Tests for acute and chronic bronchitis: blood, sputum and urine tests

Bronchitis is a common serious inflammatory disease of the respiratory system affecting the bronchial tree. Traditionally, it can occur as a complication after the invasion of a viral or bacterial infection. By duration, bronchial inflammation is classified as acute and chronic. Symptoms of acute catarrhal bronchitis progress from several days to 1 month. Signs of the disease are identical to the symptoms of ENT diseases affecting the upper segments of the respiratory system. A characteristic feature of chronic bronchitis is a dry or sputum-producing obsessive cough that does not stop for a long time. This type of bronchitis can be provoked by smoking or a non-infectious irritant. To determine the cause of the inflammatory process in the bronchial tree, the patient should undergo a thorough examination and the necessary tests.

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Indications for the procedure

The basis for conducting tests when there is a suspicion of an inflammatory process in the bronchi is the presence of a corresponding clinical picture:

• prolonged cough (dry or wet);
• pain in the sternal region when coughing;
• feverish state;
• symptoms of intoxication.

To confirm or refute a preliminary diagnosis of bronchitis, the doctor prescribes an analysis of characteristically changing blood parameters, sputum culture and microscopy, and urine testing.

What tests should be taken for bronchitis?

When diagnosing acute bronchitis, doctors recommend:

• general blood and urine tests;
• blood biochemical test results;
• sputum bacterioscopy;
• sputum culture with determination of the sensitivity of the infectious agent to antimicrobial drugs;
• determination of the gas composition of arterial blood.

Tests for bronchitis in adults

From a wide range of studies, adult patients with inflammation of the bronchial tree are prescribed the following:

• Clinical blood test.
• General urine analysis.
• Blood biochemistry.
• Bacteriological analysis of sputum.
• Serological tests to detect antibodies to various disease agents.

In adults with acute bronchitis of bacterial genesis, the general capillary blood test results show a high content of neutrophils, indicating inflammation, and the ESR increases several times. The concentration of gamma globulins, alpha globulins, and proteins increases in venous blood. Hypoxemia develops with an increased concentration of oxygen in the gas composition of the blood. Serological studies can detect various titers of antibodies to mycoplasma, viruses, and bacteria. With a long course of purulent chronic bronchitis, a positive CRP (C-reactive protein) is determined.

If bronchitis is of allergic genesis, the level of leukocytes remains within the normal range. The content of neutrophils and lymphocytes does not exceed the limit of standard normal values, provided that the patient does not have concomitant chronic diseases. ESR is moderately elevated. The number of eosinophils increases. Biochemical analysis records an increase in the level of seroglycoids and sialic acids.

The indicators of microscopic examination of sputum will differ for different types of bronchitis. Acute catarrhal bronchitis (Bronchitis catarrhalis acuta) is characterized by mucus of a jelly-like consistency. It contains neutrophilic granulocytes and epithelial cells. The localization of the inflammation site is determined by the type and size of the observed epithelial cells of the bronchial tree. If large ciliated epithelial cells appear in the material, this indicates that the inflammation site is in the main bronchi or lower segments of the trachea. The detection of medium-sized epithelial cells indicates an inflammatory process in the middle bronchi with a diameter of 2-5 mm. If the infection affects small bronchi, small epithelial cells are observed in the sputum. In case of inflammation of the bronchioles, small epithelial cells are detected in the material under study and Curschmann's spirals (dense strands of mucus) are found.

Acute catarrhal-purulent bronchitis is characterized by the presence of purulent-mucous exudate, moderately viscous in consistency with an increased concentration of leukocytes and a relatively small content of epithelial cells.

In acute purulent bronchitis, a high leukocyte concentration is detected. Epithelial cells are not visualized, the presence of single erythrocytes may be noted.

All types of acute bronchitis are characterized by inflammation of the bronchial mucosa with the formation of a fibrinous film that separates from the walls and is evacuated from the lungs along with sputum in the form of a lump of mucus during a strong cough.

With asthmatic bronchitis, a small amount of viscous sputum is released, which contains eosinophils, Charcot-Leyden crystals, Curschmann spirals, epithelial cells, and fibrin.

Chronic bronchitis is characterized by the detection of pollutant substances (toxic substances that negatively affect the function of the bronchial tree) in sputum. Such substances include tobacco resins and industrially produced toxic substances.

