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Chronic bronchitis - Diagnosis
Last reviewed: 06.07.2025

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Laboratory data
- General blood analysis without significant changes. In case of severe exacerbation of chronic purulent bronchitis, slight neutrophilic leukocytosis and moderate increase in ESR are possible.
- Sputum analysis is a macroscopic examination. Sputum may be mucous (white or transparent) or purulent (yellow or yellow-green). If there is a small admixture of pus to the mucus, the sputum is considered mucopurulent. Black sputum may be present if it contains coal dust particles. Blood streaks are characteristic of hemorrhagic bronchitis. Sometimes mucous and purulent plugs and bronchial casts are found in sputum. Fibrinous bronchitis is characterized by the presence of casts, "bronchial dummies", in the sputum. N. V. Syromyatnikova and O. A. Strashinina (1980) suggest determining the rheological properties of sputum, its viscosity and elasticity. The rheological properties of sputum depend on the content of protein, fibrin, sialic acids, nucleic acids, immunoglobulins, and cellular elements. Purulent sputum is characterized by increased viscosity and decreased elasticity, while mucous sputum is characterized by decreased viscosity and increased elasticity.
Microscopic examination of purulent sputum reveals a large number of neutrophilic leukocytes, often bronchial epithelial cells, macrophages, and bacterial cells. Bacteriological examination of sputum reveals various types of infectious agents and their sensitivity to antibacterial agents. The most reliable results are those of bacteriological examination of sputum obtained during bronchoscopy (aspirates and bronchial washings).
Biochemical blood test. Based on the determination of biochemical indicators of the activity of the inflammatory process, its severity is judged.
Instrumental research
Bronchoscopy. Bronchoscopically, diffuse and limited bronchitis and the degree of bronchial inflammation are distinguished. In diffuse bronchitis, the inflammatory process extends to all endoscopically visible bronchi - main, lobar, segmental, subsegmental. Primary chronic bronchitis is characterized by diffuse bronchial damage. Partial diffuse bronchitis is characterized by the fact that the upper lobe bronchi are intact, while the remaining bronchi are inflamed. In strictly limited bronchitis, the inflammation affects the main and lobar bronchi, and the segmental bronchi of the upper and lower lobes are unchanged.
The intensity of inflammation is assessed as follows.
- Stage I - the mucous membrane of the bronchi is pale pink, covered with mucus, does not bleed. Translucent vessels are visible under the thinned mucous membrane.
- Stage II - the mucous membrane of the bronchi is bright red, thickened, often bleeds, covered with pus.
- Grade III - the mucous membrane of the bronchi and trachea is thickened, purple-blue in color, bleeds easily, covered with purulent secretion.
Bronchography should be performed after the bronchial tree has been sanitized, otherwise signs such as rupture, thinning, and deformation of the bronchi may not be due to true changes, but to the accumulation of thick, viscous secretions in the bronchi.
The most common bronchographic symptoms of chronic bronchitis are the following:
- bronchi of the IV, V, VI, VII orders are cylindrically dilated, their diameter does not decrease towards the periphery, as is normal; lateral branches are obliterated, the distal ends of the bronchi are blindly torn off (amputated);
- In a number of patients, the dilated bronchi are narrowed in certain areas, their contours are altered (the shape of “rosary beads”), the internal contour of the bronchi is jagged, and the architecture of the bronchial tree is disrupted.
Bronchoscopy and bronchography are not mandatory methods of examination for chronic bronchitis; they are usually used for differential diagnostics with other bronchopulmonary diseases (tuberculosis, bronchocarcinoma, congenital anomalies, bronchiectasis, etc.). Preference is given to fibrobronchoscopy; in necessary cases, a biopsy of the bronchial mucosa is performed.
X-ray and radiography of the lungs. X-ray signs of chronic bronchitis are detected only in those who have been ill for a long time, and are characterized by an increase and deformation of the pulmonary pattern according to the loop-cell type, an increase in the transparency of the pulmonary fields, and an expansion of the shadows of the roots of the lungs. In some cases, thickening of the bronchial walls can be seen due to peribronchial pneumosclerosis.
Study of the function of external respiration. Spirometry, as well as pneumotachometry, peak flowmetry do not reveal any disturbances of bronchial patency in chronic non-obstructive bronchitis. However, approximately 30% of patients show an increase in the residual volume of the lungs, a decrease in MOC w and MOC„ (maximum volumetric velocity at the level of 50 or 75% of forced vital capacity) with normal values of vital capacity and peak volumetric velocity.
Blood gas composition study. In chronic non-obstructive bronchitis, blood gas composition disorders are usually not observed; in severe clinical presentation, especially during exacerbation, moderate arterial hypoxemia is possible due to disturbances in gas exchange conditions in the lungs due to regional changes in the ratio of alveolar ventilation and pulmonary blood flow.
