Drug allergies: intolerance to certain drugs (penicillin and other antibiotics, sulfonamides, novocaine, vitamins, iodine preparations, vaccines, serums, etc.), which is manifested by attacks of suffocation, skin rashes, and sometimes anaphylactic shock. Professional allergy: the appearance of attacks of suffocation at work in contact with a professional allergen, improving the state of health at home, on vacation.
2. Primarily young age (75-80% of patients under the age of 30 years).
3. Positive skin tests with certain allergens.
4. Positive provocative tests (nasal, conjunctival, inhalation) on certain allergens (conducted according to strict indications).
5. Identification of a specific food allergen by keeping a diary, observing an elimination diet followed by provocation.
6. Laboratory criteria: elevated blood levels of IgE; increased content in the blood and sputum of eosinophils; Shelley's basophilic test (study of the morphological changes in basophils as a result of interaction between the patient's blood serum and a specific allergen); positive reaction of alteration of neutrophils of a patient with an allergen; increased glycogenolysis in lymphocytes under the influence of adrenaline in the presence of an allergen; increasing the viscosity of phlegm under the influence of an allergen; revealing the features of erythrocytes (more than 11% of microcytomas, an increase in the number of hemolyzed erythrocytes in the hypotonic solution with obzidanom).

[28], [29], [30], [31]

Diagnostic criteria of infectious-dependent bronchial asthma

1. Clinical examination: complaints, anamnesis, objective data indicating the association of bronchial asthma with a respiratory infection, acute bronchitis, influenza, pneumonia, exacerbation of chronic bronchitis or chronic pneumonia.
2. General blood test: leukocytosis, increased ESR.
3. Biochemical analysis of blood: the appearance of PSA, an increase in sialic acids, alpha2 and gamma globulins, seromucoid, haptoglobin, the activity of sialic acids.
4. General sputum analysis: mucopurulent, in the smear is dominated by neutrophilic leukocytes, the detection of pathogenic bacteria in the diagnostic titer.
5. Radiography of the lungs in 3 projections, according to the indications bronchography, tomography, radiography of the paranasal sinuses: detection of infiltrative shadows in pneumonia, signs of local or diffuse pneumosclerosis, blackout of the paranasal sinuses.
6. Fibrobronchoscopy with the study of the contents of the bronchi: signs of inflammation of the mucous membrane, a thick muco-purulent secret, the predominance of non-schrophilic leukocytes in the washings of bronchial tubes, the detection of pathogenic bacteria of pneumococcus, staphylococcus and others with quantitative counting and determination of sensitivity to antibiotics.
7. Determination of bacterial sensitization (intradermal tests with bacterial allergens, cellular diagnostic methods, provocative tests): positive samples with appropriate bacterial allergens (local and general reactions).
8. Mycological examination of sputum: sowing from sputum, urine, feces, fungi and yeast of the genus Candida.
9. Virological research: detection of viral antigens in the epithelium of the nasal mucosa by the method of immunofluorescence, serodiagnosis, high titers of antibacterial and antiviral antibodies in the blood.
10. . Consultation of otorhinolaryngologist, dentist: detection of foci of infection in the upper respiratory tract, nasopharynx and oral cavity.

[32], [33], [34]

Diagnostic criteria for glucocorticoid insufficiency

1. Clinical observation and detection of glucocorticoid insufficiency: no effect with long-term treatment with glucocorticoids, corticostependence, the appearance of skin pigmentation, the tendency to arterial hypotension, deterioration of the state (sometimes the development of an asthmatic condition) with the abolition of prednisolone or a decrease in dose.
2. Reduction in the blood cortisol, 11-ACS, a decrease in urinary excretion of 17-ACS, an inadequate increase in urinary excretion of 17-ACS after administration of adrenocorticotropic hormone, a decrease in the number of glucocorticoid receptors on lymphocytes.

[35], [36], [37]

Diagnostic criteria of the disovarial variant of bronchial asthma

1. Deterioration of the patient's condition before or during the menstrual cycle, due to pregnancy and during menopause.
2. Cytological examination of the vaginal smear: signs of a decrease in the content of progesterone (inferiority of the second phase of the cycle or anovulation).
3. Measurement of basal (rectal) temperature: decrease in the second phase of the menstrual cycle.
4. Radioimmunological determination of estrogens and progesterone in the blood plasma: an increase in the content of estrogens in the second phase of the menstrual cycle, a violation of the ratio of estrogens / progesterone.