General urine analysis for acute and chronic bronchitis does not show any characteristic changes; an increase in the amount of squamous epithelium and the presence of single leukocytes or their accumulations are noted.

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Tests for bronchitis in children

To determine the cause that provoked inflammation of the bronchial tree and to determine the location of the infectious focus in the lungs, pediatric patients are prescribed the same laboratory and instrumental examinations as adults. The characteristic features of the general analysis of the elements of the capillary blood composition can determine the genesis of the disease - inflammation of bacterial, viral or allergic etiology. With the help of the general analysis, differential diagnostics of allergic pathology and inflammatory process of viral-bacterial nature are carried out.

Sputum analysis helps to assess the condition of the pulmonary and bronchial structures in a child. The study is carried out for diagnostic purposes to determine:

• forms of bronchitis;
• confirmation or refutation of the diagnosis: bronchial asthma;
• the severity of the small patient's condition with pulmonary edema,
• differentiation of pneumonia and bronchitis;
• type of respiratory disease.

Sputum examination allows us to determine the type of pathological process in the bronchial tree as accurately as possible, and in some cases determine the etiology.

In children under 3 years of age, acute bronchitis is caused by respiratory infections, influenza viruses, adenovirus or cytomegalovirus. Bronchitis caused by microorganisms rarely leads to obstruction symptoms. In children aged three and older, bronchitis can be caused by mycoplasma (Mollicutes), chlamydia (Chlamydia trachomatis), intracellular parasitic protozoa. In order to determine the pathogen in obstructive bronchitis in children, an analysis of antibody titers in the bloodstream for mycoplasmosis and chlamydia is carried out. If treatment is started late or if diagnostics and prescription of pharmacological agents are incompetent, these diseases cause serious complications, so the analysis is mandatory. Blood tests help diagnose:

• Mycoplasmosis is a disease that has a symptom complex identical to catarrhal phenomena.
• Chlamydia pulmonaria is a respiratory infection caused by chlamydia.

In childhood, it is important to differentiate bronchitis of infectious and allergic etiology. A history of allergic reactions and heredity of this pathology will help to establish and confirm an accurate diagnosis. Characteristic changes in laboratory tests will indicate an allergic nature of bronchitis symptoms. Infectious obstructive inflammations of the bronchial tree are closely associated with the presence of respiratory viral infections. Symptoms develop gradually with the presence of hyperthermia. Bronchitis of allergic genesis does not have a clear dependence on the presence of signs of ARVI. It begins to actively manifest itself after contact with a specific allergen. The diagnosis is confirmed by an increase in total IgE in the blood serum and skin tests for allergic reactions with the determination of the provoking allergen.

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Tests for chronic bronchitis

Chronic bronchitis is a persistent bronchial disease of inflammatory etiology, characterized by a recurrent course over a long period of time (more than two years). If chronic bronchitis is suspected, the patient must undergo diagnostic procedures and examinations:

• general clinical blood test with formula,
• general urine analysis,
• biochemical blood test,
• sputum culture,
• determination of serological antibody titers.

During the period of calm of inflammatory reactions in the bronchial tree, the general clinical analysis of capillary blood does not have significant changes. During an exacerbation or relapse of bronchitis, an increase in the concentration of leukocytes, an increase in ESR, and a shift in the leukocyte formula to the left are observed in the clinical blood test. Serological tests for antibodies to various types of infection are recommended in cases where bronchitis is practically not amenable to therapy, has frequent relapses and short remissions.

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Tests for acute bronchitis

Acute bronchitis is a complication after the invasion of viruses, pathogenic bacteria, local irritants. The disease is often combined with inflammation of the nose, pharynx, trachea. Doctors note the characteristic seasonality (spring-autumn period) of the onset of diseases. In the general clinical blood test, increased leukocytosis and an increase in ESR are observed. In biochemical indicators, the concentration of sialic acids, alpha-, gammaglobulins increases significantly, CRP (C-reactive protein) appears, the activity of angiotensin-converting enzyme (ACE) increases, hypoxemia may occur. To detect the pathogen, it is necessary to conduct a sputum bacteriology, which will allow prescribing competent treatment. Serological testing is aimed at identifying antibodies to pathogens, which will help the doctor in making the correct diagnosis and prescribing adequate therapy. Serological analysis can confirm the presence of various viruses, mycoplasma (Mycoplasma pneumoniae), Haemophilus influenzae, pneumococci (Streptococcus pneumoniae), gram-negative cocci (Moraxella catarrhalis).

