Types of pneumonia: types of disease, diagnosis and treatment
The content of the article:
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How pathology develops
- Ways of penetration of infection into the body
- Development mechanism
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Types of pneumonia
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Clinical classification of pneumonia
- Out-of-hospital form
- Hospital form
- Pathology associated with immunodeficiency states
- Aspiration pneumonia
- Viral pneumonia
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- Criteria for determining the severity of the course of the disease
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Diagnostics
What is included in the diagnosis
- Treatment
- Video
Types of pneumonia - what are they? Are there any differences in the cause of the development and course of the disease, the method of transmission of the pathogen and the approach to treatment? These questions are often asked by people who have developed characteristic signs of pathology.
Pneumonia develops when pathogenic microorganisms enter the lung tissue
Pneumonia is an infectious lesion of the pulmonary alveoli that occurs in response to the introduction of microorganisms into the lower respiratory tract. In this case, the alveoli are filled with liquid, which prevents oxygen from entering the blood vessel.
How pathology develops
Ways of penetration of infection into the body
The most frequent route of penetration of pathogens into the lung tissue is bronchogenic. This can be facilitated by the inhalation of microbes from the environment (airborne droplets), aspiration, resettlement of pathogenic flora from the nose, pharynx.
The infection can enter the lungs through the bloodstream
Also, infection is possible during various medical procedures, including bronchoscopy, tracheal intubation, artificial ventilation of the lungs, inhalation of medicinal substances, etc.
Less common is the hematogenous route of spread of infection (with blood flow): during intrauterine infection, drug addiction with the intravenous route of drug administration and septic processes. The lymphogenous pathway of penetration of pathogens is much less common.
Development mechanism
With any type of pneumonia, the infection is fixed and multiplies in the epithelium of the respiratory bronchioles. In the future, there is the development of acute bronchitis or bronchiolitis. Pneumonia is caused by inflammation of the lung tissue after the spread of microorganisms outside the respiratory bronchioles. Due to a violation of bronchial patency, foci of atelectasis and emphysema appear.
The spread of infection from the focus occurs when sneezing and coughing
The body reflexively, with the help of sneezing and coughing, tries to restore breathing and bronchial patency. However, the infection spreads to healthy tissues, resulting in new foci of pneumonia.
Respiratory, oxygen, in severe cases - heart failure develops. Often there is an involvement in the process of regional lymph nodes - bronchopulmonary, bifurcation, paratracheal.
Types of pneumonia
Types of pneumonia by typical / atypical pathogen (and, as a consequence, the difference in symptoms):
- typical: Streptococcus pneumoniae, Haemophilus influenzae, less often Streptococcus pyogenes and Staphylococcus aureus;
- atypical: Mycoplasma pneumoniae, Legionella pneumophila, Chlamydophila pneumoniae, Bordetella pertussis.
According to the prevalence of the inflammatory process (X-ray picture), the following types of pneumonia are distinguished:
| Type of pneumonia | Description |
| Focal | Inflammation occupies a small area of the lung |
| Segmental | The process extends to one or more segments of the lung |
| Lobar | Inflammation covers the entire lobe of the lung, a typical example of lobar pneumonia is the croupous form, in which inflammation occurs mainly in the alveoli and adjacent areas of the pleura |
| Drain | It is characterized by the fusion (unification) of small foci into larger |
| Total | The inflammatory process spreads to the entire lung area |
If only one lung is affected, pneumonia is called unilateral, if both lungs are involved in the inflammation - bilateral.
However, in terms of choosing an adequate etiotropic therapy, this classification is not very informative. The most optimal, according to modern concepts of microbiology, pharmacotherapy and pulmonology, is the division of the disease based on the etiological principle. This allows you to select targeted etiotropic treatment, which minimizes the likelihood of complications.
Clinical classification of pneumonia
Clinical classification of pathology:
- community-acquired acquired (home) pneumonia;
- nosocomial (nosocomial, hospital) pneumonia;
- pneumonia, which has arisen against the background of immunodeficiency states;
- atypical pneumonia.
The division of pneumonia into community-acquired and nosocomial pneumonia is mainly associated with differences in the etiological structure.
Out-of-hospital form
The leading role in the development of the community-acquired form of the disease belongs to Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus. Atypical pathogens can also lead to the occurrence of pathology: Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella pneumophila.
Hospital form
The causative agents of the hospital form of pathology are usually conditionally pathogenic and gram-negative flora. First of all, these are S. Aureus, E. Coli, Proteus vulgaris, Legionella pneumophila. High mortality is noted when infected with Klebsiella pneumoniae, Pseudomonas aeruginosa.
Pathology associated with immunodeficiency states
In persons with immunodeficiency, the disease can be caused by Pneumocystis carinii, Streptococcus pneumoniae, Haemophilus influenzae, Mycobacterium tuberculosis, cytomegalovirus, pathogenic fungi, atypical mycobacteria, as well as other microorganisms.
Immunodeficiency states predispose to the invasion of certain microorganisms (depending on the form of immunodeficiency), for example:
- severe hypogammaglobulinemia: encapsulated bacteria including Streptococcus pneumoniae and Haemophilus influenzae;
- severe neutropenia: Enterobacteriaceae, Pseudomonas aeruginosa, Staphylococcus aureus, Aspergillus.
Aspiration pneumonia
Aspiration pneumonia is in many cases caused by obligate anaerobes or their associations with aerobic gram-negative microflora that inhabit the pharynx and oral cavity. These include: Prevotella melaninogenica, Porphyromonas gingivalis, Actinomyces spp., Fusobacterium nucleatum, spirochetes, and anaerobic streptococci.
Anaerobic disease is especially common with aspiration of large volumes of vomit.
