Acute pneumonia classification. General features of pneumonia, classification. Pneumonia severity criteria

For quotation: Nikonova E.V., Chuchalin A.G., Chernyaev A.L. PNEUMONIA: EPIDEMIOLOGY, CLASSIFICATION, CLINICAL AND DIAGNOSTIC ASPECTS // Breast cancer. 1997. No. 17. S. 2

The article presents modern data on the epidemiology of pneumonia, morbidity and mortality rates among various age categories of the population both in our country and abroad. The characteristics of various factors predisposing to the occurrence of pneumonia are given, and their role in the development of severe disease and mortality is determined. A modern classification according to the international agreement on pneumonia is presented. The etiological characteristics of community-acquired and nosocomial pneumonia are given, and the role of etiological diagnosis in making a diagnosis is highlighted. The issue of correct diagnosis of pneumonia is discussed, information is provided on the frequency of under- and overdiagnosis, and their causes are indicated. The clinical and radiological picture is described and the basic principles of treatment of pneumonia are given.

The paper presents the currently available data on the epidemiology of pneumonia, morbidity and mortality in different age groups in our and foreign countries. It also characterizes various factors predisposing to pneumonia, defines their contribution to their severity and death. The paper gives the present-day classification according to the international agreement on pneumonia, outlines out hospital and inhospital pneumonias, covers the role of etiological diagnosis in establishing the diagnosis of the disease. It also discusses whether the diagnosis of pneumonia is made correctly, provides data on the frequency of hypo- and hyperdiagnosis, indicates their reasons. The clinical and X-ray of the disease are outlined and the basic principles in the treatment of pneumonia are given.

Research Institute of Pulmonology, Ministry of Health of the Russian Federation, Moscow
A. G. Chuchalin - Director of the Research Institute of Pulmonology of the Ministry of Health of the Russian Federation, Academician of the Russian Academy of Medical Sciences, Professor
A. L. Chernyaev - head. laboratory pathological anatomy Research Institute of Pulmonology of the Ministry of Health of the Russian Federation, professor, doctor of medicine. sciences
E. V. Nikonova - graduate student of the Research Institute of Pulmonology of the Ministry of Health of the Russian Federation
Research Institute of Pulmonology, Ministry of Health of the Russian Federation, Moscow
Prof. A. G. Chuchalin, Academician of the Russian Academy of Medical Sciences, Director, Research Institute of Pulmonology, Ministry of Health of the Russian Federation
Prof. A. L. Chernyaev, MD, Head, Laboratory of Pathoanatomy, Research Institute of Pulmonology, Ministry of Health of the Russian Federation
Yes. V. Nikonova, Postgraduate Student, Research Institute of Pulmonology, Ministry of Health of the Russian Federation

P Neumonia is one of the most common diseases, occurs at any age, and has certain course characteristics in different age periods. It is a complex of pathological processes developing in distal sections lung tissue. The main manifestation of these processes is infectious, exudative, and less often interstitial inflammation, caused by microorganisms of various natures, and dominant in the entire picture of the disease. From a clinical point of view, the concept of “pneumonia” should be defined as infection lower respiratory tract, confirmed x-ray.

Epidemiology of pneumonia

Modern ideas about pneumonia were formed as a result of their centuries-long study. Hippocrates also described pneumonia, its symptoms and treatment. Ancient authors said that a number of successive stages can be distinguished in the development of pneumonia. The question of the beginning and primary source of development has remained unresolved to this day, although it seems obvious that the primary source of pneumonia as an infectious disease is its etiological factor - a pathogenic pathogen.
Epidemiology of pneumonia in modern stage is characterized by a trend towards increasing morbidity and mortality that has emerged since the late 80s, both in our country and throughout the world. In developed countries, the incidence of pneumonia ranges from 3.6 to 16 per 1000 people. Currently, throughout the world, pneumonia ranks 4th - 5th in the structure of causes of death after cardiovascular pathology, cancer, cerebrovascular pathology and chronic obstructive pulmonary diseases (COPD), and among infectious diseases it ranks 1st. In the United States, 3-4 million people fall ill with community-acquired pneumonia annually, 30-40% of them require hospitalization. Approximately 50 - 70% of patients are treated as outpatients, and the mortality rate among them is only 1 - 5%.
The incidence in the age group over 60 years is from 2 0 to 44 per 1000 population per year. The mortality rate from pneumonia in this category of patients is 10 - 33%, and in pneumonia complicated by bacteremia it reaches 50%. The mortality rate from pneumonia is high among newborns and young children and reaches 25% in children under 5 years of age. According to WHO, the mortality rate of children under 1 year in our country is 2-4 times higher (25.1 per 1000 population) than in other economically developed countries.
Great importance assigned to hospital-acquired (nosocomial) pneumonia. It accounts for approximately 10 - 15% of all hospital-acquired infections. The mortality rate for nosocomial pneumonia ranges from 30 - 60 to 80%.
Among patients with pneumonia, men predominate. They constitute, according to many authors, from 52 to 56% patients, while women - from 44 to 48%.
The incidence of pneumonia clearly increases with age. Patients aged 40 to 59 years make up 38.4 - 55.7% of cases, over 60 years old - from 31 to 60%.
The duration of temporary disability is on average 25.6 days and can range from 12.8 to 45 days. According to foreign authors, the average number of bed days for patients over 60 years of age is 21.

Risk factors for pneumonia

In the occurrence of pneumonia, predisposing factors, or risk factors that lead to damage to one or more defense mechanisms. Most often, pneumonia occurs in the cold season, i.e. the incidence is seasonal, but it should be noted that the disease can occur at any time of the year. One of the most common provoking factors is hypothermia. Viruses are of great importance in the occurrence of pneumonia, especially during influenza epidemics, most often these are influenza viruses A, B, C, parainfluenza, adenoviruses, respiratory syncytial viruses and coronaviruses. Age over 60 years is another important risk factor, which is primarily associated with suppression of the cough reflex, impaired mucociliary clearance, and changes in microbial flora. In addition, at this age, a risk factor is the presence of COPD, pathology of cardio-vascular system, kidney, gastrointestinal tract. Another important factor is smoking: smoking up to 15 - 20 cigarettes per day leads to impaired mucociliary clearance, increased chemotaxis of macrophages and neutrophils, their activation, destruction of elastic tissue, and decreased effectiveness of mechanical protection. The occurrence of pneumonia is predisposed by disturbances of consciousness, alcohol intoxication, brain injury, epileptic seizure, anesthesia, overdose of sleeping pills and narcotic drugs. In all these cases, aspiration of the contents of the oropharynx and gastrointestinal tract, carrying large quantities of various aerobic and anaerobic flora, can occur. Pneumonia can also develop in the postoperative period, primarily through operations on the chest organs and abdominal cavity; in this case, nosocomial pneumonia occurs, the frequency of which ranges from 20 to 50%, and the mortality rate ranges from 19.2 to 80%. A big problem is the occurrence of pneumonia in patients on mechanical ventilation (ALV) for more than a day. At the same time, the probability of nosocomial pneumonia is extremely high, its frequency ranges from 13 to 55%.
An important role in the occurrence of pneumonia is played by the primary and secondary immunodeficiency. The main contingent is patients with various tumor diseases: hemoblastoses, myelotoxic agranulocytosis, autoimmune diseases, patients receiving chemotherapy, radiation, immunosuppressive therapy, suffering from drug addiction and AIDS. The main pathogens are opportunistic, gram-negative flora, fungi (often Aspergillus spp.), Pneumocystis, cytomegalovirus, Noca rdia. One cannot fail to mention pneumonia in severe neutropenia caused by the use of chemotherapy for malignant neoplasms, the causative agents of which are both gram-positive cocci and gram-negative flora. Against the background of these pneumonias, septic conditions develop; the mortality rate is high. Risk factors for pneumonia may also include contact with birds, rodents, and travel.

Classification of pneumonia

The current division of pneumonia according to the clinical and pathomorphological principle into parenchymal - lobar and focal, as well as the identification of interstitial and mixed pneumonia is not very informative in terms of choosing the optimal etiotropic therapy. Recent advances in microbiology, pulmonology and pharmacotherapy dictate the need to develop the concept and classification of various types of pneumonia. The division of pneumonia should be based on the etiological principle, which will allow for targeted etiotropic pathogenetic treatment. Today, within the framework of the European Society of Pulmonologists and the American Thoracic Society, a discussion continues on the issue of classification of pneumonia. To streamline diagnostic methods and especially treatment methods, a clinical classification of pneumonia is recommended. There are four forms of pneumonia:

• community-acquired (home-acquired);
• in-hospital (nosocomial);
• against the background of immunodeficiency states;
• atypical pneumonia.

This classification reflects not only the place of origin of the disease, but also significant features (epidemiological, clinical and radiological), and most importantly - a certain range of pathogens, the course, outcome and treatment programs for patients with pneumonia. In foreign classifications and in periodical literature, pneumonia is divided into primary (community-acquired) and secondary (nosocomial-acquired).
IN Lately Medical practice requires greater detail of pneumonia, taking into account their diversity and wide range of pathogens. It is necessary to distinguish between aspiration pneumonia, post-traumatic pneumonia, postoperative pneumonia, pneumonia developing against the background of COPD, chronic alcoholism, malignant neoplasms, immunodeficiency, nosocomial pneumonia. Risk factors for the occurrence of pneumonia of the latter group are the presence of patients on mechanical ventilation, the presence of a tracheostomy, the postoperative period, massive antibacterial therapy.
Of great importance is the grouping of pneumonia by severity, which makes it possible to identify patients in need of intensive care, outline the most rational therapy, and assess the prognosis. The main clinical criteria for the severity of the disease are the degree of respiratory failure, severity of intoxication, presence of complications, decompensation concomitant diseases.

