Sputum is a secret released during inflammation of the trachea, bronchi and lungs. Its appearance is noted not only with damage to the respiratory organs, but also with violations of the heart and blood vessels. Methods for the study of sputum include macroscopic, chemical and microscopic determination of its characteristics.
What analysis reveals
Sputum examination makes it possible to detect microorganisms that cause a pathological process, to indicate the presence of mycobacteria in tuberculosis, to identify cancer cells, blood and purulent impurities, and to determine the resistance of bacteria to antibiotics.
Under what conditions is the analysis shown
Sputum examination for general analysis is carried out under the following conditions:
- cough;
- pneumonia;
- inflammation of the bronchi;
- suppuration of the lung;
- tuberculosis;
- bronchiectasis;
- pulmonary gangrene;
- tumor in lungs;
- acute bronchitis;
- chronic bronchitis;
- chronic tonsillitis;
- tuberculosis;
- whooping cough;
- silicosis;
- acute form of obstructive bronchitis;
- pneumonia;
- anthrax.
Preparing for the study
Mucus will stand out better if you take an expectorant the day before the test or drink a large amount of warm drink. Before collection, it is recommended to brush your teeth and mouth by rinsing it with warm boiled water.
Basic collection rules
It is advisable to collect sputum for bacteriological examination in the morning (it accumulates the night before meals) in a sterile container that is issued by the laboratory. For analysis, a quantity of 5 ml is sufficient. The secret is analyzed no later than 2 hours after its collection. The container with the contents must be kept closed in the refrigerator until sent for examination.
Amount of sputum in various diseases
The amount of secretion released varies depending on the nature of the pathological process. Usually it varies from a few spittles to 1 liter per day. A small amount is released during inflammation of the bronchi, congestive processes in the lungs and at the onset of an attack of bronchial asthma. At the end of the attack, the volume increases. It can be up to 0.5 liters, and also stand out in large quantities if there is pulmonary edema.
A lot of mucus is released during a purulent process in the lungs when communicating with the bronchi, with suppuration, bronchiectasis andgangrene.
Sputum TB test shows lung tissue breakdown. In particular, such a process provokes a cavity that communicates with the bronchi.
What is the reason for the decrease or increase in secretion
An increase in the amount of secretion secreted may be associated with a deterioration in the patient's condition and be observed during an exacerbation. The increase may also refer to the positive dynamics of the development of the disease.
A decrease in the amount of secreted mucus may indicate a regression of inflammation or a violation in the area of drainage of a cavity filled with pus. At the same time, there is a deterioration in the patient's well-being.
Character of discharge
Mucoid secretion is secreted in acute or chronic bronchitis, bronchial asthma, pneumonia, lung cancer, bronchiectasis, lung echinococcosis accompanied by suppuration, actinomycosis.
Sputum mixed with pus is observed in lung abscess, echinococcosis and bronchiectasis.
Mucus mixed with blood or consisting entirely of blood is inherent in tuberculosis. The appearance of blood may indicate the presence of oncology, bronchiectasis, suppuration of the lung. Also, this phenomenon is observed in the syndrome of the middle lobe, infarction in the lung, trauma, actinomycosis and syphilitic lesions. Blood can also be released during lobar and focal inflammation of the lungs, congestive processes, cardiac asthma and pulmonary edema.
Serous sputum is noted with swelling of the lungs.
Sputum color
Sputum examination reveals its different coloration. Mucous and serous discharge is colorless or whitish.
The addition of pus gives the secret a greenish tint, which characterizes such pathological processes as lung abscess, gangrene, bronchiectasis, actinomycosis of the lung.
Discharges with a hint of rust or brown indicate that they do not contain fresh blood, but a product of its breakdown - hematin. Such a secret can be released with lobar pneumonia, anthrax, pulmonary infarction.
Greenish color with an admixture of dirt or a yellow secret indicates a pathology of the respiratory system in combination with jaundice.
Sputum stains bright yellow in eosinophilic pneumonia.
Ocher-colored mucus is found in siderosis of the lung.
A blackish or grayish secret is noted when there is an admixture of dust from coal. With pulmonary edema, serous sputum is observed in large quantities. As a rule, it is colored evenly in a pinkish color, which is explained by the presence of red blood cells. Such discharge is similar to liquid cranberry juice.
The secret can also be stained from some medications. For example, the antibiotic Rifampicin can turn it red.
Smell
The smell of the secret can also indicate the nature of the pathological process in the respiratory organs. Sputum gives off the smell of rot with gangrene of the lung or putrefactive damage to the bronchi, oncological neoplasms,complicated necrosis of bronchiectasis.
Presence of layers
Often, the study of secretions reveals the presence of layers. With a stagnant character, sputum mixed with pus is observed with suppuration of the lung and bronchiectasis.
The rotted secret contains three layers. The top layer looks like foam, the middle one is serous, and the bottom layer is purulent. This composition characterizes lung gangrene.
Impurities
Admixture of food can be observed in the presence of a malignant tumor in the esophagus when communicating with the bronchi and trachea. When echinococcus enters the bronchi, hooks or scolex of the parasite can be detected in the sputum. Very rarely, adult ascaris are found, which penetrate the respiratory organs of weakened people.
Pulmonary fluke eggs appear when a cyst ruptures, which forms in the lungs when parasites are present.
Gangrene and suppuration of the lungs cause the appearance of pieces of lung necrosis. With a tumor, their fragments may be present in the discharge.
Fibrin-containing bundles are found in patients with fibrinous bronchitis, tuberculosis and pneumonia.
Rice bodies, or Koch lenses, are inherent in tuberculosis.
