Study of effusion (serous) fluids - Physical properties. Serous fluid

The serous membranes lining the internal cavities of the body secrete a proteinaceous, clear fluid called serous fluid. This substance arises as a result of ultrafiltration of fluid from blood vessels, and in addition to protein, it contains a certain amount of cellular elements, such as fallen mesothelial cells, leukocytes and a number of others. If blood and lymph circulation are impaired, serous fluid may accumulate, which is called transudate.

The serous membrane is a thin connective tissue membrane, the thickness of which is on average one millimeter, covered with flat single-layer epithelium. Serous membranes are considered to be the pleura, peritoneum, pericardium and a number of other similar formations.

Functions of serous fluid

This specific serous fluid is produced and absorbed by the serous membrane. It is designed to maintain dynamic properties internal organs In addition, it also has a protective function. When inflammation occurs, smooth tissue transforms into rough, dense and cloudy tissue and in cases serious pathologies the serous membrane can grow until it sticks together.

The study of effusion fluid significantly helps to establish the correct diagnosis for a variety of diseases in which transudates and exudates occur, as well as to monitor treatment for infectious and.

A certain amount of fluid is always present in the serous cavities of a healthy body, but in pathological conditions the amount of this fluid increases. Liquids divided into transudates and exudates differ from each other in the way excess liquid is formed.

When hydrostatic and colloid-osmotic pressure in the lymph, blood and serous cavities is disrupted, transudates occur. The reason for their formation is, for example, an increase in venous pressure with poor blood circulation, kidney disease and cirrhosis of the liver, in which capillary permeability increases. The permeability of capillaries, and therefore the production of transudates, can also increase due to exposure to various toxins, rising temperature and nutritional disorders. In addition, a decrease in protein concentration in the blood serum leads to a drop in colloid osmotic pressure, resulting in edema and transudates. Blockage lymphatic vessels is fraught with the occurrence of chylous transudates. The serous membranes are not involved in the primary pathological process.

When are the serous membranes exposed? primary lesion or are involved in the inflammatory process, exudates are formed.

In some cases, effusion fluids are mixed.

To carry out diagnostics, effusion fluids are obtained using puncture of the serous cavities in the hospital by experienced medical personnel.

Examination of serous fluid

Macroscopic and microscopic examinations help to identify serous, serous-purulent, putrefactive, purulent, hemorrhagic, chyle-like, chylous, cholesterol effusions. Serous-fibrinous exudates are characterized by a significant number of lymphocytes, which suggests tuberculosis, rheumatism, syphilis and a number of other diseases. Serous-purulent and purulent exudates are possible, for example, with peritonitis and pleural empyema. Putrefactive exudates are characteristic of processes in which tissue decay occurs, for example, gangrene of the lung. Hemorrhagic exudates are observed as in neoplasms, but they can also be observed in pulmonary infarctions, injuries, and hemorrhagic diathesis. Chylous exudates occur when large lymphatic vessels are destroyed due to abscesses, injuries, and tumors. Milky, chyle-like exudates indicate abundant cell breakdown in tuberculosis, sarcoidosis, neoplasms and atrophic cirrhosis of the liver. Cholesterol exudates with a pearlescent sheen are possible when fluids accumulate in the serous cavities, when a chronic inflammatory process occurs in tuberculosis and malignant tumors.

MACROSCOPIC STUDY
During laboratory testing, differential diagnosis exudate and transudate, evaluate general properties(macroscopic view) liquid: color, transparency, consistency.

Transudate and exudate
Transudate is a fluid that accumulates in body cavities and is formed as a result of the influence of systemic factors on the formation of fluid and its resorption. For transudative effusion, sheets serous membranes are not involved in the primary pathological process. Transudate occurs when hydrostatic or colloid osmotic pressure changes to such an extent that the fluid filtered into the serous cavity exceeds the volume of reabsorption.

This happens most often as a result of:
disorders of general and local circulation, for example in chronic venous congestion (cardiovascular, renal failure, portal hypertension, etc.)

d.);
reducing oncotic pressure in blood vessels during hypoproteinemia;
disorders of electrolyte metabolism.

Transudate accumulated in the pleural cavities is called hydrothorax, in abdominal cavity- ascites, in the pericardial cavity - hydropericardium. Transudate is usually transparent, almost colorless or with a yellowish tint, less often - slightly cloudy due to the admixture of desquamated epithelium, lymphocytes, lipocytes; specific gravity does not exceed 1.015 g/ml.

Exudate is formed as a result of damage to the serous membranes, most often due to increased permeability of the capillaries of the membranes, but can also occur when lymphatic outflow from the serous cavity is impaired. For infections, some systemic diseases ( rheumatoid arthritis, systemic lupus erythematosus) exudate is formed as a result of impaired capillary permeability; with tumor growth, the cause of its formation is often blockade lymphatic system.

However, this pattern is not universal: for example, with a severe inflammatory process, in particular with bacterial empyema, lymphatic outflow may be impaired due to swelling of mesothelial cells or the accumulation of cellular debris, fibrin and collagen, blocking lymphatic drainage.

For many years, the differentiation of serous effusion into transudate and exudate was carried out based on the protein content in the fluid. However, using only this criterion in 10% of cases may give erroneous results.

If the effusion is a transudate, further diagnostic studies is not required, treatment can be directed to the underlying pathology of the effusion (congestive heart failure, cirrhosis, etc.). Conversely, if the effusion turns out to be an exudate, further diagnostic studies are necessary to identify the causes of its formation.

GENERAL PROPERTIES (MACROSCOPIC VIEW) OF THE LIQUID
When describing the macroscopic appearance of a liquid, transparency, color, and consistency are assessed.

Depending on the nature of the liquid, the quantitative content of protein and cellular composition effusions are distinguished: serous, serous-purulent, purulent, putrefactive, hemorrhagic, chylous, chyle-like, cholesterol, mucous, fibrinous.

Serous effusion (transudate or exudate) can be transparent or cloudy, usually yellowish in color of varying intensity. Sometimes the serous fluid turns out to be sharply turbid, and large granular inclusions can be seen in it, quickly settling to the bottom of the vessel. This type of effusion may occur during inflammatory processes, tuberculosis, syphilis, rheumatism, etc.

Serous-purulent and purulent exudate is a cloudy, yellowish-green liquid with abundant loose sediment. Purulent exudate occurs with pleural empyema, peritonitis, etc.

Putrid exudate is a cloudy liquid of gray-green color with a pungent putrefactive odor; characteristic of lung gangrene and other processes accompanied by tissue decay.

