Diagnosis of pneumonia

Diagnosis of pneumonia is based on the identification of the five most simple and sufficiently informative clinical and laboratory and instrumental signs, called the "gold standard" of diagnosis:

1. An acute onset of the disease, accompanied by an increase in body temperature above 38 ° C.
2. Sudden appearance or marked increase in cough with separation of sputum mainly purulent and / and hemorrhagic nature.
3. The appearance of previously missing local blunting (shortening) of percussion sound and the above described auscultatory phenomena characteristic of lobar (focal) or focal pneumonia (weakening of breathing, bronchial breathing, crepitation, wet small bubble sonorous rattles, pleural friction noise).
4. Leukocytosis or (less often) leukopenia in combination with neutrophil shift.
5. X-ray signs of pneumonia - focal inflammatory infiltrates in the lungs, which had not previously been detected.

Differential diagnosis of pneumonia

Nevertheless, modern approaches to etiotropic treatment of patients with pneumonia require a number of additional laboratory and instrumental tests to identify the causative agent, perform differential diagnosis of pulmonary disease, assess the functional state of the respiratory system and timely diagnosis of complications of the disease. To this end, in addition to chest X-ray, general and biochemical blood analysis, the following additional studies are envisaged:

• sputum examination (microscopy of the colored preparation and sowing to identify the pathogen);
• evaluation of the function of external respiration;
• The study of blood gases and oxygen saturation of arterial blood (in cases
• pneumonia of severe course to be treated in the ICU;
• repeated blood tests "for sterility" (with suspicion of bacteremia and sepsis);
• X-ray computed tomography (with insufficient informativeness of the traditional X-ray study);
• Pleural puncture (in the presence of effusion) and some others.

The choice of each of these methods is individual and should be based on an analysis of the clinical picture of the disease and the effectiveness of the diagnosis, differential diagnosis and treatment.

[1], [2], [3], [4], [5], [6]

Radiographic diagnosis of pneumonia

X-ray methods of investigation are crucial in the diagnosis of pneumonia. Currently, the clinic is widely used methods such as X-ray and chest X-ray, tomography, computed tomography. Practical physician should well represent the possibilities of these methods, in order to select the most informative ones in each specific case of the disease and, if possible, to reduce the radiation load on the patient.

X-ray examination

It should be borne in mind that one of the most accessible and common methods of X-ray examination - chest X-ray - has a number of significant disadvantages, namely:

1. differs in the well-known subjectivity of the interpretation of the radiographic picture,
2. does not provide an opportunity to objectively compare the radiographic data obtained during repeated studies and
3. accompanied by a large radiation burden on the patient and the medical staff.

Therefore, the field of application of the fluoroscopic method in clinical practice should apparently be limited to the study of chest organs in the course of their movement (for example, the study of the mobility of the diaphragm, the nature of the movements of the heart when it is contracted, etc.) and clarifying the topography of pathological changes in the lungs when using different positions of the patient.

Radiography

The main method of radiographic examination of the respiratory system is radiography in two projections - direct and lateral, which allows obtaining objective and documented information on the state of the organs of the thorax. In this case, it is necessary, as far as possible, to encircle not only the nature of the pathological process, but also to accurately determine its localization, corresponding to the projection of this or that proportion of the lung and pulmonary segments.

X-ray diagnosis of pneumonia is based on the results of a study of pulmonary fields, including the evaluation of:

• features of the pulmonary pattern;
• condition of the roots of the lungs;
• presence of widespread or limited darkening of pulmonary fields (compaction of lung tissue);
• the presence of limited or diffuse bleaching of lung tissue (increased airiness).

Of great importance is also the evaluation of the state of the skeleton of the thorax and the determination of the position of the diaphragm. 

The roots of the lungs located in the middle zone of the pulmonary fields between the anterior ends of the II and IV ribs are formed by shadows of the branches of the pulmonary artery and pulmonary veins, as well as of the large bronchi. Depending on their location in relation to the plane of the screen, they are represented on the X-ray in the form of branching strips or clear round or oval formations. The shadows of the vessels forming the root of the lung continue and beyond its limits in the pulmonary fields, forming a pulmonary pattern. Normally, it is well marked in the central basal zone, and on the periphery is represented by only a few, very small, vascular branches.

Below is a brief description of the radiographic pattern characteristic of two clinical and morphological variants of pneumonia (croup and focal), as well as some features of radiographic changes in pneumonia of different etiology.

Tomography

Tomography is an additional method of "layer-by-layer" radiological examination of organs, which is used in patients with pneumonia for a more detailed study of the pulmonary pattern, the nature of the pathological process in the pulmonary parenchyma and interstitium, the state of the tracheobronchial tree, the roots of the lungs, mediastinum, etc.

The principle of the method is that as a result of the synchronous movement of the X-ray tube and the film cassette in the opposite direction on the film, a fairly clear image of only those parts of the organ (its "layers") located at the center level or the axis of rotation of the tube and cassette is obtained. All the other details ("elephant") that are outside this plane are, as it were, "smeared", their image becomes blurred.

To obtain a multi-layered image, special cassettes are used, in which several films are placed at a suitable distance from each other. More commonly used is the so-called longitudinal tomography, where the separated layers are in the longitudinal direction. The "swing angle" of the tube (and cassette) is usually 30-45 °. This method is used to study pulmonary vessels. To evaluate the aorta, pulmonary artery, lower and upper hollow, it is better to use a transverse tomography.

In all cases, the choice of the depth of tomographic examination, exposure value, swing angle and other technical parameters of the study is carried out only after the analysis of the pre-made X-ray.

In diseases of the respiratory system, the tomography method is used to clarify the nature and individual details of the pathological process in the lungs, as well as to assess morphological changes in the trachea, bronchi, lymph nodes, vessels, etc. This method is particularly important in the study of patients who are suspected of having a tumor in the lungs, bronchi and pleura.

The program of examination for suspected pneumonia

According to the consensus of the Russian Congress of Pulmonology (1995), the following research is recommended for pneumonia.