Viral pneumonia
During epidemics of influenza A and B, the incidence of viral pneumonia increases. Many doctors are of the opinion that the virus itself does not cause disease, but it develops after the attachment of mycoplasma or bacterial flora.
Mixed infections account for about half of all cases of morbidity.
Criteria for determining the severity of the course of the disease
It is important to classify the disease by severity: mild, moderate, severe and extremely severe. This allows you to outline the most rational treatment and assess the prognosis. Based on this, patients are identified who need intensive care.
One of the main reasons for hospitalization is a severe course of the disease
The main clinical criteria for the severity of the disease include:
- the degree of respiratory failure;
- presence / absence of complications;
- the severity of intoxication;
- decompensation of concomitant diseases.
Diagnostics
In determining the type of pneumonia, five signs are assessed: cough, fever, leukocytosis, sputum and radiographically detectable infiltration.
The radiograph is of important diagnostic value for determining the type of pathology
Research Needed:
- chest x-ray;
- markers of bacterial inflammation;
- blood culture;
- virological research;
- microbiological examination of sputum;
- detection of pneumococcal antigens in urine.
Gram staining of sputum smear is of great diagnostic value for determining the cause of the development of the disease. Thanks to this method, it is possible to identify gram-positive and gram-negative pathogens, extracellular and intracellular localization of microorganisms.
The main differences in the clinical picture of the disease depending on the causative agent of the pathology:
| Causative agent | Features of the flow |
| Streptococcus | The pathology is characterized by a pronounced necrosis of the lung tissue, while the hemorrhagic component is less pronounced; lymphogenous and hematogenous dissemination are observed more often than in pathology caused by staphylococci |
| Pneumococcus | Of the community-acquired forms of the disease, pneumococcal pneumonia is the most common. It is characterized by the rare development of abscess formation and necrosis; fibrinous inflammation is typical when the process is caused by type I or II pneumococci |
| Staphylococcus | The disease is characterized by necrosis of the lung tissue, around which there is an accumulation of neutrophils; alveoli on the periphery of the inflammatory focus contain fibrinous or purulent exudate without bacteria; against the background of a severe course in places of accumulation of staphylococci, destruction of lung tissue is noted (staphylococcal destruction of the lungs) |
| Klebsiella pneumoniae (Friedlander's stick) | The process can extend over one or more lobes; with this type of pneumonia, extensive infarct-like necrosis of the lung tissue is formed (due to thrombosis of small vessels); exudate, like the secreted sputum, are slimy |
| Pseudomonas aeruginosa | This type of disease is characterized by an inflammatory focus of a doughy consistency of gray-red color; there is the formation of multiple small foci of necrosis, surrounded by a zone of plethora and hemorrhage |
| Mycoplasma and viruses | The pathology is characterized mainly by interstitial lesions, edema, infiltrative-proliferative changes in the interlobular and interalveolar septa, perivascular and peribronchial tissue, almost complete absence of exudate in the alveoli are also noted; at the same time, there are signs of inflammation of the mucous membrane of the bronchioles and bronchi |
What is included in the diagnosis
The diagnosis should characterize the disease as fully as possible, it reflects:
- nosological form with an indication of the etiology (presumptive, most probable, verified);
- the severity of the pneumonia;
- localization and prevalence of pulmonary inflammation (segment, lobe, unilateral or bilateral lesion).
Additionally, the presence of background pathology, complications (pulmonary and extrapulmonary) and phase (height, resolution, convalescence) may be indicated.
An example of a diagnosis:
- community-acquired, pneumococcal etiology, non-severe, segmental right lung;
- community-acquired, viral etiology, severe, polysegmental bilateral;
- community-acquired, etiology is unknown, severe, left-sided lower lobe.
Treatment
For treatment, antibiotics are used, symptomatic and detoxification therapy is carried out.
In elderly patients and with concomitant chronic obstructive pulmonary disease, levofloxacin may be the drug of choice. The use of rifampicin, aminoglycosides, co-trimoxazole, lincomycin is not recommended.
Drugs of choice for severe community-acquired pneumonia: aminopenicillins simultaneously with β-lactamase inhibitors, macrolides, II – III generation cephalosporins, or a combination of macrolide and β-lactam, or pneumotropic fluoroquinolones. The optimal route of administration of antibiotics during hospitalization of patients is intravenous.
Antibiotic therapy in the treatment of other types of pathology:
- hospital pneumonia: Cefotaxime, Ceftriaxone, Cefepim intravenously at maximum doses. Alternative drugs - respiratory fluoroquinolones, 3rd generation cephalosporins in combination with 2nd – 3rd generation aminoglycosides;
- aspiration pneumonia: fluoroquinolones, aminoglycosides, II – III generation cephalosporins, carbapenems and various combinations;
- pneumonia in persons with immunodeficiency: Imipenem, Meropenem, combinations of II – III generation aminoglycosides with Ceftazidime, etc. Fluoroquinolones may be considered as an alternative.
Preservation of individual laboratory, clinical or radiological symptoms of pneumonia after the end of the prescribed course is not an absolute indication for continuing antibiotic therapy. Usually, their resolution occurs on their own with the continuation of symptomatic treatment.
Long-term elevated body temperature to subfebrile numbers (37.1–38.0 ° C) in adults and children does not apply to signs of bacterial infection. Also, during the recovery period, weakness, shortness of breath, chest pain when coughing on the affected side may still be observed.
It must be borne in mind that minimizing the treatment time and the likelihood of developing serious complications is possible only with timely access to a doctor and following all his recommendations.
Video
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Anna Kozlova Medical journalist About the author
Education: Rostov State Medical University, specialty "General Medicine".
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