Diagnostic criteria for the autoimmune form of bronchial asthma

1. Severe, continuously recurring course of the disease (with the exclusion of other causes of the severity of the disease).
2. Positive intradermal test with autolymphocytes.
3. High level of acid phosphatase in the blood.
4. Positive RBTL with phytohemagglutinin.
5. Reduction in the blood level of complement and the identification of circulating immune complexes, anti-pulmonary antibodies.
6. The presence of severe, often disabling complications of glucocorticoid therapy.

[38], [39], [40], [41]

Diagnostic criteria for adrenergic imbalance

1. Clinical observation - the identification of factors contributing to the formation of adrenergic imbalance: excessive use of sympathomimetics, viral infection, hypoxemia, acidosis, endogenous gaperkateholaminemia due to stressful situation, transformation of asthma attack to asthmatic status.
2. The paradoxical effect of sympathomimetics is an increase in bronchospasm in their use.
3. Laboratory and instrumental diagnostics:
   • functional examination of bronchial patency before and after inhalation of selective beta2-adrenomimetics: no increase or decrease in FVC, expiratory flow after inhalation of sympathomimetic;
   • decrease in the degree of hyperglycemic response to adrenaline, the emergence of paradoxical reactions (decrease in glucose in response to the introduction of adrenaline);
   • Eosinopenic test with adrenaline: decreased eosinopenic response to adrenaline (the absolute number of eosinophils per 1 mm ^{3 of} blood decreases in response to adrenaline administration by less than 50%);
   • glycogenolysis of lymphocytes: decrease in the degree of glycogenolysis in lymphocytes after incubation with adrenaline.

[42], [43]

Diagnostic criteria of the neuropsychiatric variant of bronchial asthma

1. Detection of neuropsychic disorders in the premorbid period, in the course of the development of the disease, according to anamnesis - the psychological characteristics of the individual; presence in the anamnesis of mental and craniocerebral injuries, conflict situations in the family, at work, disorders in the sexual sphere, iatrogenic effects, diencephalic disorders.
2. Clarification of the neuropsychological pathogenetic mechanisms (produced by a psychotherapist) is determined by a hysterical, neurasthenic, psihastenopodobnye mechanisms that contribute to the occurrence of attacks of suffocation.

[44], [45], [46], [47], [48],

Diagnostic criteria of the vagotonic (cholinergic) variant of bronchial asthma

1. Disturbance of bronchial patency mainly at the level of large and medium bronchi.
2. Bronchorea.
3. High effectiveness of inhalation anticholinergics.
4. Systemic manifestations of vagotonia are a frequent combination with duodenal ulcer, hemodynamic disorders (bradycardia, hypotension), marbling of the skin, sweating of the palms.
5. Laboratory features: high blood levels of acetylcholine, a significant decrease in serum cholinesterase activity, an increase in the content of cyclic guanosine monophosphate in the blood and urine.
6. Detection of the predominance of the tone of the parasympathetic nervous system by the method of variational pulsometry.

[49],

Diagnostic criteria of primary-altered bronchial reactivity

1. Clinical observations - the emergence of attacks of suffocation after physical exertion, with the inhalation of cold or hot air, weather change, from sharp odors, tobacco smoke in the absence of evidence of the leading role of other pathogenetic mechanisms that generate altered reactivity.
2. Decrease in bronchial patency, according to spirography and peakflowmetry, cold air samples, acetylcholine, PgF2a, obzidan.
3. Positive acetylcholine test. Immediately before the test, solutions of acetylcholine are prepared at concentrations of 0.001%; 0.01%; 0.1%; 0.5% and 1%, and determine FEV1 and the Tiffno index. Then, using an aerosol inhaler, the patient inhales the aerosol acetylcholine at the highest dilution (0.001%) for 3 minutes (if the patient begins coughing earlier 3 minutes - the inhalation is stopped earlier).