Etiology of pneumonia

The etiological approach in diagnosing pneumonia is extremely important. A practicing doctor almost always has to prescribe antibacterial therapy to a patient, not only in the absence of verification of the pathogen in the first days, but also without any prospects for obtaining microbiological data about the pathogen. The first publicly accessible and mandatory step is to establish a presumptive etiological diagnosis based on clinical and epidemiological data, taking into account the etiological structure of modern pneumonia. Of great importance for the diagnosis of pneumonia upon admission of a patient to a hospital is Gram staining of a sputum smear, which makes it possible to identify gram-positive and gram-negative pathogens, intracellular and extracellular localization of microorganisms. Comparison of bacterioscopy data with clinical and radiological features makes it possible to make an early clinical and bacteriological diagnosis in 86% of all patients with pneumonia and in 70% of patients with pneumococcal pneumonia. When diagnosing pneumonia, it is important bacteriological examination sputum (culture on media) and determination of sensitivity to antibiotics, identification of pathogens using a quantitative method in diagnostically significant titers (10 6 microbial cells or more in 1 ml of sputum). Abroad, along with the study of sputum, studies of aspirate, washings obtained during fiberoptic bronchoscopy, materials obtained during transtracheal aspiration, blood culture, and determination of antibodies to antigens of various pathogens in blood serum are widely carried out. The division of pneumonia into community-acquired and nosocomial is justified primarily by differences in the etiological structure. In the occurrence of community-acquired pneumonia, the leading role belongs to Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus occupies a certain place. The occurrence of community-acquired pneumonia can also be caused by atypical pathogens: Mycoplasma pneumoniae, Legionella pneumophilla and Chlamydia pneumoniae.
In the occurrence of nosocomial pneumonia, the role of opportunistic and gram-negative flora is great. This is primarily S. aureus, the occurrence of which ranges from 2.7 to 30%. The pathogen of the Enterobacteriacea family, Klebsiella pneumoniae, accounts for from 9.8 to 1 2.6% of pneumonia, with mortality ranging from 40 to 71%. The specific gravity of E.coli ranges from 17.3 to 32.3%, Proteus vulgaris - from 8.2 to 24%. Pseudomonas aeruginosa is responsible for the development of nosocomial pneumonia in 17% of cases, mortality reaches 80%. The share of Legionella pneumophilla as the causative agent of nosocomial pneumonia reaches 33%.
The role of viral pneumonia increases during epidemics of influenza A, B and ranges from 8.6 to 35%. The presence of purely viral pneumonia is not recognized by all authors. It is believed that they are conductors who prepare the “soil” for the addition of bacterial and mycoplasma flora.
The relevance of the problem of mixed infections in recent years is determined primarily by the fact that they account for up to 30 - 50% of cases of the disease, monoculture occurs in 40.5 - 50% of cases.
The etiology of pneumonia in more than 50% of cases cannot be established at all. The reasons are most often the following:

• lack of microbial research;
• improper collection of material;
• pathogen unknown;
• previous treatment with antibiotics (before taking material);
• uncertain clinical significance of the isolated pathogen;
• use of an inadequate treatment method.

Diagnosis of pneumonia

There is the concept of a “gold standard” in the diagnosis of pneumonia, which includes the assessment of five signs: fever, cough, sputum, leukocytosis and radiologically detectable infiltrate. However, following only this standard leads to diagnostic errors.
Despite significant achievements in the study of pneumonia, the synthesis of new antibacterial drugs, a wide selection, expansion of the spectrum laboratory diagnostics, the level of correct diagnosis of pneumonia remains insufficient.
The frequency of overdiagnosis of pneumonia ranges from 16 to 55%, and underdiagnosis - from 2.2 to 30.5%. The most common discrepancies in diagnoses are in clinics. An analysis of materials dating back to the 70s showed that a complete coincidence of the outpatient diagnosis with the clinical diagnosis is observed only in 20% of cases.
It should be noted that one of the important reasons for untimely diagnosis is the late seeking of medical care by patients both at the pre-hospital and hospital stages.
Underdiagnosis of pneumonia is largely due to defects in x-ray examination - both x-ray underdiagnosis and the lack of lung x-rays. Although we must not forget about the so-called X-ray negative pneumonia, which accounts for accounts for about 20%.
The situation is poor with the differential diagnosis between influenza and pneumonia, while instead of pneumonia, influenza, acute respiratory infection. This is most often observed at the prehospital, outpatient stage, especially during influenza epidemics. Pneumonia, which occurs in various severe concomitant diseases: COPD, cardiovascular, cerebrovascular, oncological diseases, as well as in weakened and elderly patients who abuse alcohol. The severity and danger of death from pneumonia is not given due importance.
In hospital patients over 60 years of age, errors in diagnosing pneumonia are associated with concomitant pathology, since in this case extrapulmonary symptoms come to the fore, such as cardiovascular failure, impaired consciousness, exacerbation and decompensation of concomitant diseases.
Daily mortality in hospital ranges from 6 to 1 4% . Incorrect interpretation of the clinical picture can also occur in young patients and in patients under 50 years of age. Myocardial infarction (5.1%), acute abdomen (3.1%), acute cerebrovascular insufficiency (7.1%), and other diseases (29.6%) are often diagnosed.
Reliable etiological diagnosis is currently difficult. Epidemiological, clinical, X-ray laboratory criteria, of course, in a number of cases allow, with varying degrees of probability, the etiological diagnosis of pneumonia, but cannot serve as the basis for a reliable conclusion about the agent. Often in Russian hospitals, sputum bacterioscopy is not performed, which makes it possible to determine gram-positive and gram-negative flora; bacteriological control is poorly developed and practically absent in urgent situations. Often sputum examination is not performed and treatment usually remains empirical. Due to erroneous diagnosis of pneumonia, antibacterial therapy is either started late or it is inadequate to the clinical picture, which also leads to the development of complications and increased mortality.
Subjective and objective reasons for errors in the diagnosis of pneumonia are identified.
Subjective reasons include:

• loss of clinician interest in patients over 60 years of age;
• negligence and haste during the examination;
• illogical understanding of the obtained clinical and laboratory data;
• overestimation and underestimation of research methods, consultations with specialists;
• lack of a survey system and poor knowledge of survey methods;
• ignoring or inept use of medical history data;
• incorrect and incomplete formulation of the final diagnosis.

Objective reasons include:

• severity of the patient's condition;
• lack of time for correct diagnosis;
• atypical course of the disease;
• limited medical capabilities.

If it is true that no kind of human activity can do without mistakes, then this is also true for healing. According to I.V. Davydovsky (1928), “medical errors” are a type of conscientious errors made by a doctor in his judgments and actions when performing special medical duties. Despite the enormous achievements of modern therapy, the rule remains: “bene diagnostitur, bene curatur” - without a good diagnosis there cannot be a high level of the treatment process. It must be said that an exhaustively collected anamnesis allows one to establish the correct diagnosis in 50% of cases, while a clinical examination - in 30%, additional research - in 20% . A diagnosis made based on clinical data is often a presumptive diagnosis that requires confirmation. Diagnostic errors reduce the effectiveness of treatment and in 30 - 40% lead to a protracted course of pneumonia.

Clinical course of pneumonia

The clinical picture of pneumonia is determined by the characteristics of the pathogens and the state of the macroorganism. The main manifestations include various combinations of bronchopulmonary and extrapulmonary symptoms. Bronchopulmonary symptoms include cough, shortness of breath, chest pain, sputum production, which can be mucous, mucopurulent, and sometimes bloody. Dullness of percussion sound, weakened vesicular and bronchial breathing, crepitus, and pleural friction noise are also determined. Extrapulmonary include hypotension, weakness, tachycardia, chills, myalgia, fever, confusion, meningism, changes in peripheral blood parameters. In some patients, mainly in weakened and elderly patients, as well as in the presence of severe concomitant pathology, extrapulmonary symptoms prevail over bronchopulmonary ones.
The clinical and radiological picture of pneumonia depends primarily on the etiological agent. The division of pneumonia according to etiology is of fundamental importance for determining the course, prognosis and treatment. Diagnosis of pneumonia is based primarily on establishing the presence of pneumonia as an independent nosological form: analysis of clinical and radiological data with mandatory consideration of the etiological characteristics of the inflammatory process. When diagnosing this nosology, the doctor must conduct differential diagnosis with a number of diseases that have syndromic-similar symptoms, but differ in essence and require different treatment. The doctor has to solve the following differential diagnostic problems:

• distinguishing pneumonia from extrapulmonary diseases;
• differentiation of pneumonia from other respiratory diseases;
• differentiation of pneumonia according to various criteria (etiology, extent of the process, complication).

Pneumonia should be distinguished from diseases of the cardiovascular system, thromboembolism pulmonary artery, viral infection, chronic nonspecific lung diseases, tuberculosis, lung cancer, interstitial lung diseases, pneumonitis with systemic vasculitis, drug-induced lung damage, atelectasis, heart attack and pulmonary contusion.
With pneumonia, recovery occurs within up to 4 weeks. Clinical criteria for recovery are considered to be the normalization of the patient’s well-being and condition, the disappearance of physical and radiological signs of inflammation, and the normalization of blood counts. However, often the dynamics clinical signs recovery is not consistent with the x-ray picture of the lungs. It may take from 3 weeks to 6 months to restore the structure of the lung tissue. The prolonged course of pneumonia is characterized by the absence of normalization of the clinical and radiological picture within 4 weeks.

Treatment of pneumonia

It seems necessary to discuss the issue of where to treat a patient with pneumonia. According to the current situation in our country, this diagnosis is a mandatory indication for hospitalization of the patient. This position is controversial. In foreign guidelines, inpatient treatment of community-acquired pneumonia is reserved for patients with severe disease, in the presence of complications, bilateral lesions, serious concomitant diseases, for elderly patients, as well as for situations where there is no effect of treatment or there are social indications for hospitalization. The basis for the treatment of pneumonia is rational antibacterial therapy.
Treatment should begin without waiting for the results of a microbiological study, i.e. empirically. Upon receipt of bacteriological data, treatment is adjusted if it is insufficiently effective.
When choosing antibacterial drugs, one should take into account: the type of pathogen (probable, determined by clinical data), the severity of the disease, the potential toxicity of the drugs and possible contraindications. In addition, it is necessary to take into account allergy history.

• It is necessary to decide on the use of monotherapy or a combination of several antibacterial drugs.
• It is very important to take into account the resistance of microbial flora to antibacterial therapy.
• The dose and frequency of drug administration should be commensurate with the intensity of the pathological process.
• The therapeutic effect of the drug should be monitored and possible adverse reactions should be monitored.
• When choosing antibacterial treatment, it is advisable to also use the results of sputum examination using Gram staining.
• The cost of the drug used cannot be ignored.

Thus, the treatment of pneumonia remains a pressing problem at the present stage of development. clinical medicine. Diagnosing pneumonia is still quite a difficult task, which dictates the need for continuous improvement of diagnostic and treatment methods, as well as advanced training for doctors of all specialties.

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Pneumonia (P) – an acute infectious disease of predominantly bacterial etiology, characterized by the formation of an inflammatory infiltrate in the lung parenchyma.

The definition of pneumonia emphasizes the acute nature of inflammation, so you don’t need to use the term “acute pneumonia” (in the ICD – 10 revision (1992) there is no heading “acute pneumonia”).

