Classification of pneumonia

In the past, there were several successful clinical classifications of pneumonia, which included their division depending on the etiology, the clinical and morphological variant of pneumonia, the localization and extent of the lesion, the severity of the clinical course, the presence of respiratory insufficiency and other complications.

For a long time, the division of pneumonia predominantly according to the clinical and morphological principle into croupous (lobar) and focal pneumonia (bronchopneumonia) prevailed in domestic medical practice for a long time, differing significantly in morphological changes in the lung parenchyma, pathogenesis, clinical manifestations and prognosis. However, in recent years, new data have been obtained, suggesting that such a division does not reflect the whole variety of clinical variants of pneumonia and, most importantly, is of little information in terms of the choice of optimal etiotropic therapy.

Thus, significant features of the clinical course and outcomes of the disease caused by intracellular pathogens of pneumonia (legionella, mycoplasma, chlamydia, etc.), gram-negative microflora, anaerobic bacteria, etc. Were shown. Essential features of aspiration pneumonia, as well as pneumonia, developing against the background of immunodeficiency states and other associated diseases are described. Thus, the crucial importance of the etiologic factor was demonstrated.

According to modern concepts, the basis for the classification of pneumonia is the etiological principle, which provides for the identification of the causative agent of pneumonia. This principle was implemented to the greatest extent in the International Statistical Classification of Diseases of the 10th revision, 1992 (ICD-X).

However, it should be recognized that at present in real clinical practice not only in our country, but also abroad, the etiological interpretation of pneumonia at the first contact with the patient is practically impossible. Moreover, reliable identification of the causative agent of pneumonia in the next 4-7 days from the onset of the disease, even in a well-equipped specialized hospital, does not exceed usually 60-70%, and in outpatient conditions - 10%. Nevertheless, adequate and, if possible, individually selected etiotropic therapy should be prescribed to the patient immediately, immediately after clinical or radiological confirmation of the diagnosis of pneumonia.

Therefore, in the last 10 years, the classification of pneumonia, proposed by the European Society of Pulmonology and the American Thoracic Society and approved by the Vth National Congress on Respiratory Diseases (Moscow, 1995), has been universally recognized. According to this classification, four main forms of pneumonia are distinguished, each of which differs by a quite definite spectrum of the most probable pathogens of pneumonia.

1. Community acquired pneumonia (Community acquired pneumonia), developing outside the hospital, in "home" conditions and being the most common form of pneumonia.
2. Hospital (hospital, nosocomial) pneumonia that develops no earlier than 48-72 hours after admission of the patient to hospital. The specific gravity of these forms of pneumonia is 10-15% of all cases, but lethality also reaches some cases of 30-50% or more and the connection with the specific virulence and resistance to antibacterial therapy of gram-negative microflora, which is the main cause of this form of pneumonia.
3. "Atypical" pneumonia - pneumonia caused by intracellular ("atypical") pathogens (legionella, mycoplasma, chlamydia, etc.).
4. Pneumonia in patients with immunodeficiency states.

Despite all the conventionality and internal inconsistency of this classification, its application in clinical practice is now fully justified, since the division of pneumonias into community-acquired and hospital (nosocomial) in most cases allows the practitioner to more rationally approach the choice of the optimal antibacterial treatment, and immediately the same after collecting anamnesis and clinical examination of the patient.

At the same time, many researchers dispute the legitimacy of separating the so-called "atypical" pneumonia into a separate group, since the latter, caused mainly by intracellular pathogens, can develop both in "home" (outside the hospital) and in hospital settings. Therefore, in modern guidelines of the American and British Thoracic Societies (2001), it is generally recommended to avoid the use of the term "atypical" pneumonia.

On the other hand, there is an increasing discussion of the advisability of isolating other types of pneumonia, the emergence of which is associated with a clinical situation: aspiration of gastric contents, use of mechanical ventilation, surgery, trauma, etc.