1. Research mandatory for all patients
   • clinical examination of patients;
   • a clinical blood test;
   • X-ray of the lungs in two projections;
   • bacterioscopy of sputum stained by Gram;
   • sputum culture with a quantitative assessment of the flora and the definition of its sensitivity to antibiotics;
   • general urine analysis.
2. Studies conducted according to the indications
   • study of the function of external respiration in case of ventilation disorders;
   • study of blood gases and acid-base balance in severe patients with respiratory failure;
   • pleural puncture followed by a pleural fluid study in patients with fluid in the pleural cavity;
   • tomography of the lungs with suspected destruction of lung tissue or lung neoplasm;
   • serological tests (detection of antibodies to the pathogen) - with atypical pneumonia;
   • biochemical analysis of blood in severe pneumonia in persons over 60;
   • fibrobronchoscopy - if suspected of swelling, hemoptysis, with prolonged pneumonia;
   • the study of the immunological status - with a prolonged course of pneumonia and in persons with signs of immunodeficiency;
   • scintigraphy of the lungs - with suspected PE.

X-ray signs of croupous pneumonia

Stage of the tide

The earliest radiologic change that occurs in the first day of the croupous inflammation of the lungs (tidal stage) is an increase in the pulmonary pattern in the affected lobe, due to an increase in the blood filling of the pulmonary vessels, as well as inflammatory edema of the lung tissue. Thus, in the tidal stage, both vascular and interstitial components of the pulmonary pattern are intensified.

There is also a slight expansion of the lung root on the side of the lesion, its structure becomes less distinct. In this case, the transparency of the pulmonary field is practically unchanged or slightly reduced.

If the focus of the forming croupous pneumonia is located in the lower lobe, a decrease in the mobility of the corresponding dome of the diaphragm is observed.

The stage of custody

The stage of curation is characterized by the appearance on the 2nd-3rd day of the onset of the disease of intense homogeneous darkening, corresponding to the projection of the affected lobe of the lung. The intensity of the shadow is more pronounced on the periphery. The size of the affected lobe is slightly enlarged or not changed; a decrease in the volume of the share is observed comparatively rarely. There is an expansion of the lung root on the side of the lesion, the root becomes unstructured. The pleura is compacted. The lumen of large bronchi with croupous pneumonia remains free.

Stage of resolution

The resolution stage is characterized by a gradual decrease in the intensity of the shadow and its fragmentation. In uncomplicated pneumonia, 2.5-3 weeks later, complete resolution of the infiltrate occurs. In other cases, the reinforcement of the pulmonary pattern with areas of its deformation is preserved on the site of the affected part, which is the radiographic evidence of pneumofibrosis. At the same time, a small seal of the pleura remains.

X-ray signs of focal pneumonia

Focal bronchopneumonia is characterized by infiltration of alveolar and interstitial tissue and involvement in the inflammatory process of the lung root on the side of the lesion. At the initial stages of the disease there is a local enhancement of the pulmonary pattern and a slight expansion of the lung root. After a while in the pulmonary field, relatively small (from 0.3 to 1.5 cm in diameter) and diverse in form foci of infiltration (dimming) begin to appear. They are characterized by a multiplicity, different size, low intensity of the shadow, blurred outlines and, as a rule, are accompanied by an intensification of the pulmonary pattern. The roots of the lungs become enlarged, slightly structured, with indistinct contours.

Often there are several enlarged peribronchial lymph nodes. There is also a limitation of the mobility of the dome of the diaphragm.

In uncomplicated cases, under the influence of anti-inflammatory treatment, a positive dynamics of the radiographic pattern is usually observed and after 1.5-2 weeks pulmonary infiltrates dissolve. Sometimes bronchopneumonia can be complicated by reactive pleurisy or destruction of lung tissue.

X-ray signs of staphylococcal pneumonia

X-ray picture of staphylococcal pneumonia is characterized by the presence of multiple inflammatory infiltrates, most often located in both lungs. Inflammatory infiltrates often merge. There is a tendency to their disintegration with the formation, against the background of shadows, of limited bleaching with a horizontal liquid level. With the "bullous form" of pneumonia, the cavities can disappear without a trace in one place and appear in others. Often there is effusion in the pleural cavity.

After the resolution of staphylococcal pneumonia, for a long time, the enhancement of the pulmonary pattern persists, and in some cases the regions of pionmosclerosis are formed, the cysts remain on the site of the cavities, and the pleural sheets (mooring) are retained.

X-ray signs of pneumonia caused by Klebsiella

The peculiarity of Friedlander pneumonia, caused by klebsiella, is the vastness of the lesion of lung tissue, which radiologically manifests itself from the first days of the disease. Multiple large or smaller inflammatory infiltrates quickly merge with each other, capturing large areas of the lung, often corresponding to the projection of an entire lobe of the lung ("pseudoblacial" pneumonia). Quite quickly in the infiltrate, multiple decay cavities appear, which also tend to merge and form a large cavity with a horizontal liquid level. Often, the disease is complicated by the development of exudative pleurisy.

The course of Friedlander pneumonia is long (up to 2-3 months). After recovery, as a rule, remain areas of pronounced pynmosclerosis and lung lining. Often formed bronchiectasises, and the pleural cavity is partially obliterated.

X-ray signs of pneumonia caused by intracellular pathogens

With legionellosis pneumonia, radiographic changes are diverse. Most often, multiple infiltrates are detected in both lungs, which later merge into a large shared darkening. Disintegration of the tissue and the formation of abscesses are rare. Degeneration of infiltrates and normalization of the radiographic pattern in uncomplicated course of the disease occurs in 8-10 weeks.

With mycoplasmal pneumonia, only local enhancement and deformation of the pulmonary pattern can be detected on the radiographs, reflecting the infiltration of the interstitial tissue. Some patients in this foyer have low intensity focal shadows that tend to merge. Normalization of the radiographic pattern occurs through 2-4 pedules.

In chlamydial pneumonia, focal reinforcement and deformation of the pulmonary pattern, expansion of the lung root and pleural reaction in the form of its consolidation are also initially determined. Further on this background, numerous inflammatory foci, of low intensity, with indistinct contours can appear. After their disappearance against the background of treatment for a long time, the enhancement of the pulmonary pattern persists, and sometimes discoid atelectasis is seen. Normalization of the radiographic pattern occurs in 3-5 weeks.

Computed tomography with pneumonia

Computed tomography (CT) is a highly informative method of X-ray examination of a patient, which is becoming increasingly common in clinical practice. The method is characterized by high resolution, allowing to visualize foci up to 1-2 mm in size, the possibility of obtaining quantitative information on tissue density and the convenience of presenting an x-ray picture in the form of thin (up to 1 mm) consecutive transverse or longitudinal "slices" of the organs under study.

