Methods for laboratory diagnosis of pneumonia:

• Clinical blood test (nonspecific inflammatory signs: leukocytosis, changes in the leukocyte formula, accelerated ESR).
• Biochemical blood tests (C-reactive protein test, liver and kidney function tests, glycemic levels, etc.).
• Sputum examination: bacterioscopy of a Gram-stained smear; cultural research; determination of sensitivity to antibacterial drugs.
• Microbiological examination of blood samples with media for the cultivation of aerobes and anaerobes (in patients requiring hospitalization in the intensive care unit).
• Serological methods for diagnosing intracellular pathogens (mycoplasma, chlamydia, legionella).
• Determination of arterial blood gases (in patients with signs of respiratory failure).
• Bronchoscopic examination methods using bronchoalveolar lavage (BAL) and “protected” brush biopsy (in cases of treatment failure in patients with severe community-acquired pneumonia, immunodeficiency conditions or suspected presence of an unusual pathogen).

Methods for radiological diagnosis of pneumonia:

• Survey radiography of the chest organs in the anterior direct and lateral projections.
• Computed tomography (CT) of the lungs (if X-ray examination is uninformative, if differential diagnosis is necessary, in cases of pneumonia with delayed resolution).
• Ultrasound examination (ultrasound) to assess the condition of the pleura and pleural cavities during the development of parapneumonic exudative pleurisy.

Criteria for the diagnosis of pneumonia

The diagnosis of pneumonia is definite if the patient has radiologically confirmed focal infiltration of the lung tissue and at least two clinical signs from among the following:

• acute fever at the onset of the disease (t>38°C);
• cough with phlegm;
• physical signs of focal pulmonary process;
• leukocytosis (> 10x10/l) and/or band shift (> 10%).

The absence or unavailability of radiological confirmation of focal infiltration in the lungs makes the diagnosis of community-acquired pneumonia, based on the epidemiological history, complaints and corresponding local symptoms, inaccurate/uncertain.

Examples of diagnostic reports:

1. Community-acquired pneumonia caused by Streptococcus pneumoniae in S5 of the right lung, non-severe course.
2. Community-acquired pneumonia caused by Haemophilus influenzae, subtotal (in the middle and lower lobes of the right lung), severe course. Complications: Right-sided exudative pleurisy. Acute respiratory failure, grade 2.
3. Acute cerebrovascular accident in the basin of the right middle cerebral artery. Nosocomial pneumonia caused by Pseudomonas spp. in the lower lobe of the left lung. Complications: Acute respiratory failure, stage 2.
4. Chronic granulomatous disease. Pneumonia caused by Aspergillus spp. is bilateral, with decay cavities in the lower lobe on the right and the upper lobe on the left. Complications: Pulmonary hemorrhage. Spontaneous pneumothorax.
5. Closed craniocerebral injury. Aspiration pneumonia caused by Bacteroides ovatus, with the formation of a single abscess in the upper lobe of the right lung. Complications: Pleural empyema with bronchopleural communication.

O. Mirolyubova and others.

State sanitary and epidemiological regulation
Russian Federation

MICROBIOLOGICAL FACTORS

Laboratory diagnostics
community-acquired pneumonia

Guidelines
MUK 4.2.3115-13

Official publication

4.2. CONTROL METHODS. BIOLOGICAL AND
MICROBIOLOGICAL FACTORS

Laboratory diagnosis of community-acquired pneumonia

Guidelines MUK 4.2.3115-13

1 area of ​​use

1.1. These guidelines justify and define the methodological foundations and algorithms for laboratory diagnosis of pneumonia in the implementation of epidemiological surveillance of community-acquired pneumonia.

1.2. The guidelines are intended for specialists from bodies and institutions of the Federal Service for Supervision of Consumer Rights Protection and Human Welfare, and can also be used by specialists from medical organizations and other interested organizations.

1.3. Guidelines are mandatory when carrying out epidemiological surveillance of community-acquired pneumonia, during anti-epidemic measures and during epidemiological investigations of possible epidemic outbreaks of community-acquired pneumonia.

2. Terms and abbreviations

WHO - World Health Organization.

CAP - community-acquired pneumonia.

LPO is a treatment and preventive organization.

ICD-10 - international classification of diseases.

ARVI is an acute respiratory viral infection.

PCR - polymerase chain reaction.

RT-PCR - real-time polymerase chain reaction.

RIF - immunofluorescence reaction.

ELISA - enzyme immunoassay.

ICA - immunochromatographic analysis.

ABT - antibacterial therapy.

ICU - intensive care unit.

BAL - bronchoalveolar lavage.

3. General information about community-acquired pneumonia

Pneumonia is a group of acute infectious diseases, different in etiology, pathogenesis, and morphological characteristics, characterized by focal damage to the respiratory parts of the lungs with the obligatory presence of intra-alveolar exudation. In the International Classification of Diseases, Injuries and Causes of Death, 10th revision (ICD-10, 1992), pneumonia is clearly separated from other focal inflammatory lung diseases of non-infectious origin. The modern classification of pneumonia takes into account, first of all, the epidemiological conditions of the development of the disease, the characteristics of infection of the lung tissue and the state of the immunological reactivity of the patient’s body. Based on the nature of acquisition, community-acquired pneumonia (CAP) and nosocomial (nosocomial) pneumonia are distinguished. Recently, in addition to the term “nosocomial pneumonia”, a broader term has been used - “pneumonia associated with the provision of medical care” ( healthcare-associated pneumonia). This category, in addition to nosocomial pneumonia, includes pneumonia in persons in nursing homes or other long-term care facilities. It should be emphasized that such a division has nothing to do with the severity of the disease; the main criterion for differentiation is the epidemiological conditions and environment in which pneumonia developed. However, they usually differ from CAP in the etiological structure of pathogens and the profile of antibiotic resistance.

CAP should be understood as an acute illness that arose in a community setting - that is, outside a hospital or later than 4 weeks after discharge from it, or diagnosed in the first 48 hours after hospitalization, or developed in a patient who was not in a nursing home/long-term medical unit. observation for 14 days or more - accompanied by symptoms of lower respiratory tract infection (fever, cough, sputum production, possibly purulent, chest pain, shortness of breath) and radiological signs of “fresh” focally infiltrative changes in the lungs in the absence of an obvious diagnostic alternative.

The modern classification of CAP, taking into account the state of the immunological reactivity of the patient’s body, allows us to distinguish 2 main groups, suggesting differences in the etiological structure of pneumonia:

Typical CAP (in patients with no significant immune disorders);

CAP in patients with severe immune disorders (acquired immunodeficiency syndrome; other diseases or pathological conditions).

4. Modern ideas about the etiological structure of community-acquired pneumonia

The absolute significance of the etiological role of a particular CAP pathogen can only be determined in relation to a specific region, epidemic focus or epidemiological situation. Broader generalizations make it possible to identify the main trend that determines the significance of a given pathogen in human infectious pathology based on the appropriate level of standardization and frequency of use of laboratory diagnostic methods, as well as the approximate ratio of CAPs caused by the main pathogen of pneumonia - pneumococcus and other pathogens.

According to domestic and foreign researchers S. pneumoniae is the dominant etiological agent of pneumonia, causing from 30 to 80% of CAP in people of all age groups (Pokrovsky V.I. et al., 1995; Zubkov M.N., 2002, Cuhna V.A., 2003, Chuchalin A.G. ., 2006).

Against the backdrop of an increase in populations with severe immune defects (HIV infection, congenital immunodeficiency, oncohematological diseases, etc.), the etiological significance of such opportunistic pathogens of CAP as Pneumocystis juroveci, cytomegalovirus. Taking into account the high level of carriage of these pathogens, diagnosis of the corresponding nosology should be carried out only in groups at risk using modern laboratory research algorithms.

The concept of “viral pneumonia” has not yet found widespread use in diagnosing CAP, however, ICD-10 distinguishes pneumonia caused by influenza viruses, parainfluenza, adenoviruses and others from the group of respiratory tract infection pathogens. At the same time, the viral-bacterial etiology of CAP is quite widely known and described against the background of influenza and acute respiratory infections epidemics. The domestic standard of specialized medical care for severe pneumonia with complications includes J10.0 “Influenza with pneumonia” (influenza virus identified) and J11.0 “Influenza with pneumonia” (influenza virus not identified) as nosological units.

Viral respiratory tract infections are more severe in children under 5 years of age and older people (over 65 years of age), which is reflected in the high level of hospitalizations for pneumonia and mortality among people of this age. In these age groups, viral and viral-bacterial pneumonia are more often recorded.

During influenza epidemics, the risk of developing pneumonia may increase for those age groups in which the level of anamnestic antibodies to the antigenic variant of the influenza virus circulating in a particular epidemic season is below protective, as for example, this was observed in the case of pandemic influenza A/H1N1pdm2009 for people from 30 to 60 years. Risk groups for developing pneumonia with influenza should also include people suffering from chronic diseases of the cardiovascular system, metabolic disorders (obesity, diabetes mellitus), chronic diseases of the bronchopulmonary system, and pregnant women.

The etiological structure of CAP in children differs significantly from the etiology of CAP in adults and varies depending on the age of the child and the severity of the disease, which should be taken into account in the algorithm for diagnosing pneumonia in children. Risk groups for severe pneumonia include children under 5 years of age, frequently ill children, and especially those born at 24–28 weeks of gestation.

Bacterial pathogens of pneumonia are found in 2 - 50% of children, more often in hospitalized children, compared to children undergoing outpatient treatment. The most common bacterial pathogens of community-acquired pneumonia in children over one year of age are considered S. pneumoniae, less often isolated N. influenzae type b, S. pneumoniae is the cause of one third of pneumonia with radiological confirmation in children under 2 years of age. In cases of severe pneumonia requiring intensive care, an infection caused by group A streptococci or S. aureus, which are found in 3 - 7% of cases. Moraxella catarrhalis found in 1.5 to 3.0% of cases of pneumonia in children. Mixed viral-bacterial pneumonia is diagnosed in children, according to various sources, in 8.2 - 33.0% of cases, and when taking into account all mixed: bacterial or viral-bacterial pneumonia in children, their frequency ranges from 8 to 40%. Among pneumococcal pneumonia in children, combination with viral infections is observed in 62% of cases.

In case of CAP in children, it is necessary to take into account the possibility of a mixed bacterial-viral infection, the etiological significance of well-known and recently discovered respiratory viruses: respiratory syncytial, metapneumovirus, bocavirus and rhinoviruses. Various viral pathogens of respiratory infections are found in 30 - 67% of cases of pneumonia in children, and their proportion is higher in young children (up to 80% of cases from 3 months to 2 years), and are much less common in children over 10 years of age. M. pneumoniae And C. pneumoniae predominantly cause pneumonia in school-age children, and are not typical for children from 1 to 5 years of age. These pathogens are more often detected during epidemic rises in morbidity in foci of infection.

In endemic regions and according to epidemiological indicators, when etiologically diagnosing CAP, it is necessary to take into account the possibility of the occurrence of zoonotic infections, which are characterized by inflammatory processes in the lungs (Q fever, psittacosis, tularemia, etc.). An important element in the examination of patients with CAP is the exclusion of the etiological role of the causative agent of tuberculosis and other mycobacteria.

5. Logistics support for laboratory research

1. Laminar flow hood, 2nd class biological safety.

2. Binocular microscope with illuminator, set of lenses and eyepieces.

3. Electric thermostats for growing bacteria, maintaining the temperature in the chamber within (37 ± 1) °C.

4. CO 2 incubator, maintaining the temperature in the chamber within (37 ± 1) °C, CO 2 content at 3 - 7%, or an anaerostat.