Epidemiology. The incidence of pneumonia is on average 1%, that is, every year one out of 100 people gets sick. This rate is significantly higher in children and people over 60 years of age. Men get sick more often than women. In a number of patients (up to 20%), pneumonia is not diagnosed, occurring under the guise of bronchitis or other diseases.

The average mortality rate from pneumonia is 1 – 5%, in severe forms of the disease reaches 40 – 50%. Among all causes of human death, pneumonia ranks 4th after cardiovascular diseases, malignant neoplasms, injuries and poisoning, and among all infectious diseases it ranks 1st.

Etiology. The causative agents of pneumonia can be almost all known infectious agents: more often - gram-positive and gram-negative bacteria, less often - mycoplasma, chlamydia, legionella, viruses, etc. Associations of two or more microorganisms are possible. The etiological structure of pneumonia depends on the conditions under which the disease occurs.

According to the International Consensus and Standards (protocols) for the diagnosis and treatment of patients with nonspecific lung diseases, the Ministry of Health of the Russian Federation (1998), based on epidemiological and clinical-pathogenetic features, all pneumonia is divided into 4 groups:

Community-acquired (out-of-hospital) pneumonia that developed in community-acquired conditions, including “atypical” pneumonia caused by “atypical” intracellular microorganisms.

Intrahospital (hospital or nosocomial) pneumonia that developed within 48–72 hours or more after the patient was admitted to the hospital for another disease.

Pneumonia in immunodeficiency states ( congenital immunodeficiency , HIV infection, drug (iatrogenic) immunosuppression).

Aspiration pneumonia.

Each group of pneumonia is characterized by its own spectrum of infectious pathogens, which makes it possible to more specifically prescribe antibacterial therapy for initial stage treatment until the pathogens are verified.

I. When community-acquired pneumonia the most common pathogens are: pneumococcus (40–60%), mycoplasma (15–20%), Haemophilus influenzae (15–25%), Staphylococcus aureus (3–5%), Klebsiella pneumoniae (3–7%), Legionella ( 2–10%), respiratory viruses (2–15%), chlamydia.

II. For nosocomial pneumonia the most typical gram-negative infectious agents are: Klebsiella pneumoniae (Friedlander's bacillus), Pseudomonas aeruginosa, Escherichia coli, Proteus, and Staphylococcus aureus and anaerobes. They highlight.

III. Pathogens of pneumonia in patients with immunodeficiency conditions in addition to the usual gram-positive and gram-negative bacteria, there are cytomegaloviruses, which are considered markers of HIV infection, pneumocystis, pathogenic fungi, and atypical mycobacteria.

IV. Aaspiration pneumonia most often caused by associations of Staphylococcus aureus and gram-negative bacteria with anaerobic microorganisms, always present in the oral cavity and nasopharynx.

During periods of influenza epidemics, the etiological role of viral-bacterial associations, as well as opportunistic microorganisms, increases. By damaging the mucous membranes of the respiratory tract, respiratory viruses (influenza viruses, adenoviruses, respiratory syncytial viruses, etc.) open the “gate” for bacterial flora, most often staphylococci.

Determining the etiology of pneumonia is difficult. At the initial stage, the etiological diagnosis is empirical (presumptive) and is made taking into account clinical and epidemiological data. Thus, with the development of nosocomial pneumonia in a patient in a purulent surgical department, staphylococcal etiology is most likely. Community-acquired lobar pneumonia is most often pneumococcal. A group outbreak is characteristic of mycoplasma pneumonia. In order to identify pathogens, the patient’s sputum and bronchial washings are examined. In the diagnosis of mycoplasma and viral pneumonia, the complement fixation reaction (CFR) is used with the patient’s blood serum and antigens of viruses or mycoplasma. Even with a well-equipped microbiological laboratory, the etiology of pneumonia can only be determined in 50-60% of cases.

Pathogenesis. Risk factors pneumonia are hypothermia, childhood and old age, smoking, stress and overwork, smoking and alcohol abuse, exposure to adverse environmental and occupational factors on the respiratory system, influenza epidemics, chronic bronchitis, congestion in the pulmonary circulation, immunodeficiency states, contact with birds and rodents, staying in air-conditioned rooms, prolonged bed rest, bronchoscopic examinations, mechanical ventilation, tracheostomy, anesthesia, septic conditions, etc.

In pathogenesis pneumonia, the pathogenic properties of infectious microorganisms and the patient’s defense mechanisms interact.

The lower respiratory tract is normally sterile thanks to the system of local bronchopulmonary protection: mucociliary clearance (mucociliary lifting cleansing of the bronchi), production in the bronchi and alveoli of humoral protective factors (Ig A, lysozyme, complement, interferons, fibronectin), alveolar surfactant and phagocytic activity of alveolar macrophages, the protective function of broncho-associated lymphoid tissue.

Pneumonia pathogens enter the respiratory tracts of the lungs from the environment most often bronchogenic through inhaled air or aspiration from the oral cavity and nasopharynx. Hematogenous And lymphogenous routes of infection into the lungs are observed in sepsis, general infectious diseases, thromboembolism, and chest injuries. Inflammation of the lung tissue can develop without exposure to external infectious agents - with the activation of opportunistic microflora located in the patient’s respiratory tract, which occurs when the general reactivity of the body decreases.

When infectious microorganisms enter the respiratory tract, they adhere to the surface of the bronchial and alveolar epithelium, leading to damage to cell membranes and colonization of pathogens in epithelial cells. This is facilitated by previous damage to the epithelium by viruses, chemicals, weakening of general and local protective mechanisms as a result of exposure to infectious and other unfavorable factors of the external and internal environment.

Further development of the inflammatory process is associated with the production of endo- or exotoxins by infectious agents, the release of humoral and cellular inflammatory mediators in the process of damage to lung tissue by the influence of infectious microorganisms, neutrophils and others. cellular elements. Humoral mediators of inflammation include complement derivatives, kinins (bradykinin). Cellular mediators of inflammation are represented by histamine, arachidonic acid metabolites (prostaglandins, thromboxane), cytokines (interleukins, interferons, tumor necrosis factor), lysosomal enzymes, reactive oxygen metabolites, neuropeptides, etc.

Pneumococci, Haemophilus influenzae, Klebsiella pneumoniae produce endotoxins(hemolysins, hyaluronidase, etc.), which sharply increase vascular permeability and contribute to pronounced swelling of the lung tissue.

Pneumococcal(lobar or lobar) pneumonia begins as a small focus of inflammation in lung parenchyma, which, due to the formation of excess edematous fluid, spreads “like an oil stain” from alveoli to alveoli through the Kohn pores until it captures the entire lobe or several lobes. With early treatment inflammatory process may be limited lung segment. Pneumococci are located on the periphery of the inflammatory focus, and in its center a germ-free zone of fibrinous exudate is formed. The term “lobar pneumonia,” common in Russian pulmonology, comes from the word “croup,” which means a certain type of fibrinous inflammation.

Friedlander's pneumonia, caused by Klebsiella and similar in development to pneumococcal pneumonia, is characterized by thrombosis of small vessels with the formation of necrosis of the lung tissue.

Streptococci, staphylococci and Pseudomonas aeruginosa allocate exotoxins, destroying lung tissue and forming foci of necrosis. Microorganisms are located in the center of the inflammatory-necrotic focus, and inflammatory edema is observed along its periphery.

Micoplasma, chlamydia and legionella are characterized by long-term persistence and replication within the cells of the macroorganism, which determines their high resistance to antibacterial drugs.

In the pathogenesis of pneumonia, sensitization of the body to infectious microorganisms is of particular importance, the severity of which determines the characteristics of the clinical course of the disease. The body's response in the form of the formation of antimicrobial antibodies and immune complexes (antigen-antibody-complement) contributes to the destruction of pathogens, but at the same time leads to the development of immunoinflammatory processes in the lung tissue. When the pulmonary parenchyma is damaged by infectious microorganisms, autoallergic reactions of the cellular type may develop, contributing to the protracted course of the disease.

A hyperergic inflammatory reaction in the alveolar zone is especially characteristic of pneumococcal (lobar) pneumonia, which is associated with sensitization of the body to pneumococcus, which is present in the normal microflora of the upper respiratory tract in 40–50% of healthy individuals. Focal pneumonia often manifests itself as a normo- or hypergic inflammatory reaction.

Taking into account pathogenetic factors, pneumonia is divided into primary and secondary. Primary pneumonia develops as an acute infectious-inflammatory process in a previously healthy person, secondary pneumonia occurs against the background of chronic respiratory diseases or pathologies of other organs and systems.

According to the mechanism of development, secondary pneumonia is often bronchopneumonia – First, local bronchitis develops, and then the inflammatory process spreads to the alveolar tissue.

Pathological picture most typical for pneumococcal (lobar) pneumonia, which has a cyclic course. Highlight high tide stage(from 12 hours to 3 days), which is characterized by hyperemia and inflammatory edema of the lung tissue. In the next stage, lesions appear red and gray hepatization of lung tissue(from 3 to 6 days) as a result of diapedesis of erythrocytes, leukocytes and effusion of plasma proteins, primarily fibrinogen, into the alveoli. Stage permissions(duration varies individually) is characterized by gradual dissolution of fibrin, filling of the alveoli with macrophages and restoration of airiness in the affected parts of the lungs. Against the background of the separation of purulent sputum through the respiratory tract (in the stage of resolution), local bronchitis is usually associated with pneumonia. Pneumococcal pneumonia is characterized by fibrinous pleurisy.

With focal pneumonia, a mosaic pathological picture is observed within one or several segments. The inflammatory process involves lobules or groups of lobules, alternating with areas of atelectasis and emphysema or normal lung tissue. The exudate is most often serous, but can be purulent or hemorrhagic. Focal confluent pneumonia often develops. The pleura is usually not affected.

Classification. When making a diagnosis, be sure to indicate epidemiological group of pneumonia(according to the International Consensus and Standards (protocols) for the diagnosis and treatment of patients with nonspecific lung diseases, Ministry of Health of the Russian Federation, 1998), updated etiology(according to ICD-10 revision) and basic clinical and morphological signs taking into account the widespread classification of pneumonia in Russia, developed by N.S. Molchanov (1962) in a later modification by E.V. Gembitsky (1983).

This article will present the classification of pneumonia.

This disease is a pathological condition that is characterized by an acute inflammatory process in the lungs, mainly of infectious origin, affecting and affecting all elements of the structure of this organ, especially interstitial tissue and alveoli. This disease is quite common and is diagnosed in approximately 20 people out of 1000, and in older people, mainly after 55 years, this ratio is 30:1000.