The transmission of each tissue layer is carried out in a pulsed mode by means of an X-ray tube with a slot collimator that rotates about the longitudinal axis of the patient's body. The number of such X-ray transmission at different angles amounts to 360 or 720. Each time the X-rays pass through a layer of tissue, the radiation attenuates, depending on the density of the individual structures of the layer under study. The degree of attenuation of X-ray radiation is measured by a large number of special highly sensitive detectors, after which all the information obtained is processed by a high-speed computer. As a result, a cut image of the organ is obtained in which the brightness of each coordinate point corresponds to the density of the tissue. Image analysis is carried out both in automatic mode using computers and special programs, and visually.

Depending on the specific tasks of the study and the nature of the pathological process in the lungs, the operator can choose the thickness of the axial sections and the direction of tomography, as well as one of the three modes of investigation.

1. Continuous CT, when all images of all sections of the organ are successively obtained. This method of tomography makes it possible to obtain maximum information about morphological changes, but it differs in the large radiation load and in the cost of the study.
2. A discrete CT with a given relatively large interval between slices, which significantly reduces the radiation load, leading to the loss of some information.
3. Aimed CT scan consists of a careful layer-by-layer examination of one or more areas of the organ of interest to the physician, usually in the area of pathology previously identified.

Continuous CT of the lungs allows to obtain a maximum of information about pathological changes in the organ and is shown primarily in volume processes in the lungs, when there is no evidence of lung cancer or metastatic organ damage. In these cases, CT provides an opportunity to study in detail the structure and dimensions of the tumor itself and clarify the presence of metastatic lesions of the pleura, lymph nodes of the mediastinum, the roots of the lungs and retroperitoneal space (with CT of the abdominal cavity and retroperitoneal space).

Discrete CT is more indicated for diffuse pathological processes in the lungs (pyevmoconiosis, alveolitis, chronic bronchitis, etc.), when operative treatment is supposed.

Sighting CT is used mainly in patients with established diagnosis and the established nature of the pathological process, for example, to clarify the contour of volume formation, the presence of necrosis, the state of the surrounding lung tissue, etc.

Computer tomography has significant advantages over conventional X-ray examination, since it allows to detect more subtle details of the pathological process. Therefore, indications for the use of CT in clinical practice are in principle quite broad. The only significant factor limiting the application of the method is its high cost and its low availability for some medical institutions. Considering this, one can agree with the opinion of a number of researchers that "the most common indications for CT of the lungs arise when the informative value of an ordinary radiologic examination is insufficient to establish a languorous diagnosis and the results of CT can influence the tactics of treatment."

In patients with pneumonia, the need for CT is about 10%. With CT, infiltrative changes in the lungs are detected at earlier stages of the disease.

[7], [8], [9], [10], [11], [12], [13]

General clinical blood test for pneumonia

The general clinical analysis of blood is included in the mandatory plan of examination of all inpatients and outpatients with pneumonia. The greatest diagnostic value is counting the number of leukocytes, determining the leukocyte formula and ESR.

Number of leukocytes

Normally, the total number of leukocytes is (4.0-8.8) x 10 ⁹ / l.

Leukocytosis is typical for the majority of patients with bacterial pneumonia. It indicates the acceleration of the maturation of leukocytes in the organs of hematopoiesis under the influence of numerous natural stimulants of leukopoiesis: physical and chemical factors of inflammation, including inflammatory mediators, tissue decay products, hypoxemia, immune complexes, some toxic substances, functions of the pituitary-adrenal system, which controls the maturation of leukocytes, and others. Most of these factors are natural signals to the activation of protective functions of leukocytes.

Leukocytosis in patients with pneumonia in most cases reflects a satisfactory reactivity of the system of bone marrow hematopoiesis in response to the action of external and internal stimulants of leukopoiesis. At the same time, leukocytosis is a fairly sensitive marker of the severity of the inflammatory process in the lungs

At the same time, it should be remembered that in pneumonia caused by chlamydia, in most cases there is moderate leukopenia (a decrease in the number of white blood cells is less than 4.0 x 10% / l). With mycoplasmal pneumonia, the total number of leukocytes usually remains normal (about 8.0 x 10 ⁹ / L), although in 10-15% of cases, leukocytosis or leukopenia is determined. Finally, viral infections are usually accompanied by an increase in ESR and a normal or reduced number of leukocytes (leukopenia).

In all other cases of bacterial pneumonia caused by pneumococci, streptococci, staphylococci, hemophilic rod, Legionella, Klebsiella, Pseudomonas aeruginosa, etc., the appearance of leukopenia, as a rule, indicates a significant inhibition of leukopoiesis in the hematopoietic organs and is a very unfavorable prognostic sign. More often it is observed in the elderly, exhausted and weakened patients, which is associated with a decrease in immunity and the general resistance of the body. In addition, it should be remembered that leukopenia can be associated with the use of certain drugs (antibiotics, cytostatics, non-steroidal anti-inflammatory drugs, etc.) and autoimmune processes complicating, in particular, the course of pneumonia.

Leukocytosis is typical for most patients with bacterial pneumonia. The exception is pneumonia caused by chlamydia and mycoplasma, as well as most viral infections in which moderate leukopenia or normal white blood cell count can be observed.

The appearance of leukopenia in patients with bacterial pneumonia may indicate a significant inhibition of leukopoiesis and is a very unfavorable prognostic sign, indicating a decrease in immunity and overall resistance of the organism. In addition, leukopenia can develop on the background of treatment with antibiotics, cytostatics and non-steroidal anti-inflammatory drugs.

Leukocyte formula

The leukocyte formula is the percentage of different types of leukocytes in the peripheral blood. Counting of the leukocyte formula is carried out by immersion microscopy of stained smears stained by Romanovsky-Giemsa or by other methods.

Differentiation of different types of leukocytes and counting of the leukocyte formula requires a good knowledge of the morphological features of various leukocytes and the general scheme of hematopoiesis. Myeloid hematopoiesis is represented by cells of granulocyte, megakaryocytic, monocytic and erythrocyte germs of hematopoiesis.

Granulocytes are blood cells, the most characteristic morphological feature of which is the clearly expressed granularity of the cytoplasm (neutrophilic, eosinophilic or basophilic). These cells have a common precursor and a single evolution up to the stage of promyelocyte, after which the gradual differentiation of granulocytes into neutrophils, eosinophils and basophils, which differ significantly in their structure and function, occurs.