5. Distiller.

6. Electric autoclave.

7. Refrigerator maintaining a temperature of 4 - 6 °C for storing cultures, biological substrates and reagents.

8. Alcohol lamps and gas burners.

9. Automatic and semi-automatic colony counters for counting colonies.

10. Disposable sterile containers for collecting and transporting sputum, pleural fluid, tracheal aspirate, BAL with a stable base, made of transparent material (preferably plastic to prevent breakage, facilitate disinfection and disposal of the container); the lid must seal the containers tightly and be easy to open; the container should not contain chemicals that negatively affect the viability of bacteria in the sputum.

11. Set of reagents for Gram staining of microslides.

12. Nutrient media for cultivation S. pneumoniae(eg blood agar, CNA agar).

13. Nutrient media for the cultivation of bacteria of the genus Haemophilus(such as chocolate agar), gram-negative bacteria and S. aureus(Endo agar, MacConkey agar, yolk salt agar).

14. Bacteriological dishes (Petri) for growing microbiological cultures.

15. Glass slides and coverslips of standard sizes for microslides.

16. Racks and trays for test tubes and containers, transportation of Petri dishes, cuvettes and rail racks for fixing and staining smears.

17. Bacteriological loops.

18. Semi-automatic variable volume dispensers.

19. Sterile tips for variable volume dispensers.

20. Drygalsky spatulas are sterile.

21. Laboratory glassware.

22. Plastic Pasteur pipettes for standardizing the volume and transfer of liquids.

23. McFarland turbidity standard or device for determining the concentration of bacterial cells.

24. Discs with antibiotics (optoquin, oxacillin, cefoxitin, etc.).

25. Enzyme immunoassay analyzer included.

26. Fluorescence microscope included.

27. Equipment for a PCR laboratory equipped in accordance with MU 1.3.2569-09

28. Diagnostic reagent kits (test systems) for identifying antigens and DNA/RNA of pneumonia pathogens, as well as specific antibodies to pneumonia pathogens, approved for use in the Russian Federation in the prescribed manner.

6. Diagnosis of community-acquired pneumonia

6.1. Diagnosis of pneumococcal pneumonia

Streptococcus pneumoniae (S. pneumoniae) is the most common bacterial pathogen of CAP. Pneumococcal pneumonia is registered in patients of any age, occurring both in outpatient practice and in hospital (including among those hospitalized in the ICU). An increase in the incidence of CAP of pneumococcal etiology in the Northern Hemisphere is observed in the winter season; pneumococcal pneumonia is more often registered among patients with concomitant chronic diseases - chronic obstructive pulmonary disease, diabetes mellitus, alcoholism, asplenia, immunodeficiency, and often occurs with bacteremia (up to 25 - 30%).

Pneumococcal CAP is usually characterized by an acute onset, high fever, and chest pain. However, clinical, laboratory and radiological manifestations of CAP caused by S. pneumoniae, are not specific enough and cannot be considered an adequate predictor of the etiology of the disease.

To diagnose pneumococcal CAP, culture methods are most often used. Clinical material for research is sputum, venous blood, less often - invasive respiratory samples (BAL, material obtained during bronchoscopy, protected brush biopsy, etc.) and pleural fluid.

When examining sputum, special attention should be paid to the need to assess the quality of the delivered sample. The analysis must begin with the preparation of a smear, since the results of microscopy influence not only the assessment of the suitability of the material, but also the further direction of bacteriological research. The criteria for the suitability of sputum for bacteriological examination are the presence of more than 25 segmented leukocytes and no more than 10 epithelial cells per field of view when viewing at least 20 fields of view of a Gram-stained smear (under magnification × 100). Microscopy of a Gram-stained smear (under magnification × 1,000 using an immersion objective) reveals gram-positive cocci (usually lanceolate diplococci) with a diameter of 0.5 - 1.25 µm, without spores and flagella; most have a polysaccharide capsule.

The study of pleural fluid involves bacterioscopy of a Gram-stained smear followed by a cultural examination. It is performed in the presence of pleural effusion and conditions for safe pleural puncture (visualization on the laterogram of freely displaced fluid with a layer thickness > 1.0 cm). Culture testing of invasive respiratory samples for CAP is recommended for patients with immunodeficiency; this method can be used in some cases with severe CAP, as well as the ineffectiveness of initial antibiotic therapy (ABT).

Clinically significant in an acute inflammatory process are considered microorganisms isolated from BAL in quantities of ≥ 10 4 CFU/ml, from a biopsy obtained using protected brushes - ≥ 10 3 CFU/ml, sputum - ≥ 10 5 CFU/ml.

To highlight S. pneumoniae from clinical material, it is necessary to use nutrient media enriched with defibrinated animal blood (sheep, horse or goat) at a concentration of 5%. The use of defibrinated human blood gives slightly worse results. Due to the scarcity of defibrinated blood in practical laboratories and its short shelf life, one should remember the possibility of using commercially prepared chocolate agar for the isolation of pneumococci, which is simultaneously used for the isolation of hemophiliacs. Another cultivation condition S. pneumoniae- incubation in an atmosphere with a CO 2 content increased to 3 - 7%, since it is a facultative anaerobe. Probability of allocation S. pneumoniae from respiratory samples increases when using selective media containing additives that inhibit the growth of saprophytic and gram-negative microorganisms (colistin, nalidixic acid, gentamicin).

A key test for differentiating pneumococci from other α-hemolytic streptococci is sensitivity to optochin (the test is based on the ability of optochin to selectively inhibit the growth of pneumococci over other viridans streptococci). However, among S. pneumoniae the number of optoquine-resistant strains is growing, which requires the use of alternative methods for identifying the pathogen (lysis in the presence of bile salts, Neufeld test, agglutination with diagnostic pneumococcal sera).

The informative value of cultural examination of respiratory samples and blood largely depends on compliance with generally accepted rules for their collection, storage and transportation (see appendix). In addition, the likelihood of identifying St. pneumoniae significantly decreases when obtaining clinical samples against the background of systemic ABT. For blood culture, it is preferable to use commercial vials of culture media.

Among the non-culture methods for diagnosing pneumococcal pneumonia, the most widely used in recent years is the immunochromatographic test, which involves the detection of pneumococcal cell polysaccharide antigen in the urine. Its main advantage is the ability to use it “at the patient’s bedside” due to the ease of implementation and quick results. The pneumococcal rapid test demonstrates acceptable sensitivity (50 - 80%) and fairly high specificity (> 90%) for CAP in adults compared to traditional methods. Disadvantages of the test include the possibility of obtaining false-positive results in cases of pneumococcal carriage (the test is not recommended for children under 6 years of age) and in persons who have recently had CAP.

Methods for identifying St. pneumoniae in clinical material using PCR. Autolysin genes ( lytA), pneumococcal surface antigen ( psaA) and pneumolysin ( ply) and other target genes. However, these methods are not widely used in clinical practice and their place in the etiological diagnosis of CAP requires clarification.

6.2. Diagnosis of other bacterial pneumonias

An important clinically significant bacterial pathogen of CAP is Haemophilus influenzae (H. influenzae). Community-acquired pneumonia is usually caused by non-typeable strains N. influenzae. According to a number of studies, H. influenzae is more common in patients with concomitant COPD and active smokers; the incidence of infection with this pathogen is higher in patients with non-severe CAP.

Representatives of the family Enterobacteriaceae (Klebsiella pneumoniae, Escherichia coli etc.) and Pseudomonas aeruginosa (P. aeruginosa) are detected in less than 5% of patients with CAP and belong to the category of rare pathogens. However, the importance of these microorganisms may increase in patients with severe CAP, and infection increases the likelihood of an unfavorable prognosis several times.

As epidemiological studies show, the frequency of occurrence of enterobacteria is higher in patients with chronic concomitant diseases, in persons who abuse alcohol, during aspiration, in the case of recent hospitalization and previous ABT. Additional risk factors for infection P. aeruginosa are chronic bronchopulmonary diseases (severe COPD, bronchiectasis), long-term use of systemic steroids, cytostatics.

Another bacterial pathogen is Staphylococcus aureus (S. aureus) - rarely occurs among outpatients with CAP, at the same time, in people with severe disease, its proportion can increase to 10% or more. To infection S. aureus Many factors predispose - old age, living in nursing homes, drug addiction, alcohol abuse. It is known that the relevance S. aureus as a causative agent, CAP increases significantly during influenza epidemics.

There are no specific clinical, laboratory or radiological signs that are typical for CAP caused by these pathogens and that allow it to be distinguished from pneumonia of other etiologies. In some cases, mainly in people with immunosuppression or alcohol abuse, K. pneumoniae can cause lobar pneumonia with localization of the lesion in the upper lobe of the lung, rapid progression of disease symptoms and high mortality.

For the etiological diagnosis of CAP caused by these pathogens, the cultural method of research is of primary importance. N. influenzae, like pneumococcus, belongs to the category of “fastidious” microorganisms that require the presence of factors X, V and 5-7% CO 2 in the nutrient media in the incubation atmosphere for cultivation. To highlight N. influenzae From clinical material, chocolate agar or selective agar is usually used to isolate bacteria of the genus Haemophilus. Culture of clinical material to identify family members Enterobacteriaceae And P. aeruginosa carried out on selective media for the isolation of gram-negative bacteria (Endo, MacConkey agar, etc.), S. aureus- on yolk-salt agar, mannitol-salt agar, etc.

Clinical material for testing may include sputum, venous blood, invasive respiratory specimens and pleural fluid. When examining sputum, as for identifying pneumococci, assessing the quality of the collected sample is important. The study of pleural fluid is performed in the presence of pleural effusion and conditions for safe pleural puncture, invasive respiratory samples - only for certain indications.

It should be noted that non-typeable strains H. influenzae And S. aureus are part of the normal microflora of the upper respiratory tract (URT), and the frequency of asymptomatic carriage can be quite high. With age, in the presence of chronic concomitant diseases, as well as recent systemic ABT, the frequency of colonization of the oral cavity and upper respiratory tract with Enterobacteriaceae increases. This fact must be taken into account when clinically interpreting the results of bacteriological examination of respiratory samples, especially sputum.

The informative value of cultural examination of respiratory samples and blood largely depends on compliance with generally accepted rules for their collection, storage and transportation. Identification is based on determining the nutritional requirements of the pathogens and the results of biochemical tests. To identify all of these microorganisms, commercial biochemical panels and reagent kits have been developed; automated microbiological analyzers can be used, which reduce the labor intensity of cultural research.

If you suspect CAP caused by S. aureus, it is important not only to isolate and identify the pathogen, but also to determine its sensitivity to oxacillin. Despite the lack of documented evidence of detection of methicillin-resistant S. aureus In patients with CAP on the territory of the Russian Federation, the danger of their appearance and spread is quite real. Among the phenotypic methods for detecting methicillin resistance, the most commonly used are disk diffusion testing with a disk containing 30 μg of cefoxitin or 1 mg of oxacillin, or screening on Mueller-Hinton agar supplemented with 4% NaCl and oxacillin at a concentration of 6 mg/l. To confirm infection with methicillin-resistant S. aureus commercial test systems based on identifying the gene in clinical material have been developed mecA by PCR method.

6.3. Diagnosis of pneumonia caused by Mycoplasma pneumoniae

The causative agent of respiratory mycoplasmosis is Mycoplasma pneumoniae- class representative Mollicutes, uniting wallless bacteria capable of autonomous existence, occupying an intermediate position between bacteria and viruses in terms of the level of structural organization.

