Sputum is a secret secreted by 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. Sputum research methods 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 identify the presence of mycobacteria in tuberculosis, to identify cancer cells, blood and purulent impurities, and also to determine the resistance of bacteria to antibiotics.
Under what conditions is the analysis shown
A sputum test for a general analysis is performed under the following conditions:
- cough;
- pneumonia;
- inflammation of the bronchi;
- suppuration of the lung;
- tuberculosis;
- bronchiectatic disease;
- pulmonary gangrene;
- swelling in the lungs;
- acute bronchitis;
- chronic bronchitis;
- tonsillitis in chronic form;
- tuberculosis;
- whooping cough;
- silicosis;
- acute form of obstructive bronchitis;
- pneumonia;
- anthrax.
Study preparation
Mucus will be better allocated if on the eve before taking the test, take an expectorant or use a large amount of warm drink. Before harvesting, it is recommended to brush your teeth and oral cavity 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, which is issued by the laboratory. An amount of 5 ml is sufficient for analysis. Analysis of the secret is carried out no later than 2 hours after its collection. The container with the contents should be kept closed in the refrigerator until sent to the study.
Sputum in various diseases
The amount of secreted secret varies depending on the nature of the pathological process. Usually it varies from a few spits to 1 liter per day. A small amount is released during inflammation of the bronchi, congestive lung processes, 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 l, and also stand out in large quantities if there is pulmonary edema.
A lot of mucus is secreted during a purulent process in the lungs when communicating with the bronchi, with suppuration, bronchiectasis and gangrene.
A study of sputum for tuberculosis shows the breakdown of lung tissue. 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 secreted secretion can be associated with a deterioration in the patient's condition and can be observed during an exacerbation. The increase may relate to the positive dynamics of the development of the disease.
A decrease in the amount of mucus secreted may indicate a regression of inflammation or a violation in the drainage area of the cavity filled with pus. At the same time, the patient is feeling worse.
The nature of the discharge
The mucous secretion is released in acute or chronic bronchitis, bronchial asthma, pneumonia, lung cancer, bronchiectasis, pulmonary echinococcosis, accompanied by suppuration, actinomycosis.
Sputum with an admixture of pus is observed with lung abscess, echinococcosis and bronchiectasis.
Mucus with an admixture of 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, such a phenomenon is observed with an average lobe syndrome, heart attack in a lung, trauma, actinomycosis and syphilitic lesion. Blood can be released during croupous and focal pneumonia, congestion, cardiac asthma and pulmonary edema.
Serous sputum is observed with pulmonary edema.
Sputum color
Examination of sputum reveals its various color. Mucous and serous secretions do not have color or have a whitish hue.
The addition of pus gives the secret a greenish tint, which characterizes pathological processes such as lung abscess, gangrene, bronchiectasis, lung actinomycosis.
Discharges with a touch of rust or brown indicate that they do not contain fresh blood, but the product of its decay - hematin. Such a secret can be released with croupous pneumonia , anthrax, and pulmonary infarction.
A greenish color with an admixture of dirt or a yellow secret indicates a pathology of the respiratory system in combination with jaundice.
In bright yellow sputum is painted with eosinophilic pneumonia.
Ocher mucus occurs in siderosis of the lung.
A blackish or grayish secret is noted in the presence of an admixture of dust from coal. With pulmonary edema, serous sputum is observed in large quantities. As a rule, it is painted evenly in pinkish color, which is explained by the presence of red blood cells. Such secretions are similar to liquid cranberry juice.
Secret can be stained with some drugs. For example, the Rifampicin antibiotic can give it a red color.
Smell
The smell of a secret may also indicate the nature of the pathological process in the respiratory organs. Sputum gives off the smell of rot with lung gangrene or putrefactive damage to the bronchi, oncological neoplasms, complicated necrosis of bronchiectasis.
The presence of layers
Often, a study of the discharge reveals the presence of layers. With a stagnant character, sputum with an admixture of pus is observed with suppuration of the lung and bronchiectasis.
The secret with an admixture of rot contains three layers. The upper layer is similar to foam, medium serous, and the lower layer with an admixture of pus. This composition characterizes the gangrene of the lung.
Impurities
An admixture of food can be noted in the presence of a malignant tumor in the esophagus when it communicates with the bronchi and trachea. When echinococcus enters the bronchi in the sputum, hooks or scolex parasites can be detected. Very rarely, adult Ascaris are found that penetrate the respiratory system in weakened people.
The eggs of the pulmonary fluke appear when the cyst ruptures, which forms in the lungs in the presence of parasites.
Gangrene and suppuration of the lungs cause pieces of lung necrosis to appear. With a tumor, fragments of them may be present in the discharge.
Convolutions containing fibrin are found in patients with fibrinous bronchitis, tuberculosis and pneumonia.
Rice bodies, or Koch lenses, are inherent in tuberculosis.