Hemorrhagic exudate is a clear or cloudy liquid of a reddish or brownish brown color. The number of red blood cells can vary - from a small admixture, when the liquid has a faint pink color, to an abundant content, when it resembles whole blood. The most common cause of this effusion is a neoplasm, but the hemorrhagic nature of the fluid is large diagnostic value does not have, since it is also observed in a number of cases non-tumor diseases(trauma, pulmonary infarction, pleurisy, hemorrhagic diathesis). At the same time, in malignant processes with extensive dissemination of the tumor along the serous membrane, a serous transparent effusion may occur.

Chylous exudate is a milky, turbid liquid containing tiny fat droplets in suspension. When ether is added, the liquid becomes clear. Such effusion is caused by the entry of lymph from destroyed large lymphatic vessels or the thoracic lymphatic duct into the serous cavity; it occurs with injuries of lymphatic vessels, abscesses, infiltration of vessels by a tumor, filariasis, lymphoma, etc.

Chyle-like exudate is a milky-turbid liquid that appears as a result of abundant breakdown of cells with fatty degeneration. Since, in addition to fat, this exudate contains a large number of fat-degenerated cells, the addition of ether leaves the liquid cloudy or slightly clears it. Chyle-like exudate is characteristic of effusion fluids, the appearance of which is associated with atrophic cirrhosis of the liver, malignant neoplasms, tuberculosis, sarcoidosis, etc.

Cholesterol exudate is a thick yellowish or brownish liquid with a pearlescent tint with shiny flakes consisting of clusters of cholesterol crystals. An admixture of destroyed red blood cells can give the effusion a chocolate tint. On the walls of the test tube, moistened with effusion, casts of cholesterol crystals in the form of tiny sparkles are visible. This is the character of an encysted effusion that exists for a long time (sometimes for several years) in the serous cavity. Under certain conditions - reabsorption of water and some mineral components of the exudate from the serous cavity, as well as in the absence of fluid influx into the closed cavity, exudate of any etiology can acquire the character of cholesterol. Cholesterol exudate occurs in tuberculosis, malignant neoplasms, and cyst rupture.

Mucous exudate contains a significant amount of mucin and pseudomucin, and can occur with mesothelioma, mucinous ovarian tumor, pseudomyxoma. Fibrinous exudate contains a significant amount of fibrin. There are also mixed forms of exudate (sero-hemorrhagic, muco-hemorrhagic, serous-fibrinous). None of the listed types of exudate is pathognomonic for a malignant tumor, since it can also occur in non-tumor processes. In malignant neoplasms involving the serous membranes, hemorrhagic exudate is most common.

MICROSCOPIC INVESTIGATION
Counting the number of cellular elements in the effusion fluid is easier and more reliable to carry out in the Goryaev chamber. The cellular composition of the effusion is examined from the sediment obtained by centrifugation for 5-10 minutes at 1500-3000 rpm. The best way liquid processing is centrifugation in a special cytocentrifuge such as Cytospin.
Sediment research

The amount of sediment, its color and density depend on the cellular composition of the liquid, its viscosity and various inclusions. The sediment may be grayish, yellowish, bloody; loose and dense; single-layer and two-layer, occasionally three-layer. In serous clear fluid, the sediment is usually small (0.1-0.3 ml), fine-grained, grayish-white. When the serous fluid is turbid with a large number of cellular elements, the sediment is significant (up to 1.0-1.5 ml), coarse-grained. Hemorrhagic fluid with a large admixture of red blood cells, as a rule, gives a two-layer sediment: an upper layer in the form of a thin whitish film and a large lower layer of red blood cells.

If the liquid contains a significant admixture of leukocytes, including partially disintegrated ones, and a large number of destroyed red blood cells, the sediment may be three-layered. The top layer of sediment consists of cell breakdown products, followed by a layer of preserved cells and a bottom layer consisting of red blood cells.

Depending on the nature of the sediment, it is removed from the centrifuge tube in different ways. A single-layer small loose sediment is shaken, a drop of sediment is applied to the glass. It is advisable to remove sediment having 2-3 layers layer by layer. This is especially important when there is a large admixture of blood, since almost all cellular elements are concentrated in the upper layer, which looks like a thin whitish film. It must be taken into account that dense tissue fragments of the tumor may be present at the bottom of a large bloody sediment, therefore, after careful suction and removal of the bulk of the sediment, it is also necessary to prepare smears from the last small portion from the bottom of the tube.

A very dense sediment is taken in small portions onto separate glass slides and distributed over the glass using the edge of a puncture needle, a glass rod or a thin wire loop. A loop with cellular elements deposited on it is passed over the entire area of ​​the glass in different directions, which allows the cells to be evenly distributed over the glass. Smears from the gelatinous sediment are prepared with dissecting needles. If small crumb-like masses or individual clumps are found in the sediment, they should be transferred to another slide and carefully stretched.

Conduct a study of native and colored preparations. It is advisable to use microscopic examination of native (wet, unstained) preparations as an auxiliary technique to the main method of studying fixed stained smears. This makes it possible to quickly get an idea of ​​the qualitative and quantitative content of cellular elements in the test liquid and correctly select the material for staining.

Staining preparations from loose sediment are prepared like blood smears. For cytological examination, 4-6 stained smears are usually prepared. With a large number of cells in the effusion, accurate cytological diagnosis can be diagnosed by microscopy of 1-3 preparations.

There is far more than one difference between transudate and exudate, although both of these terms are incomprehensible to an ignorant person. But a professional physician must be able to distinguish one from the other because these types of effusion fluid require a different approach. Let's try to talk about transudates and exudates in a way that is understandable even to a person without a medical education.

What are effusion fluids

Effluent fluids form and accumulate in serous cavities, which include the pleural, abdominal, pericardial, epicardial and synovial spaces. In the listed cavities there is present, providing normal functioning relevant internal organs (lungs, abdominal organs, heart, joints) and preventing their friction against the membranes.

Normally, these cavities should contain only serous fluid. But with the development of pathologies, effusion can also form. Cytologists and histologists study them in detail, because competent diagnosis of transudates and exudates makes it possible to prescribe the correct treatment and prevent complications.

Transudate

From Latin trans – through, through; sudor - sweat. Effusion of non-inflammatory origin. May accumulate due to problems with blood and lymph circulation, water-salt metabolism, and also due to increased permeability of vascular walls. Transudate contains less than 2% protein. These are albumins and globulins that do not react with colloidal proteins. In terms of characteristics and composition, transudate is close to plasma. It is transparent or has a pale yellow tint, sometimes with cloudy admixtures of epithelial cells and lymphocytes.

The occurrence of transudate is usually due to stagnation. This may be thrombosis, renal or heart failure, hypertension. The mechanism of formation of this fluid is associated with an increase in internal blood pressure and a decrease in plasma pressure. If the permeability of the vascular walls is increased, then transudate begins to be released into the tissue. Some diseases associated with the accumulation of transudates have special names: hydropericardium, abdominal ascites, ascites-peritonitis, hydrothorax.