Neutrophils have abundant, fine, dust-like granularity of a pinkish-violet color. Mature eosinophils differ large, occupying the entire cytoplasm, granularity, which has a scarlet color ("ketovaya caviar"). The granularity of basophils is large, heterogeneous, dark purple or black in color.

Young immature cells of granulocytes (myeloblast, promyelocyte, neutrophilic, eosinophilic and basophilic myelocytes and megalocytes) of larger sizes have a large round or slightly concave nucleus with a more tender and fine pattern and a light color. Their nuclei often contain nucleols (nucleoli).

Mature granulocytes (rod and segmented nuclei) are smaller in size, their nuclei of a darker color have the appearance of curved rods or individual segments connected by a "thread" of nuclear matter. The nuclei do not contain nucleol.

Cells of monocyte sprouts are characterized by a pale blue or grayish color of the cytoplasm, devoid of the pronounced granularity that is characteristic of granulocytes. In the cytoplasm, only individual small azurophil granules can be detected, as well as vacuoles. In immature cells of the monocytic series (monoblast, promonocyte), the nucleus is large, occupying a large part of the cell. The nucleus of a mature monocyte is smaller and has the appearance of a butterfly or fungus, although it can often take quite bizarre forms.

For cells of the lymphoid germ of hematopoiesis (lymphoblasts, prolymphocytes and lymphocytes), a very large, rounded, sometimes Bobovidio nucleus of a dense structure that occupies almost the entire cell is characteristic. The blue or blue cytoplasm is located in a narrow band around the nucleus. It is devoid of specific granularity, and therefore lymphocytes along with monocytes are called agranulocytes. Normally, as is known, in peripheral blood only mature cells of leukocytes are detected:

• segmented neutrophils, eosinophils and basophils;
• stab neutrophils (sometimes - eosinophils);
• monocytes;
• lymphocytes.

Degenerative forms of leukocytes

In addition to the cells described above, with pneumonia, infections and purulent-inflammatory diseases, there are so-called pre-generative forms of leukocytes. The most common are their following forms

1. Neutrophils with toxic granularity and vacuolation of the cytoplasm. The toxic granularity of neutrophils arises from the coagulation of the cytoplasmic protein under the influence of an infectious or toxic agent. In these cases, in addition to the fine, fine granularity typical for neutrophils, large coarse basophil-colored granules and vacuoles appear in the cytoplasm. The toxic granularity and vacuolization of the cytoplasm of neutrophils and monocytes is often found in severe pneumonia, for example, in severe pneumococcal croupous pneumonia and other purulent-inflammatory diseases accompanied by severe intoxication.
2. Hypersegmented neutrophils, the core of which consists of 6 or more segments, occur with B12-folic deficiency anemia, leukemia, and also with certain infections and purulent-inflammatory diseases, reflecting the so-called nuclear shift of neutrophils to the right.
3. Degenerative changes in lymphocytes in the form of a picnotically altered nucleus, sometimes having a bilobate structure, and weak development or absence of cytoplasm
4. Atypical mononuclears are cells that combine certain morphological signs of lymphocytes and monocytes: they are larger than normal lymphocytes, but they do not reach monocytes in size, although they contain a monocyte nucleus. By morphology, lymphomonocytes resemble blast cells and are often found in infectious mononucleosis.

[14], [15], [16], [17], [18]

Interpretation of results

Leukocyte formula in healthy people

	Granulocytes				Agranulocytes
	Neutrophils		Eosinophiles	Basic Fillets	Lymphocytes	Mono-tsits
	Rod-nuclear	Segmento-nuclear
% of the total number of leukocytes	1-6%	47-72%	0.5-5%	0-1%	19-37%	3-11%
Absolute quantity (nx 10 9 / l)	0.04-0.3	2.0-5.5	0.02-0.3	0-0.65	1.2-3.0	0.09-0.6

At various pathological conditions, including at pneumonia, can occur:

• change in the leukocyte formula (increase or decrease of any type of white blood cells);
• the appearance of various degenerative changes in the nucleus and cytoplasm of mature leukocyte cells (neutrophils, lymphocytes and monocytes);
• appearance in the peripheral blood of young immature leukocytes.

To correctly interpret changes in the leukocyte formula, it is necessary to evaluate not only the percentage ratios of different types of leukocytes, but also their absolute content in 1 liter of blood. This is due to the fact that the change in the percentage of individual types of white blood cells does not always correspond to their true increase or decrease. For example, with leukopenia due to a decrease in the number of neutrophils, a relative increase in the percentage of lymphocytes and monocytes can be found in the blood, whereas their absolute number will in fact be normal.

If along with the percentage increase or decrease of individual types of leukocytes, a corresponding change in their absolute content in 1 liter of blood is observed, it is said about their absolute change. The increase or decrease in the percentage of cells with their normal absolute content in the blood corresponds to the concept of relative change.

Consider the diagnostic significance of some changes in the leukocyte formula, the most common in clinical practice, including in patients with pneumonia.

Neutrophilia - an increase in the number of neutrophils greater than 6.0 x 10 ⁹ / l - is a reflection of a unique defense of the organism in response to the action of numerous exogenous and endogenous factors. The most frequent (but not the only) causes of neutrophilia, in most cases combined with leukocytosis, are:

1. Acute infections (bacterial, parasitic, fungal, rickettsial, etc.).
2. Acute inflammatory and purulent processes (pneumonia, sepsis, abscess, exudative pleurisy, empyema of the pleura and many others).
3. Diseases accompanied by necrosis, decay and tissue damage.
4. Intoxication.

When evaluating the diagnostic and prognostic significance of a neutrophil shift, it is important to determine the percentage of immature and mature forms of neutrophils. To do this, calculate the nuclear neutrophil shift index - the ratio of the content of myelocytes, metamyelocytes and stab neutrophils to segmented nuclei.

Nuclear shear index = myelocytes + metamyelocytes + stab-stem / segment-nuclear

Normally, the nuclear shear index is 0.05-0.1.

• The shift of the blood formula to the left is an increase in the number of stab neutrophils in the peripheral blood and (rarely) the appearance in a small number of immature granulocytes (metamyelocytes, myelocytes, and even single myeloblasts), which indicates significant bone marrow irritation and acceleration of leukopoiesis. The nuclear neutrophil shift index exceeds 0.1.
• The shift of the blood formula to the right is an increase in the number of mature segment neutrophils in the peripheral blood, the appearance of hypersegmented ones, and the decrease or disappearance of stab neutrophils. The nuclear shear index is less than 0.05.