The causes of pneumonia are of interest to many.

Statistics

Despite the fact that today there are many modern antibacterial substances of a new generation that have a wide spectrum of antimicrobial activity, the incidence of pneumonia is still relevant, as is the risk of various serious complications of this pathology. Mortality from pneumonia today is approximately 10% of all cases, which corresponds to 5th place in the list of the main causes of death among the population. Pneumonia occurs after cardiovascular and oncological diseases, injuries and intoxications due to poisoning. According to WHO statistics, 17% of all deaths in children under 4 years of age in the world are due to this pathology. We will consider the types of pneumonia below.

Etiology of the disease

This pathology is characterized by polyetiology, i.e. There are many reasons that can provoke this disease. Inflammatory processes are of both infectious and non-infectious nature, and pneumonia occurs in most cases as a complication of a certain underlying disease, but can occur in isolation, in the form of an independent disease. However, bacterial infection ranks first among the factors leading to damage to lung tissue. The onset of the inflammatory process can also be triggered by a viral or mixed (bacterial-viral) infection.

Pathogens

The main causative agents of this pathology are:

1. Gram-positive microorganisms: pneumococcus (Streptococcus pneumoniae) - 72–95%, staphylococcus (Staphylococcus aureus) - no more than 6%, streptococcus (Streptococcus pyogenes and other less common species) - 2.8%.
2. Gram-negative enterobacteria: Pseudomonas aeruginosa and Pfeiffer bacilli (Haemophilus influenzae) – no more than
3. Klebsiella pneumoniae - from 3 to 7%, Legionella pneumophila, rod-shaped intestinal bacteria (Escherichia coli), etc. - up to 4.7%.
4. Mycoplasma (Mycoplasma pneumoniae) – 5% to 22%.
5. Various viruses: adenovirus, picornavirus, influenza or herpes virus, which account for 3–9%.
6. Fungi: candida (Candida), dimorphic yeast (Histoplasma capsulatum), etc.

Non-infectious causes that contribute to the development of pneumonia are:

1. Inhalation of certain toxic substances, such as chlorophos, kerosene vapor, oil or gasoline.
2. Chest injuries, for example, due to compression, blows, bruises.
3. Various allergens, for example, plant pollen, microparticles of animal hair and saliva, dust, some medications, etc.
4. Burn of the respiratory tract.
5. Consequences of radiation therapy used as a method of treating cancer.

The occurrence of acute pneumonia can be caused by the causative agent of the underlying serious disease against which it develops, for example, anthrax, scarlet fever, measles, leptospirosis and some other infections. Based on this list of pathogens, a classification of pneumonia has been compiled.

Prerequisites for the occurrence

Factors that significantly increase the risk of this pathology in children and adolescents include:

1. Hereditary immunodeficiency conditions.
2. Hypoxia or intrauterine asphyxia of the fetus.
3. Congenital abnormalities of the heart or lungs.
4. Cystic fibrosis.
5. Birth injuries.
6. Hypotrophy.
7. Pneumopathy.
8. Early smoking.
9. Foci of chronic infection in the sinuses and nasopharynx.
10. Caries.
11. Acquired heart defects.
12. Weakened immunity as a result of frequent viral or bacterial infections.

There may be other causes of pneumonia.

In adults, these factors are:

1. Chronic respiratory tract diseases (for example, bronchitis).
2. Alcoholism and smoking.
3. Diseases of the endocrine system.
4. Decompensated stages of heart failure.
5. Immunodeficiencies, including AIDS and HIV infection.
6. Drug addiction, especially when inhaling drugs through the nose.
7. Prolonged lying down, for example, after strokes.
8. As a complication after surgical interventions on the chest.

An epidemic of viral pneumonia was recorded in 2017. The media reported large number sick with mycoplasma form of pathology in some regions of Russia. Cases were registered in the Yaroslavl, Vladimir, Novgorod, Tula and Amur regions.

Mechanism of the disease

The most common causative agent of pneumonia is pneumococcus.

There are three main routes of entry of pathogenic microorganisms that cause pneumonia into the lung parenchyma - bronchogenic, hematogenous and lymphogenous pathway. Bronchogenic is considered the most common. In this case, harmful microorganisms penetrate into the bronchioles with the inhaled air, and this is most likely in the presence of any inflammatory lesion of the nasal cavity, when the swollen mucous membrane is not able to retain microbes. It is possible for the infection to spread to the lungs from chronic foci located in the pharynx, nasal sinuses, and also in the tonsils. The development of pneumonia is also promoted by aspiration and various medical procedures, for example, bronchoscopy or tracheal intubation.

The hematogenous route of infection with the causative agent of pneumonia is observed much less frequently. Penetration of bacteria into lung tissue through the bloodstream is possible due to intrauterine infection, sepsis or intravenous injections of narcotic substances.

The lymphogenous route of infection is the rarest. IN in this case pathogens penetrate the lymphatic system, after which they spread throughout the body with the lymph flow and pass into the lungs.

In one of the ways described above, infectious agents enter the mucous membrane of bronchioles, where they attach and begin to multiply, which leads to the development of acute bronchitis or bronchiolitis. If such a process is not stopped at this stage, then pathogenic microorganisms through the interalveolar septa go beyond the branches of the bronchial tree and begin to provoke diffuse or focal inflammation of the interstitial tissues of the lungs. In addition to the segments of both lungs, the pathological process affects the paratracheal, bifurcation and bronchopulmonary lymph nodes.

Impairment of bronchial conduction can result in the development of emphysema - pathological expansion of the cavities of the distal bronchioles, as well as collapse of the affected lobe of the lung. Mucus forms in the alveoli, which prevents the flow of oxygen into the tissues of the organ. As a result, acute respiratory failure, accompanied by significant oxygen starvation, and in severe stages of the disease – heart failure.

The inflammatory process caused by viruses often leads to desquamation and necrosis of epithelial tissue, inhibiting cellular and humoral immunity. The occurrence of an abscess is typical for pneumonia caused by staphylococci. In this case, the necrotic focus contains a large number of pathogenic microbes, and zones of fibrinous and serous exudate appear along its perimeter. An inflammatory phenomenon of a serous nature with the spread of infection that multiplies in the area of ​​inflammation is very typical for pneumonia, which is caused by pneumococci.

So, what types of pneumonia are there?

Classification of the disease

This pathology is divided into types depending on the forms, stages and pathogens.

Depending on the type of infection, pneumonia can be:

• viral,
• fungal;
• bacterial;
• mycoplasma;
• mixed.

Depending on epidemiological data, pneumonia occurs:

• in-hospital;
• cytostatic;
• ventilation;
• aspiration;
• out-of-hospital.

As for clinical and morphological manifestations, the types of pneumonia are as follows:

• Parenchymatous.
• Croupous.
• Mixed.
• Focal.
• Interstitial.

There are also types of pneumonia based on severity.

Depending on the characteristics of the disease:

• acute protracted;
• acute;
• atypical.
• chronic.

Based on the characteristics of the spread of the pathological process:

• focal;
• segmental;
• share;
• drain;
• basal;
• sublobular;
• two-sided;
• one-sided;
• total.

Let us describe some types of pneumonia in more detail.

Lobar pneumonia

This type of pneumonia begins acutely and suddenly. The temperature reaches its maximum and lasts up to 10 days, accompanied by chills and severe intoxication - cephalgia, myalgia, arthralgia, severe weakness. The patient's face looks haggard, there is swelling around the eyes, and a feverish flush appears on the cheeks. In this case, it is possible that the herpes virus present in the body is constantly attached, which is manifested by herpetic eruptions on the edge of the lips and wings of the nose. A patient with this type of pneumococcal pneumonia is greatly bothered by chest pain and shortness of breath. A cough is also observed, at first dry and unproductive, and from about the second day of the inflammatory process, glassy viscous sputum streaked with blood begins to come out when coughing. The amount of discharge gradually increases, and the sputum becomes thinner. What are the features of lobar pneumonia?

At the onset of the disease, the patient experiences vesicular breathing. It may be weakened due to damage to the pleura and limitation of respiratory movements. On approximately the fourth day of pneumococcal pneumonia of this type, various dry and moist rales are heard on auscultation. As fibrin accumulates in the alveoli, the percussion sound begins to dull, crepitus disappears, and bronchophony increases. The dilution of the exudate leads to a decrease or complete disappearance of bronchial breathing, the occurrence of crepitus, which becomes more severe. Resorption of sputum in the respiratory tract may be accompanied by harsh vesicular breathing with the presence of moist rales.

In severe cases, frequent shallow breathing, frequent arrhythmic pulse, muffled heart sounds, and decreased blood pressure are detected.

Streptococcal pneumonia

This is a common complication of other infections such as measles, whooping cough, tonsillitis, tonsillitis, chicken pox etc. But sometimes streptococci can penetrate the lung tissue, while other body systems are not affected.

This pathology is often diagnosed in children, since this is facilitated by the physiology and structure of the lungs, as well as the entire respiratory system.

A patient with this type of illness suffers from:

• elevated temperature;
• chills;
• muscle pain;
• joint pain;
• shortness of breath;
• cough;
• discharge of blood from the respiratory tract;
• decreased performance.

In the case when streptococci provoke an inflammatory process in the pleura (the occurrence of exudative pleurisy), the patient may feel pain in the side.

This diagnosis is detected in every third child with pneumonia.

Sometimes the pathology leads to a chronic purulent-destructive limited process in the lungs (abscess), purulent pericarditis, glomerular nephritis, infectious infection blood (sepsis).

Diagnosis of pneumonia

The main basis for diagnosis is a physical examination of the patient (percussion, history taking and auscultation of the lungs), as well as the clinical picture of the disease and the results of instrumental and laboratory research methods.

Basic diagnosis of pneumonia includes:

1. Biochemical blood test, which usually shows leukocytosis, an increase in ESR and the number of band neutrophils.
2. X-ray of the lungs in two projections, which is the main diagnostic method and helps to identify focal or diffuse lesions of different sizes, interstitial changes and other signs of inflammation in the lungs. An x-ray is taken at the onset of the disease, a control image is taken on the 10th day of therapy to determine its effectiveness, and then on the 30th day to confirm the subsidence of the inflammatory process.
3. Bacteriological culture of sputum to identify the infectious agent and determine its resistance to antibacterial, antifungal and other medications.
4. Pulse oximetry is a non-invasive method for determining the level of oxygen saturation in the blood.
5. Microscopy of mucus with Gram stain to identify gram-negative and gram-positive bacteria.
6. If the development of tuberculosis is suspected, a study with Ziehl-Neelsen staining is prescribed.