By the way! With proper treatment, the transudate can resolve and the disease will go away. If you start it, extravasation will increase, and over time, the stagnant fluid can become infected and turn into exudate.

Exudate

From Latin exso - I go outside; sudor - sweat. Formed in small blood vessels as a result of inflammatory processes. The fluid exits through the vascular pores into the tissue, infecting them and contributing to the further development of inflammation. Exudate contains from 3 to 8% protein. It may also contain shaped elements blood (leukocytes, erythrocytes).

The formation and release of exudate from vessels is caused by the same factors (increased blood pressure, increased permeability of vascular walls), but in addition there is also inflammation in the tissues. Because of this, the effusion fluid has a different composition and is inflammatory in nature, which is more dangerous for the patient. This is the main difference between transudate and exudate: the latter is more dangerous, so more time is devoted to its research.

Important! They try to get rid of the detected exudate as soon as possible. Otherwise, cancer cells may begin to form in it, causing cancer organ in the cavity of which there is effusion fluid.

Exudate and its types

Different types of exudates differ from each other in their composition, causes of inflammation and its characteristics. The type of effusion fluid can be determined using a puncture, after which the evacuated (pumped out) contents of a particular cavity are sent for laboratory testing. Although the doctor can sometimes make primary conclusions based on appearance liquids.

Serous exudate

In essence, serous effusion is a transudate that has begun to modify due to infection. Almost completely transparent; the protein content is moderate (up to 5%), there are few leukocytes, no red blood cells. The name reflects the fact that such exudate is found in the serous membranes. Can form as a result of inflammation caused by allergies, infection, deep wounds or burns.

Fibrinous exudate

Contains a large amount of fibrinogen - a colorless protein, the increased content of which indicates the presence of acute inflammatory or infectious diseases: influenza, diphtheria, myocardial infarction, pneumonia, cancer. Fibrinous exudate is found in the bronchi, gastrointestinal tract, and trachea. The danger of fibrinous deposits lies in the risk of their growth into the connective tissue and the formation of adhesions.

Purulent exudate

Or just pus. Contains dead or destroyed cells, enzymes, fibrin threads and other elements. Due to their decomposition, such exudate has a pronounced foul odor and a color that is pathological for organic liquids: greenish, brownish, bluish. Purulent exudate is also characterized by increased viscosity, which is due to the content of nucleic acids in it.

A type of pus is putrefactive exudate. It is formed as a result of inflammation caused by anaerobic (not requiring oxygen) bacteria. Has a more pronounced disgusting odor.

Hemorrhagic exudate

It has a pinkish tint, which is explained by the increased content of red blood cells in it. Hemorrhagic exudate often forms in pleural cavity as a result of tuberculosis. Some of the liquid may be coughed up.

Other types of exudates (serous, fibrinous, purulent) can be modified into hemorrhagic with a progressive increase in vascular permeability or with their destruction. Other diseases reported by hemorrhagic exudate: smallpox, anthrax, toxic flu.

Slimy

Contains a large amount of mucin and lysozyme, which provides it with a mucous structure. More often formed when inflammatory diseases nasopharynx (tonsillitis, pharyngitis, laryngitis).

Chylous exudate

Contains chyle (lymph), as evidenced by its milky color. If chylous exudate stagnates, a fattier layer with lymphocytes, leukocytes and a small amount of red blood cells forms on its surface. Most often, such an inflammatory effusion is found in the abdominal cavity; less often - in the pleural space.

There is also pseudochyle exudate, which is also formed by lymph, but the amount of fat in it is minimal. Occurs with kidney problems.

Cholesterol

Quite thick, with a beige, pinkish or dark brown (if there is a large number of red blood cells) tint. Contains cholesterol crystals, from which it gets its name. Cholesterol exudate may be present in any cavity for a long time and discovered by chance during surgery.

Rarely occurring exudates

IN exceptional cases in the cavities, neutrophilic (consists of neutrophils), lymphocytic (from lymphocytes), mononuclear (from monocytes) and eosinophilic (from eosinophils) exudates are found. Outwardly, they are almost no different from those listed earlier, and their composition can only be clarified using chemical analysis.

Laboratory studies of effusion fluids

The importance of determining the type and composition of effusion fluids is evidenced by the fact that the first laboratory studies began in the 19th century. In 1875, the German surgeon Heinrich Quincke pointed out the presence tumor cells isolated from fluids of serous cavities. With the development of chemical analysis and the advent of new research methods (in particular, staining biological fluids) it became possible to determine the characteristics cancer cells. In the USSR, clinical cytology began to actively develop in 1938.

Modern laboratory analysis is based on a specific algorithm. The nature of the effusion fluid is first determined: inflammatory or not. This is determined by the content of several indicators:

• protein (key indicator);
• albumins and globulins;
• cholesterol;
• leukocyte count;
• absolute amount of liquid (LDH), its density and pH.

A comprehensive study allows you to accurately distinguish exudate from transudate. If the inflammatory nature is determined, then a series of tests follows to determine the composition of the exudate and its type. The information allows the doctor to make a diagnosis and prescribe treatment.

Authors): O.Yu. KAMYSHNIKOV veterinary pathologist, Veterinary Center for Pathomorphology and Laboratory Diagnostics of Dr. Mitrokhina N.V.
Magazine: №6-2017

Keywords: transudate, exudate, effusion, ascites, pleurisy

Key words: transudate, exudate, effusion, ascites, pleurisy

annotation

The study of effusion fluids is currently of high importance in diagnostics. pathological conditions. The data obtained from this study allow the clinician to obtain information about the pathogenesis of effusion formation and to correctly organize therapeutic measures. However, on the path of diagnosis, certain difficulties always arise that can lead to a diagnostic trap. The need for this work arose in connection with the growing need for the development and application of the method of studying effusion fluids in the clinic by clinical laboratory diagnostic doctors and cytologists. Therefore, attention will be paid to both the main tasks of laboratory doctors - to differentiate effusion into transudate and exudate, and the most important task of cytologists - to verify cellular component fluid and formulate a cytological conclusion.

Examination of effusion fluids currently has a high significance in the diagnosis of pathological conditions. The findings of this study allow the clinician to obtain information on the pathogenesis of effusion formation, and to correctly organize medical interventions. However, on the path of diagnosis, there are always certain difficulties that can lead to a diagnostic trap. The need for this work has emerged in connection with the growing need for mastering and applying the method of examining exudate fluids in the clinic by physicians of clinical laboratory diagnostics and cytologists. Therefore, attention will be paid, as well as the main tasks of laboratory assistants - to differentiate the effusion to transudate and exudate, and the most important task of cytologists is to verify the cellular component of the fluid and formulate a cytological conclusion.

Abbreviations: ES – exudate, TS – transudate, C – cytology, MK – mesothelial cells.