In addition to the verification of the etiologic factor, pneumonia is of great importance in the modern clinical classification, diagnosing the severity of pneumonia, localizing and extending the lung lesion, diagnosing complications of pneumonia, which allows more objective evaluation of the disease prognosis, choosing a rational program for complex treatment and isolating a group of patients requiring intensive care . There is no doubt that all these headings, along with empirical or objectively confirmed information about the most likely causative agent of the disease, should be presented in the modern classification of pneumonia.

The most complete diagnosis of pneumonia should include the following headings:

• form of pneumonia (community-acquired, nosocomial, pneumonia on the background of immunodeficiency states, etc.);
• availability of additional clinical and epidemiological conditions for the onset of pneumonia;
• the etiology of pneumonia (a verified or suspected infectious agent);
• localization and extent;
• Clinico-morphological variant of pneumonia;
• severity of pneumonia;
• degree of respiratory failure;
• presence of complications.

From the point of view of the correct interpretation of clinico-radiological signs, it is also important to pay attention to the clinical and morphological substrate of the disease - focal or croupous pneumonia, which differ in their clinical manifestations and some features of etiology and pathogenesis. It should be borne in mind that the terms "shared" and "croupier" pneumonia are not synonymous in the strict sense of the word, since the defeat of a whole lobe of lung (pleuropneumonia) in some cases may result from the formation of focal bronchopneumonia discharge with lesions of several segments. On the other hand, there are cases when croupous inflammation of the lungs acquires an abortive course and ends with the corresponding lesion of only a few segments of the lobe fraction.

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

Working Classification of Pneumonia

According to the form

• Community-acquired (home-based)
• Intrahospital (hospital, nosocomial)
• Pneumonia in patients with immunodeficiency status

By etiology (verified or suspected pathogen)

• Streptococcus pneumoniae
• Haemophilus influenzae
• Moraxella catarrhalis
• Mycoplasma spp.
• Chlamydophila (Chlamydia pneumoniae)
• Legionella spp.
• Staphylococcus aureus
• Klebsiella pneumoniae
• Eschenchiae coli
• Proteus vufgans
• Pseudomonas aeruginosa
• Anaerobic bacteria (Fusobacterium spp., Bacteroides spp., Peptostreptococcus spp., Etc.)
• Viruses
• Mushrooms
• Other pathogens

On the basis of clinical and epidemiological conditions

• Aspiration
• Early WAP
• Late WAA
• Postoperative
• Post-traumatic
• Against COPD
• Against the background of alcoholism
• Against the background of malignant neoplasms
• Against the background of immunodeficiency states
• Persons under 25 years of age
• Persons over 60 years of age
• Other options

According to clinical and morphological features

• Focal (bronchopneumonia)
• Drain Focal
• Equity (croupier)
• Two-sided (with indication of localization and extent)

By localization and extent

• Total
• Equity (indicating the proportion)
• Segmented (with the number of the segment)

By the severity of the flow

• Heavy current
• The course of medium gravity
• Easy flow

Complications

• Respiratory failure (acute or chronic) indicating the degree
• Pleural effusion
• Abscessed
• Infectious-toxic shock
• Sepsis
• Acute Respiratory Distress Syndrome
• Other complications

* - The so-called "atypical" pneumonia is excluded, the eligibility of which is currently disputed

Below are some examples of the formulation of the diagnosis of pneumonia, taking into account all the headings presented in the working classification.

Examples of diagnosis

• Community-acquired pneumococcal bronchopneumonia with involvement of IX and X segments of the right lung, moderate severity of the course, complicated by grade II diabetes.
• Hospital (nosocomial) ventilation-aspiration pneumonia (causative agent - Pseudomonas aeruginosa) with defeat of VIII-X segments of the right lung, severe course, complicated by exudative pleurisy, infectious-toxic shock and DN III st.
• Community-acquired legionellosis pneumonia with localization in the lower lobe of the right lung (lobar), severe course, complicated by parapneumonic effusion pleurisy, infectious-toxic shock and DN III st.
• Community-acquired lobar (pleural) pleuropneumonia of unexplained etiology, with localization in the lower lobe of the right lung, moderate severity of the course, complicated by DN II st.

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