Dietrich plugs, which include decay products of bacteria and tissue of lung cells of fatty acids, are found in putrefactive bronchitis or gangrene of the lung.
Chronic form of tonsillitis involves the release of plugs from the tonsils, similar to Dietrich plugs.
Chemical method
Sputum chemical examination involves determination:
- Indicator of a protein that can help in the differential diagnosis of chronic bronchitis and tuberculosis. With chronic bronchitis, traces of protein are noted in the secret, and with tuberculous lesions, the amount of protein in the sputum will be much higher, and it can be indicated by numbers (up to 100-120 g / l).
- Bile pigments. They are found in sputum when the respiratory system is affected in combination with hepatitis. In this case, the liver communicates with the lungs. Bile pigments are inherent in pneumonia, which is due to the breakdown of red blood cells inside the lungs and the subsequent change in hemoglobin.
Cytological method for examining the secret
For the differential diagnosis of tuberculosis and many other lung lesions, the cytological method is widely used, which includes two stages: clinical and microscopic examination of sputum.
Clinical testing helps determine which method should be collected to obtain the correct test result.
There are two main types of material that require microscopic examination of sputum: spontaneous and reduced. The second type of secret is obtained by exposure to a variety of stimuli (expectorants, inhalation, etc.).
Needle biopsy material
Cytological examination of sputum involves the study of macroscopic and microscopic analysis of its cells.
Most information for cytological analysis is sputum taken in the morning onempty stomach. Prior to examination, it should be stored no more than 4 hours.
- Squamous epithelial cells are found in sputum, which are examined microscopically. But for the diagnosis they do not matter. Cells of the cylindrical epithelium - both single and in a group - can be observed in diseases such as bronchial asthma, bronchitis and lung cancer. It should be noted that the cylindrical epithelium may also appear due to the penetration of mucus from the nasopharynx.
- Alveolar macrophages are reticuloendothelial cells. Macrophages, which are contained in the protoplasm (phagocytic particles or dust cells), can be found in patients who have inhaled dust for a long time.
- Macrophages of protoplasm (formed by the breakdown of hemoglobin) are called heart disease cells. They can occur during congestive processes in the lungs, mitral valve stenosis, pulmonary infarction.
- A small amount of white blood cells is found in any sputum. Their increased content is noted in secret with an admixture of pus.
- Eosinophils. Such cells are rich in sputum in asthmatics. Cells can be seen in eosinophilic pneumonia, helminth infections, tuberculosis, and pulmonary infarction.
- Erythrocytes. Single erythrocytes do not display a picture of the disease. The appearance of an increased amount indicates the presence of bleeding in the lungs. In fresh blood, unchanged erythrocytes are determined. If there is an admixture of blood, whichstagnant in the lungs for a long time, then leached red blood cells are detected.
- Cancer cells. They can be found secretly in groups. They indicate the presence of a tumor. When finding single cells, it is often difficult to diagnose. In such cases, a second sputum test is performed.
- Elastic fibers, the appearance of which is caused by the breakdown of lung tissue, provoked by tuberculosis, abscess, gangrene, tumor. Gangrene is not always characterized by such cells, because due to the action of secreted enzymes, they can be dissolved.
- Kurshman spirals. These are special bodies that look like tubes. They are found when examined under a microscope. Sometimes visible to the eye. Usually, spirals are inherent in diseases such as bronchial asthma, pulmonary tuberculosis and pneumonia.
- Charcot-Leiden crystals are found in sputum with a high content of eosinophils in lesions such as bronchial asthma, eosinophilic pneumonia. The opening of the focus of tuberculosis in the lumen of the bronchi can be characterized by the presence in the secret of elastic fibers-crystals of cholesterol, MBT and amorphous lime (the so-called Ehrlich's tetrad) - 100%.
Use of bacterioscopy
Sputum collection for bacterioscopic examination involves the analysis of the secret to detect mycobacteria characteristic of tuberculosis in it. They look like thin, curved sticks of different lengths, thickened on the sides or in the middle, which are located either singly or in groups.
Detection of Mycobacterium tuberculosis is notis a dominant feature for diagnosis and requires bacteriological confirmation. Tuberculous mycobacteria are not detected secretly in normal conditions.
The basis for the analysis is purulent particles, which are taken from forty-six different areas and carefully ground to a homogeneous mass with two glasses. Then they are dried in air and fixed with a burner flame.
Bacteriological examination of sputum by the Ziehl-Neelsen method suggests its staining in red. In this case, all secretion particles, with the exception of mycobacteria, acquire a blue tint, and mycobacteria become red.
If tuberculosis is suspected, after a three-time test for the presence of mycobacteria with a negative response, the flotation method (Pottenger analysis) is used.
The usual way to study a stained smear for MTB gives a positive result only if the amount of MTB is at least 50,000 units in 1 ml of sputum. It is impossible to judge the presence of tuberculosis by the number of mycobacteria.
Bacterioscopy of patients with nonspecific lung diseases
Laboratory tests of sputum in the presence of nonspecific lung diseases during bacterioscopy can reveal the following bacteria:
- In case of pneumonia - pneumococci, Frenkel diplococci, Friedlander bacteria, streptococci, staphylococci (100%).
- With gangrene of the lungs, you can find a spindle-shaped stick incombined with Vincent's spirochete (80%).
- Yeast-like fungi (70%), which require secretion culture to determine their species.
- Druze of actinomycete (100%) with actinomycosis.
Secret volume in a he althy person
The volume of mucus secreted by the trachea and bronchi in a person who does not suffer from any pathologies ranges from 10 to 100 ml / day.
Normally, the level of leukocytes is low, and the study of the stained smear for mycobacteria is negative.