Background

I would like to highlight some historical data that shaped the modern image of laboratory diagnostics of effusion fluids. The study of fluids from serous cavities was used already in the 19th century. In 1875 H.J. Quincke and in 1878 E. Bocgehold pointed to such characteristic features tumor cells, such as fatty degeneration and larger size compared to mesothelial cells (MCs). Success similar studies was relatively small, since a method for studying fixed and stained preparations did not yet exist. Paul Ehrlich in 1882 and M.N. Nikiforov in 1888 described specific methods for fixing and staining biological fluids, such as blood smears, effusion fluids, discharge, etc. J.C. Dock (1897) indicated that signs of cancer cells are a significant increase in the size of the nuclei, changes in their shape and location. He also noted atypia of the mesothelium due to inflammation. The Romanian pathologist and microbiologist A. Babes created the basis of the modern cytological method using azure dyes. Further development of the method occurred together with the entry into practical medicine of laboratory diagnostics, which in our country included cytologists among its specialists. Clinical cytology in the USSR as a method clinical examination patients began to be used in 1938 N.N. Schiller-Volkova. The development of clinical laboratory diagnostics in veterinary medicine occurred with a significant lag, so the first fundamental work domestic doctors and scientists in this field of knowledge saw the light only in 1953–1954. It was a three-volume volume “Veterinary Research Methods in Veterinary Medicine” edited by prof. S.I. Afonsky, Doctor of V.S. MM. Ivanova, prof. Ya.R. Kovalenko, where for the first time laboratory diagnostic methods, undoubtedly extrapolated from the field of human medicine, were clearly presented. From those ancient times to the present, the method of studying effusion fluids has been constantly improved, based on the foundation of previously acquired knowledge, and now occupies an integral part of any clinical diagnostic laboratory study.

In this work, an attempt is made to highlight the basics and essence of the laboratory study of effusion fluids.

general characteristics

Exudate fluids are components of blood plasma, lymph, tissue fluid, which accumulate in serous cavities. According to the generally accepted belief, effusion is fluid in the body cavities, and edematous fluid accumulates in tissues according to the same principle. Serous body cavities are a narrow gap between two layers of the serous membrane. Serous membranes are films originating from the mesoderm, represented by two layers: parietal (parietal) and visceral (organ). The microstructure of the parietal and visceral layer is represented by six layers:

1. mesothelium;

2. limiting membrane;

3. superficial fibrous collagen layer;

4. superficial non-oriented network of elastic fibers;

5. deep longitudinal elastic network;

6. deep lattice layer of collagen fibers.

Mesothelium – single layer squamous epithelium, consisting of polygonal cells tightly adjacent to each other. Despite its epithelial shape, the mesothelium is of mesodermal origin. Cells are very diverse in their morphological properties. Binucleate and trinucleate cells can be observed. The mesothelium constantly secretes fluid that performs a sliding and shock-absorbing function, is capable of extremely intense proliferation, and exhibits the characteristics of connective tissue. On the surface of the urinary tract there are many microvilli, increasing the surface of the entire membrane of the serous cavity by approximately 40 times. The fibrous layer of connective tissue of the serous membranes determines their mobility. The blood supply to the serous membrane of the visceral layer is carried out by the vessels of the organ that it covers. And for the parietal leaf, the basis of the circulatory system is a wide-loop network of arterio-arteriolar anastomoses. The capillaries are located immediately under the mesothelium. Lymphatic drainage from the serous membranes is well developed. Lymphatic vessels communicate with serous spaces thanks to special openings - stomata. Because of this, even minor blockage of the drainage system can lead to the accumulation of fluid in the serous cavity. And the anatomical properties of the blood supply lead to the rapid occurrence of bleeding when the mesothelium is irritated and damaged.

Clinical laboratory diagnostics effusion fluids

During a laboratory study, the question of whether the effusion is a transudate or an exudate is resolved, and the general properties (macroscopic appearance of the liquid) are assessed: color, transparency, consistency.

Fluid that accumulates in the serous cavities without an inflammatory reaction is called transudate. If fluid collects in the tissues, then we are dealing with edema ( edema). Transudate may accumulate in the pericardium ( hydropericardium), abdominal cavity ( ascites), pleural cavity ( hydrothorax), between the membranes of the testicle ( hydrocele). The transudate is usually transparent, almost colorless or with a yellowish tint, less often slightly cloudy due to the admixture of desquamated epithelium, lymphocytes, fat, etc. The specific gravity does not exceed 1.015 g/ml.

The formation of transudate can be caused by the following factors.

1. An increase in venous pressure, which occurs with circulatory failure, kidney disease, and cirrhosis of the liver. Transudation is the result of an increase in the permeability of capillary vessels as a result of toxic damage, hyperthermia, and nutritional disorders.
2. By reducing the amount of protein in the blood, the osmotic pressure of colloids decreases when plasma albumin decreases to less than 25 g/l ( nephrotic syndrome of various etiologies, severe liver damage, cachexia).
3. Blockage of lymphatic vessels. In this case, chylous edema and transudates are formed.
4. Violations of electrolyte metabolism, mainly increased sodium concentration (hemodynamic heart failure, nephrotic syndrome, cirrhosis of the liver).
5. Increased aldosterone production.

In one phrase, the formation of a transudate can be characterized as follows: a transudate occurs when hydrostatic or colloid-osmotic pressure changes to the extent that the fluid filtered into the serous cavity exceeds the volume of reabsorption.

The macroscopic characteristics of exudates make it possible to classify them as the following types.

1. Serous exudate may be clear or cloudy, yellowish or colorless (as determined by the presence of bilirubin), varying degrees turbidity (Fig. 1).

2. Serous-purulent and purulent exudate - a cloudy, yellowish-green liquid with abundant loose sediment. Purulent exudate occurs with pleural empyema, peritonitis, etc. (Fig. 2).

3. Putrid exudate – a cloudy liquid of gray-green color with a pungent putrefactive odor. Putrid exudate is characteristic of lung gangrene and other processes accompanied by tissue decay.

4. Hemorrhagic exudate - a clear or cloudy liquid, reddish or brownish-brown in color. The number of red blood cells can vary: from a small admixture, when the liquid has a faint pink color, to abundant, when it looks like whole blood. The most common cause of hemorrhagic effusion is a neoplasm, but the hemorrhagic nature of the fluid does not have much diagnostic significance, since it is also observed in a number of non-tumor diseases (trauma, pulmonary infarction, pleurisy, hemorrhagic diathesis). At the same time, in malignant processes with extensive dissemination of the tumor along the serous membrane, there may be a serous, transparent effusion (Fig. 3).

5. Chylous exudate is a milky, turbid liquid containing tiny fat droplets in suspension. When ether is added, the liquid becomes clear. Such an effusion is caused by lymph entering the serous cavity from destroyed large lymphatic vessels, an abscess, vascular infiltration by a tumor, filariasis, lymphoma, etc. (Fig. 4).