Respiratory mycoplasmosis is a common anthropogenic disease. A feature of respiratory mycoplasmosis is the frequency of epidemics at intervals, according to various sources, varying from 3 to 7 years. The spread of infection is facilitated by the frequency and duration of contacts among persons staying in closed and semi-closed groups (military personnel, boarding schools), especially during their formation.

In 3 - 10% of cases of mycoplasma infection, pneumonia is diagnosed radiologically. For pneumonia caused M. pneumoniae, other bacterial or viral pathogens are usually not detected, but in rare cases they are also isolated S. pneumoniae. In 1 - 5% of cases of respiratory mycoplasmosis, hospitalization is required.

Mycoplasma pneumonia is accompanied by frequent, painful and prolonged cough with scanty viscous sputum, which is poorly evacuated, chest pain is noted, and bronchial obstruction may develop. Intoxication is mild. Physical changes in the lungs are absent or mild. The X-ray picture is very variable. In most cases, lesions of the interstitium are detected; in some patients, pneumonia occurs as a focal or segmental type, sometimes inflammatory changes are of a mixed nature. The symptoms of pulmonary failure are not typical for mycoplasma pneumonia. Mycoplasma pneumonia usually has a favorable course, in rare cases the course is very severe.

Diagnosis of mycoplasma pneumonia only on the basis of clinical or radiological data is impossible, since it does not have pathognomonic features. The main role in confirming the mycoplasma etiology of pneumonia is given to laboratory etiological diagnosis. For the etiological diagnosis of mycoplasma pneumonia, the following is used:

DNA detection M. pneumoniae polymerase chain reaction (PCR), the main method for direct DNA detection M. pneumoniae Currently, the standard polymerase chain reaction (PCR) with detection by electrophoretic DNA separation is used, but PCR with real-time detection (RT-PCR) has the greatest specificity and sensitivity;

Detection of mycoplasma antigen in a direct immunofluorescence reaction (RIF);

Serological studies to detect specific IgM and IgG antibodies to M. pneumoniae in blood serum using enzyme-linked immunosorbent assay (ELISA).

Mycoplasma pneumoniae refers to difficult-to-cultivate microorganisms; The isolation process takes 3 to 5 weeks, so the culture method cannot be recommended for use by diagnostic laboratories.

For the purpose of rapid etiological diagnosis of pneumonia, it is recommended to use PCR in the study of biological material obtained from the lower respiratory tract (sputum during deep coughing, aspirates from the trachea, sputum obtained as a result of induction through inhalation of hypertonic sodium chloride solution, bronchoalveolar lavage fluid (BAL) obtained using fiberoptic bronchoscopy).

If a positive PCR result is obtained when examining biological material obtained from the lower respiratory tract, the etiology of pneumonia is considered established. If it is impossible to obtain biological material from the lower respiratory tract for PCR, it is permissible to use smears from the upper respiratory tract (a combined smear from the nasopharynx and posterior pharyngeal wall), and if a positive result is obtained, the etiology of pneumonia should be considered presumptively established. However, obtaining a negative PCR result when examining smears from the upper respiratory tract cannot indicate the absence of mycoplasma infection. In this case, serological diagnosis is recommended, taking into account the totality of results for the detection of specific antibodies of the IgM and IgG classes in paired sera examined simultaneously.

For the purpose of retrospective diagnosis, when the patient is already in the convalescent stage, it is necessary to use serological studies.

The primary immune response is characterized by the synthesis of IgM antibodies 1 to 3 weeks after infection, the detection of which indicates the acute phase of infection. Immunoglobulins of class G appear by the end of 3 - 4 weeks. The diagnosis of mycoplasma respiratory infection is confirmed by a 4-fold seroconversion of specific antibodies in paired blood sera.

Direct detection of antigens M. pneumoniae in various biosubstrates (smears from the nasopharynx, lavage fluid, biopsies) obtained from patients with respiratory pathology, are still carried out in separate diagnostic laboratories using RIF. This method, combined with the detection of specific antibodies to mycoplasma in ELISA, makes it possible to confirm the disease caused by Mycoplasma pneumoniae. It should be borne in mind that humoral antibodies persist for several years.

For a reliable and definitive etiological diagnosis of mycoplasma pneumonia, taking into account the possibility of persistence of this pathogen in the human body without pronounced clinical manifestations, additional confirmation of the established diagnosis by any of the methods listed above is recommended.

6.4. Diagnosis of pneumonia caused by Chlamydophila pneumoniae

C. pneumoniae causes pneumonia of varying severity, long-term bronchitis, pharyngitis, and sinusitis. Pneumonia caused by C. pneumoniae usually has a favorable course, in rare cases the course is very severe.

A mixed infection, for example, a combination with pneumococcus or the presence of severe concomitant diseases, especially in older people, complicates the course of the disease and increases the risk of death. Often the infection is asymptomatic.

All ages are at risk, but the incidence of chlamydial pneumonia is higher in school-age children. The incidence among men is higher than among women. Epidemic outbreaks occur every 4 - 10 years. Epidemiological outbreaks in isolated and semi-isolated groups, cases of intra-family transmission of chlamydial infection are described.

None of the currently known methods for diagnosing chlamydial pneumonia provides 100% reliability in identifying the pathogen, which dictates the need to combine at least two methods.

Microbiological isolation C. pneumoniae has limited use due to the fact that it is a long and labor-intensive process, characterized by low sensitivity and is available only to specialized laboratories. However, if a viable pathogen is isolated, the diagnosis can be made with the greatest confidence without the need for confirmatory tests. Culture isolation indicates an active infectious process, since with persistent infection the pathogen enters a non-culturable state.

The most specific and sensitive method for identifying the pathogen is PCR diagnostics. High sensitivity and the absence of false-positive results can be ensured by using only licensed kits for effective DNA extraction from clinical material and modern-generation PCR kits based on real-time PCR (RT-PCR). The method does not make it possible to differentiate acute and chronic infection.

For the purpose of rapid etiological diagnosis of pneumonia, it is recommended to use PCR in the study of biological material obtained from the lower respiratory tract (sputum during deep coughing, aspirates from the trachea, sputum obtained as a result of induction through inhalation of hypertonic sodium chloride solution, bronchoalveolar lavage fluid (BAL) obtained using fiberoptic bronchoscopy). Serological tests are used for retrospective diagnosis and retrospective analysis of the nature of epidemic outbreaks.

If a positive PCR result is obtained when examining biological material obtained from the lower respiratory tract, the etiology of pneumonia is considered established. However, in cases of pneumonia caused Chlamydophila (Chlamydia) pneumoniae, cough is often nonproductive, in such cases it is recommended to use PCR swabs from the upper respiratory tract (a combined swab from the nasopharynx and posterior pharyngeal wall), and if a positive result is obtained, the etiology of pneumonia should be considered presumptive.

If you receive a negative PCR result when examining smears from the upper respiratory tract if you suspect an infection caused by C. pneumoniae, based on epidemiological or clinical data, serological diagnosis is recommended, taking into account the totality of results for the detection of specific antibodies of the IgM and IgG classes in paired sera examined simultaneously.

For the purpose of retrospective diagnosis, when the patient is in the convalescent stage, it is necessary to use serological tests.

Currently, to detect specific IgM and IgG antibodies to C. pneumoniae use the enzyme-linked immunosorbent assay (ELISA) or immunofluorescence reaction (RIF). Serological criteria for acute C. pneumoniae- infections: a 4-fold increase in titers of IgG antibodies in paired sera or a single detection of IgM antibodies in a titer ≥ 1:16.

For a reliable and definitive etiological diagnosis of chlamydial pneumonia, taking into account the possibility of persistence of this pathogen in the human body without pronounced clinical manifestations, additional confirmation of the established diagnosis by any of the above methods is recommended.

6.5. Diagnosis of pneumonia caused by Legionella pneumonia

Due to the similarity of clinical manifestations and symptoms of legionellosis and pneumococcal pneumonia, fast and effective laboratory diagnosis becomes crucial for choosing tactics for etiotropic treatment of patients. In 1999, WHO and in 2002, the European Legionellosis Working Group adopted standards as diagnostic criteria, according to which the diagnosis of legionellosis in the case of acute lower respiratory tract infection (clinically and radiologically confirmed) is considered established:

1) when isolating a Legionella culture from the respiratory tract or lung tissue;

2) with a 4-fold or more increase in the titer of specific antibodies to Legionella pneumophila serogroup 1 in the indirect immunofluorescence reaction;

3) when determining a soluble antigen Legionella pneumophila serogroup 1 in urine by enzyme-linked immunosorbent assay (ELISA) or immunochromatographic method (ICA).

In the absence of blood serum taken in the early stages of the disease, detection of a significantly high level of antibodies to Legionella pneumophila serogroup 1 (1:128 and higher) in single serum by indirect immunofluorescence allows us to consider the diagnosis of legionellosis as presumptive. Results obtained from the detection of a pathogen or its DNA in respiratory secretions or lung tissue using direct immunofluorescence or PCR are interpreted in a similar way.

Points 2 and 3 of the laboratory diagnostic standards currently apply only to antibodies and antigen determined for Legionella pneumophila serogroups 1. For other serogroups Legionella pneumophila the results obtained from the determination of antibodies or the detection of antigen in urine allow only a presumptive diagnosis to be established. Isolation of a culture of the pathogen remains the only standard method that establishes a definitive diagnosis in case of infection caused by other serogroups Legionella pneumophila or species Legionella spp.. At the same time, it should be noted that more than 80% of sporadic and group cases of legionellosis are caused by strains Legionella pneumophila serogroup 1, and in epidemic outbreaks of community-acquired pneumonia the etiological significance of the strains L. pneumophila serogroup 1 confirmed in 96% of cases.

The main method of standards that currently allows for timely diagnosis and monitoring of Legionella infection is the determination of Legionella antigen in urine using an immunochromatic or enzyme-linked immunosorbent method. The method allows you to finally confirm the diagnosis within 1 - 2 hours. The superiority of this method over other methods included in the standard lies primarily in the timing of the study and the availability of clinical material.

The bacteriological method takes at least 4-5 days, and invasive procedures are required to obtain bronchoscopy and biopsy material, since the pathogen cannot always be isolated from sputum, especially after the start of etiotropic therapy. Detection of a diagnostic increase in antibody titers in the indirect immunofluorescence reaction is possible only in the 3rd week of the disease, when a course of antibiotic therapy has been administered and the outcome of the disease is usually clear. The need to study paired sera determines the retrospective nature of the diagnosis of legionellosis using this method.

The PCR method can be recommended primarily for the study of BAL fluid or biopsy for suspected Legionella pneumonia in immunocompromised patients. If in this category of patients the infection is caused by strains L. pneumophila, not belonging to serogroup 1, then this method is the only one that allows you to quickly establish a diagnosis.

6.6. Diagnosis of pneumonia caused by Pneumocystis jiroveci

Pneumocystosis, as a rule, occurs in the form of acute respiratory diseases, exacerbations of chronic bronchopulmonary diseases, obstructive bronchitis, laryngitis, as well as pneumonia with impaired gas exchange (interstitial pneumonia).

The typical radiological picture of Pneumocystis pneumonia is represented by bilateral hilar interstitial infiltration of the lung tissue with increasing intensity and a large volume of damage in direct proportion to the progression of the disease. Less common are single and multiple compactions of lung tissue, upper lobe infiltrates and pneumothorax. Pleurisy and enlarged intrathoracic lymph nodes are quite rare. In the absence of pathology on radiographs, high-resolution CT may detect ground-glass changes or cellular deformation of the lung pattern.