After 15 minutes, assess the patient's condition, produce auscultation of the lungs and determine FEV1 and the Tiffno index. If clinical and instrumental findings of bronchial obstruction are not detected, repeat the study with the following breeding. The test is considered positive if the Tiffno index falls by 20% or more. Even the reaction to a 1% solution is considered as positive. A positive acetylcholine test is pathognomonic for all forms of bronchial asthma.

In some cases, an inhalation histamine test is used to determine the hyperreactivity of the bronchi. In this case, the concentration of histamine <8 mg / ml, leading to a decrease in FEV1 <20%, indicates the presence of bronchial hyperreactivity.

[50]

Diagnostic criteria for "aspirin" asthma

A clear connection of an asthmatic attack with the use of aspirin or other non-steroidal anti-inflammatory drugs, as well as proprietary prescriptions containing acetylsalicylic acid (theofedrine, citramone, ascofen, etc.), products containing salicylates, and yellow food color tartrazine, and any yellow tablets (they contain tartrazine).

Analysis of the features of an attack of "aspirin" asthma. The attack of suffocation occurs within an hour after taking aspirin and is accompanied by an abundant separation of mucus from the nose, lacrimation, hyperemia of the upper half of the trunk. During an attack of suffocation, nausea, vomiting, hypersalivation, pain in the epigastric region, lowering blood pressure (sometimes to very low digits) may occur. With the passage of time, bronchial asthma acquires peculiar features: the seasonality disappears, the symptoms of asthma disturb the patient constantly, the interictal period is accompanied by a feeling of "stuffiness" in the chest, bronchodilator therapy is less effective than before, bronchial asthma gradually takes a progressive course.

The presence of an asthmatic triad, which includes:

1. "Aspirin" asthma (usually with a severe progressive course);
2. intolerance to aspirin and other non-steroidal anti-inflammatory drugs (headache, pressure in the temples, increased rhinorrhea, sneezing, lacrimation, injection sclera);
3. rhinosinusitis and recurrent polyposis of the nose (radiography of the paranasal sinuses reveals rhinosinusopage).

Positive diagnostic test AG Chuchalina - the determination of the blood content of various groups of prostaglandins against the background of taking a provocative dose of indomethacin. In patients with "aspirin" asthma and asthmatic triad, the PgR content increases as PgE decreases, while in other forms of bronchial asthma the prostaglandin level of both groups decreases.

Positive provocative test with acetylsalicylic acid. The test is started after a negative reaction to the "aspirin-placebo" (0.64 g of white clay) is obtained. Then the patient takes acetylsalicylic acid in the following doses:

1st day - 10 mg; 2nd day - 20 mg; 3rd day - 40 mg; Day 4 - 80 mg; Day 5 - 160 mg; Day 6 - 320 mg; The 7th day - 640 mg. After 30, 60 and 120 minutes after taking acetylsalicylic acid, the objective sensations of the patient, the auscultation of the lungs and the FEV1 are analyzed.

A provocative test is considered positive when the following symptoms appear:

• sensation of suffocation;
• obstruction of nasal breathing;
• rhinorrhea;
• lacrimation;
• decrease in FEV1 by 15% or more from the baseline.

Dahlen and Zetteistorm (1990) proposed an inhalation provocation test with lysine-acetylsalicylic acid for the diagnosis of aspirin asthma. In this case, the dose of the drug is increased every 30 minutes, the entire sample lasts several hours.

[51],

Diagnostic criteria for asthma physical effort

Asthma physical effort (postnagruzochny bronchospasm) is rarely found in isolation, but mostly against the background of other pathogenetic variants of bronchial asthma. Asthma physical effort is observed more often in children than in adults. The main diagnostic criteria for asthma physical effort are:

• indications in the anamnesis for a clear connection of an attack of suffocation with physical exertion, and unlike usual bronchial asthma or obstructive bronchitis, the attack of suffocation does not occur during exercise, but within the next 10 minutes after its end ("postnagruzochny bronchospasm");
• more frequent connection of an attack of asthma with certain types of physical exercises - running, playing football, basketball; less dangerous lifting of weights, well-tolerated swimming;
• positive provocative test with physical activity.