How to determine pneumonia without fever?

The hidden appearance characterizes insufficient listening of organs. Therefore, the patient is prescribed a thorough examination.

When a diagnosis of pneumonia is made, there are peculiar symptoms without fever. The patient often has a pale complexion and a bright blush, indicating inflammation in the body. Pulmonary disease is also recognized by red spots on the cheeks.

There is a whistling sound when the patient breathes. Any physical activity is manifested by shortness of breath and increased heart rate.

Treatment of the disease

Moderate and severe forms of pneumonia require hospitalization. An uncomplicated disease can be treated on an outpatient basis, under the supervision of a physician.

Basic in treatment of this disease is etiotropic therapy, which is aimed at destroying the infectious pathogen. Considering that bacterial pneumonia is most often diagnosed, etiotropic treatment consists of a course of antibiotics. Selection medication or their complex in the diagnosis of pneumonia is carried out by a doctor based on the condition and age of the patient, the severity of symptoms, the presence of complications and allergies to medications.

Antibiotics of the following groups are used to treat pneumonia:

• Semi-synthetic penicillins.
• Macrolides.
• Lincosamides.
• Cephalosporins.
• Fluoroquinolones.
• Aminoglycosides.
• Carbapenems.

Symptomatic treatment is as follows:

1. Antipyretic drugs.
2. Mucolytics and expectorants.
3. Antihistamines to relieve allergy symptoms.
4. Bronchodilators.
5. Immunomodulatory therapy.
6. Detoxification therapy.
7. Vitamins.
8. Corticosteroids.
9. Physiotherapy.

The average duration of therapy is approximately 14 days.

Pneumonia is an acute infectious disease of predominantly bacterial etiology, characterized by damage to the respiratory parts of the lungs with intra-alveolar exudation, infiltration by inflammatory cells and saturation of the parenchyma with exudate, the presence of previously absent clinical and radiological signs of local inflammation not associated with other causes.

EPIDEMIOLOGY

Pneumonia is one of the most common respiratory diseases: the incidence is 300-900 cases per 100,000 population.

CLASSIFICATION

The clinical classification of pneumonia involves the separation of focal (or bronchopneumonia) and lobar.

With focal pneumonia, the inflammatory process affects individual areas of the lung tissue - the alveoli and adjacent bronchi.

Croupous pneumonia is characterized by the rapid involvement in the process of an entire lobe of the lung and the adjacent area of ​​the pleura and high content fibrin in alveolar exudate.

Classification of pneumonia in accordance with ICD-10 is presented in table. 22-1.

Table 22-1. Classification of pneumonia in accordance with ICD-10

	Nosological form
	Viral pneumonia, not elsewhere classified
	Adenoviral pneumonia
	Pneumonia caused by respiratory syncytial virus
	Pneumonia caused by parainfluenza virus
	Other viral pneumonia
	Viral pneumonia, unspecified
	Pneumonia caused by Streptococcus pneumoniae
	Pneumonia caused by Haemophilus influenzae
	Bacterial pneumonia, not elsewhere classified (excludes: pneumonia caused by Chlamydia spp. - J16.0 and Legionnaires' disease - A48.1)
	Pneumonia caused by Klebsiella pneumoniae
	Pneumonia caused by Pseudomonas spp.
	Pneumonia caused by Staphylococcus spp.
	Pneumonia caused by group B streptococci
	Pneumonia caused by other streptococci
	Pneumonia caused by Escherichia coli
	Pneumonia caused by other aerobic gram-negative bacteria
	Pneumonia caused by Mycoplasma pneumoniae
	Other bacterial pneumonias
	Bacterial pneumonia of unspecified etiology
	Pneumonia caused by pathogens not classified elsewhere (excluded: psittacosis - A70, Pneumocystis pneumonia - B59)
	Pneumonia caused by Chlamydia spp.
	Pneumonia caused by other established pathogens
	Pneumonia in diseases classified elsewhere
	Pneumonia in diseases of a bacterial nature classified in other headings (pneumonia in actinomycosis - A42.0; anthrax - A22.1; gonorrhea - A54.8; nocardiosis - A43.0; salmonellosis - A022.2; tularemia - A721.2; typhoid fever- A031; whooping cough - A37)
	Pneumonia in viral diseases classified in other headings (pneumonia in cytomegalovirus disease - B25.0; measles - B05.2; rubella - B06.8; chickenpox - B01.2)
	Pneumonia due to mycoses
	Pneumonia in diseases classified in other headings (pneumonia in psittacosis - A70; Q fever - A78; acute rheumatic fever - I00; spirochetosis - A69.8)
	Pneumonia without specifying the pathogen

* Pneumonia is indicated for diseases classified in other headings and not included in the heading “Pneumonia”.

According to the International Consensus and the Russian Therapeutic Protocol (Order of the Ministry of Health Russian Federation № 300, 1998; Practical recommendations Ministry of Health of the Russian Federation, 2003) additional characteristics of pneumonia have been introduced into the classification, allowing for optimization of empirical etiotropic treatment.

. Community-acquired pneumonia (primary, acquired outside a medical institution, synonyms: home, outpatient).

. Nosocomial(hospital, nosocomial) pneumonia acquired in medical institution.

. Pneumonia at persons With heavy defects immunity(congenital immunodeficiency, HIV infection, iatrogenic immunosuppression).

. Aspiration pneumonia.

When making a diagnosis, indicate the localization of the process (lobe, segment), if possible, the etiology (pneumococcal, staphylococcal, etc.), complications (pleurisy, pericarditis, infectious-toxic shock, respiratory failure, etc.). Based on severity, pneumonia is divided into those that do not require hospitalization and those that require hospitalization (severe).

ETIOLOGY

The cause of pneumonia is damage to the respiratory parts of the lungs by a pathogenic pathogen. The spectrum of pathogens depends on the type of pneumonia.

In community-acquired pneumonia, the most common pathogens are Streptococcus pneumoniae(30-95% in different regions), Mycoplasma pneumoniae(up to 30% in people under 45 years of age, 9% in people over 45 years of age), Haemophilus influenzae (5-18%), Chlamydia pneumoniae (2-8%); Legionella spp., more often Legionella pneumophila (2-10%), Staphylococcus aureus(less than 5%), Moraxella catarrhalis (1-2%), Escherichia coli, Klebsiella pneumoniae(less than 5%), influenza virus (during an epidemic). In 20-30% of cases, the etiology of pneumonia cannot be established. Thus, the most likely etiological factors of community-acquired pneumonia are pneumococci ( Streptococcus pneumoniae), intracellular pathogens and Haemophilus influenzae.

In nosocomial pneumonia, the most common pathogens among gram-positive microflora are Staphylococcus aureus And Streptococcus pneumoniae, among gram-negative microflora - Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Proteus mirabilis, Legionella pneumophila, Haemophilus influenzae, as well as anaerobes, viruses, Aspergillus, Candida, Rneumocystis carinii. Gram-negative intestinal microflora and Pseudomonas aeruginosa more common among persons living in nursing homes than among persons living at home. A significant problem in nosocomial pneumonia is the multiresistance of pathogens to antibacterial agents. A special place is occupied by ventilator-associated pneumonia, which develops in wards and intensive care units. Early ventilator-associated pneumonia (developing within 48-96 hours of being on mechanical ventilation) is usually associated with normal microflora of the oral cavity ( S. pneumoniae, H. influenzae, M. catarrhalis, S. aureus), late (more than 96 hours on mechanical ventilation) - with nosocomial gram-negative bacteria ( P. aeruginosa, Enterobacter spp., Acinetobacter spp., K. pneumoniae, E. coli) And S. aureus.

Pneumonia in immunocompromised individuals may be caused by cytomegalovirus, Rneumocystis carinii, pathogenic fungi, atypical mycobacteria, as well as other microorganisms. HIV-associated pneumonia is caused by Rneumocystis carinii, Streptococcus pneumoniae, Haemophilus influenzae, it should also be remembered that one of the main pulmonary markers of acquired immunodeficiency syndrome (AIDS) is Mycobacterium tuberculosis ( Mycobacterium tuberculosis).

Aspiration pneumonia is often caused by obligate anaerobes or their associations with aerobic gram-negative microflora living in oral cavity and pharynx (about 50% of healthy adults aspirate oropharyngeal secretions into the lower respiratory tract during sleep). Pneumonia caused by anaerobes is especially often observed when a large volume of vomit is aspirated or when it contains virulent anaerobic microflora (aspiration of food or necrotic matter). Impaired cough reflex also increases the risk of pneumonia, as does impaired mucociliary clearance and alveolar macrophage dysfunction. The source of anaerobic pathogens of pneumonia ( Porphyromonas gingivalis, Prevotella melaninogenica, Fusobacterium nucleatum, Actinomyces spp., spirochetes and anaerobic streptococci) consider the gaps between teeth and gums and dental plaque.

PATHOGENESIS

The development of pneumonia is associated with the mechanisms of infection, the conditions of this penetration and the state of the human body.

ROUTES OF PENETRATION OF THE PATIENT

Aspiration of oropharyngeal secretions is an important route of infection in pneumonia. 15% healthy people Staphylococcus aureus is sown from the nose and back of the throat, and in another 15% from the mouth, pharynx, and upper part of the trachea - Streptococcus pneumoniae, in 15-25% of cases the trachea and bronchi can be sown H. influenzae, M. catarrhalis. Therefore, to get pneumonia, you do not necessarily need contact with a patient; a decrease in the local and general defense of the macroorganism is sufficient.

The distribution of inhaled particles in the respiratory tract primarily depends on their size. Particles with a diameter of more than 10 microns settle mainly in the nasal cavity and upper respiratory tract. Particles with a diameter of less than 3-5 microns (also called aerogenic droplet nuclei) containing 1-2 microorganisms do not settle in environment, but hang in the air for a long time until they get on the air filter or are inhaled by a person. This infectious aerosol is fine enough to overcome the protection of the upper and lower respiratory tract of the macroorganism. The smaller the particles, the greater their number settles in small bronchioles and alveoli. Inhalation of one such particle may be sufficient for the pathogen to penetrate the alveoli and cause disease. Therefore, the etiology of pneumonia is often associated with inhalation pathogens, including pathogens of tuberculosis, influenza, legionellosis, psittacosis, and histoplasmosis.

In case of hematogenous dissemination from an extrapulmonary lesion, the pathogen (usually Staphylococcus aureus) penetrates the lung through the bloodstream during bacterial endocarditis or infection of the venous catheter (the same as in drug addicts who inject drugs intravenously). Infection of the retropharyngeal tissues caused by Fusobacterium(Lemierre's syndrome: retropharyngeal abscess and thrombophlebitis of the jugular vein), also disseminates to the lungs.