In most patients with pneumonia, acute infections, purulent inflammatory and other diseases accompanied by neutrophilia, the shift of the blood formula to the left is limited only by an increase in the number of stab neutrophils (hyporegenerative nuclear shift), which, in combination with mild leukocytosis, usually indicates a relatively easy leaky infection or a limited purulent-inflammatory process and good resistance of the body.

With a severe course of the disease and the preserved resistance of the body, a shift in the blood formula to metamyelocytes, myelocytes, and (more rarely) to myeloblasts (hyperregenerative nuclear shift to the left) is observed, which, in combination with high leukocytosis and neutrophilia, is referred to as myeloid type leukemoid reaction, because it resembles a picture of blood in myeloleukemia . These changes are usually accompanied by hypo- and aneosinophilia, relative lymphocytopenia and monocytopenia.

Neutrophilia with a degenerative nuclear shift to the left, which is manifested by an increase in immature forms of neutrophils and the appearance of degenerate altered segment neutrophils in the peripheral blood (toxic granularity, pycnosis of nuclei, vacuolation of the cytoplasm) is also observed in severe pneumonia. Purulent-inflammatory diseases and endogenous intoxications and indicates oppression of the functional activity of the bone marrow.

Neutrophilia with a pronounced shift of the blood formula to the left in combination with a small leukocytosis or leukopenia usually indicates a severe course of the pathological process and poor resistance of the organism. Often such a picture of blood is observed in elderly and senile patients and in weakened and depleted patients.

Neutrophilism with a nuclear shift to the right (increase in segmented and hyperpigmented neutrophils, decrease or disappearance of stab neutrophils), as a rule, indicates a good, adequate protective reaction of bone marrow hematopoiesis on infection or inflammation and the favorable course of the disease.

The severe course of many pneumonia, as well as infectious, generalized pyoinflammatory, degenerative and other diseases with preserved body resistance is often accompanied by severe neutrophilia, leukocytosis and hyperregenerative shift of the blood formula to the left.

The appearance in the peripheral blood of degenerative forms of neutrophils (toxic granularity, pycnosis of nuclei and other changes), as well as pronounced neutrophilia and nuclear shift to the left in combination with a slight leukocytosis or leukopenia, in most cases indicate oppression of bone marrow functional activity, decrease in body resistance and are very adverse signs.

Neutropenia - a decrease in the number of neutrophils below 1.5 x 10 ⁹ / l - indicates functional or organic oppression of bone marrow hematopoiesis or the intensive destruction of neutrophils under the influence of antibodies to leukocytes, circulating immune complexes or toxic factors (autoimmune diseases, tumors, aleukemic forms of leukemia, the effect of certain medications, hypersplenism, etc.). It should also be borne in mind the possibility of a temporary redistribution of neutrophils within the vascular bed, which can be observed, for example, in shock. Neutropenia is usually combined with a decrease in the total number of leukocytes - leukopenia.

The most common causes of neutropenia are:

1. Infections: viral (influenza, measles, rubella, chicken pox, infectious hepatitis, AIDS), some bacterial (typhoid fever, paratyphoid, brucellosis), rickettsial (typhus), protozoal (malaria, toxoplasmosis).
2. Other acute and chronic infections and inflammatory diseases that occur in severe form and / or acquire the character of generalized infections
3. The effect of certain medications (cytostatics, sulfonamides, analgesics, anticonvulsants, antithyroid drugs, etc.).

Neutropenia, especially combined with a neutrophilic shift to the left, and developing against a background of purulent-inflammatory processes, for which neutrophilia is typical, indicates a significant decrease in the body's resistance and unfavorable prognosis of the disease. Such a reaction of bone marrow hematopoiesis in patients with pneumonia is most typical for depleted, weakened patients and persons of elderly and senile age.

Eosinophilia - an increase in the number of eosinophils in the peripheral blood more than 0.4 x 10 ^e / l - is most often a consequence of pathological processes, which are based on the formation of antigen-antibody complexes or diseases accompanied by autoimmune processes or bone marrow proliferation of the eosinophilic germ of hematopoiesis:

1. Allergic diseases (bronchial asthma, hives, hay fever, angioedema, serum sickness, drug disease).
2. Parasitic infestations (trichinosis, echinococcosis, opisthorchiasis, ascariasis, diphyllobothriasis, giardiasis, malaria, etc.).
3. Diseases of connective tissue (nodular periarteritis, rheumatoid arthritis, scleroderma, systemic lupus erythematosus).
4. Nonspecific ulcerative colitis.
5. Diseases of the skin (dermatitis, eczema, pemphigus, skinwort, etc.).
6. Diseases of the blood (lymphogranulomatosis, erythremia, chronic myelogenous leukemia).
7. Eosinophilic lung infiltrate.
8. Fibroplastic parietal endocarditis of Leffler.

Moderate eosinophilia often develops during the reconvalescence of patients with pneumonia and other acute infectious and inflammatory diseases ("scarlet dawn of recovery"). In these cases, eosinophilia, as a rule, is combined with a decrease in the previously observed neutrophilia and leukocytosis.

Eosinopenia - the decrease or disappearance of eosinophils in the peripheral blood - is often detected in infectious and purulent inflammatory diseases and, along with leukocytosis, neutrophilia and nuclear shift of the blood formula to the left, is an important laboratory sign of an active inflammatory process and a normal (adequate) response of bone marrow hematopoiesis to inflammation .

Eosinopenia, detected in patients with pneumonia and purulent-inflammatory diseases, combined with neutropenia, leukopenia and a shift of the blood formula to the left, usually reflects a decrease in the body's resistance and is a very unfavorable prognostic sign.

Basophilia - an increase in the number of basophils in the blood - in clinical practice, including with pneumonia, is rare. Among the diseases most often accompanied by basophilia, we can distinguish the following:

1. Myeloproliferative diseases (chronic myelogenous leukemia, myelofibrosis with myeloid metaplasia, true polycythemia - Vaquez disease);
2. Hypothyroidism (myxedema);
3. Lymphogramulomatosis;
4. Chronic hemolytic anemia.