In adults, Pneumocystis pneumonia usually develops against the background of secondary immunodeficiency. The incubation period is short - from 2 to 5 days, the onset is acute. Pneumocystis pneumonia can develop in patients receiving immunosuppressive therapy (corticosteroids). With drug immunosuppression, this disease manifests itself against the background of a decrease in the dose of corticosteroids. The prodromal period usually lasts 1 - 2 weeks; in AIDS patients - 10 days.

Pneumocystis pneumonia in AIDS is usually characterized by a sluggish chronic process. Initially, auscultatory symptoms are not detected. Respiratory failure associated with a sharp disruption of pulmonary ventilation and gas exchange leads to death. Abscesses, spontaneous pneumothorax and exudative pleurisy are also possible.

Pneumocystosis in children usually develops at 4–6 months of life, when the newborn’s immune system has not yet fully formed. The most susceptible to this disease are premature infants, patients with rickets, with malnutrition and damage to the central nervous system.

In young children, pneumocystis occurs as classic interstitial pneumonia with clear stages of pathological processes.

Based on morphological changes during the manifest course of the disease, three stages of the affected lung are distinguished:

Edema (7 - 10 days);

Atelectatic (up to 4 weeks);

Emphysematous (its duration is variable).

Risk groups for infection Pneumocystis jiroveci are:

Premature children, weakened newborns and young children with hypogammaglobulinemia, malnutrition and rickets;

Patients with leukemia, cancer patients, organ recipients receiving immunosuppressants;

Patients with tuberculosis, cytomegaly and other infections;

HIV-infected.

The most universal method for identifying cysts, trophozoites and sporozoites is the Romanovsky-Giemsa method. Vital staining with neutral red also allows you to identify the pathogen in the active phase.

All of the listed staining methods require highly qualified researchers for accurate identification. Pneumocystis jiroveci; Moreover, these methods serve only for indication and are aimed at common fungal polysaccharides of the cyst shell.

The immunofluorescence method (RIF) for identifying cysts and trophozoites using monoclonal or polyclonal antibodies in lavage fluid has higher specificity and sensitivity than histochemical staining of preparations.

An immunological method that detects specific antibodies of the IgG and IgM classes (ELISA) also plays a significant role in the diagnosis of pneumocystis, especially when diagnosing when it is impossible to take lavage fluid or sputum from the patient. Antibodies of class G among the healthy population are detected quite often (60 - 80%). Therefore, the study of antibodies should occur over time with mandatory titration of serum. Detection of a 4-fold increase in IgG and/or determination of IgM antibodies against Pneumocystis jiroveci speaks of an acute infectious process caused by this pathogen.

Polymerase chain reaction (PCR) is one of the highly sensitive diagnostic methods that allows the detection of single cells or DNA fragments of the pathogen Pneumocystis jiroveci in sputum or bronchoalveolar lavage.

6.7. Diagnosis of viral and viral-bacterial pneumonia

The viral or viral-bacterial etiology of pneumonia in adults can be suspected during an increase in the incidence of influenza and ARVI, as well as when group cases of the disease occur within a month after the formation of closed and semi-closed groups. The risk group for severe viral pneumonia includes people suffering from heart failure and chronic diseases of the bronchopulmonary system. Concomitant pathologies in severe influenza are also obesity, diabetes mellitus, and pregnancy, especially in the third trimester.

The main causative agents of viral and viral-bacterial pneumonia in immunocompetent adults are considered to be influenza A and B viruses, adenoviruses, PC virus, parainfluenza viruses; Metapneumovirus is less frequently detected. In adults with influenza, complications develop in 10-15% of cases, 80% of which are pneumonia.

It is important to diagnose viral infections during CAP in children, in the etiological structure of which viral infections play a significant role.

Modern methods of etiological diagnosis of acute viral respiratory tract infections are based primarily on: identifying RNA/DNA pathogens using nucleic acid amplification methods, in particular using the most widely used PCR; on the detection of antigens using immunochromatography (ICA), enzyme-linked immunosorbent assay (ELISA), immunofluorescence (RIF). Mainly for retrospective diagnostics, methods for detecting specific antibodies in blood serum (complement fixation reaction (CFR), neutralization reaction (PH), hemagglutination inhibition reaction (HIR), indirect hemagglutination reaction (IRHA), enzyme-linked immunosorbent assay (ELISA)) remain important. Cultivation is possible for influenza A and B viruses, respiratory syncytial virus, parainfluenza viruses types 1 - 3, human metapneumovirus and adenoviruses.

Culture studies are labor-intensive and time-consuming; in routine practice, they are used only when monitoring influenza, while the initial detection of positive samples is carried out by PCR, followed by isolation in culture.

Immunofluorescence reactions allow the detection of antigens of influenza viruses, respiratory syncytial virus, parainfluenza viruses 1 - 3 and adenoviruses. Material for studies using immunofluorescence must be collected no later than three days from the onset of a respiratory infection (in the acute phase of the disease, since the method is most effective when the intracellular content of viral antigens is highest), which makes this method uninformative for the etiological diagnosis of pneumonia. In addition, the method is characterized by subjectivity when interpreting the analysis results.

Serological tests detect antibodies to respiratory syncytial virus (PH, RSK, RNGA, ELISA), parainfluenza viruses 1 - 4 (RTGA, RSK, ELISA), adenoviruses (ELISA), rhinoviruses (RSK); The study is usually retrospective in nature. Compared to RSC, ELISA is more sensitive. When interpreting, the change in the titer of specific antibodies over time in paired sera (obtained at an interval of 2 weeks) is assessed, and their results largely depend on the state of the patient’s immune system.

Recognized evidence of primary viral pneumonia (or mixed viral-bacterial pneumonia) according to international criteria (ESCMID 2011, BTS, 2009 - 2011) is the detection of nucleic acids of an influenza virus or other respiratory virus by PCR. More often, smears from the nasopharynx and from the posterior wall of the pharynx are used for diagnosis, while the greatest sensitivity due to the higher content of viruses in the test sample can be achieved with a combination of smears from both loci. For this purpose, smears are taken from the patient with two different probes from the mucous membrane of the lower nasal passage, and then from the back wall of the oropharynx, while tampons from both probes, after taking smears, are sequentially broken off into one tube.

However, in the case of influenza viruses replicating in lung tissue (A/H5N1, A/H1N1pdm2009) in the second week of pneumonia, the concentration of the virus in smears may no longer be sufficient for its detection, especially if the material is collected inadequately. In addition, in order to simultaneously detect both viral and bacterial agents, it is advisable to use material from the lower respiratory tract (sputum from deep coughing, sputum obtained as a result of induction by inhalation of hypertonic sodium chloride solution, tracheal aspirates, bronchoalveolar lavage fluid (BAL) obtained using fiberoptic bronchoscopy).

To identify the most significant pathogens of acute respiratory viral infections: influenza viruses A and B, PC virus, metapneumovirus, parainfluenza viruses 1 - 4, coronaviruses (229E, OS43, NL63, HKUI), rhinoviruses, adenoviruses (B, C, E), bocavirus, PCR reagent kits are available in formats with electrophoretic detection, fluorescence endpoint detection, and real-time detection of accumulation of amplification products (RT-PCR). Tests based on real-time PCR achieve the maximum level of specificity and sensitivity; tests with the simultaneous detection of several pathogens have an advantage. The use of specific conserved regions of the viral genome as targets results in high rates of diagnostic sensitivity and specificity of PCR, approaching 100%, compared to culture studies. When diagnosing influenza, it is possible to determine the subtype of influenza A viruses, including the highly pathogenic avian influenza virus A/H5N1 and the new pandemic variant A/H1N1pdm2009, the so-called swine influenza virus.

Polymerase chain reaction in the format of electrophoretic detection requires special measures to prevent contamination (false-positive results), achieved by taking special measures and observing special rules for organizing a laboratory in accordance with MU 1.3.2569-09 “Organization of the work of laboratories using nucleic acid amplification methods when working with material containing microorganisms of I - IV pathogenicity groups.”

The etiology of “pneumonia caused by the influenza virus” should be considered established if RNA of the influenza virus (or in combination with other viruses) is detected by PCR in the material of the lower respiratory tract with a negative result of a bacteriological blood test (or in the absence of DNA of bacterial pathogens of pneumonia in the blood according to PCR results, or when insignificant DNA concentrations are detected in the material of the lower respiratory tract in quantitative PCR). If it is impossible to obtain material from the lower respiratory tract, the influenza etiology of pneumonia can most likely be proven if influenza virus RNA is detected in smears from the nasopharynx and oropharynx.

The etiology of pneumonia caused by other respiratory viruses is considered established if the RNA/DNA PCR method detects one respiratory virus (or several viruses at the same time) in the material of the lower respiratory tract with a negative result of a bacteriological blood test (or in the absence of DNA of bacterial pathogens of pneumonia in the blood according to the results PCR, or when insignificant concentrations of DNA are detected in the material of the lower respiratory tract in quantitative PCR).

The viral etiology of pneumonia is considered presumptively established if the RNA/DNA PCR method detects one respiratory virus (or several viruses at the same time) in smears from the nasopharynx and oropharynx with a negative result of a bacteriological blood test (or in the absence of DNA of bacterial pathogens of pneumonia in the blood according to PCR results, or when insignificant concentrations of DNA are detected in the material of the lower respiratory tract in quantitative PCR), as well as if bacteriological studies have not been carried out.

The viral etiology of pneumonia is considered presumptively established if the RIF method detects antigens of one respiratory virus (or several viruses at the same time) with a negative result of a bacteriological blood test (or in the absence of DNA of bacterial pathogens of pneumonia in the blood according to PCR results, or if insignificant concentrations of DNA are detected in the material of the lower respiratory tract in quantitative PCR), as well as if bacteriological studies were not carried out.

The viral-bacterial etiology of pneumonia is considered established if the RNA/DNA PCR method detects one virus (or several viruses at the same time) in the material of the lower respiratory tract with a positive result of a bacteriological blood test (or detection of significant concentrations of DNA in the blood or in the material of the lower respiratory tract in quantitative PCR).

The viral-bacterial etiology of pneumonia is considered presumptively established if the RIF or ICA method detects antigens of one respiratory virus (or several viruses at the same time) with a positive result of a bacteriological blood test (or detection of significant concentrations of DNA in the blood or in the material of the lower respiratory tract in quantitative PCR).

The results of serological studies allow us to judge the presence or absence of a viral infection against which pneumonia developed.

6.8. Differential diagnosis between zoonotic lung diseases and tuberculosis

Differential diagnosis with zoonotic diseases that cause lung lesions (ornithosis, Q fever, tularemia, etc.) is carried out according to epidemiological indicators and in regions endemic for these pathogens in accordance with the sanitary rules “Prevention of ornithosis”, “Prevention of Q fever”, “Prevention of tularemia " Differential diagnosis with tuberculosis is also an important and necessary component of the examination of patients with severe pneumonia.

7. Algorithm for diagnosing community-acquired pneumonia

The algorithm for laboratory diagnosis of typical CAP (in patients with no severe immune disorders) is different for severe and non-severe pneumonia, for patients with severe immune disorders and children. Timely etiological diagnosis of CAP is especially important for severe pneumonia in patients hospitalized in the ICU.

In case of severe pneumonia, first of all, it is necessary to conduct a bacteriological study for pneumococcus and other bacterial etiological agents, taking into account the spectrum of their sensitivity to antibiotics, and also to exclude Legionella etiology using a rapid test for determining the Legionella antigen in the urine of patients. During an increase in the incidence of influenza and ARVI, the likelihood of severe pneumonia of a viral or viral-bacterial nature is quite high. In this case, the diagnostic algorithm for severe pneumonia should take into account the possibility of bacterial, viral or viral-bacterial etiology. Underestimation at the stage of laboratory diagnosis of any of the above-mentioned etiological variants of severe pneumonia in ICU patients can lead to fatal outcomes. Mortality in severe CAP can range from 25 to 50%.