Direct spread of the pathogen implies its direct introduction into the lung tissue due to tracheal intubation or chest injury. Contiguous spread is characterized by the penetration into the lung tissue of an infection that affects neighboring areas (for example, lower lobe pneumonia with a subdiaphragmatic abscess).

STATE OF THE BODY, EFFECTIVENESS OF DEFENSE MECHANISMS

In the pathogenesis of pneumonia, factors related to the human condition and the effectiveness of defense mechanisms play an important role. The latter include the closure of the glottis by the epiglottis during swallowing, the cough reflex, a thin layer of mucus on the surface of the respiratory tract containing Ig, mucociliary clearance, and the phagocytic activity of alveolar macrophages and neutrophils.

Aspiration of the contents of the oral cavity occurs more often and is more pronounced in persons with impaired consciousness (alcoholics, drug addicts, persons who have suffered a stroke, general anesthesia, etc.), in patients with neurological disorders (with impaired innervation of the oropharynx, swallowing disorders), and with mechanical obstacles (nasogastric, endotracheal tubes, etc.).

The frequency of colonization of the mucous membrane of the oropharynx with aerobic gram-negative microorganisms (in healthy people is less than 2%) increases with hospitalization, severe mental retardation, severe underlying diseases, alcoholism, diabetes mellitus and in old age. These changes may also be a consequence of an increase in the proteolytic activity of saliva, which destroys fibronectin, a glycoprotein that covers the surface of the mucous membrane, promotes the development of normal gram-positive microflora of the oropharynx and prevents the penetration of aerobic gram-negative microbes. Their source may be the patient's stomach (where colonization of these microorganisms is possible during atrophic gastritis or after the use of histamine H2 receptor blockers or antacids), contaminated ventilator equipment, the hands of medical personnel or contaminated food. A nasogastric tube in intensive care units facilitates the passage of bacteria from the stomach into the throat.

Immunodeficiency conditions may predispose to invasion by certain microorganisms (depending on the form of immunodeficiency). For example, patients with severe hypogammaglobulinemia (less than 2 g/L) are at high risk of infection caused by encapsulated bacteria, such as Streptococcus pneumoniae And Haemophilus influenzae. Severe neutropenia (less than 0.5×10 9 /l) increases the risk of infections caused by Pseudomonas aeruginosa, Enterobacteriaceae, Staphylococcus aureus and (if neutropenia is long-lasting) Aspergillus. The risk of developing tuberculosis is especially high among HIV-infected people when the content of circulating CD4 + lymphocytes decreases to less than 0.5 × 10 9 / l; when the content of CD4 + lymphocytes is less than 0.2 × 10 9 / l, the risk of diseases caused by Pneumocystis carinii, Histoplasma capsulatum And Cryptococcus neoformans, and with a content of less than 0.05×10 9 /l - Mycobacterium avium-intracellulare and cytomegalovirus. Long-term treatment HA increases the likelihood of developing tuberculosis and nocardiosis.

Factors contributing to the development of pneumonia also include viral infections upper respiratory tract, obstruction of the bronchial tree, smoking and industrial air pollution, chest injuries, postoperative period, congestive heart failure, old age, debilitating diseases, post-stress conditions.

PATHOMORPHOLOGY

The morphological criterion of pneumonia is inflammation of the respiratory part of the lungs. Damage to the bronchi is not constant, but is quite typical. The inflammation is exudative in nature and is usually limited to the anatomical units of the lungs.

In bronchopneumonia, the process is limited to the alveoli and adjacent bronchi.

In lobar pneumonia, an entire lobe of the lung is affected.

Confluent pneumonia (fusion of individual small inflammatory foci into larger ones) can be indistinguishable from lobar pneumonia.

Cavities in the lungs develop when a necrotic area of ​​lung tissue communicates with the respiratory tract, leading to necrotizing pneumonia (multiple small cavities up to 2 cm in diameter in one or more bronchopulmonary segments or lobes) or a lung abscess (one or more cavities with a diameter of more than 2 cm in diameter). cm).

The pathomorphological picture of pneumonia largely depends on the etiology of the infectious process.

Pneumococcal pneumonia (the most common of community-acquired pneumonias) is characterized by the rare development of necrosis and abscess formation. If the process is caused by type I or II pneumococci, fibrinous inflammation is typical.

Streptococcal pneumonia is characterized by pronounced necrosis of lung tissue with a less pronounced hemorrhagic component. More often than with staphylococcal pneumonia, lymphogenous and hematogenous dissemination is observed.

Staphylococcal pneumonia is manifested by necrosis of the lung tissue, around which neutrophils accumulate. Along the periphery of the inflammatory focus, the alveoli contain purulent or fibrinous exudate that does not contain bacteria. In severe cases, in places where staphylococci accumulate, destruction of the lung tissue occurs (staphylococcal destruction of the lungs).

Pneumonia caused by Pseudomonas aeruginosa is characterized by an inflammatory focus of a gray-red color with a doughy consistency. Multiple foci of necrosis are formed, surrounded by a zone of plethora, stasis, and hemorrhages.

For pneumonia caused Klebsiella pneumoniae(Friedlander's pneumonia), the inflammatory process can involve the lobes. Exudate, as well as secreted sputum, are mucous in nature. The formation of extensive infarct-like necrosis of the lung tissue is characteristic, as a consequence of thrombosis of small vessels.

Viral and mycoplasma pneumonias are accompanied mainly by interstitial lesions. In this case, edema, infiltrative-proliferative changes in the interalveolar and interlobular septa, peribronchial and perivascular tissue are noted. Exudate in the alveoli is almost completely absent; at the same time, signs of inflammation of the mucous membrane of the bronchi and bronchioles, capillary paresis, blood stagnation, and hemorrhages are observed.

CLINICAL PICTURE AND DIAGNOSTICS

The clinical picture of pneumonia depends on the extent of damage to the lung tissue, the severity of the disease, the virulence of the pathogen, the resistance of the macroorganism, the presence of concomitant diseases, the age of the patient and other factors.

COMPLAINTS

The most common complaints of patients with pneumonia are weakness, loss of appetite, chills, shortness of breath, and chest pain. The pain can be pleuritic (caused by the reaction of the pleura or its involvement in the process) or due to intercostal neuralgia or myalgia, for example due to a decrease in general resistance and activation of herpes infection. Damage to the diaphragmatic pleura can cause pain in the abdominal cavity and even mimic the picture " acute abdomen"The appearance of a cough is usually preceded by coughing. In the initial period of the disease, the cough is dry and painful. In typical cases, sputum appears on the 3-4th day, the cough softens. The nature of the sputum is varied - from mucous to purulent. Sometimes it contains streaks of blood or has "rusty" tint (the latter is more typical for lobar pneumonia). Copious purulent sputum often accompanies the formation of an abscess, sputum with a putrid odor - lung gangrene.

PHYSICAL EXAMINATION

On examination, pallor may be detected skin, cyanosis. Patients with weakened immune systems sometimes develop herpetic rashes on the lips. In persons with severe illness and the elderly, disturbances of consciousness and delirium are possible. The participation of auxiliary respiratory muscles and flaring of the wings of the nose indicate the development of respiratory failure. The respiratory rate can increase to 25-30 per minute, sometimes you can notice a lag in the affected half of the chest when breathing. Lobar pneumonia is characterized by a sharp rise in body temperature to febrile values; a decrease in body temperature occurs critically. In bronchopneumonia, the nature of the temperature curve is not constant; its decrease is often lytic.

Palpation: the first sign of compaction of the lung tissue is considered to be increased vocal tremors on the affected side, which is reinforced by auscultation by the manifestation of bronchial breathing. This sign is detected in confluent and lobar pneumonia.

When an area of ​​lung tissue located subcortically becomes denser, a shortening of the percussion sound over this area can be detected quite early (if more than one segment of the parenchyma is affected). An oblique upper level of dullness of percussion sound with the highest point along the posterior axillary line allows one to suspect pleural effusion (“pleuropneumonia” - when the pleura is involved in the process or its reaction to an adjacent focus of inflammation). In the presence of COPD, the dullness of the percussion sound is masked by emphysema, leading to a boxy sound when tapping.

With bronchopneumonia, dry and moist rales may be heard. Listening to crepitus during the onset of the disease ( crepeitatio indux) and resolution stage ( crepeitatio redux) is especially characteristic of lobar pneumonia, at the height of which characteristic bronchial breathing is heard. When the process spreads to the pleura, a pleural friction noise (dry pleurisy) is heard, and when pleural effusion is formed, a sharp weakening of breathing is heard. On the affected side, increased bronchophony can be detected. In severe cases of pneumonia, auscultation of the heart reveals tachycardia, an accent of the second tone over the pulmonary artery.

INSTRUMENTAL RESEARCH

X-RAY EXAMINATION

X-ray examination is a key method for diagnosing pulmonary infiltrates. An X-ray of the chest organs in two projections makes it possible to establish the presence and localization of pulmonary infiltrate, determine the extent of the lesion, identify damage to the pleura, lung cavities, root lymphadenopathy and evaluate the response to antibacterial therapy. However, the radiograph may remain normal when the patient is initially hyporesponsive (for example, with agranulocytosis), as well as in the early stages of infiltration (for example, with hematogenous pneumonia caused by Staphylococcus aureus, or with Pneumocystis pneumonia in AIDS).

Bronchopneumonia is characterized by the presence of a group of merging focal shadows measuring 1-1.5 cm. The forms of infiltrates can be different. The lower parts of the lungs are most often affected, but any other location of the infiltrate does not exclude pneumonia. In Fig. Figure 22-1 shows frontal and lateral radiographs of a patient with middle lobe pneumonia.

Rice. 22-1. Direct plain (a) and right lateral (b) radiographs of a patient with middle lobe pneumonia (from: http://www.medscape.com).

The X-ray picture of lobar pneumonia is characterized by changes within the lobe of the lung. During the high tide stage, the pulmonary pattern becomes stronger, the root on the affected side expands somewhat. On the 2-3rd day from the onset of the disease, intense shading appears in the image in the projection of the affected lobe. The intensity and uniformity of shading increases towards the periphery. The adjacent pleura may become denser, sometimes an effusion is formed, which is best identified on laterograms (direct photographs taken in the position on the affected side). At the resolution stage, the intensity of the shadow decreases, it fragments and decreases in size. Expansion and disruption of the root structure persist for a long time. The pulmonary pattern remains enhanced for 2-3 weeks.