6. Chyle-like exudate is a milky-turbid liquid that appears as a result of abundant breakdown of cells with fatty degeneration. Since, in addition to fat, this exudate contains a large number of fat-degenerated cells, the addition of ether leaves the liquid cloudy or slightly clears it. Chyle-like exudate is characteristic of effusion fluids, the appearance of which is associated with atrophic cirrhosis of the liver, malignant neoplasms, etc.

7. Cholesterol exudate is a thick yellowish or brownish liquid with a pearlescent tint with shiny flakes consisting of clusters of cholesterol crystals. An admixture of destroyed red blood cells can give the effusion a chocolate tint. On the walls of the test tube, moistened with effusion, casts of cholesterol crystals in the form of tiny sparkles are visible. This is the character of an encysted effusion that exists for a long time (sometimes for several years) in the serous cavity. Under certain conditions - reabsorption of water and some mineral components of the exudate from the serous cavity, as well as in the absence of fluid influx into the closed cavity - exudate of any etiology can acquire the character of cholesterol.

8. Mucous exudate – contains a significant amount of mucin and pseudomucin, can occur with mesothelioma, mucus-forming tumors, pseudomyxoma.

9. Fibrinous exudate – contains a significant amount of fibrin.

There are also mixed forms of exudate (sero-hemorrhagic, muco-hemorrhagic, serous-fibrinous).

In native effusion fluid, it is necessary to conduct a cytosis study. To do this, immediately after puncture, the liquid is taken into a tube with EDTA to prevent it from clotting. Cytosis, or cellularity (in this method, only the number of nucleated cells is determined) is carried out according to standard methods in a Goryaev chamber or on a hematology analyzer in whole blood counting mode. The number of nuclear cells is taken to be the WBC (white blood cell, or leukocyte) value in thousands of cells per milliliter of liquid.

After determining the cytosis, the liquid can be centrifuged to obtain a sediment for microscopic examination. The supernatant, or supernatant, can also be tested for protein, glucose, etc. content. However, not all biochemical parameters can be determined from a liquid with EDTA, therefore it is also recommended that, along with taking the effusion into a test tube with an anticoagulant, simultaneously taking the liquid into a clean, dry test tube (for example, a centrifuge tube or for biochemical research). It follows that to study effusion fluid in the laboratory, it is necessary to obtain the material in at least two containers: a test tube with EDTA and a clean dry test tube, and the liquid must be placed there immediately after its evacuation from the body cavity.

The sediment is examined in the laboratory by a laboratory assistant or a cytologist. To sediment the effusion fluid, it is necessary to centrifuge it at 1500 rpm for 15–25 minutes. Depending on the type of effusion, a precipitate of varying quantity and quality is formed (it can be grayish, yellowish, bloody, single- or double-layered, and occasionally three-layered). In a serous transparent effusion, there may be very little sediment, its character is fine-grained, and the color is grayish-white. In a turbid purulent or chylous effusion with a large number of cells, a copious, coarse-grained sediment is formed. In hemorrhagic effusion with a large admixture of red blood cells, a two-layer sediment is formed: the upper layer in the form of a whitish film and the lower in the form of a dense accumulation of red blood cells. And when the sediment is divided into 3 layers, the upper one is often represented by a component of destroyed cells and detritus. When preparing smears on glass slides, material from the sediment is taken from each layer and at least 2 smears are prepared. For a single-layer deposit, it is recommended to make at least 4 glasses. If the amount of sediment is scanty, 1 smear is prepared with the maximum amount of material in it.

Smears dried in air at room temperature are fixed and stained with azure-eosin according to the standard method (Romanovsky-Giemsa, Pappenheim-Kryukov, Leishman, Nocht, Wright, etc.).

Differential diagnosis of transudates and exudates

To differentiate transudate from exudate, you can use several methods, which are based on determining the physical and biochemical parameters of the liquid. The distinction is based on protein content, cell type, color of the liquid and its specific gravity.

Transudate, in contrast to exudate, is an effusion of non-inflammatory origin, and it is fluid that accumulates in body cavities as a result of the influence of systemic factors regulating homeostasis on the formation and resorption of fluid. The specific gravity of transudate is lower than that of exudates and is less than 1.015 g/ml versus 1.015 or more for exudates. The total protein content of transudates is less than 30 g/l versus a value exceeding 30 g/l for exudates. There is a high-quality test that allows you to verify transudate from exudate. This is the well-known Rivalta test. She entered laboratory practice more than 60 years ago and has held important place in the diagnosis of effusion fluids up to the development of biochemical methods and their simplification and accessibility, which made it possible to move from the qualitative method of the Rivalta test to quantitative characteristics of protein content. However, now many researchers are proposing to use the Rivalta test to quickly and fairly accurately obtain data on effusion. Therefore, it is necessary to describe this sample a little.

Rivalta sample

In a narrow cylinder with weak solution acetic acid(100 ml of distilled water + 1 drop of glacial acetic acid) add the test effusion liquid drop by drop. If this drop, falling down, gives a streak of turbidity trailing behind it, then the liquid is an exudate. Transudates positive test do not give or give a weakly positive short-term turbidity reaction.

“Cytological Atlas of Dogs and Cats” (2001) R. Raskin and D. Meyer propose to distinguish the following types of serous fluids: transudates, modified transudates and exudates.

Modified transudate is a transitional form from transudate to exudate, containing “intermediate values” of protein concentration (between 25 g/l and 30 g/l) and specific gravity (1.015–1.018). In modern Russian literature the term “modified transudate” is not given. However, the formulations “more data for transudate” or “more data for exudate” are allowed based on the results of the differential characteristics parameters.

In table Table 1 shows the parameters, the determination of which allows one to verify transudate from exudate.

Table 1. Differential characteristics transudates and exudates

	Transudates	Exudates
Specific gravity, g/ml		more than 1,018
Protein, g/l	less than 30 g/l	more than 30 g/l
Clotting	usually absent	usually happens
Bacteriology	Sterile or contain “travel” microflora	At microbiological research microflora is detected (streptococci, staphylococci, pneumococci, E. coli, etc.)
Sediment cytology	Mesothelium, lymphocytes, sometimes erythrocytes (“travel”)	Neutrophils, lymphocytes, plasma cells, macrophages and red blood cells in abundance, eosinophils, reactive mesothelium, tumor cells
Total protein effusion/serum ratio
LDH, ratio LDH effusion/LDH serum
Glucose concentration, mmol/l	more than 5.3 mmol/l	less than 5.3 mmol/l
Cholesterol concentration, mmol/l	less than 1.6 mmol/l	more than 1.6 mmol/l
Cytosis (nucleated cells)	less than 1×10 9 /l	more than 1×10 9 /l

Microscopic examination of exudates

Description of cytograms of effusion fluids

In Fig. Figure 5 shows a micrograph of the reactive effusion sediment. In the sediment, mesothelial cells are observed, often binucleate, with abundant intensely basophilic cytoplasm and rounded hyperchromatic nuclei. The edge of the cytoplasm is uneven, villous, often with a sharp transition from basophilic to bright oxyphilic staining along the edge of the cell. The nuclei contain dense compact heterochromatin; nucleoli are not visible. Macrophages and segmented neutrophils are present in the microenvironment. The background of the drug is not determined.