The term “non-severe pneumonia” is used for pneumonia that is treated on an outpatient or inpatient basis, but does not require admission to the ICU. In the absence of adequate timely treatment, mild pneumonia can lead to serious complications and chronic diseases of the bronchopulmonary system. The mortality rate can range from 1 to 10%. Along with bacteriological testing for pneumococcus and other bacterial etiological agents, taking into account the spectrum of their sensitivity to antibiotics, the diagnosis of non-severe pneumonia should take into account the possibility of mycoplasma or chlamydial etiology. During an increase in the incidence of influenza and ARVI, there is a high probability of mild viral pneumonia, as well as mixed infections of the mentioned viruses with bacteria, chlamydia or mycoplasma.

Requires an expanded analysis of the etiological structure of CAP in patients with severe immune disorders (acquired immunodeficiency syndrome, other diseases or pathological conditions). In addition to bacteriological testing for pneumococcus, other bacterial etiological agents, taking into account the spectrum of their sensitivity to antibiotics, and legionella, for this group of patients there is a high probability of developing pneumonia caused by “opportunistic etiological agents”, primarily Pneumocystis jiroveci, as well as cytomegalovirus, fungi, herpes virus. Differential diagnosis with tuberculosis and other mycobacterioses is also an important and necessary component of the examination of patients with CAP who have severe immune disorders. To exclude legionella etiology of pneumonia in immunocompromised patients, bronchoalveolar lavage or biopsy is examined using a bacteriological method, or PCR for L. pneumophila serogroups 2 - 15 and Legionella spp..

With CAP in children, the polyetiology is most pronounced, which must be taken into account in the process of laboratory diagnosis. Along with bacteriological testing for pneumococcus and other bacterial etiological agents, taking into account the spectrum of their sensitivity to antibiotics, the diagnosis of pneumonia in children should take into account a wide range of respiratory viruses, and not only during epidemic increases in the incidence of influenza and ARVI (influenza viruses, RS virus, metapneumovirus, parainfluenza viruses, adenoviruses, coronaviruses, bocavirus, rhinoviruses), as well as the etiological role of mycoplasmas and chlamydia. With CAP in children, there is a high probability of a mixed bacterial-viral infection, including a mixed infection with chlamydia and mycoplasma.

8. Quality control of laboratory tests

An obligatory component of modern laboratory diagnostics is a quality system for laboratory research and ensuring its functioning. The quality system includes internal control at the stages of laboratory research and external control.

Internal quality control of microbiological studies is a set of measures and procedures carried out by the laboratory aimed at preventing the adverse effects of factors arising in the process of preparation, performance and evaluation of analysis results that can affect the reliability of the result.

Internal quality control includes:

1. Monitoring compliance with the requirements for the conditions of analysis: (laboratory premises, air environment, temperature conditions for incubation and storage, disinfection and sterilization regimes, etc.).

2. Perform the procedure for maintaining reference bacterial cultures.

3. Quality control of culture media.

4. Quality control of test systems and reagents.

5. Quality control of distilled water.

The structure of the organization of internal quality control, the frequency and frequency of procedures performed is established by the quality management system in force in the laboratory in accordance with GOST ISO/IEC 17025 and GOST R ISO 15189.

Documentation of the results of the control procedures carried out is carried out according to the forms approved by the current quality management system. Registration and storage of control results can be carried out on electronic media.

A mandatory section of internal quality control is a periodic, but at least once a year, analysis of the results of the control procedures performed, taking into account which the quality manual of the testing laboratory is adjusted.

Ensuring internal quality control of molecular genetic (PCR) studies is additionally carried out in accordance with MU 1.3.2569-09 “Organization of the work of laboratories using nucleic acid amplification methods when working with material containing microorganisms of I-IV pathogenicity groups.”

External quality control is carried out in accordance with the requirements of GOST ISO/IEC 17025 and GOST R ISO 15189 in the form of participation in interlaboratory comparative tests (ICT) and/or proficiency testing programs by indicators and with frequency in accordance with established requirements and the needs of laboratories.

9. Safety requirements

Studies of biological (clinical) material are carried out in accordance with current regulatory legal and methodological documents regarding work with microorganisms of III - IV and I - II pathogenicity groups, depending on the type of suspected pathogen.

Application

In order to determine the etiological agent(s) of lower respiratory tract infection when CAP is suspected, sputum obtained by deep coughing, sputum obtained by induction by inhalation of a sterile 5% sodium chloride solution through a nebulizer, sputum obtained by aspiration from the trachea using a surgical vacuum or electrical suction, bronchoalveolar lavage (BAL) obtained using fiberoptic bronchoscopy, as well as blood and pleural fluid.

If it is impossible to obtain material from the lower respiratory tract when testing for respiratory viruses, mycoplasma and chlamydia, it is permissible to use smears from the upper respiratory tract (from the lower nasal passage and from the back wall of the pharynx), which are taken from the patient as early as possible from the onset of acute respiratory infections symptoms in one tube and tested as one sample.

In hospitalized patients, material for research should be collected as early as possible upon admission (no later than the second day), since at a later date the possibility of superinfection through contact with other patients cannot be excluded. Collection of biological material for bacteriological research should be carried out before prescribing antibiotics.

In case of death, post-mortem (autopsy) material is examined.

Rules for obtaining freely separated sputum for bacteriological and PCR studies

To collect sputum, use sterile, hermetically sealed plastic containers. Before collecting sputum, the patient should be asked to rinse their mouth thoroughly with boiled water. Sputum collection is carried out on an empty stomach or no earlier than 2 hours after eating.

The patient is asked to take several deep breaths, holding the breath for a few seconds, then exhale forcefully, which promotes a productive cough and clears the upper respiratory tract of mucus. The patient is then asked to cough well and collect secretions from the lower respiratory tract (not saliva!) into a sterile container. The volume of the sputum sample should be at least 3 ml for adults and about 1 ml for children.

Should be stored in the refrigerator at a temperature of 4 - 8 °C. The duration of storage of sputum at room temperature should not exceed 2 hours.

For PCR studies It is allowed to store a sputum sample for 1 day at a temperature of 2 to 8 ° C, for a longer period - at a temperature not higher than - 16 ° C.

Rules for obtaining venous blood for bacteriological research

To collect blood for the purpose of bacteriological research, commercial hermetically sealed glass vials or vials made of impact-resistant autoclavable plastic of two types (containing a nutrient medium for isolating aerobes and anaerobes) are used. Blood is drawn with a syringe; the blood is aseptically transferred into a bottle with a transport medium directly through a rubber stopper.

2 samples of venous blood are taken with an interval of 20 - 30 minutes from various peripheral veins - for example, the left and right ulnar vein. One sample will be placed in a bottle to isolate aerobes, the other to isolate anaerobes. The blood volume for each venipuncture should be at least 10 ml for adults and 3 ml for children.

Immediately before venipuncture, the skin at the venipuncture site is disinfected using circular movements from the center to the periphery twice with a 70% alcohol solution or 1 - 2% iodine solution. It is necessary to wait until the disinfectant has completely dried and carry out the manipulation without touching the skin treated area.

After venipuncture, the remaining iodine should be removed from the surface of the skin to avoid burns.

Until transportation from the purpose of bacteriological research The sample along with the direction is stored at room temperature (no more than 2 hours) or in a thermostat.

Rules for obtaining venous blood for PCR testing

Blood should be taken on an empty stomach or 3 hours after a meal from the cubital vein in a sitting position. Blood is drawn into tubes with an anticoagulant (EDTA).

Immediately before venipuncture, the skin at the venipuncture site is disinfected using circular movements from the center to the periphery twice with a 70% alcohol solution or 1 - 2% iodine solution. It is necessary to wait until the disinfectant has completely dried and carry out the manipulation without touching the skin treated area. After venipuncture, the remaining iodine should be removed from the surface of the skin to avoid burns.

After drawing blood, the tube should be gently turned upside down several times so that the blood in the tube is thoroughly mixed. Place the test tube in a rack.

Until transport to the laboratory for the purpose of PCR research the sample along with the direction is stored at a temperature of 20 - 25 ° C for 6 hours from the moment of receiving the material - for the quantitative determination of nucleic acids, and for 12 hours - for the qualitative determination of nucleic acids; at a temperature of 2 - 8 °C - no more than one day for qualitative and quantitative determination of DNA/RNA of infectious objects. Whole blood samples should not be frozen.

Rules for obtaining pleural fluid for bacteriological and PCR studies

Take the material into disposable, tightly screwed tubes with a volume of 10 - 15 ml.

Before the manipulation, the skin is disinfected with 70% ethyl alcohol, then with 1 - 2% iodine solution, excess iodine is removed with a gauze cloth moistened with 70% alcohol to avoid burns to the patient’s skin. Percutaneous aspiration is then performed to obtain a sample of pleural fluid using careful aseptic technique. The sample volume must be at least 5 ml. All air bubbles are removed from the syringe, after which the sample is immediately transferred to a sterile plastic container. The container is tightly closed with a lid.

Before transportation, the sample along with the direction for bacteriological examination stored in the refrigerator at a temperature of 4 - 8 ° C. The duration of storage of pleural fluid at room temperature should not exceed 2 hours.

For PCR studies It is allowed to store the sample for 1 day at a temperature from 2 to 8 °C, for a longer period - at a temperature not higher than -16 °C.

Bronchoscopy is performed under oxygen therapy (oxygen inhalation through nasal catheters, using a Venturi mask or a mask with a reservoir). If it is not possible to ensure sufficient oxygenation of the blood, bronchoscopy is performed under non-invasive ventilation. In patients on mechanical ventilation, the procedure is performed under general anesthesia in conditions of myoplegia through a respirator adapter equipped with a valve for a bronchoscope. Bronchoalveolar lavage is performed according to accepted rules. The fiberoptic bronchoscope is passed into the bronchus until it jams, after which a 0.9% sodium chloride solution heated to 37 °C is injected using disposable syringes, 8 portions of 20 ml each (150 - 160 ml). In order to prevent collapse of the alveoli, suction is carried out at 50 - 80 mm Hg. Art. This procedure allows you to obtain the required number of alveolar macrophages in which the causative agent of CAP multiplies.

In life lung tissue obtained by transbronchial biopsy using a bronchoscope, which allows identifying pneumocystis in 66 - 98%, however, this method of collecting material is not indicated for all patients. Obtaining material for research is also possible with an open lung biopsy or using percutaneous intrathoracic aspiration with a pulmonary needle in patients who are contraindicated for transbronchial biopsy with a progressive course of the disease. The method of open lung biopsy gives the best (100%) results and is equivalent in result to surgical intervention, while obtaining a sufficiently large volume of material for research and a false negative result is completely excluded.

Currently, clinics have begun to actively research bronchoalveolar lavage to identify cysts and trophozoites.

Posthumous material collected during the first day after the death of the patient, smears-imprints of the lung or smears from the foamy contents of the alveoli are prepared.

Rules for obtaining tracheal aspirate for PCR testing

The manipulation is carried out on an empty stomach after brushing the teeth and rinsing the mouth with water. The patient is asked to take several deep breaths, holding the breath for a few seconds, then exhale forcefully. This promotes a productive cough and clears the upper respiratory tract of mucus. After connecting the mucus extractor through an adapter tube to the suction, a catheter for collecting tracheal aspirate was inserted into the pharynx through the oral cavity. Due to irritation of the mucous membrane in the glottis area, a cough reflex is provoked and the tracheal contents are removed through a sterile catheter (size 6 or 7) using suction. The volume of tracheal aspirate should be at least 3 - 5 ml.