Absence of basophils in peripheral blood (basbopenia) has no diagnostic value. It is sometimes seen in hyperthyroidism, acute infections, after taking corticosteroids.

Lymphocytosis - an increase in the number of lymphocytes in the peripheral blood. In clinical practice, there is a relative lymphocytosis, that is, an increase in the percentage of lymphocytes with a normal (or even slightly reduced) absolute number of lymphocytes. Relative lymphocytosis is revealed in all diseases accompanied by absolute neutropenia and leukopenia, including in viral infections (influenza), purulent inflammatory diseases that occur against the background of decreased resistance of the body and neutropenia, as well as in typhoid, brucellosis, leishmaniasis, agranulocytosis and others. .

Absolute increase in the number of lymphocytes in the blood more than 3.5 x 10 ⁹ / l (absolute lymphocytosis) is typical for a number of diseases:

1. Acute infections (including so-called childhood infections: whooping cough, measles, rubella, chicken pox, scarlet fever, infectious mononucleosis, mumps, acute infectious lymphocytosis, acute viral hepatitis, cytomegalovirus infection, etc.).
2. Tuberculosis.
3. Hyperthyroidism.
4. Acute and chronic lymphatic leukemia.
5. Lymphosarcoma.

Contrary to popular belief, lymphocytosis with purulent-inflammatory diseases and pneumonia can not be considered a reliable laboratory sign of compensatory response of the immune system and the onset of recovery. Lymphocytopenia - a decrease in the number of lymphocytes in the peripheral blood. Relative lymphocytopenia is observed in such diseases and at a stage of development of the pathological process, which is characterized by an absolute increase in the number of neutrophils (neutrophilia): various infections, purulent-inflammatory diseases, pneumonia. Therefore, in most cases, such relative lymphocytopenia of independent diagnostic and prognostic value does not matter

Absolute lymphocytopenia with a decrease in the number of lymphocytes below 1.2 x 10 ⁹ / l may indicate a deficiency of the T-system of immunity (immunodeficiency) and requires a more thorough immunological examination of blood, including estimates of the parameters of humoral cellular immunity and phagocytic activity of leukocytes.

Monocytosis is also relative and absolute.

Relative monocytosis is often found in diseases that occur with absolute neutropenia and leukopenia, and its independent diagnostic value in these cases is small.

Absolute monocytosis, detected in certain infections and purulent-inflammatory processes, should be evaluated, first of all, bearing in mind that the main functions of the monocyte-macrophagal series are:

1. Protection against certain classes of microorganisms.
2. Interaction with antigens and lymphocytes in separate stages of the immune reaction.
3. Elimination of affected or aged cells.

Absolute monocytosis occurs in the following diseases:

1. Some infections (infectious mononucleosis, subacute septic endocarditis, viral, fungal, rickettsial and protozoal infections).
2. Prolonged leaking inflammatory diseases.
3. Granulomatous diseases (active tuberculosis, brucellosis, sarcoidosis, nonspecific ulcerative colitis, etc.).
4. Diseases of the blood: acute myocytic leukemia, chronic myelogenous leukemia, myeloma, lymphogranulomatosis, other lymphomas, aplastic anemia.

In the first three cases (infections, purulent-inflammatory diseases), absolute monocytosis may indicate the development of pronounced immune processes in the body.

Monocytonies - a decrease or even a complete absence of monocytes in peripheral rabbit - often develops during severe pneumonia, infectious and purulent-inflammatory diseases.

Leukemoid reactions are pathological reactions of the hematopoietic system, accompanied by the appearance in the peripheral blood of young immature leukocytes, which indicates a significant stimulation of the bone marrow and acceleration of leukopoiesis. In these cases, the picture of the blood outwardly resembles the changes detected in leukemia. Leukemoid reactions are more often combined with pronounced leukocytosis, although in more rare cases can develop and against the background of a normal number of leukocytes or even leukopenia.

There are leukemoid reactions 1) myeloid type, 2) lymphatic (or monocytic-lymphatic) type, 3) eosinophilic type.

The leukemoid reaction of the myeloid type is accompanied by a shift in the blood formula to metamyelocytes, myelocytes and myeloblasts and are observed in severe infectious, purulent-inflammatory, septic, degenerative and other diseases and intoxications characterized by a hyperregenerative nuclear shift of neutrophils to the left. A particularly severe and prognostically unfavorable sign in these diseases is the combination of leukemoid reaction with normal or decreased number of leukocytes and neutrophils (leukopenia and neutropenia).

Erythrocyte sedimentation rate (ESR)

The determination of ESR is based on the property of erythrocytes to settle on the bottom of the vessel under the influence of gravity. To this end, the micromethod TP is usually used. Panchenkov. ESR is determined 1 h after the start of the study for plasma column size over the settled red blood cells. In norm or rate ESR at men makes 2-10, and at women - 4-15 mm at an o'clock.

The mechanism of agglomeration of erythrocytes and their sedimentation is extremely complex and depends on many factors, primarily on the qualitative and quantitative composition of the blood plasma and on the physicochemical properties of the erythrocytes themselves.

As is known, the most frequent cause of an increase in ESR is an increase in the plasma content of large-dispersed proteins (fibrinogen, a-, beta and gamma globulins, paraproteins), as well as a decrease in albumin content. Coarse proteins have a smaller negative charge. Adsorbed on negatively charged erythrocytes, they reduce their surface charge and promote the convergence of red blood cells and their faster agglomeration.

Increased ESR is one of the characteristic laboratory signs of pneumonia, the immediate cause of which is the accumulation in the blood of coarsely dispersed fractions of globulins (often a-, beta and gamma fractions), fibrinogen and other proteins of the acute phase of inflammation. There is a definite correlation between the severity of inflammation of the lung tissue and the degree of ESR increase.

At the same time, it should be remembered that the increase in ESR is, although very sensitive, according to the nonspecific hematological index, the increase of which can be associated not only with inflammation, but with any pathological process leading to severe disproteinemia (connective tissue diseases, hemoblastoses, tumors , anemia, tissue necrosis, liver and kidney disease, etc.).

On the other hand, in patients with pneumonia, ESR may not be increased, if there is also a thickening of blood (increase in viscosity) or a decrease in pH (acidosis), which causes, as is well known, a decrease in erythrocyte agglomeration

In addition, in the early stages of some viral infections there is also no increase in ESR, which may to a certain extent distort the results of the study in patients with viral-bacterial pneumonia.