The sample is performed in the absence of contraindications - heart failure, IHD, arterial hypertension (above 150/90 mmHg), cardiac rhythm and conduction disorders, cerebral blood flow disorders, throat phlebitis of the shins of the shins, high degree of myopathy. Within 12 hours before the study, the patient should not take bronchodilators and intala (or tileeds). Indicators of bronchial patency are measured before and after the end of the test.

During the sample with physical activity, it is necessary to fulfill the following requirements for its standardization:

• the intensity of exercise should be such as to cause an increase in the heart rate to 85% of the maximum heart rate, calculated by the formula: HRMSax = 209 - 0.74 x age in years;
• the duration of the load is -10 minutes;
• physical load is carried out using veloergometry or treadmill (treadmill), the form of the load is stepwise increasing;
• indicators of bronchial patency are determined before and after 5, 30, 60 minutes after its termination.

The most informative for the diagnosis of asthma physical effort is to determine the indicators of the "flow-volume" curve. An easy degree of asthma physical effort is characterized by a deterioration in the flow-volume curve by 15-30%, a severe degree by 40% or more.

If it is not possible to carry out a rigorous standardization of the test, a simpler test can be carried out, which is recommended by VI Pytsky and co-workers. (1999). It is performed as follows. The initial pulse rate and expiratory power are recorded using pneumotachometry or spirography. Then the physical load is given - free running or squats until the pulse rate reaches 140-150 / min. Immediately after the end of the exercise and after 5, 10, 15 and 20 minutes, a physical examination is again performed and the power (speed) of exhalation is determined. If the exhalation power is reduced by 20% or more, the test is considered positive, i.e. Indicates an asthma of physical effort.

[52],

Differential diagnosis of bronchial asthma

[53], [54], [55],

Chronic obstructive bronchitis

Most often bronchial asthma must be differentiated from chronic obstructive bronchitis. Essential help in this regard can be provided by the list of diagnostic reference signs of chronic bronchitis according to Vermeire (quoted by A. L. Rusakov, 1999):

• the actual bronchial obstruction is a decrease in FEV1 <84% and / or a decrease in the Tiffno index <88% of the expected values;
• irreversibility / partial reversibility of bronchial obstruction, variability (spontaneous variability) of FEV1 values during the day <12%;
• Stably confirmed bronchial obstruction - at least 3 times during a yearly observation;
• age, as a rule, is more than 50 years;
• frequently detected functional or radiographic signs of pulmonary emphysema;
• smoking or exposure to industrial aerosolutions;
• progression of the disease, which is manifested in increasing dyspnea and a steady decline in FEV1 (annual decrease by more than 50 ml).

[56], [57], [58], [59], [60], [61], [62]

Tracheobronchial dyskinesia

The syndrome of tracheobronchial dyskinesia is the expiratory collapse of the trachea and large bronchi due to the prolapse of a thin and dilated membrane wall partially or completely overlapping the lumen of the trachea and major bronchi during the exhalation phase or during coughing. Features of the clinical picture of tracheobronchial dyskinesia - a cough that is prone in appearance and expiratory dyspnea. Coughing attacks are caused by physical activity, laughter, sneezing, acute respiratory viral infection, sometimes abrupt transition from a horizontal position to a vertical one. Cough has a bitonal character, sometimes a rattling, nasal hue. Coughing attacks cause short-term dizziness, darkening in the eyes, a brief loss of consciousness. During a fit of cough, there is a pronounced dyspnea of expiratory type, down to choking.

Diseases that cause obturation and compression of the bronchi and trachea

Significant difficulties in breathing, especially exhalation, can occur when the trachea and large bronchi are compressed (compressed) by benign and malignant tumors, sharply enlarged lymph nodes, and aortic aneurysm. Tumors can cause obturation of the bronchus with growth in the lumen of the bronchus.