Dietrich’s plugs, including the breakdown products of bacteria and tissue of lung cells of fatty acids, are found in putrefactive bronchitis or lung gangrene.
The chronic form of tonsillitis involves the isolation from the tonsils of traffic jams, similar to Dietrich's traffic jams.
Chemical method
Chemical sputum examination involves the determination of:
- A protein indicator that can help in the differential diagnosis of the chronic form of bronchitis and tuberculosis. With chronic bronchitis, traces of protein are observed in secret, and with tuberculosis, the amount of protein in sputum will be much higher, and it can be indicated by numbers (up to 100-120 g / l).
- Pigment bile. They are found in sputum with damage to the respiratory system in combination with hepatitis. In this case, the liver communicates with the lungs. Biliary pigments are inherent in pneumonia, which is due to the breakdown inside the lungs of red blood cells and the subsequent change in hemoglobin.
Cytological method of secretion research
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.
A clinical study helps determine which method should be used to collect the material to obtain the correct analysis result.
There are two main types of material that microscopic examination of sputum requires: spontaneous and reduced. The second type of secret is obtained by exposure to a variety of irritants (means for expectoration, inhalation, etc.).
Needle Biopsy Material
Cytological examination of sputum involves the study of macroscopic and microscopic analysis of its cells.
Most of the information for cytological analysis is sputum taken in the morning on an empty stomach. Before the study, it should be stored no more than 4 hours.
- Sputum squamous cells are found in the sputum, which are examined microscopically. But for the diagnosis, they do not matter. The cells of the cylindrical epithelium - both single and in the group - can be observed in diseases such as bronchial asthma, bronchitis and lung cancer. It should be noted that a cylindrical epithelium can also appear due to the penetration of mucus from the nasopharynx.
- Alveolar macrophages are reticuloendothelial cells. Macrophages contained in the protoplasm (phagocytic particles or dust cells) can be found in patients who inhaled dust for a long time.
- Protoplasm macrophages (formed during 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 noted with an eosinophilic form of pneumonia, helminth infections, tuberculosis and pulmonary infarction.
- Red blood cells. Single red blood cells do not display a picture of the disease. The appearance of an increased amount indicates the presence of bleeding in the lungs. Unchanged red blood cells are detected in fresh blood. If there is an admixture of blood that has stagnated in the lungs for a long time, leached red blood cells are found.
- Cancer cells. They can be found in secret by groups. They indicate the presence of a tumor. When finding single cells, difficulty in diagnosis often arises. In such cases, a re-analysis of sputum is performed.
- Elastic fibers, the appearance of which is caused by the collapse of the lung tissue, provoked by tuberculosis, abscess, gangrene, tumor. Such cells are not always characterized by gangrene, since due to the action of the secretion enzymes, they can be dissolved.
- Kurshman spirals. These are special tubes-like bodies. They are detected by examination under a microscope. Sometimes visible with 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 with lesions such as bronchial asthma, eosinophilic pneumonia. Opening a focal point of tuberculosis in the lumen of the bronchi can be characterized by the presence in the secret of elastic fiber crystals of cholesterol, MBT and amorphous lime (the so-called Erlich tetrad) - 100%.
The use of bacterioscopy
Sputum collection for examination by the bacterioscopic method involves the analysis of the secret to detect mycobacteria characteristic of tuberculosis in it. They look like thin, thickened on the sides or in the middle of the curved sticks of different lengths, which are located both individually and in groups.
The detection of mycobacterium tuberculosis is not a dominant sign for diagnosis and requires confirmation by a bacteriological method. Mycobacterium tuberculosis is normally not found in secret.
The basis for the analysis is purulent particles, which are taken from forty-six different areas and are thoroughly ground to a homogeneous mass with two glasses. Then they are dried in air and fixed by the flame of the burner.
A bacteriological study of sputum by the Ziehl-Nielsen method involves its staining in red. In this case, all particles of the secret, with the exception of mycobacteria, acquire a blue tint, and mycobacteria acquire a red color.
If tuberculosis is suspected, after a three-time study for the presence of mycobacteria with a negative response, they resort to the use of the flotation method (Pottenger analysis).
The usual method for examining a stained smear on MTB gives a positive result only with an MTB count of at least 50,000 units in 1 ml of sputum. By the number of mycobacteria, it is impossible to judge the presence of tuberculosis.
Bacterioscopy of patients with non-specific lung diseases
Laboratory tests of sputum in the presence of non-specific lung diseases during bacterioscopy can reveal the following bacteria:
- With pneumonia - pneumococci, Frenkel diplococci, Friedlander bacteria, streptococci, staphylococci (100%).
- With lung gangrene, a spindle-shaped rod can be found in combination with Vincent’s spirochete (80%).
- Yeast-like mushrooms (70%), the sowing of the secret is required to determine the type of which.
- Druze actinomycete (100%) with actinomycosis.
The amount of secretion in a healthy 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 a stained smear on mycobacteria gives a negative result.