In Fig. Figure 6 shows a micrograph of the reactive effusion sediment. Macrophages are observed in the sediment (the figure shows 2 cells in close proximity). Cells irregular shape, have abundant inhomogeneous “lacey” cytoplasm with many vacuoles, phagosomes, and inclusions. The cell nuclei are irregular in shape and contain delicately reticulated and looped chromatin. Remnants of nucleoli are visible in the nuclei. There are 2 lymphocytes in the microenvironment. The background of the preparation contains red blood cells.

In Fig. Figure 7 shows a micrograph of the reactive effusion sediment. Mesothelial cells with pronounced signs reactive changes: hyperchromia of both the cytoplasm and nuclei, swelling of the cytoplasm, mitotic figures. Macrophages in the microenvironment have signs of erythrophagocytosis, which is often observed in acute hemorrhages in the serous cavities.

In Fig. Figure 8 shows a microphotograph of the sediment of the reactive-inflammatory effusion. Macrophages, lymphocytes and segmented neutrophils with signs of degenerative changes are observed in the sediment. Degenerative changes in neutrophils are regarded as an indicator of the duration of inflammation and the activity of the inflammatory reaction. The “older” the inflammation, the more pronounced the degenerative signs. The more active the process, the more often typical cells are found against the background of altered neutrophils.

A big problem in the interpretation of cytograms is created by mesothelial cells, which are capable, under the influence of unfavorable factors and irritation, of acquiring signs of atypia, which can be mistakenly taken for signs of malignancy.

The criteria for malignancy (atypia) of cells in the effusion are shown in comparison in Table. 2.

Table 2. Distinctive features of reactive mesothelial cells and malignant neoplasm cells.

Malignant tumors of the serous membranes can be primary (mesothelioma) and secondary, i.e. metastatic.

Common metastases malignant tumors along the serous membranes:

1. for the pleural and abdominal cavity – breast cancer, lung cancer, gastrointestinal cancer, ovarian, testicular cancer, lymphoma;

2. for the pericardial cavity - most often lung and breast cancer.

It is possible that metastases may also be detected in the serous cavities of the body. squamous cell carcinoma, melanoma, etc.

In Fig. Figure 9 shows a micrograph of a sediment of effusion fluid when the abdominal cavity is affected by metastases of glandular cancer. In the center of the microphoto, a multilayered complex of atypical epithelial cells is visible - metastasis of glandular breast cancer. The boundaries between cells are indistinguishable, the hyperchromic cytoplasm hides the nuclei. The background of the preparation contains red blood cells and inflammatory cells.

In Fig. Figure 10 shows a micrograph of a sediment of effusion fluid when the abdominal cavity is affected by metastases of glandular cancer. In the center of the microphotograph a spherical structure of atypical epithelial cells is visualized. The complex of cells has a glandular structure. The boundaries of neighboring cells are indistinguishable. Cell nuclei are characterized by moderate polymorphism. The cytoplasm of the cells is moderate, intensely basophilic.

In Fig. Figures 11 and 12 show microphotographs of effusion fluid sediment when the pleural cavity is affected by metastases of glandular cancer. The figures show complexes of atypical polymorphic cells of epithelial origin. The cells contain large polymorphic nuclei with fine-grained dispersed chromatin and 1 large nucleolus. The cytoplasm of the cells is moderate, basophilic, containing fine oxyphilic granules - signs of secretion.

In Fig. Figure 13 shows a micrograph of a sediment of effusion fluid when the abdominal cavity is affected by metastases of glandular cancer. The microscope is shown at low magnification - the cell complex is very large. And in Fig. Figure 14 shows a more detailed structure of cancer cells. The cells form a glandular complex - the clearing of the noncellular component in the center of the complex is surrounded by rows of atypical tumor epithelial cells.

Forming a conclusion about the belonging of the found tumor cells to the primary focus is possible on the basis of anamnesis data and the specific structure of the cells and their complexes. With an undetected primary tumor focus, lack of medical history, low cell differentiation, and severe atypia, it is difficult to determine the tissue affiliation of tumor cells.

Rice. 15 shows a giant atypical cancer cell in the effusion fluid. The primary focus in this case was not identified. The cell contains a large, “bizarrely shaped” nucleus, moderate basophilic cytoplasm with inclusions and the phenomenon of empiriopolosis.

When lymphoma disseminates along the serous membranes, many atypical lymphoid cells will enter the effusion (Fig. 16). These cells are often of the blast cell type and are distinguished by polymorphism and atypia: they contain polymorphic nucleoli, have an uneven karyolemma with depressions, and uneven chromatin (Fig. 17).

Mesothelioma creates significant difficulties at the stage of diagnosing damage to the serous membranes by malignant tumors.

Mesothelioma – primary malignancy serous membranes. According to statistics, it is more common in the pleural than in the peritoneal cavity. Mesothelioma is extremely difficult for histological and even more so cytological diagnosis, since it becomes necessary to differentiate it from reactive mesothelium and from almost all possible types of cancer found in serous cavities.

In Fig. Figures 18–19 show micrographs of mesothelioma cells in the effusion. The cells are distinguished by severe atypia, polymorphism, and gigantic size. However morphological characteristics mesothelial cells are so diverse that without much practical experience It is almost impossible for a cytologist to “recognize” mesothelioma.

Conclusion

Based on the above, we can conclude that cytological examination of exudates from serous cavities is the only method for diagnosing the nature of the effusion. And the routine examination of effusion fluids when determining whether they belong to exudate should be supplemented by a cytological examination of the sediment.

Literature

1. Abramov M.G. Clinical cytology. M.: Medicine, 1974.

2. Balakova N.I., Zhukhina G.E., Bolshakova G.D., Mochalova I.N. Fluid testing

from serous cavities. L., 1989.

3. Volchenko N.N., Borisova O.V. Diagnosis of malignant tumors by serous exudates. M.: GEOTAR-Media, 2017.

4. Dolgov V.V., Shabalova I.P. etc. Exudate fluids. Laboratory research. Tver: Triad, 2006.

5. Klimanova Z.F. Cytological examination of exudates in metastatic lesions of the peritoneum and pleura by cancer: Guidelines. M., 1968.