In the differential diagnosis of bronchial asthma, it should be noted that in the above situations, auscultatory symptoms (wheezing dry wheezes, sharply elongated exhalation) are observed in one side, and not over the entire surface of the lungs, as in bronchial asthma. It is also necessary to analyze the clinical symptoms characteristic of diseases that cause occlusion or compression of the trachea and bronchi (bronchus cancer, lymphogranulomatosis, lymphatic leukemia, mediastinal tumor, aortic aneurysm). The mediastinal tumor is characterized by the syndrome of the superior vena cava (cyanosis and swelling of the neck and face, swelling of the cervical veins). To clarify the diagnosis bronchoscopy, x-ray tomography of the mediastinum, computed tomography of the lungs are performed.

[63],

Carcinoid

Carcinoid is a tumor of APUD-system, consisting of cells producing serotonin, bradykinin, histamine, prostaglandins. Usually, the tumor is localized in the gastrointestinal tract, in 7% of cases - in the bronchi. With bronchial carcinoid localization, a clinic of bronchospasm appears. In contrast to bronchial asthma, with carcinoid syndrome, along with bronchospasm, there are blood tides with pronounced reddening of the face, venous telangiectasias, profuse diarrheas, endocardial fibrosis of the right heart with the formation of tricuspid valve failure (diagnosed with echocardiography), urinary excretion of a large number of 5- hydroxyindoleacetic acid - a product of the metabolism of seratonin.

[64], [65], [66], [67]

Cardiac asthma

Cardiac asthma is a manifestation of severe left ventricular failure.

[68], [69], [70]

Pulmonary embolism

With thromboembolism of the pulmonary artery (PE), there is suddenly a feeling of lack of air and pronounced dyspnea, with auscultation determined dry wheezes, which causes differentiation of PE and bronchial asthma.

Violations of the nervous regulation of respiration

In patients suffering from neuroses, hysteria, especially in women, often have attacks of dyspnea, which makes it differentiate with bronchial asthma. As a rule, patients suffering from neurogenic breathing disorders, associate a feeling of lack of air and shortness of breath with an acute psychoemotional stressful situation, often are very neurotic. The main diagnostic sign that distinguishes neurotic or hysterical asthma from bronchial asthma is the absence of wheezing in auscultation of the lungs.

Foreign body of trachea or bronchi

When you get into the trachea or bronchi foreign body, there is an attack of suffocation, which can resemble an attack of bronchial asthma. However, in the presence of a foreign body, a strong cough, cyanosis appears in the airways; At the same time, wheezing is not heard in auscultation of the lungs. In the formulation of the correct diagnosis, anamnestic data and bronchoscopy are helpful.

[71], [72], [73], [74], [75]

Syndrome of bronchial obstruction in parasitic invasions

Bronchial obstruction may be accompanied by invasion of ascarids, hookworms, schistosomes, filarias and other parasites. The characteristic signs in the broncho-obstructive syndrome of parasitic etiology are pronounced eosinophilia of blood and sputum, pulmonary infiltrates, detection of helminth eggs during coprologic examination. It is also necessary to take into account the relevant clinical symptoms of parasitic invasion and quite often the disappearance of the bronchial obstruction syndrome after successful dehelminthization.

Reflux-induced bronchial asthma

Reflux-induced bronchial asthma are attacks of suffocation caused by aspiration of gastric contents due to gastroesophageal reflux. The attack of asphyxia associated with aspiration of gastric contents was first described by Oder in 1892.

The prevalence of gastroesophageal reflux disease (GERD) among the US population and in a number of European countries is 20-40%, and among patients with bronchial asthma this figure reaches 70-80% (Stanley, 1989). The main factors of the pathogenesis of GERD are a decrease in the tone of the lower esophageal sphincter, increased intragastric pressure, a decrease in the peristalsis of the esophagus, and a slowdown in the esophageal clearance.

The pathogenesis of bronchial asthma arising from the background of GERD is associated with the following factors (Goodall, 1981):

• development of bronchospasm due to casting (microaspiration) of gastric contents into the lumen of the bronchial tree;
• stimulation of vagal receptors of the distal part of the esophagus and induction of bronchoconstriction reflex.