FIBRONCHOSCOPY

Fiberoptic bronchoscopy is a safe and fairly well-tolerated procedure that has become a standard invasive study for obtaining secretions from the lower respiratory tract in seriously ill patients or patients with immunodeficiency in combination with progressive pneumonia, as well as in all cases where sputum cannot be obtained. Fiberoptic bronchoscopy allows you to examine the lower respiratory tract. The material obtained during bronchoscopy must be stained according to Gram, using acid-fast technology (Ziehl-Neelsen), with direct fluorescent antibodies to Legionella. It is also necessary to carry out cultures for typical aerobic and anaerobic microflora, legionella, mycobacteria and fungi. The material is obtained directly during bronchoscopy using a brush protected on both sides (to exclude contamination of the material in the upper respiratory tract), bronchoalveolar lavage, or during transbronchial biopsy from the area of ​​lung compaction (to exclude a tumor or specific process).

Brush biopsy is usually still contaminated with oropharyngeal microflora. A quantitative culture of 1 ml of the sterile medium into which the brush is placed after removal from the catheter should be performed to differentiate contamination (‹1000 microbes per ml) from infection (≥1000 microbes per ml). The results of a brush biopsy are highly specific and sensitive, especially if the patient has not previously received antibiotics.

For bronchoalveolar lavage, 150-200 ml of sterile saline, non-antibacterial solution is usually used. If the anesthetic used during bronchoscopy has antibacterial activity, this reduces the sensitivity of the results of bacteriological examination. Quantitative bacteriological assessment of bronchial lavage fluid allows one to obtain results similar to the results of brush biopsy. Gram-stained centrifuged lavage fluid samples provide rapid information for the choice of antibacterial therapy before obtaining bacteriological results.

AUXILIARY METHODS OF RESEARCH

High-resolution CT is currently considered the most informative method of radiation diagnostics and differential diagnosis of respiratory diseases, however, the high cost of the study and its insufficient availability do not yet allow it to be classified as a routine method in the diagnosis of pneumonia. Its implementation is indicated when there is doubt about the diagnosis, when it is necessary to exclude the presence and clarify the nature of cavitary formations, bronchiectasis, changes in the mediastinum, or suspected dissemination. Preference should be given to helical CT.

A study of the ventilation capacity of the lungs (spirometry, pneumotachometry) is indicated if the patient has shortness of breath or concomitant chronic lung diseases. In the absence of these factors, assessment of the ventilation capacity of the lungs is considered an optional component of the examination of a patient with pneumonia. Ventilation parameters for pneumonia often correspond mixed type violations. Isolated obstruction is observed in every fifth patient. At large volume lesions and pleural effusion, restriction predominates.

An ECG for pneumonia usually reveals sinus tachycardia. In severe pneumonia, the ECG may show signs of overload of the right side of the heart, conduction disturbances along the right bundle branch, and metabolic disorders.

LABORATORY RESEARCH

CLINICAL BLOOD TEST

In a patient with typical pneumonia, leukocytosis is usually detected with a shift in the leukocyte formula to the left. In severe lobar pneumonia, toxic granularity of leukocytes and a shift to the left to metamyelocytes and myelocytes may appear. In severe cases, aneosinophilia is characteristic. ESR can be increased moderately or significantly, reaching 50-60 mm/h in lobar pneumonia. The absence of a blood reaction with a pronounced clinical and radiological picture indicates suppression of the immune response.

Sputum examination

Routine microbiological diagnosis of pneumonia in outpatient practice is not informative enough and does not have a significant impact on the choice of antibacterial drugs. An antibiotic should be prescribed no later than 8 hours from the onset of the disease, and during this time it is difficult to culture and determine the sensitivity of the pathogen to antibacterial drugs. Unfortunately, expectorated material is often contaminated with opportunistic bacteria. This contamination limits the diagnostic specificity of any sample collected from the lower respiratory tract. Moreover, it was found that with normal laboratory methods in patients with bacteremic pneumococcal pneumonia Streptococcus pneumoniae found in sputum in less than 50% of cases. This low sensitivity may be due to misidentification of α-hemolytic colonies Streptococcus pneumoniae, as non-pathogenic α-hemolytic streptococci (“normal microflora”), stronger growth of other microflora or death of pneumococci during late transportation and improper processing of the material. In addition, such pathogens that are very typical for lung damage, such as anaerobes, mycoplasmas, chlamydia, pneumocystis, mycobacteria, fungi and legionella, cannot be detected using routine bacteriological methods. Because expectorated material is usually contaminated with anaerobes, the diagnosis of anaerobic pulmonary infection is often preliminary. To confirm this diagnosis, a culture test for anaerobic microflora of non-contaminated material from the lower respiratory tract obtained by tracheal aspiration, transthoracic puncture or protected brush biopsy during bronchoscopy is required. These procedures are invasive and are usually not used until the doctor is satisfied that empiric therapy has failed.

Expectorated sputum is easy to collect in patients with a severe productive cough, but quite difficult in patients with an atypical syndrome, in the elderly and in patients with mental disorders. If the patient does not have sputum, then its secretion should be induced by inhalation of a 3% sodium chloride solution using an ultrasonic inhaler or compression nebulizer.

Material for microbiological testing should be collected before the start of antibacterial therapy. Otherwise, temporarily stop treatment to carry out diagnostic studies inappropriate.

The time of transportation and storage of biological samples should not exceed 4 hours. In case of non-compliance this condition the likelihood of isolating the true infectious agent is reduced, and the likelihood of contaminating flora is increased.

To obtain uncontaminated material, fibrobronchoscopy with a “protected” branch biopsy of the bronchial mucosa, as well as bronchoalveolar lavage, is used.

In microbiological examination of bronchoalveolar lavage fluid, a titer of microbial bodies >10 4 colony-forming units per ml (CFU/ml) is considered diagnostically significant; material obtained using “protected” branch biopsy - >10 3 CFU/ml.

Standard methods microbiological research- bacterioscopy with Gram stain and culture of sputum obtained during deep coughing.

Before starting a microbiological study, it is necessary to stain the smear according to Gram. If there are less than 25 leukocytes and/or more than 10 epithelial cells in the smear (when viewing at least 8-10 fields of view at low magnification) further research inappropriate, since in this case the material being studied most likely represents the contents of the oral cavity. In patients with typical pneumonia with purulent sputum, the sensitivity and specificity of Gram-stained sputum smears minimally contaminated in the upper respiratory tract (more than 25 polymorphonuclear leukocytes and less than 10 epithelial cells in one low-power field) in identifying pneumococcus is 62% and 85%, respectively. The Gram stain in this case is more specific and probably more sensitive than sputum culture.

The diagnostic value of sputum examination results can be assessed as high when a potential pathogen is isolated in a concentration of ≥10 6 CFU/ml.

Interpretation of the results of bacterioscopy and sputum culture should be carried out taking into account clinical data.

Additional methods microbiological research

If a mycobacterial infection is suspected, the smear is stained using special methods to identify acid-fast pathogens (Ziehl-Neelsen).

Examination by an experienced pathologist of a sputum smear stained according to Romanovsky-Giemsa in patients with AIDS gives quite satisfactory results in the diagnosis of Pneumocystis pneumonia. The sensitivity of sputum examination increases with the use of monoclonal antibodies to Pneumocystis.

Blastomycosis can be diagnosed by examining wet mounts of sputum.

Microscopy of sputum stained with specific fluorescent antibodies can be used to detect Legionella, although this test often gives false negative results. Therefore, sputum must be cultured on Legionella-specific media.

Crops venous blood carried out in seriously ill patients (including the majority of hospitalized patients) before starting antibacterial therapy (2 blood samples are taken from 2 different veins with an interval of 30-40 minutes; at least 20 ml of blood must be taken from adult patients for each sample).

Serological diagnostics infections caused Mycoplasma pneumoniae, Chlamydophila pneumoniae And Legionella spp. is not considered among the mandatory research methods.

Study gas composition arterial blood

Gas composition research arterial blood indicated for severe pneumonia and complications. In this case, various degrees of hypoxemia and hypercapnia are detected, as well as a decrease in hemoglobin oxygen saturation, which is an indication for oxygen therapy.

COURSE OF PNEUMONIA

COMMUNITY-ACQUIRED PNEUMONIA

Community-acquired pneumonia is traditionally divided into two syndromes: typical and atypical manifestations. And although recent data indicate that these two syndromes do not have such clear boundaries as previously thought, nevertheless, the characteristics of these signs have a certain diagnostic value. For subsequent rational empirical therapy, it is important to distinguish between typical and atypical pneumonia.

The typical pneumonia syndrome is characterized by the sudden onset of fever, cough with purulent sputum and, in some cases, pleuritic chest pain, signs of compaction of the lung tissue, such as dullness to percussion, increased vocal tremors, bronchial breathing and wheezing, which can be detected by projection of radiological changes . The typical pneumonia syndrome is usually associated with the most common pathogen of community-acquired pneumonia - Streptococcus pneumoniae, but can also occur in the presence of other pathogens - Haemophilus influenzae, mixed anaerobic and aerobic microflora of the oral cavity.

Atypical pneumonia syndrome is characterized by a more gradual onset, dry cough, and a predominance of extrapulmonary symptoms ( headache, muscle pain, weakness, sore throat, nausea, vomiting and diarrhea) and the presence of an x-ray picture with minimal signs detected during physical examination. Classic atypical pneumonia is caused by Mycoplasma pneumoniae, and Legionella pneumophila, Klebsiella pneumoniae, anaerobes of the oral cavity, Pneumocystis carinii, Streptococcus pneumoniae, as well as more rare pathogens - Chlamydia psittaci, Coxiella burnetii, Francisella tularensis, Histoplasma capsulatum And Coccidioides immitis. Cough and sputum production, signs of lung compaction may be insignificant in patients with a mild inflammatory reaction, for example, with agranulocytosis. The main manifestations of the disease in this case may be fever, tachypnea, and mental disorders. In elderly people and seriously ill patients There may not be a fever. More rare forms of atypical pneumonia are discussed in table. 22-2.