The above changes in the parameters of external respiration and blood gas composition indicate damage to predominantly the peripheral parts of the bronchi, instability of their lumen and decreased elasticity of the lungs.
Diagnostics
The following can be considered diagnostic criteria for chronic bronchitis:
- 1. Persistent cough with sputum production for at least 3 months over 2 or more consecutive years (WHO criteria). If the duration of productive cough does not meet the WHO criteria and the cough recurs repeatedly, the following situations should be considered:
- • smoker's cough;
- • cough as a result of irritation of the respiratory tract by industrial hazards (gases, vapors, fumes, etc.);
- • cough due to pathology of the nasopharynx;
- • prolonged or recurrent course of acute bronchitis;
- • respiratory discomfort and cough due to contact with volatile irritants;
- • a combination of the above factors. All of the above conditions are called “prebronchitis” by the Institute of Pulmonology of the Russian Academy of Medical Sciences.
- A typical auscultatory picture is coarse, hard, vesicular breathing with prolonged exhalation, scattered dry and moist rales.
- Inflammatory changes in the bronchi according to bronchoscopy data (the method is used primarily for differential diagnostics).
- Exclusion of other diseases that manifest as a long-term productive cough, i.e. bronchiectasis, chronic lung abscess, tuberculosis, pneumoconiosis, congenital pathology of the bronchopulmonary system, cardiovascular diseases that occur with blood stagnation in the lungs.
- Absence of bronchial patency disorders during examination of external respiratory function.
Diagnosis of exacerbation
The following signs indicate an active inflammatory process in the bronchi:
- increased general weakness, appearance of malaise, decreased overall performance;
- the appearance of severe sweating, especially at night (the “wet pillow or sheet” symptom);
- increased cough;
- increase in the amount and “purulence” of sputum;
- subfebrile body temperature;
- tachycardia at normal temperature;
- the appearance of biochemical signs of inflammation;
- a shift in the leukocyte formula to the left and an increase in ESR to moderate figures;
- increased activity of alkaline and acid phosphatases of leukocytes (cytochemical study).
Differential diagnosis
Chronic non-obstructive bronchitis should be differentiated from:
- acute protracted and recurrent bronchitis; protracted acute bronchitis is characterized by the presence of symptoms for more than 2 weeks, recurrent acute bronchitis is characterized by repeated but short-term episodes of the disease three times a year or more. Thus, protracted and recurrent acute bronchitis does not meet the time criteria for chronic bronchitis proposed by WHO;
- bronchiectasis (especially when coughing up purulent or mucopurulent sputum); bronchiectasis is characterized by the appearance of a cough from early childhood, the discharge of a large amount of purulent sputum ("full mouth"), the connection of sputum secretion with a certain body position, thickening of the terminal phalanges in the form of "drumsticks" and nails in the form of "watch glasses", local purulent endobronchitis during fibrobronchoscopy, detection of bronchial dilations during bronchography;
- tuberculosis of the bronchi - it is characterized by symptoms of tuberculosis intoxication (night sweats, anorexia, weakness, subfebrile body temperature), hemoptysis, absence of "purulence" of sputum, presence of Koch's bacilli in sputum and bronchial washings, family history of tuberculosis, positive tuberculin tests, local endobronchitis with scars and fistulas during fibrobronchoscopy, positive effect from treatment with tuberculostatic drugs;
- bronchial cancer - it is more common in male smokers and is characterized by a hacking cough with blood, atypical cells in the sputum, and in advanced stages - chest pain, emaciation, hemorrhagic exudative pleurisy. Fibrobronchoscopy and biopsy of the bronchial mucosa play a decisive role in the diagnosis of bronchial cancer;
- expiratory collapse of the trachea and large bronchi (tracheobronchial dyskinesia), with expiratory stenosis due to prolapse of the membranous part. The basis of clinical diagnosis is cough analysis. Its characteristic features are: dry, paroxysmal, "trumpet-like", "barking", "rattling", rarely - bitonal; provoked by sharp bends, turns of the head, forced breathing, laughter, cold, straining, physical exertion; accompanied by dizziness, sometimes fainting, urinary incontinence, a feeling of suffocation. During forced exhalation, a characteristic "notch" is visible on the spirogram. The diagnosis is clarified by fibrobronchoscopy. M. I. Perelman (1980) identifies three degrees of expiratory stenosis: 1 degree - narrowing of the lumen of the trachea or large bronchi by 50%, 2 degree - up to 2/3, 3 degree - more than 2/3 or complete occlusion of the lumen of the trachea.