[19], [20], [21], [22],

Biochemical blood test for pneumonia

Evaluation of the results of biochemical blood testing in patients with pneumonia, especially in dynamics - in the course of the development of the disease, has great diagnostic and prognostic value. Changes in various biochemical parameters, being in most cases nonspecific, make it possible to judge the nature and degree of disturbance of metabolic processes both in the whole organism and in separate organs. Comparison of this information with the clinical picture of the disease and the results of other laboratory and instrumental methods of investigation makes it possible to assess the functional state liver, kidney, pancreas, endocrine organs, the system of hemostasis, and often - to make representations about the nature of pathogens cal process of inflammation activity and promptly recognize a number of complications of pneumonia.

[23], [24], [25], [26], [27], [28], [29], [30]

Protein and protein fractions

Determination of protein and protein fractions in patients with pneumonia is of particular importance, primarily to assess the activity of the inflammatory process. The concentration of proteins in a healthy person's plasma ranges from 65 to 85 g / l. The bulk of the total protein of the blood plasma (about 90%) is accounted for by albumins, globulins and fibrinogen.

Albumins are the most homogeneous fraction of simple proteins, almost exclusively synthesized in the liver. About 40% of albumin is in the plasma, and 60% in the intercellular fluid. The main functions of albumin are the maintenance of colloid osmotic (oncotic) pressure, as well as the participation in the transport of many endogenous and exogenous substances (free fatty acids, bilirubin, steroid hormones, magnesium ions, calcium, antibiotics and others).

Globulins of blood serum are represented by four fractions (a1, a2, beta and gamma), each of which is not homogeneous and contains several proteins that differ in their functions.

The composition of a1-globulins normally includes two proteins that have the greatest clinical significance:

• a1-antitrypsin, which is an inhibitor of a number of proteases (trypsin, chymotrypsin, kallikrein, plasmin);
• a1-glycoprotein, involved in the transport of progesterone and testosterone, binding small amounts of these hormones.
• and 2-globulins are represented by the following proteins:
• a2-macroglobulin - an inhibitor of a number of proteolytic enzymes (trypsin, chymotrypsia, thrombin, plasmin, kallikrein), is synthesized outside the liver;
• Haptoglobin - a protein that binds and transports free hemoglobin A into the cells of the reticuloedothelial system;
• ceruloplasmin - has oxidase activity and oxidizes bivalent iron to trivalent, which provides its transport with transferrin;
• apoproteids A, B and C, which are part of the lipoproteins.

The globulin fraction also contains several proteins:

• transferrin - a protein involved in the transport of ferric iron;
• hemopexin - a carrier of free heme and porphyrin, binds the hemine-containing chromoproteins (hemoglobin, myoglobia, catalase) and delivers them to the cells of liver RES;
• lipoproteins;
• a part of immunoglobulins;
• some protein components of complement.

Gamma globulins are immunoglobulins, which are characterized by the function of antibodies produced in the body in response to the introduction of various substances possessing antigenic activity; modern methods allow to distinguish several classes of immunoglobulins (IgG, IgA, IgM, IgD and IgE).

Fibrinogen is the most important component of the blood coagulation system (factor I). It forms the basis of a blood clot in the form of a three-dimensional network in which blood cells are retained.

The content of total serum protein in a healthy person ranges from 65 to 85 g / l, and albumin - from 35 to 50 g / l. It should be emphasized that in different clinical laboratories using different automatic analyzers and methods for determining protein fractions, the standards may differ slightly from those given in the table.

Normal values of protein fractions of blood serum (in%)

Protein Fractions	Electrophoresis on cellulose acetate films		Electrophoresis on paper
	Coloring
	Crimson C	Bromophenol Blue
Albumen	52 (46.9-61.4)	58 (53.9-62.1)	50-70
A1-globulins	3.3 (2.2-4.2)	3.9 (2.7-5.1)	3-6
A2-globulins	9.4 (7.9-10.9)	8.8 (7.4-10.2)	9-15
Beta globulins	14.3 (10.2-18.3)	13.0 (11.7-15.3)	8-18
Y-globulins	21.4 (17.6-25.4)	18.5 (15.6-21.4)	15-25

The albumin-globulin coefficient (A / G) is normally 1.2-1.8.

The change in the content of globulin fractions, which is very typical for any acute or chronic inflammation, is usually found in patients with pneumonia,

An increase in the content of the a1 and a2 fractions of globulins is most often observed. This is due to the fact that the so-called acute phase proteins (al-antitrypsin, o1-glycoprotein, a2-macroglobulin, haptoglobulin, ceruloplasmin, seromucoid, C-reactive protein) are included in the composition of a-globulins, which regularly increase in any inflammatory process in the body . In addition, an increase in the content of a-globulins is observed with significant damage and decay of tissues (dystrophic, necrotic processes), accompanied by cell destruction and the release of tissue proteases, kallikrein, thrombin, plasmin, etc., which naturally leads to an increase in the content of their natural inhibitors (al-antitrypsin, al-glycoprotein, a2-macroglobulin, etc.). Damage to tissues also results in the release of pathological C-reactive protein, which is the product of cell disintegration and is part of the a1 fraction of globulins.

An increase in the beta-globulin fraction is usually observed in acute and chronic diseases, accompanied by an increase in the content of immunoglobulins in the blood (usually simultaneously with an increase in the content of y-globulins), including infections, chronic inflammatory processes in the bronchi, cirrhosis, connective tissue diseases, malignant neoplasms, autoimmune and allergic diseases.

An increase in the fraction of y-globulin is found in diseases accompanied by intensification of immune processes, since the fraction of y-globulin consists mainly of immunoglobulins: chronic infections, chronic liver diseases (chronic hepatitis and cirrhosis of the liver), autoimmune diseases (including connective tissue diseases - RA, SLE, etc.), chronic allergic diseases (bronchial asthma, recurrent urticaria, drug disease, atopic dermatitis and eczema, etc.). An increase in the y-globulin fraction is also possible with pneumonia, especially prolonged flow.

Proteins of the acute phase of inflammation

In addition to the described changes in protein fractions in patients with pneumonia, an increase in the content of the so-called acute phase inflammation proteins: fibrinogen, ceruloplasmin, haptoglobulin, a2-macroglobulin, C-reactive protein, etc., which also refer to nonspecific markers of the inflammatory process

Glycoproteins

Among the important in the diagnostic relation carbohydrate-containing compounds are glycoproteins - proteins containing relatively short carbohydrate chains, consisting of 10-20 monosaccharides. Their concentration in the blood also significantly increases with inflammatory processes and tissue damage (necrosis).