In acute bronchitis, sputum consists of mucus with a small amount of purulent impurities. When examining sputum with pus, the presence of neutrophilic granulocytes, bronchial epithelial cells, mononuclear phagocytes, and Curschmann spirals is noted.

Immunological blood tests confirm a decrease in the concentration of T-lymphocytes and T-suppressors.

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Tests for obstructive bronchitis

Taking into account the clinical picture of the disease, to clarify the diagnosis, for obstructive bronchitis the following is prescribed:

• General clinical blood test.
• Microbiological examination of sputum.
• PCR method for determining the type of pathogen in the bloodstream and sputum.
• Spirometry is used to assess the degree of obstruction.

Based on clinical symptoms, taking into account the results of the above types of examinations, the doctor confirms or refutes the diagnosis of obstructive bronchitis.

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Blood test for bronchitis

To determine the severity of the inflammatory process in the bronchial tree, a clinical analysis of capillary blood is necessary.

The clinical blood test results may change and give false information if the patient has not followed the rules for preparing for the test. On the eve of the procedure, it is necessary to reduce the intensity of physical activity, completely exclude salty, spicy, fatty foods. Alcoholic and carbonated drinks are prohibited. The test results of the study will be more accurate if at least 8 hours pass between the collection of material and the last meal. For infants, the break can be 2-3 hours.

Blood is collected strictly on an empty stomach. Capillary or venous blood is used for the study (the referral must indicate that the blood is venous). Before collecting the material, a medical institution laboratory technician treats the working area with a 70% alcohol solution. To collect capillary blood, you will need a test tube, a special thin glass capillary, a slide and other laboratory instruments. The procedure is carried out by pricking a finger with a special sterile scarifier-spear. Before collecting venous blood for analysis, a nurse or laboratory technician applies a tourniquet just above the site of material collection. The skin in the area of the proposed venipuncture is treated with 70% alcohol and blood is collected using a syringe.

Biochemical blood test for bronchitis

A biochemical blood test is a comprehensive examination showing changes in the content of globulins and the presence of C-reactive protein. Thanks to biochemistry, it is possible to obtain a general picture associated with metabolic processes and the concentration of various components. For the reliability of the indicators, it is necessary to stop eating 12 hours before the start of the procedure, only clean still water is allowed. Blood is collected from a vein with a sterile syringe. Then it is placed in a sterile test tube. Blood can be collected in a vacuum sterile test tube. The material is delivered to the laboratory within 24 hours. The results will be ready in 1-3 working days.

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Sputum analysis for bronchitis

Bacterioscopic examination of sputum will help to determine the pathogen (Koch's bacterium, the introduction of pinworms or other types of worms) that caused the onset and development of the disease. The doctor pays close attention to microscopy of the discharge during bronchitis and the presence of characteristic components:

• Bronchial epithelial cells.
• Macrophages (mononuclear phagocytes).
• Erythrocytes.
• Leukocytes.

Bronchial epithelial cells present in sputum are not the main indicator of the inflammatory process in the bronchial tree. The normal content of bronchial epithelial cells in the sample under study is up to 10 units on a special scale. If a high concentration of epithelial cells is noted during sputum analysis, this confirms the presence of inflammation of the mucous membrane of the bronchi and trachea. Clinically, the presence of a focus of inflammation in the bronchi is confirmed by an unproductive obsessive cough with pain in the chest area.

Mononuclear phagocytes are constantly present in sputum, but with persistent inflammation they increase significantly.

Leukocytes (white blood cells) are always present in sputum in small quantities, but during inflammation their concentration increases significantly.

The appearance of red blood cells indicates a deep lesion of the bronchi, affecting the integrity of the capillaries and larger vessels. An obsessive cough during bronchitis can lead to injury of the delicate epithelial tissue.