Rules for obtaining induced sputum for bacteriological and PCR studies

Before the procedure, patients receive salbutamol (children - 200 mcg) through a metered dose inhaler to prevent bronchospasm. Then, for 15 minutes, oxygen is supplied through a jet nebulizer (aerosol apparatus) at a rate of 5 l/min with 5 ml of a 5% sterile NaCl solution. After this, tapping is carried out on the anterior and posterior walls of the chest to stimulate the discharge of sputum.

The patient is then asked to cough well and collect secretions from the lower respiratory tract (not saliva!) into a sterile container. The volume of the sputum sample should be at least 3 ml for adults and about 1 ml for children.

If sputum is not coughed up, it is recommended to combine the procedure with subsequent tracheal aspirates to suction the trachea using standard suction using a sterile 6- or 7-gauge catheter.

Before transportation, the sample along with the direction for bacteriological examination stored in the refrigerator at a temperature of 4 - 8 ° C. The duration of storage of sputum at room temperature should not exceed 2 hours.

For PCR studies storage is allowed for 1 day at a temperature of 2 to 8 °C, for a longer period - at a temperature not exceeding -16 °C.

Rules for obtaining swabs from the upper respiratory tract for PCR testing

The material is taken after rinsing the mouth with boiled water at room temperature. If the nasal cavity is filled with mucus, it is recommended to blow your nose before the procedure. For 6 hours before the procedure, you should not use medications that irrigate the nasopharynx or oropharynx or medications for resorption in the mouth.

Smears from the patient are taken with two different probes, first from the mucous membrane of the lower nasal passage, and then from the oropharynx, while the ends of the probes with tampons after taking smears are sequentially placed in one test tube with a volume of 1.5 - 2.0 ml with 0.5 ml of transport medium.

Nasopharyngeal smears in children taken with a dry sterile nasopharyngeal velor swab on a plastic applicator. The probe is inserted with a slight movement along the outer wall of the nose to a depth of 2 - 3 cm to the inferior concha, slightly lowered downwards, inserted into the lower nasal passage under the inferior nasal concha, a rotational movement is made and removed along the outer wall of the nose. The total depth of insertion of the probe should be approximately half the distance from the nostril to the ear opening (3 - 4 cm for children and 5 - 6 cm for adults). After collecting the material, the end of the probe with a swab is lowered into a sterile disposable tube with a transport medium to the point of breakage, while the flexible part of the probe is rolled up into a spiral, then, covering the top of the tube with a lid, the probe handle is lowered down, achieving complete breaking off of the upper part of the probe. The test tube is hermetically sealed.

Nasopharyngeal smears in adults It is also permissible to take it with a dry sterile polystyrene probe with a viscose swab. The probe is inserted with a slight movement along the outer wall of the nose to a depth of 2-3 cm to the inferior concha, slightly lowered downwards, inserted into the lower nasal passage under the inferior nasal concha, a rotational movement is made and removed along the outer wall of the nose. The total depth of insertion of the probe should be approximately half the distance from the nostril to the ear opening (5 cm for adults). After collecting the material, the end of the probe with the swab is lowered to a depth of 1 cm into a sterile disposable tube with transport medium and broken off, holding the tube cap. The test tube is hermetically sealed.

Oropharyngeal swabs take a dry sterile polystyrene probe with a viscose swab with rotational movements from the surface of the tonsils, palatine arches and the posterior wall of the oropharynx, gently pressing the patient’s tongue with a spatula. After collecting the material, the working part of the probe with a swab is placed in a sterile disposable tube with transport medium and a probe with a nasopharyngeal swab. The end of the probe with the swab (1 cm) is broken off, holding the lid of the test tube so that it allows the test tube to be tightly closed. Storage is allowed for three days at a temperature of 2 - 8 ° C, for a longer period - at a temperature not exceeding -16 ° C.

Rules for obtaining material for serological diagnostics
(Detection of specific antibodies)

For a serological study (determination of antibodies), two blood serum samples are required, the 1st sample is taken on the day of the initial diagnosis, the 2nd sample - 2 - 3 weeks after the first. Blood is taken from a vein in a volume of 3 - 4 ml, or from the third phalanx of the middle finger in a volume of 0.5 - 1.0 ml into a disposable plastic tube without an anticoagulant. Blood samples are left at room temperature for 30 minutes or placed in a thermostat at 37 °C for 15 minutes. After centrifugation (10 min at 3000 rpm), the serum is transferred into sterile tubes using a separate aerosol barrier tip for each sample. The shelf life of whole blood is no more than 6 hours; freezing is unacceptable. The shelf life of blood serum at room temperature is for 6 hours, at a temperature of 2 - 8 ° C - for 5 days, for a longer period - at a temperature not exceeding -16 ° C (multiple freezing/thawing is unacceptable).

Rules for obtaining autopsy material for PCR research

Post-mortem material is collected during the first day after the death of the patient using a sterile individual instrument (individually for each organ) from an area of ​​damaged tissue with a volume of 1 - 3 cm 3, placed in disposable sterile plastic containers with a hermetically screwed lid, frozen and stored at a temperature not exceeding - 16 °C.

Rules for obtaining and transporting urine to determine the antigen of Legionella or pneumococcus

Urine samples for research in a volume of 5 - 10 ml are placed in standard plastic containers and stored at room temperature (15 - 30 ° C) for no more than 24 hours after collection before performing the reaction. If necessary, samples can be stored at 2 - 8 °C for up to 14 days or at -20 °C for a long time for initial or repeated testing. Boric acid can be used as a preservative. Before testing, refrigerated or frozen urine samples are tested for the presence of antigen after reaching room temperature.

Requirements for labeling material for laboratory research

The label of the test tubes (containers) with the material indicates: the name and surname of the person being examined, the date the material was taken, and the type of material.

In the accompanying document (referral) to the material collected for research in the laboratory, you must indicate:

Name of the institution that sends the material for research and telephone number;

Last name and first name of the patient being examined;

Age;

Date of illness or contact with the patient;

Probable diagnosis, severity of the disease or reason for examination;

The severity of the disease;

Data on influenza vaccination in the current epidemic season (vaccinated / not vaccinated / no data);

Date and signature of the medical person.

Transporting material produced in thermal containers at the recommended storage temperature. Samples from each patient are additionally packaged in an individual sealed bag with absorbent material.

Processing of biological material before laboratory research

In the laboratory, before starting PCR studies of biological material with a viscous consistency (sputum, tracheal aspirates), it must be pretreated in order to reduce the viscosity, for example, using a drug like “Mucolysin”, according to the instructions. The autopsy material is subjected to homogenization, followed by the preparation of a 20% suspension using a buffer solution (saline sodium chloride solution or phosphate buffer).

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14. MU 2.1.4.1057-01 “Organization of internal quality control of sanitary and microbiological studies of water.”

15. MR No. 01/14633-8-34 “Identification of bacterial antigen Legionella pneumophila serogroup 1 in clinical material using the immunochromatographic method” (approved by the Chief State Sanitary Doctor of the Russian Federation on December 9, 2008).

16. MUK 4.2.1890-04 “Determination of the sensitivity of microorganisms to antibacterial drugs” (approved by the Chief State Sanitary Doctor of the Russian Federation on March 4, 2004).

1. General blood test in bacterial pneumonia, it reveals neutrophilic leukocytosis with a shift in the leukocyte formula to the left, an increase in ESR. The degree of these changes determines the severity of the process.

With lobar (lobar) pneumonia, leukocytosis reaches 20 - 30 10 9 / l with a shift of the leukoformula to the left to young forms. Severe toxic granularity of neutrophils (MM) is revealed, in severe cases - eosinopenia.

In focal pneumonia, blood leukocytosis reaches 10 -12 10 9 /l with a shift of the leukoformula to the left to 10 - 15% of band forms, moderate toxic granularity of neutrophils is noted (++).

Viral and chlamydial pneumonia are characterized by leukopenia (4 10 9 / l) with a slight increase in ESR. With mycoplasma pneumonia, a normal leukocyte count or slight leukocytosis is accompanied by a noticeable increase in ESR.

The appearance of leukopenia in patients with bacterial pneumonia is an unfavorable sign, as it indicates toxic inhibition of leukopoiesis and indicates a decrease in immunity and general resistance of the body.

2. Biochemical blood test reveals an increase in the content of proteins of the acute phase of inflammation (a 2 - globulins, fibrinogen, ceruloplasmin,

the appearance of C-reactive protein) and glycoproteins (sialic acids, seromucoid). In severe pneumonia, signs of blood hypercoagulation are determined - the level of fibrinogen increases 2-3 times.

As the inflammatory process resolves, the fibrinolytic activity of the blood increases.

With a prolonged course of pneumonia, the content of γ-globulins increases.

3. Sputum analysis. Lobar (lobar) pneumonia in the red hepatization stage is characterized by “rusty” sputum or sputum streaked with blood, in the gray hepatization stage - purulent sputum, in the resolution stage - mucopurulent, and then mucous. The initial stage of focal pneumonia is characterized by scanty mucous sputum. In the stage of active inflammatory process, the sputum becomes mucopurulent or purulent and has a yellowish or greenish tint.

Sputum microscopy can detect large numbers of neutrophils (in bacterial pneumonia), erythrocytes (in lobar, Friedlander, influenza pneumonia), and alveolar macrophages. The appearance of elastic fibers in the sputum indicates the destruction of lung tissue and the formation of a lung abscess.

Microbiological examination of sputum is carried out to determine the type of bacterial pathogen and its sensitivity to antibiotics. It should be noted that in clinical practice, in a hospital setting, it is possible to identify the causative agent of pneumonia no more often than in 60 - 70% of cases, and in an outpatient setting - only in 10%. The information content of the microbiological method increases when examining fluid obtained using bronchoalveolar lavage during fibrobronchoscopy (FBS). Atypical pathogens are not detected in sputum.

4. X-ray examination chest organs is the most informative diagnostic method that allows

establish the presence and prevalence of pneumonia. As a rule, large-frame fluorography and radiography of the lungs in three projections (direct and lateral) are used.

With lobar (lobar) pneumonia, intense homogeneous darkening of the lung tissue within a lobe or segment is determined. On the affected side, there is an expansion of the lung root, which loses its structure (Fig. 4, 5, 6). In uncomplicated pneumococcal pneumonia, the infiltration resolves within 2 to 3 weeks.

Lobar lesions (usually the upper lobe) are also characteristic of Friedlander pneumonia, and segmental lesions are characteristic of staphylococcal pneumonia. The last two variants of pneumonia are characterized by the rapid development of multiple foci of destruction of lung tissue (abscess formation).

With focal pneumonia, foci of infiltration of various sizes and intensity are detected, most often in the lower lobes of the lungs (Fig. 7,8). There is a slight expansion of the root of the lung. Sometimes foci of infiltration merge (focal confluent pneumonia), occupying a segment or lobe of the lung. With adequate treatment, focal pneumonia resolves within 10 to 14 days.

“Atypical” pneumonia is characterized by an increase in the pulmonary pattern due to the interstitial component.

5. Spirography reflects the state of the external respiration function of patients. A schematic representation of a normal spirogram is shown in Fig. 9.

Main lung volumes:

DO - tidal volume,

Vital capacity - vital capacity of the lungs,

FVC - forced vital capacity of the lungs,

FEV1 - forced expiratory volume in 1 second,

MVL - maximum ventilation.