The composition of carbohydrate components of glycoproteins, the quantitative determination of which underlies the majority of diagnostic tests, includes:

1. hexoses (galactose, mannose, less often - glucose);
2. pentoses (xylose and arabinose);
3. deoxysugars (fucose and rhamnose);
4. aminosugar (acetylglucosamine, acetylgalactosamine);
5. sialic acids - derivatives of neuraminic acid (acetylneuraminic and glycolylneuraminic acid).

In clinical practice, the most widely used methods are the determination of sialic acids and the total amount of protein-bound hexoses.

An important diagnostic value is also the determination of hexoses associated with the so-called seromucoids. Seromucoids are a special group of carbohydrate-containing proteins that differ from conventional glycoproteins with the ability to dissolve readily in perchloric acid. This last property of seromucoids makes it possible to identify them from other glycoproteins containing hexoses.

Normally, the total content of hexoses associated with plasma proteins or serum is 5.8-6.6 mmol / l. Of these, the share of seromucoids is 1.2-1.6 mmol / l. The concentration in the blood of sialic acids in a healthy person does not exceed 2.0-2.33 mmol / l. The content of total hexose, seromucoid, and sialic acids associated with proteins increases substantially in all inflammatory processes and tissue damage (pneumonia, myocardial infarction, tumors, etc.).

Lactate dehydrogenase (LDH)

Lactate dehydrogenase (LDH) (KF 1.1.1.27) is one of the most important cellular enzymes involved in the glycolysis process and catalyzes a reversible reaction for the reduction of pyruvate (pyruvate) into lactate (lactate).

As is known, pyruvate is the final product of glycolysis. Under aerobic conditions, pyruvate, undergoing oxidative decarboxylation, is converted to acetyl-CoA and then oxidized in a cycle of tricarboxylic acids (Krebs cycle), releasing a significant amount of energy. Under anaerobic conditions, pyruvate is reduced to lactate (lactic acid). This last reaction is catalyzed by lactate dehydrogenase. The reaction is reversible: in the presence of O2, lactate is again oxidized to pyruvate.

During electrophoresis or chromatography, it is possible to detect 5 isoenzymes of LDH, which differ in their physico-chemical properties. The most important are two isoenzymes - LDG1 and LDG5. Most organs contain a complete set of LDH isoenzymes, including fractions of LDH2, 3, 4.

Normally, serum LDH activity does not exceed 0,8-4,0 mmol / h х l). Any damage to tissue cells that contain a large amount of LDH, including damage from inflammation of the lungs, increases the activity of LDH and its isoenzymes in the blood serum.

Nonspecific biochemical criteria of the inflammatory process in patients with pneumonia are:

• an increase in the content of alpha and beta globulin in the blood serum, and with a more significant activation of the immune system and / or process chronicization, an increase in the content of y-globulins;
• an increase in the content of acute phase proteins in the blood: fibrinogen, ceruloplasmin, haptoglobulin, C-reactive protein, etc .;
• increase in the content of total, protein-bound hexoses, seromucoid and sialic acids;
• an increase in the activity of lactate dehydrogenase (LDH) and its isoenzymes LDH3.

Determination of sensitivity to antibiotics

The determination of sensitivity to antibiotics is based on the evaluation of the growth of microorganisms cultivated in dense or liquid nutrient media in the presence of antibiotics. The easiest way is to seed a suspension of microorganisms of the isolated culture onto the surface of a dense nutrient medium (agar) in Petri dishes. Disks with antibiotics in standard concentrations are placed on the surface of the dishes and incubated at 37.5 ° C for 18 hours. The results are evaluated using a ruler diameter of the zone of growth retardation of microbes.

More accurate data can be obtained by using quantitative methods with the determination of the minimum inhibitory concentration (MIC) of antibiotics. To this end, a series of two-fold dilutions of antibiotics in a liquid nutrient medium (broth) is prepared and 0.2 ml of a suspension of culture of the microorganisms under study at a concentration of 10 ⁵ -10 ⁶ mt / ml is added . All samples, including control, containing no antibiotics, are incubated at 37.5 ° C for 24 hours. The minimum concentration of antibiotic in the last tube in which the total growth inhibition was observed corresponds to the MIC of the preparation and reflects the degree of sensitivity of the microorganisms to the antibiotic.

According to the degree of sensitivity to antibiotics, microorganisms are divided into three groups:

1. Sensitive - microorganisms, the growth of which is suppressed at the BMD, corresponding to the concentration of the drug in the blood serum when using the usual therapeutic doses of the drug.
2. Moderately resistant - such strains of microorganisms, IPC of which is achieved with the appointment of maximum therapeutic doses of antibiotic.
3. Stable microorganisms, the growth of which is not suppressed by the maximum permissible doses of drugs.

Such a determination of the degree of sensitivity to antibiotics is possible with the use of quantitative methods of dilution in liquid nutrient media. Nevertheless, there is a definite correlation between the MIC values and the size of the microbial growth retention zones when using paper discs with antibiotics, which makes it possible to use this simple and convenient method for an approximate quantitative description of the degree of sensitivity.

It should nevertheless be remembered that the results of determining the sensitivity to antibiotics in vitro do not always correspond to the real clinical situation, especially with a mixed infection, a decrease in the immunological reactivity of the organism, difficulties arising when trying to isolate the culture of the main pathogen, etc.

[31], [32], [33], [34], [35], [36]

Formulation of the diagnosis

When formulating the diagnosis of pneumonia, it is necessary to reflect:

• etiological variant;
• localization and prevalence of the inflammatory process (segment, proportion, one- or two-sided lesion);
• severity of pneumonia;
• presence of complications;
• phase of the disease (height, resolution, reconvalescence, prolonged course);
• accompanying illnesses.

Examples of the formulation of the diagnosis

1. Pneumococcal lobar pneumonia in the lower lobe of the right lung, severe course, high-grade phase. Acute subcompensated respiratory failure.
2. Streptococcal pneumonia in 6, 8, 10 segments of the right lung, moderate course, midsection. The initial stage of acute respiratory failure. Exudative pleurisy.

[37], [38], [39], [40]