Clinical features of bronchial asthma arising from GERD are:

• occurrence of an attack of suffocation mainly at night;
• presence of concomitant clinical manifestations of GERD: heartburn, belching, regurgitation, pain in the epigastrium or behind the breastbone, while passing food through the esophagus;
• the appearance or intensification of attacks of suffocation, as symptoms of GERD, under the influence of abundant food, horizontal position after eating, taking medications that damage the mucous membrane of the stomach and esophagus, physical activity, flatulence, etc .;
• prevalence of symptoms of bronchial asthma over other manifestations of GERD.

Nighttime bronchial asthma

Night bronchial asthma is the occurrence of asthma attacks in patients with bronchial asthma in the night or early morning hours.

According to Turner-Warwick (1987), one-third of patients with bronchial asthma suffer from night attacks of suffocation.

The main pathogenetic factors of nocturnal bronchial asthma are:

• increased contact of the patient with bronchial asthma with aggressive allergens at night (high concentration of spore fungi in the air on warm summer nights, contact with bedding containing allergens - pillow feather, ticks - dermatophagoids in mattresses, blankets, etc.);
• the maximum synthesis of IgE-antibodies (reactans) in the period from 5 to 6 am;
• the influence of gastroesophageal reflux at night;
• the influence of the horizontal position (in the horizontal position and during sleep, the mucociliary clearance worsens, the tone of the vagus nerve increases and, consequently, its bronchoconstrictor effect);
• the presence of circadian rhythms of changes in bronchial patency (maximum bronchial patency is observed from 13 to 17 hours, the minimum - from 3 to 5 am;
• daily fluctuations in barometric pressure, relative humidity and air temperature. The respiratory ways of patients with bronchial asthma are hypersensitive to a decrease in ambient temperature at night;
• circadian rhythm of cortisol secretion with a decrease in its level in the blood at night;
• decrease in blood concentrations of catecholamines, cAMP and beta 2-adrenoreceptor activity at night and early morning hours;
• the presence of the syndrome of nocturnal sleep apnea, especially obstructive form, promotes the development of bouts of nocturnal bronchial asthma.

Survey program

1. The general analysis of a blood, urine, a feces (including on eggs of helminths).
2. Biochemical blood test: determination of the content of total protein, protein fractions, seromukov, haptoglobin, fibrin, C-reactive protein.
3. Immunological analysis of blood: the content of B- and T-lymphocytes, subpopulations of T-lymphocytes, immunoglobulins, circulating immune complexes, complement, determination of the functional activity of T-lymphocytes.
4. Sputum analysis: cellular composition, Charcot-Leiden crystals, Kurshman spirals, atypical cells, Koch bacilli.
5. X-ray of the lungs (according to the indications - radiography of the paranasal sinuses).
6. Spirography, determination of indicators of the volume-flow curve (pneumotachography), peakflowmetry.
7. Consultations of an allergist, otorhinolaryngologist, dentist.
8. FGDS (in the phase of remission, according to indications - in the presence of a clinic that allows to suspect gastroesophageal reflux disease).
9. ECG.
10. The setting in an off-trial period of samples with allergens, and according to indications - provocative samples and research.

Formulation of the diagnosis

When formulating the diagnosis of bronchial asthma, it is advisable to consider the following provisions:

• call the form of bronchial asthma according to ICD-X (allergic, non-allergic, mixed, unspecified genesis). It should be noted that the classification of bronchial asthma Professor G. B. Fedoseev can also be used in the formulation of the diagnosis of bronchial asthma, as it successfully classifies clinico-pathogenetic variants and actually clearly determines which forms of bronchial asthma should be attributed to non-allergic bronchial asthma;
• To specify, to what allergen there is a sensibilization at an allergic form of a bronchial asthma;
• reflect the severity and phase of bronchial asthma (exacerbation, remission);
• indicate concomitant diseases and complications of bronchial asthma.

Examples of the formulation of the diagnosis of asthma

1. Bronchial asthma, allergic form (sensitization to house dust), mild episodic course, DN0, remission phase. Allergic rhinitis.
2. Bronchial asthma, non-allergic form (infectious-dependent), severe course, exacerbation phase. Chronic purulent-catarrhal obstructive bronchitis. Emphysema of the lungs. DNIIst

From the examples given, it is clear that for clinical and practical purposes it is expedient to use the classification of G. B. Fedoseyev, for statistical reporting - the ICD-X classification.

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