In case of lobar or segmental pneumonia, spirography reveals disturbances in the function of external respiration of a restrictive type, manifested by a decrease in minute volume of respiration (MVR), VC and MVL.

In case of focal pneumonia that has developed against the background of chronic obstructive bronchitis, disturbances in the function of external respiration of the obstructive type are possible, as evidenced by a decrease in FEV1 and test values. Tiffno(FEV1/FVC). In these cases, disorders of the external respiration function are more often determined to be of a mixed type.

6. Serological studies carried out to identify mycoplasma, rickettsial, legionella, ornithosis and viral pneumonia. The titer of specific antibodies to the suspected pathogen in the patient’s blood serum is determined (ELISA). An increase in titer of 4 times or more is significant. The polymerase chain reaction (PCR) method is used to determine the DNA of viruses, mycoplasma, chlamydia, etc.

In severe or atypical cases of pneumonia, there is a need to use more complex examination methods, such as bronchoscopy, computed tomography of the lungs, examination of pleural fluid, ultrasound of the chest and abdominal cavity.

According to indications, consultations are held with a phthisiatrician and an oncologist to exclude tuberculosis and lung tumors.

"Golden" diagnostic standard early diagnosis of pneumonia already at the outpatient stage includes the following signs (A.G. Chuchalin, 2000):

1. Acute onset of illness with fever and intoxication.

2. The appearance of a dry cough or with sputum, chest pain.

3. Dullness of percussion sound, appearance of auscultatory signs of pneumonia (crepitus, fine moist rales).

4. Leukocytosis or, less commonly, leukopenia with a shift to the left.

5. Detection of infiltrate in the lung during x-ray examination.

According to severity, all pneumonia is divided into three groups:

1 . Pneumonia with a mild course that does not require hospitalization of patients who can be treated on an outpatient basis under the supervision of a doctor or in a day hospital of a clinic.

2. Pneumonia is moderate, requiring hospitalization of patients in a hospital. This group includes pneumonia that has pronounced clinical symptoms or occurs against the background of chronic diseases of internal organs.

Direct indications for hospitalization of patients with pneumonia are: age over 70 years, concomitant broncho-obstructive diseases, chronic diseases of internal organs, diabetes mellitus, pleural pain, disturbances of consciousness, tachycardia (heart rate more than 125 per 1 min), severe shortness of breath (more than 30 breaths per 1 min ), cyanosis, arterial hypotension (90/60 mm Hg and below), inability to provide effective care on an outpatient basis or lack of effect of treatment within three days, the appearance of complications of the disease, such as exudative pleurisy, abscess formation.

3. Pneumonia with severe course, requiring hospitalization of patients in the intensive care unit and resuscitation unit. Mortality of patients reaches 40 - 50%.

Indications for intensive care of patients with pneumonia are: acute respiratory failure (hypoxemia, need for artificial ventilation), unstable hemodynamics (shock, need for vasopressors for more than 4 hours, diuresis less than 20 ml/hour), acute renal failure requiring hemodialysis, disseminated intravascular coagulation. -syndrome, meningitis, coma.

Differential diagnosis of pneumonia held:

1. With infiltrative tuberculosis lungs, which is characterized by a gradual onset, absence of severe fever and intoxication, paucity of physical data, lack of effect from conventional antibacterial therapy, unfavorable social status of the patient (homeless, etc.). In the stage of disintegration of the tuberculous infiltrate, hemoptysis or pulmonary hemorrhage appears. A general blood test reveals neutrophilic leukocytosis with a shift

to the left, lymphopenia and monocytosis. X-ray reveals large-focal inhomogeneous infiltration of the lung tissue, usually in poorly ventilated upper lobes, with a “path” to the root (lymphangitis) and foci of elimination in the lung segments adjacent to the infiltrate (Fig. 10, 11). In sputum during examination

Rice. 12. Peripheral cancer of the right lung.

Koch bacteria (KB) can be detected by flotation. The diagnosis of tuberculosis is helped by a positive Mantoux test and an increased titer of antibodies to Mycobacterium tuberculosis (ELISA).

oncological diseases (long-term smoking, family history, unfavorable environmental and professional conditions), early appearance of a dry cough, worsening in the horizontal position of the patient, hemoptysis, chest pain, weight loss. To clarify the diagnosis, fibrobronchoscopy with biopsy, layer-by-layer tomography and computed tomography of the lungs are used.

With exudative pleurisy. In the lower parts of the affected side of the chest, weakening of vocal tremors, percussion dullness with an upper border along the Damoiseau line, and absence of respiratory sounds are detected. X-ray examination reveals a homogeneous darkening on the affected side with a characteristic upper oblique border (Fig. 17). The mediastinal organs shift to the healthy side. The results of pleural puncture are of decisive diagnostic importance.

4. With infarction pneumonia with thromboembolism of the pulmonary artery (PE) - mainly of its small and medium branches. Characterized by the sudden appearance of shortness of breath and dry cough with sharp chest pain, and after 2-3 days - an increase in body temperature and the appearance of hemoptysis in the absence of symptoms of intoxication. Physical data are scarce. Clinical and ECG signs of acute overload of the right heart are revealed (P-pulmonale, T wave inversion in the right precordial leads, right bundle branch block). An important diagnostic role is played by the x-ray picture of the chest organs - bulging of the pulmonary cone and regional disappearance of the pulmonary pattern, followed by the appearance of darkening of the lung tissue in the shape of a triangle with the apex directed towards the root of the lung. A general blood test is nonspecific. The diagnosis is helped by identifying risk factors for pulmonary embolism: peripheral phlebothrombosis, prolonged immobilization, abdominal surgery, bone fractures, intravenous drug use, etc.

Complications of pneumonia (pulmonary and extrapulmonary):

1. Respiratory failure I - III degrees.

2. Acute respiratory distress syndrome is a non-cardiogenic pulmonary edema associated with increased permeability of the alveolo-capillary membrane under the influence of toxins of infectious microorganisms and endogenous inflammatory mediators.

3. Parapneumonic pleural effusion, less often - pleural empyema.

4. Lung abscess.

5. Bronchospastic syndrome.

6. Infectious-toxic shock (ITSH) with symptoms of acute vascular, cardiac and renal failure, with the development of disseminated intravascular coagulation, ulceration of the mucous membrane of the digestive tract and gastrointestinal bleeding.

7. Sepsis.

8. Infectious-allergic myocarditis.

9. Intoxication psychoses.

10 . Infectious-toxic kidney.

It is also possible to develop toxic hepatitis, infective endocarditis, pericarditis, meningitis or meningoencephalitis.

Date added: 2015-09-18 | Views: 1778 | Copyright infringement

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If a person suffers from a chronic cough for a long time, then he is rarely able to independently recognize pneumonia (pneumonia), bronchitis or other acute inflammatory process in the lower respiratory tract. Bronchitis and pneumonia often occur after a cold. Both pathologies can be of either a viral or bacterial nature.

Acute pneumonia and acute bronchitis have many similar signs and symptoms, so it is impossible to confidently determine pneumonia at home without the participation of specialists and without using “gold standards” of diagnosis.

Differential diagnosis

Differential diagnosis of pneumonia is extremely important because, unlike bronchitis, it must be treated completely differently. The differential diagnosis of pneumonia should be based on the patient’s symptoms and laboratory and instrumental criteria:

1. The disease usually begins acutely and is accompanied by a febrile state (body temperature exceeds 38°C).
2. Sputum with pus and blood impurities appears.
3. Auscultation reveals previously absent, local shortening of the pulmonary sound during percussion.
4. The leukocyte formula is observed with a shift to the left.
5. During the examination, radiology specialists will indicate the main x-ray sign - the accumulation of blood and cells in a certain area of ​​the lung, which creates a certain pattern of darkening.

Diagnosing pneumonia is not an easy task. In addition to the fact that this disease is easily confused with other pathological processes, it itself can be of several types and have a different clinical picture. The classification of pneumonia in adult and pediatric patients depends on the form, etiology, conditions of occurrence, characteristic signs, localization and possible complications.

Based on its form, this pathology is divided into the following groups:

• out-of-hospital (home) - most common;
• inflammatory-infectious process acquired during hospital stay;
• Pneumocystis - observed in patients with immunodeficiency.

Of great importance in treatment tactics is the identification of the pathogen, which may be one of the following pathogens:

• Pneumococcus;
• mycoplasma microorganisms;
• chlamydia pneumonia;
• legionella;
• Pfeiffer wand;
• Staphylococcus aureus;
• Friedlander's wand;
• non-cellular infectious agents;
• pathogenic fungi.

According to clinical signs and localization of inflammation, they are divided into the following groups:

• focal (bronchopneumonia) occurs with small localizations or confluent;
• lobar (lower lobe);
• bilateral (both lungs are affected).

Diagnosis and treatment of pneumonia should be given serious attention, since this disease can be fatal without taking appropriate measures. The mortality rate in middle-aged patients who do not suffer from serious somatic diseases is no more than 3%. But pneumonia in older people, aggravated by chronic diseases, has a poor prognosis in every third patient.

Basic diagnostic methods

Patients who value their lives will not take long to figure out how to determine pneumonia at home, and at the first suspicion of pneumonia, they will go to a medical clinic for diagnosis and treatment, or at least call a paramedic at home.

An experienced pulmonologist knows very well how to recognize pneumonia and how to distinguish bronchitis from pneumonia.

Diagnosis of pneumonia includes the following laboratory and instrumental examinations:

• fluoroscopy;
• clinical blood test;
• blood chemistry;
• Analysis of urine;
• examination of sputum and smears;
• assessment of blood gas composition.

In addition, the methodology for examining a person may include the following diagnostic procedures:

• lung biopsy;
• bronchoscopy.

However, before resorting to the methods described above, the pulmonologist begins the examination by assessing the patient’s auscultatory pattern.

Auscultation

When pulmonologists diagnose pathology using auscultation, acute pneumonia can give the following signs of the disease:

1. Increased signs of bronchial phonia appear on the sides of the affected area.
2. With focal lesions, mixed breathing can be heard. On inhalation, it is characterized as vesicular, and on exhalation, weakened bronchial breathing is observed.
3. In the lobar form of the disease, a crunching sound is heard in the initial phase and in the resolution stage.
4. Pleuropneumonia is characterized by pronounced noise created by friction of the pleural layers. And when effusion forms, a sharp weakening of breathing is observed.
5. In severe cases of the inflammatory process, listening to the heart reveals a pronounced acceleration of the heartbeat.

Especially in elderly patients, a sharp decrease in blood pressure may occur with the development of acute vascular insufficiency.

Diagnosis of the lobar form of the disease always begins with listening. This pathology has 2 informative characteristics:

1. Alveolar crackling on inspiration, which does not go away after the patient coughs.
2. Moist wheezing on inspiration. They are explained by the fact that when the air flow passes, the bubbly viscous exudate in the bronchi bursts.

With focal pneumonia, a specific crunching sound appears in the first and third stages. And wheezing due to the accumulation of liquid secretions is classified as fine-bubble ringing. Auscultation for lobar pathology helps the pulmonologist determine the stage of inflammation.

Video

Video - What is pneumonia?

X-ray diagnostics

X-ray diagnosis of the disease plays a key role in making an accurate diagnosis. But almost all patients know that when performing an X-ray for pneumonia, radiation exposure to the body cannot be avoided, so they are interested in whether fluorography will show pneumonia.

In fact, the task of fluorographic examination is to prevent serious diseases of the lower respiratory tract. And it occupies a worthy place in radiology. However, if you compare a photo of the lungs on fluorography and a lung x-ray, it becomes obvious that darkening or pathology is better visible on an x-ray.