Table 22-2. Features of the course of pneumonia depending on the pathogen

Pathogen	Clinical peculiarities
Mycoplasmas	Pneumonia may be complicated by erythema multiforme, hemolytic anemia, bullous inflammation of the tympanic membrane, encephalitis and transverse myelitis
Legionella pneumophila	Pneumonia is often accompanied by impaired consciousness, kidney and liver dysfunction, and severe hyponatremia.
Histoplasma capsulatum or Coccidioides immitis	Pneumonia is often accompanied by erythema nodosum
Chlamydia	Pneumonia is often accompanied by sore throat and hoarseness; wheezing is quite typical
Pneumocystis in HIV-infected patients	In addition to pneumonia, other diseases caused by opportunistic pathogens may also occur, such as pulmonary and extrapulmonary tuberculosis, stomatitis caused by Candida albicans, or widespread perineal ulcers due to activation of the herpes simplex virus
Influenza virus (usually as part of a winter epidemic), respiratory syncytial virus (in children and immunosuppressed individuals), measles viruses, or varicella-zoster(in combination with a characteristic rash), cytomegalovirus (in HIV-infected people or during immunosuppressive therapy associated with organ transplantation)	Primary viral pneumonia is characterized by atypical manifestations such as chills, fever, dry nonproductive cough and predominantly extrapulmonary symptoms. Influenza, measles, and chickenpox predispose to secondary bacterial pneumonia due to impaired airway barrier function. A secondary bacterial infection can follow immediately after a viral infection without interruption, or it can be delayed from a viral disease for several days, during which the symptoms subside. A bacterial infection may manifest as a sudden deterioration in the patient's condition with continued or renewed chills, fever, and a productive cough with purulent sputum; may be accompanied by pleuritic pain
Staphylococcus aureus(hematogenous spread)	Pneumonia may manifest itself only as fever and shortness of breath, the inflammatory reaction is initially limited to the pulmonary interstitium. Cough, sputum production and signs of hardening of the lung tissue develop only after the infection reaches the bronchi. Since pneumonia in this case is a hematogenous infection, signs of infective endocarditis are possible
Nocardia	Pneumonia is often complicated by metastatic lesions of the skin and central nervous system

IN-HOSPITAL (NOSOCOMIAL) PNEUMONIA

The diagnosis of nosocomial pneumonia is valid when pulmonary infiltrate occurs 48 hours or more after the patient’s hospitalization. In addition to infiltrates, typical criteria for nosocomial pneumonia include purulent sputum, fever and leukocytosis. In the presence of previous lung diseases, the information content of these signs is reduced. Nosocomial pneumonia complicating the underlying disease associated with neutropenia is often not accompanied by purulent sputum or pulmonary infiltrate, and nosocomial pneumonia complicating uremia or cirrhosis of the liver is often without fever. Moreover, in patients with a high risk of developing nosocomial pneumonia, the oropharynx and mucous membrane of the tracheobronchial tree very often contain a large number of pathogens potentially pathogenic for the lungs; therefore, the presence of these microorganisms in Gram-stained preparations or culture does not always confirm the diagnosis of pneumonia.

ASPIRATION PNEUMONIA

Although aspiration of oral anaerobes initially leads to infiltrative processes, this, as a rule, causes the appearance of putrefactive sputum, necrosis of lung tissue and the formation of a cavity in the lungs. In 75% of cases, the development of an abscess associated with anaerobic polymicrobial microflora is not accompanied by severe symptoms and is similar to pulmonary tuberculosis, manifested by cough, shallow breathing, chills, fever, night sweats, weight loss, pleuritic pain and hemoptysis for several weeks. In other patients, the disease develops more acutely. In patients with a tendency to aspiration of oropharyngeal contents or in the presence of periodontitis, abscesses caused by anaerobic infection often occur. One of the genera of anaerobes of the oral cavity - Actinomyces- leads to a chronic fibrous necrotic process and can penetrate into the pleural cavity, ribs, vertebrae and subcutaneous tissue with possible release of sulfur granules (macroscopic bacterial masses) through the skin.

PNEUMONIA IN PERSONS WITH IMMUNODEFICIENCIES

Pneumonia in people with immunodeficiencies does not have a characteristic picture, since they are caused by various pathogens and are associated with severe conditions that caused immunodeficiency. Pneumonia is severe, progresses quickly, and is accompanied by the development of complications.

COMPLICATIONS

Characteristic complications of pneumonia include the development of pleurisy (usually purulent), suppurative processes in the lungs. Pleurisy that develops before the resolution of pneumonia is called parapneumonic, after which it is called metapneumonic. In severe cases, pneumonia can be complicated by myocarditis, meningitis, glomerulonephritis, infectious-toxic shock, disseminated intravascular coagulation (DIC), respiratory failure, and acute psychosis.

DIFFERENTIAL DIAGNOSTICS

It is important to distinguish pneumonia from tuberculous infiltrate, lung cancer, pulmonary infarction, eosinophilic infiltrate

A thorough medical history is important: long-term contact with bacteria-releasing agents is typical - family or professional. Phthisiological alertness is important when examining patients receiving systemic GCs.

Infiltrative pulmonary tuberculosis is most often localized in SI, SII, SVI(less often SXI) segments of the lungs, with polysegmental lesions it is quickly complicated by destruction. Tuberculosis is characterized by the presence of screening foci. Repeated examination of sputum and bronchial lavage water allows the detection of Mycobacterium tuberculosis. In the differential diagnostic plan, it is important to carry out empirical therapy for pneumonia without the use of broad-spectrum anti-tuberculosis drugs (rifampicin, streptomycin, kanamycin, amikacin, cycloserine, fluoroquinolones).

Peripheral lung cancer remains asymptomatic for a long time and is often detected during an X-ray examination that is not associated with a suspected tumor process of the respiratory organs. Tumor growth into the pleura is accompanied by severe pain. Tumor growth into the bronchus is accompanied by cough, sputum and hemoptysis. Most often, peripheral lung cancer is localized in the anterior segments of the upper lobes. In the X-ray picture of lung cancer, such characteristic features as “radiance” of the contour and an increase in the shadow on dynamic images are distinguished. As the tumor process progresses, it gives metastases - daughter tumors to the lungs or other organs. In turn, lung tumors themselves can be metastatic.

PE develops more often in patients suffering from thrombophlebitis lower limbs and pelvis, staying in bed for a long time, with atrial fibrillation, in the postoperative period. In young women, pulmonary thromboembolism sometimes develops while taking oral contraceptives. Pulmonary infarction is characterized by chest pain, with polysegmental damage - shortness of breath and cyanosis, tachycardia and arterial hypotension. Auscultation may reveal decreased breath sounds and pleural friction rubs. When one segment is affected, radiographs reveal a homogeneous triangular shadow, with its base facing the visceral pleura and its apex facing the hilum of the lungs. It is informative to conduct a perfusion radioisotope scan, which detects ischemic “cold” zones in the lungs. The ECG shows a picture of acute or subacute overload of the right heart.

Eosinophilic infiltrate is characterized by “volatile” changes on radiographs: the disappearance and appearance of infiltration with variable localization. Eosinophilia of blood and/or sputum, a burdened allergic history or helminthic infestations are typical.

Differential diagnosis of acute respiratory disease, including nosocomial pneumonia, in hospitalized patients in serious condition is quite diverse and requires the exclusion of such non-infectious conditions as congestive heart failure, adult respiratory distress syndrome, atelectasis, oxygen toxicity of the lungs and drugs that are difficult to distinguish on radiographs from pneumonia.

TREATMENT

According to therapeutic standards adopted in Russia since 1998 (Order of the Ministry of Health of the Russian Federation No. 300), treatment of pneumonia is carried out on an outpatient basis, in therapeutic and infectious diseases hospitals and in intensive care units. Indications for hospitalization for pneumonia are presented in table. 22-3.

Table 22-3. Indications for hospitalization for pneumonia

Age over 70

Associated chronic diseases:

congestive heart failure;

chronic hepatitis;

chronic nephritis;

diabetes;

alcoholism or substance abuse;

immunodeficiencies

Ineffective outpatient treatment within 3 days

Confusion or depression of consciousness

Possible aspiration

Respiratory rate more than 30 per minute

Unstable hemodynamics

Septic shock

Infectious metastases

Multilobar lesion

Exudative pleurisy

Abscessation

Leukopenia less than 4×10 9 /l or leukocytosis more than 20×10 9 /l

Anemia with hemoglobin concentration less than 90 g/l

Renal failure: increased urea concentration more than 7 mmol/l

Social readings

The following conditions are considered indications for intensive therapy in patients with pneumonia.

Respiratory failure: the ratio of p a O 2 to FiO 2 is less than 50, signs of diaphragm fatigue (decreased amplitude and electromyographic activity), the need for mechanical ventilation.

Circulatory failure: shock - systolic blood pressure less than 90 mm Hg, diastolic blood pressure less than 60 mm Hg, the need to administer vasoconstrictors more often than every 4 hours.

Intensive therapy is also necessary for oligoanuria, acute renal failure, disseminated intravascular coagulation, meningitis and coma.

In most other cases, pneumonia is treated on an outpatient basis.

ORGANIZATION OF TREATMENT AT HOME

Organizing treatment at home involves 4 doctor visits to the patient.

I visit: diagnosis based on clinical criteria; determining the severity of the disease and indications for hospitalization. If hospitalization is not necessary, then antibiotics are prescribed, special methods examinations (radiography, bacteriological examination of sputum), blood and urine tests.

Visit II (3rd day of illness): assessment of radiographic data and blood tests, clinical assessment of the effectiveness of treatment (improvement of well-being, reduction or normalization of body temperature, reduction of chest pain, reduction/cessation of hemoptysis and sputum). If there is no effect of treatment and if the condition worsens, hospitalization is indicated. If the condition is satisfactory, it is necessary to monitor the effectiveness of treatment after 3 days.

III visit (6th day of illness): assessment of the effectiveness of treatment according to clinical criteria, if treatment is ineffective - hospitalization, if the patient’s condition normalizes - continuation of antibiotic therapy for 3-5 days after normalization of body temperature. Microbiological data are also assessed, radiography, sputum and blood tests are re-prescribed.

IV visit (7-10th day of illness): assessment of the effectiveness of treatment according to clinical criteria, final assessment of blood tests, sputum and radiographs, if the condition is satisfactory - closure of the sick leave.

ANTIBIOTIC THERAPY

The choice of antibacterial drugs is determined by the type of pneumonia. The duration of antibiotic therapy depends on the initial severity of the disease, the presence of complications, and concomitant diseases, but it must be continued for at least 3 days after body temperature normalizes. In addition to positive clinical dynamics, normalization of the X-ray picture (with the exception of interstitial changes, which can persist for quite a long time), blood and sputum parameters are considered reliable guidelines for discontinuing antibiotics. The most common errors in antibacterial therapy are discussed in table. 22-4.

Table 22-4. Common mistakes antibacterial therapy for pneumonia

Purpose