6. Kost E.A. Handbook of Clinical laboratory methods research. M.: Medicine, 1975.

7. Guide to the cytological diagnosis of human tumors. Ed. A.S. Petrova, M.P. Ptokhova. M.: Medicine, 1976.

8. Strelnikova T.V. Exudate fluids ( analytical review literature). RUDN University Bulletin, series: Agronomy and livestock breeding. 2008; 2.

9. Raskin R.E., Meyer D.J. Atlas of canine and feline cytology. W.B. Sanders, 2001.

Each of us has encountered inflammation of one kind or another. And if its serious forms, such as pneumonia or colitis, occur in special cases, then such minor troubles as a cut or abrasion are an everyday occurrence. Many people don’t pay attention to them at all. But even the most minor injuries can cause exudative inflammation. In essence, this is a condition of the affected area in which specific liquids collect in it and then seep out through the walls of the capillaries. This process is quite complex, based on the laws of hydrodynamics and can lead to complications in the course of the disease. In this article we will look in detail at the causes of exudative inflammation. We will also consider the types (outcomes for each of them are not equal) of this kind of inflammatory processes, and along the way we will explain what they depend on, how they proceed, and what treatment they require.

Is inflammation bad or good?

Many will say that, of course, inflammation is evil, because it is integral part almost any disease and brings suffering to a person. But in fact, in the process of evolution, our body has developed mechanisms of inflammatory processes for many years so that they help survive harmful influences, in medicine called irritants. They can be viruses, bacteria, any skin wounds, chemicals (for example, poisons, toxins), adverse factors external environment. Exudative inflammation should protect us from the pathological activity of all these irritants. What it is? Without going into details, it is quite simple to explain. Any irritant entering the human body damages its cells. This is called alteration. It starts the inflammatory process. Its symptoms, depending on the type of irritant and the location of its introduction, may differ. Among the common ones are:

• a rise in temperature either throughout the body or only in the damaged area;
• swelling of the sore spot;
• soreness;
• redness of the injured area.

These are the main signs by which you can understand that exudative inflammation has already begun. The photo above clearly demonstrates the manifestation of symptoms - redness, swelling.

At some point, fluids (exudate) begin to accumulate in the vessels. When they penetrate through the walls of the capillaries into the intercellular space, the inflammation becomes exudative. At first glance, this appears to be making the problem worse. But in fact, the release of exudate, or, as doctors say, exudation, is also necessary. Thanks to it, very important substances enter the tissues from the capillaries - immunoglobulins, kinins, plasma enzymes, leukocytes, which immediately rush to the source of inflammation to begin eliminating irritants and healing damaged areas.

Exudation process

Explaining what exudative inflammation is, pathological anatomy (the discipline that studies pathological processes) pays special attention to the process of exudation, the “culprit” of this type of inflammation. It consists of three stages:

1. An alteration has occurred. She put special organic compounds into work - (kinins, histamines, serotonins, lymphokines and others). Under their influence, the microvascular beds began to expand, and as a result, the permeability of the vessel walls increased.
2. In wider sections of the riverbeds, the blood flow began to move more intensely. So-called hyperemia arose, which, in turn, led to an increase in blood (hydrodynamic) pressure in the vessels.
3. Under the pressure of fluid from microvessels, exudate began to seep into the tissue through enlarged interendothelial gaps and pores, sometimes reaching the size of tubules. The particles that make it up moved to the site of inflammation.

Types of exudates

It is more correct to call liquids leaving the vessels into the tissues exudate, and the same liquids released in the cavity as effusion. But in medicine these two concepts are often combined. Exudative type inflammation is determined by the composition of the secretion, which can be:

• serous;
• fibrous;
• purulent;
• putrid;
• hemorrhagic;
• mucous;
• frail;
• chyle-like;
• pseudochyleous;
• cholesterol;
• neutrophilic;
• eosinophilic;
• lymphocytic;
• mononuclear;
• mixed.

Let us consider in more detail the most common types of exudative inflammation, the causes of its occurrence and symptoms.

A form of serous exudative inflammation

In the human body, the peritoneum, pleura, and pericardium are covered by serous membranes, so named from the Latin word “serum,” which means “serum,” because they produce and absorb fluids that resemble or are formed from blood serum. The serous membranes in their normal state are smooth, almost transparent, and very elastic. When exudative inflammation begins, they become rough and cloudy, and serous exudate appears in the tissues and organs. It contains proteins (more than 2%), lymphocytes, leukocytes, and epithelial cells.

The causes of exudative inflammation can be:

• injuries of various etiologies (violations of skin integrity, burns, insect bites, frostbite);
• intoxication;
• viral and bacterial infections(tuberculosis, meningitis, herpes, chickenpox and others);
• allergy.

Serous exudate helps remove toxins and irritants from the source of inflammation. Along with its positive functions, there are also negative ones. So, if serous exudative inflammation occurs in the lung parenchyma, respiratory failure may develop, in the pericardium - heart failure, in the meninges - cerebral edema, in the kidneys - renal failure, in the skin under the epidermis - peeling it off from the dermis and the formation of serous blisters. Each disease has its own symptoms. Some common symptoms include a rise in temperature and pain. Despite the seemingly very dangerous pathology, the prognosis in the vast majority of cases is favorable, since the exudate resolves without leaving traces, and the serous membranes are restored.

Fibrous inflammation

As noted above, all types of exudative inflammation are determined by the composition of the secretion released from the microvessels. Thus, fibrous exudate is obtained when, under the influence of inflammatory stimuli (trauma, infection), an increased amount of fibrinogen protein is formed. Normally, an adult should have 2-4 g/l. In damaged tissues, this substance is also converted into protein, which has a fibrous structure and forms the basis of blood clots. In addition, the fibrous exudate contains leukocytes, macrophages, and monocytes. At some stage of inflammation, necrosis of the tissues affected by the irritant develops. They become saturated with fibrous exudate, resulting in the formation of a fibrous film on their surface. Microbes actively develop under it, which complicates the course of the disease. Depending on the location of the film and its characteristics, diphtheria and lobar fibrous exudative inflammation are distinguished. Pathological anatomy describes their differences this way:

1. Diphtheria inflammation can occur in those organs that are covered with a multilayer membrane - in the pharynx, uterus, vagina, bladder, and gastrointestinal tract. In this case, a thick fibrous film is formed, as if grown into the membrane of the organs. Therefore, it is difficult to remove, and leaves ulcers behind. They heal over time, but scars may remain. There is another evil - under this film microbes multiply most actively, as a result of which the patient experiences high intoxication with the products of their vital activity. The most known disease This type of inflammation is diphtheria.
2. Croupous inflammation forms on the mucous membranes of organs covered with a single-layer membrane: in the bronchi, peritoneum, trachea, pericardium. In this case, the fibrous film turns out to be thin, easily removable, without significant defects mucous membranes. However, in some cases it can create serious problems, for example, if the trachea is inflamed, it can make it difficult for air to enter the lungs.