Whether the disease can be seen on fluorography and how well depends largely on the type of infection that affects the pulmonary structures. In turn, an x-ray of the lungs for pneumonia is not only a way to detect the disease, but it can also be used to monitor treatment and notice positive or negative dynamics.

Lobar pneumonia on an x-ray may look like this:

• extensive darkening;
• one-sided total or partial darkening;
• limited dimming (changes do not extend beyond the segment).

X-rays do not always show focal pneumonia, since in the initial stages the disease is characterized by the appearance of small compactions with biological structures. And yet, an experienced radiologist knows how to identify inflammatory processes even in the absence of compactions, since a focal form on an x-ray can show indirect signs:

• local pathological shadows;
• inflammation of the pleura with the formation of fibrous plaque on its surface or effusion inside it;
• enlargement of pulmonary roots;
• distortion of the pulmonary pattern in a certain area.

If the disease is clearly visualized on an x-ray, but there is a need to detect more subtle details of the pathological process, then CT is used. Computed tomography can detect pneumonia at the earliest stages, since even then it clearly shows pathological changes in tissues.

Blood test

If, when undergoing a preventive examination, patients doubt whether fluorography will show pneumonia, then ESR (erythrocyte sedimentation rate) indicators will definitely help not to miss a developing disease. During a standard examination, they can greatly exceed the norm. And even more so when a general blood test is taken for pneumonia.

As a rule, acute pneumonia has an ESR of 20-25 mm/hour. In severe cases it can reach 40-50 mm/hour. And if ESR indicators are 80 mm/hour or higher, then they may suspect oncology or an autoimmune disease. However, it is worth considering that ESR is not an absolute indicator, especially for patients who are undergoing therapy that suppresses unwanted immune reactions of the body.

In case of lobar pneumonia, diagnosis cannot be done without a blood test. The hemogram in this case has a standard description - acceleration of ESR and a shift of the leukocytosis formula to the left. If the level of leukocytes in the blood reaches more than 10-12x109/liters, then this indicates a high probability of bacterial infection, and if their level becomes below 3x109/liters or above 25x109/liters, then such indicators indicate an unfavorable prognosis.

Biochemistry is also done, but such a blood test for pneumonia does not provide specific information.

Urine and stool examination

If a pathogen is detected in feces and urine, specific treatment is selected. This is especially true in the case of its Klebsiella form. If the bacterial process is not detected in a timely manner and adequate treatment is not begun, the pathology will begin to spread to the gastrointestinal tract, hepatobiliary region, urinary system, and may even affect the brain.

If Klebsiella pneumonia appears in the urine, this indicates that the process has affected the genitourinary system. Any other acute pneumonia shows a small amount of red blood cells in the urine (microhematuria), as well as protein (proteinuria), which does not happen normally. A urine test for pneumonia is not one of the most informative tests.

If Klebsiella pneumonia is detected in the stool, the digestive system is considered to be the source of the lesion. But it should be borne in mind that this bacterium, under normal conditions, is a standard inhabitant of the large intestine and the general microflora of the gastrointestinal tract. Laboratory examination of feces makes it possible to clearly recognize abnormalities in infants. And if it turns out to detect Klebsiella pneumonia in the stool of an adult, then this information will not be so significant.

Sputum examination

At the discretion of the attending physician, who knows exactly how to determine pneumonia, a sputum test for pneumonia may be prescribed. The study of secretions obtained from the respiratory tract is carried out in order to identify the type and type of causative agent of the developed disease. The answers to bacterioscopy of a sputum smear, which is Gram stained and microbiological examination is carried out, are decisive.

To confirm chlamydial pathology, the most specific and sensitive method is the cultural method of isolating the pathogen, however, it is characterized by a lengthy and labor-intensive process and in practice is usually limited to serotyping. When performing a standard bacterioscopy of a sputum smear for mycoplasma, it is not possible to detect this pathogen, so the method of immunofluorescence or enzyme-linked immunosorbent assay is used.

In addition, there is a whole scheme for how to diagnose rare pneumonia caused by Friendlander's bacillus. Microbiological tests are being carried out to inoculate bacteria. The pathogen can be detected in a smear from the cervical canal, in a smear from the throat, and sometimes Klebsiella pneumonia is found in a smear of mucus from the throat. As a rule, the latter case is characteristic of nosocomial infection.

Formulation of diagnosis

After carrying out all the specific tests for pneumonia, assessing what pneumonia looks like in the picture, a diagnosis will be formulated. It will indicate what kind of pathology it is - bronchitis or pneumonia, as well as other details:

• the pathogen that provoked the occurrence of the pathology;
• the area of ​​location of the process and its scale (the lesion affects a segment, a lobe, one side or two at once);
• pneumonia severity criteria;
• characteristics of complications, if any;
• what phase the disease is in (beginning, peak, restoration of normal structure, resolution, final stage, protracted process);
• general picture of somatic diseases that may affect recovery.

An example of a diagnosis: “Lobar acute pneumonia caused by pneumococcus. There is a lower lobe right-sided lesion. The disease is in its peak phase and is severe. Acute partially compensated respiratory failure is observed.”

Patients who have suffered a severe form of lower respiratory tract disease must carefully monitor their health in the future and undergo regular preventive examinations. Even if they feel well, once a year they are required to undergo radiography or fluorography.

1. In a blood test for acute pneumonia, it is observed
1. leukocytosis,
2. accelerated ESR
3. agranulocytosis
4. leukopenia
5. erythrocytosis

2. The criterion for stopping antibacterial therapy in acute pneumonia is:

a) normalization of temperature

b) a period of 3-4 days after the temperature normalizes

c) a period of 8-10 days after the temperature normalizes

d) resorption of pneumonic infiltration

e) normalization of peripheral blood parameters

3. Crepitation is heard when:

a) bronchitis

b) bronchial asthma

c) lobar pneumonia

d) dry pleurisy

e) exudative pleurisy

4. The main causative agent of lobar pneumonia

a) gonococcus

b) pneumococcus

c) streptococcus

d) staphylococcus

e) Koch's wand

5. The most informative method for diagnosing pneumonia

a) sputum analysis

b) blood test

c) chest x-ray

d) pleural puncture

e) fluorography

6. Complication of focal pneumonia

a) lung abscess

b) bronchitis

c) tuberculosis

d) lung cancer

e) toxic damage to points

7. Complication of lobar pneumonia

a) bronchial asthma

b) bronchitis

c) pleurisy

d) lung cancer

e) gangrene of the lung

8. A 32-year-old patient was admitted with complaints of cough with rust-colored sputum, pain in the right side, aggravated by coughing, chills, increased body temperature to 39 0, shortness of breath. He became acutely ill after cooling down. Upon admission, the condition was serious. With percussion below the angle of the scapula - dullness of the percussion sound, weakened breathing, and crepitus. What is the patient's condition?

a) lobar pneumonia

b) bronchopneumonia

d) tuberculosis

d) acute bronchitis

9. A 25-year-old patient upon admission to the hospital complains of cough, sharp pain in the abdominal cavity on the right, nausea, and vomiting. Objectively: temperature 39.7 0 C, feverish blush on the cheeks. The chest on the right is behind in breathing. On percussion - shortening of the percussion sound on the right, below the angle of the scapula, weakened breathing there, and crepitus is heard. With deep palpation of the epigastric area, the pain does not intensify, there is no tension in the muscles of the anterior abdominal wall and there are no symptoms of peritoneal irritation. Complete blood count: leukocytosis, increased ESR. What is the patient's condition?

a) lower lobe pneumonia

b) acute stomach

d) tuberculosis

d) acute bronchitis

10. A 24-year-old patient was admitted with complaints of high fever, pain in the right side associated with breathing, dry cough, and headache. She became acutely ill. In the evening, when I came home from work, I felt healthy. After dinner I felt chills and exhaustion. There is pain in the right side, he cannot breathe deeply because of the pain. Objectively: the condition is serious. He holds his right side with his hand and groans in pain. The face is hyperemic, there is a blush on the right cheek. Herpes is noted on the lips. On percussion, dullness of the pulmonary sound to the right of the angle of the scapula, weakened breathing there, and crepitus can be heard. A general blood test showed leukocytosis.

What is the patient's condition?

a) lobar pneumonia

c) acute bronchitis

d) pulmonary tuberculosis

e) focal pneumonia

11. Lobar pneumonia is

a) inflammation of one segment of the lung

b) inflammation of the lung lobe

c) inflammation of the bronchi

d) proliferation of connective tissue

e) inflammation of the mediastinal lymph nodes

12. Acute onset, high fever, chest pain when coughing, herpes on the lips are characteristic of

a) lobar pneumonia

b) focal pneumonia

c) pneumosclerosis

d) bronchial asthma

d) tuberculosis

13. The “rusty character” of sputum is observed when

a) bronchial asthma

b) acute bronchitis

c) focal pneumonia

d) lobar pneumonia

d) dry pleurisy

14. For pneumonia, all of the following medications are prescribed, except:

a) antibiotics

b) expectorants

c) bronchospasmolytic

d) antipyretics

e) narcotic

15. Lobar pneumonia is

1. inflammation of the lung lobe

2. inflammation of the lung lobule

3. formation of a purulent cavity in the lung tissue

4. lung necrosis

5. pneumothorax

Characteristic signs of lobar pneumonia

A. intoxication, cough, chest pain, cachexia

B.cough, shortness of breath, pulmonary hemorrhage

B. hemoptysis, cough, chest pain, shortness of breath

D. shortness of breath, discharge of purulent sputum in the morning

Answers:

16. Etiopathogenesis of respiratory failure in pneumonia:

a) violation of gas diffusion

b) pulmonary hypertension

c) hypertrophy of the right half of the heart

d) decreased myocardial contractility

e) exicosis

17. The main causative agent of pneumonia

b) mycobacterium

c) pneumococcus

d) Escherichia coli

e) Escherichia

18. Inflammation of an entire lobe of the lung is observed when

a) acute bronchitis

b) bronchial asthma

c) pneumonia

d) dry pleurisy

e) exudative pleurisy

19. The most informative method for diagnosing pneumonia

a) blood test

b) sputum analysis

c) pleural puncture

d) chest x-ray

e) fluorography

20. Etiotropic treatment of pneumonia is the use

a) bronchodilators

b) expectorants

c) antibiotics

d) antipyretics

d) antispasmodics

21. Complication of pneumonia -

a) pulmonary hemorrhage

b) fever

c) chest pain

d) acute respiratory failure

e) acute heart failure

22. Main symptoms of pneumonia:

a) weakness, headache, glassy sputum

b) chest pain, shortness of breath, fever

c) prolonged low-grade fever, fatigue

d) swelling, increased blood pressure, rhythm disturbances

e) rhythm disturbance, prolonged low-grade fever

23. The most common cause of chronic pulmonary heart disease is

a) lung cancer

b) chest deformation

c) primary pulmonary hypertension

d) obstructive pulmonary disease

e) recurrent embolism of the branches of the pulmonary artery

24.Pneumonia is

1.inflammation of the lung parenchyma

2.inflammation of the pleural layers

3.inflammation of the bronchial mucosa

4.accumulation of air in the pleural cavity

5. accumulation of fluid in the pleural cavity

Etiopathogenesis of respiratory failure in pneumonia

A. violation of gas diffusion

B. pulmonary hypertension

B. hypertrophy of the right half of the heart

D.decrease in myocardial contractility

D.exicosis

Answers:

25.After acute pneumonia, clinical observation is carried out for