To obtain reliable results of sputum examination in case of an inflammatory process in the bronchial tree, the patient must adhere to the following recommendations:

It is recommended to systematically take expectorants the day before the examination, and to drink plenty of fluids.

For the study, fresh sputum is required, preferably without admixture of saliva.

To obtain accurate results, you should use a sterile medical container.

To collect material when the amount of sputum secreted is small, it is necessary to induce a reflex cough by taking deep breaths.

Urine analysis for bronchitis

Urine testing for bronchitis is necessary to exclude specific renal pathologies and gallbladder diseases. The indicators determined in the urine composition are influenced by many reasons:

• nutrition;
• drinking regime;
• intense exercise;
• active physical labor;
• experienced stressful situations;
• taking medications and nutritional supplements.

To obtain an accurate result, you should properly prepare for a general urine test:

• 1 day before taking the test, you must exclude from your diet foods that affect the color of your urine (brightly colored fruits and vegetables, smoked foods, marinades);
• the intake of alcoholic beverages, vitamins, coffee, and strong tea is contraindicated;
• visiting a bathhouse or sauna the day before the examination is excluded;
• It is necessary to inform the doctor who issued the referral for urine testing about the medications you are taking;
• In women, urine analysis is usually not performed during menstruation. The exception is emergency cases, when the material for the study is collected using a urethral catheter;
• Contraindications to urine analysis for bronchitis are high body temperature and blood pressure. They significantly affect the determined indicators and the results of the study will be distorted.

Urine is collected in special containers. The portion of material being examined should not contain foreign inclusions and impurities. Simple recommendations for collecting urine should be followed:

• A general urine analysis is performed by examining the morning portion of urine;
• Before starting to collect urine, it is necessary to carry out hygiene procedures to reduce the penetration of bacteria and obtain a more reliable result;
• To collect a portion of urine, you need a clean, preferably sterile, container. It should not have traces of detergent. You can buy special containers that are sold in pharmacies;
• urine required for general examination can be stored in a cool place for no more than 2 hours;
• Sterile medical urine collection bags are used to collect the material to be examined in infants; otherwise, the recommendations for children to submit urine are the same as for older patients. It is prohibited to collect urine for examination using a diaper. The result will be inaccurate due to urine filtration through the fabric and the inclusion of microscopic fibers in the sample.

Decoding blood test for bronchitis

In a general blood test, laboratory technicians determine the number of red blood cells, the total number of white blood cells, platelets, hemoglobin, color index, ESR, and calculate the formula (the percentage of different types of white blood cells). In a blood test for bronchitis, some indicators change.

Erythrocytes (RBC) are red blood cells synthesized by bone marrow tissues. Their main function is to deliver oxygen to various cellular structures of the body, maintain a stable oxidation process at the cellular level and remove carbon dioxide. Bronchitis is accompanied by a slight increase in the concentration of erythrocytes, because the acid-base and water-salt balance in the bronchial tree is disrupted, and red blood cells participate in its control.

In a child or adult with bronchitis, leukocytes (WBC) are the main indicators of the immune system. Their function is to fight viruses, bacteria, fungal infections, and allergens. A sharp increase in the number of leukocytes in the bloodstream should be alarming. In this situation, it is necessary to urgently contact a specialist who will prescribe a comprehensive examination of the body. If bronchitis is not advanced, then a slight increase in the level of leukocytes is considered normal. The norm for leukocyte indicators:

• in adults from 4 to 9 (x 10 to the 9th power per liter),
• in children 6-11 (x 10 to the 9th power per liter).

In case of bronchitis, the concentration of leukocytes can increase by 2 times.

ESR (RBC) – the erythrocyte sedimentation rate is a non-specific marker of inflammation. The ESR indicator always increases with the manifestation of bacterial infections during the acute phase of the disease. The focus of the infectious process can be in different organs and systems, but the peripheral blood always reflects the inflammatory reaction. The ESR indicator is also increased in diseases of viral genesis. Considering the above, with bronchitis of viral or bacterial origin, this indicator will be quite high.

If the symptom complex of bronchitis is pronounced, laboratory tests are necessary to determine its genesis and prescribe adequate treatment. Tests for bronchitis allow you to determine what led to the inflammation. A correct diagnosis and timely initiation of complex treatment will help avoid serious complications caused by inflammation of the bronchial tree.

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