Exudative purulent inflammation

This pathology is observed when the exudate is pus - a viscous greenish-yellow mass, in most cases having a characteristic odor. Its composition is approximately this: leukocytes, most of which are destroyed, albumins, fibrin threads, enzymes of microbial origin, cholesterol, fats, DNA fragments, lecithin, globulins. These substances form purulent serum. In addition to it, the purulent exudate contains tissue detritus, live and/or degenerated microorganisms, and purulent bodies. Purulent inflammation can occur in any organ. The “culprits” of suppuration are most often pyogenic bacteria (various cocci, E. coli, Proteus), as well as candida, Shigella, Salmonella, Brucella. Forms of exudative inflammation purulent in nature are like this:

1. Abscess. It is a lesion with a barrier capsule that prevents pus from entering adjacent tissues. Purulent exudate accumulates in the cavity of the lesion, entering there through the capillaries of the barrier capsule.
2. Phlegmon. In this form, the source of inflammation has no clear boundaries, and the purulent exudate spreads into adjacent tissues and cavities. This picture can be observed in the subcutaneous layers, for example, in adipose tissue, in the retroperitoneal and perinephric zones, wherever morphological structure tissue allows pus to escape beyond the focus of inflammation.
3. Empyema. This form is similar to an abscess and is observed in cavities next to which there is a focus of inflammation.

If many degenerative neutrophils are present in the pus, the exudate is called purulent neutrophilic. In general, the role of neutrophils is to destroy bacteria and fungi. They, like brave guards, are the very first to rush at enemies who have penetrated our body. Therefore on initial stage inflammation, most neutrophils are intact, undestroyed, and the exudate is called micropurulent. As the disease progresses, white blood cells are destroyed, and in the pus most of them are already degenerated.

If putrefactive microorganisms (in most cases anaerobic bacteria) enter the inflammatory focus, the purulent exudate develops into putrefactive one. It has a characteristic odor and color and promotes tissue decomposition. This is fraught with high intoxication of the body and has a very unfavorable outcome.

Treatment purulent inflammation is based on the use of antibiotics and ensuring the outflow of secretions from the lesion. Sometimes this requires surgical intervention. Prevention of such inflammation is disinfection of wounds. Treatment of this pathology can have a favorable outcome only with intensive chemotherapy with simultaneous surgical removal of rotting fragments.

Hemorrhagic inflammation

With some very dangerous diseases, such as smallpox, plague, toxic flu, hemorrhagic exudative inflammation is diagnosed. The reasons for this are the increasing permeability of microvessels up to their rupture. In this case, red blood cells predominate in the exudate, due to which its color varies from pink to dark red. External manifestation hemorrhagic inflammation is similar to hemorrhage, but, unlike the latter, not only red blood cells are found in the exudate, but also a small proportion of neutrophils with macrophages. Treatment of hemorrhagic exudative inflammation is prescribed taking into account the type of microorganisms that led to it. The outcome of the disease can be extremely unfavorable if therapy is started untimely and if the patient’s body does not have enough strength to resist the disease.

Catarrh

The peculiarity of this pathology is that the exudate with it can be serous, purulent, and hemorrhagic, but always with mucus. In such cases, a mucous secretion is formed. Unlike serous, it contains more mucin, the antibacterial agent lysozyme and A-class immunoglobulins. It is formed for the following reasons:

• viral or bacterial infections;
• effect on the body chemical substances, high temperatures;
• metabolic disorders;
• allergic reactions (for example, allergic rhinitis).

Catarrhal exudative inflammation is diagnosed in bronchitis, catarrh, rhinitis, gastritis, catarrhal colitis, acute respiratory infections, pharyngitis and can occur in acute and chronic forms. In the first case, it is completely cured in 2-3 weeks. In the second, changes occur in the mucosa - atrophy, in which the membrane becomes thinner, or hypertrophy, in which, on the contrary, the mucosa becomes thickened and can protrude into the organ cavity.

The role of mucous exudate is twofold. On the one hand, it helps fight infection, and on the other, its accumulation in cavities leads to additional pathological processes For example, mucus in the sinuses contributes to the development of sinusitis.

Treatment of catarrhal exudative inflammation is carried out with antibacterial drugs, physiotherapeutic procedures and folk methods, such as heating, rinsing with various solutions, ingesting infusions and decoctions of herbs.

Exudative inflammation: characteristics of specific exudative fluids

Mentioned above were chylous and pseudochylous exudates that appear as a result of injuries to the lymphatic vessels. For example, in the chest this could be due to a rupture of the thoracic duct. Chylous exudate is white in color due to the presence of increased amount fat

Pseudochyleous also has a whitish tint, but it contains no more than 0.15% fat, but there are mucoid substances, protein bodies, nucleins, and lecithins. It is observed in lipoid nephrosis.

The exudate is white and chyle-like, but its color is given by disintegrated degenerated cells. It is formed during chronic inflammation of the serous membranes. In the abdominal cavity this happens with cirrhosis of the liver, in the pleural cavity - with tuberculosis, pleural cancer, syphilis.

If the exudate contains too many lymphocytes (more than 90%), it is called lymphocytic. It is released from the vessels when cholesterol is present in the secretion, by analogy it is called cholesterol. It has a thick consistency, yellowish or brownish color and can be formed from any other exudative liquid, provided that water and mineral particles are reabsorbed from the cavity in which it accumulates for a long time.

As you can see, there are many types of exudates, each of which is characteristic of a specific type of exudative inflammation. There are also cases when, for any one disease, mixed exudative inflammation is diagnosed, for example, serous-fibrous or serous-purulent.

Acute and chronic forms

Exudative inflammation can occur in acute or chronic form. In the first case, it is an instant response to a stimulus and is intended to eliminate this stimulus. There can be many reasons for this form of inflammatory process. The most common:

• injury;
• infections;
• chemical poisoning;
• disruption of the functioning of any organs and systems.

Acute exudative inflammation is characterized by redness and swelling of the injured area, pain, and fever. Sometimes, especially due to infection, patients experience symptoms autonomic disorders and intoxication.

Acute inflammation lasts a relatively short time, and if therapy is carried out correctly, it is completely cured.

Chronic exudative inflammation can last for years. It is represented by purulent and catarrhal types of the inflammatory process. In this case, tissue destruction develops simultaneously with healing. And although in the remission stage chronic inflammation hardly bothers the patient, it can ultimately lead to exhaustion (cachexia), sclerotic changes in blood vessels, irreversible disruption of organ function and even the formation of tumors. Treatment is aimed mainly at maintaining the remission phase. In this case great importance given to a correct lifestyle, diet, and strengthening the immune system.