Pneumococcal pneumonia

Pneumococcal pneumonia is the most common type of pneumonia caused by Str.pneumoniae. About 5-25% of healthy people are carriers of pneumococcus, primarily children.

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Causes and pathogenesis of pneumococcal pneumonia

Pneumococcus most often causes inflammation of the entire lobe or most of the lobe of the lung, but quite often pneumococcus is the cause of the development of focal pneumonia.

There are 4 pathological stages of development of lobar pneumococcal pneumonia.

• Stage 1 (hyperemia, microbial edema, flush) - characterized by pronounced blood filling of the vessels, pronounced exudation of serous fluid, with pneumococci found in the exudate. This stage lasts from 12 hours to 3 days.
• Stage 2 - red hepatization - is characterized by the fact that the alveoli of the affected area of the lung are completely filled with exudate containing plasma proteins (primarily fibrinogen) and a large number of erythrocytes (due to their diapedesis). The inflamed area of the lung becomes airless, dense, has a reddish color, and resembles the liver in appearance. This stage lasts from 1 to 3 days.
• Stage 3 - gray hepatization. At this stage, there are a large number of leukocytes (mainly neutrophils) in the alveolar exudate, and significantly fewer erythrocytes. The lung is still dense, has a grayish-yellow color on section, and the granularity of the lung is clearly visible. Microscopic examination reveals a large number of neutrophilic leukocytes with phagocytosed pneumococci. The duration of this stage is from 2 to 6 days.
• Stage 4 - resolution - is characterized by gradual resorption of exudate in the alveoli under the influence of macrophages, leukocytes, fibrin gradually dissolves, granularity of the lung tissue disappears. The airiness of the lung tissue is gradually restored. The duration of this phase depends on the prevalence of the inflammatory process, the reactivity of the body, the type and intensity of the therapy.

It should be noted that a sequential change of stages is not always observed. More often, in the affected lobe of the lung there is a combination of signs of different stages or a predominance of one stage.

It should be noted that in pneumonia, not only the alveoli and interstitial tissue are involved in the pathological process, but also the pleura, lymphatic vessels, and regional lymph nodes.

In focal pneumonia, the inflammatory process affects a lobule or segment, with areas of inflamed, compacted tissue alternating with areas of vicarious emphysema. The exudate is predominantly serous, although it is often purulent; the fibrin content in the exudate is low.

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Symptoms of pneumococcal pneumonia

As a rule, pneumococcal pneumonia begins acutely, suddenly, with a single, stunning chill, after which the body temperature quickly rises to 38-40 ° C, pain appears when breathing on the affected side, cough (painful and initially dry, but soon mucopurulent sputum with streaks of blood begins to separate, many patients have a significant admixture of blood - "rusty sputum"). Symptoms of intoxication are expressed significantly - patients are bothered by weakness, myalgia, headache, loss of appetite, tachycardia appears. Shortness of breath is observed.

Diagnosis of pneumococcal pneumonia

Lobar pneumococcal pneumonia has typical physical manifestations that depend on the pathological stage of the disease.

In the initial phase (phase of exudate accumulation) - dull-tympanic sound over the lesion, harsh breathing with prolonged exhalation, initial (sparse) crepitation indux, sometimes in a limited area - dry and wet wheezing. In the phase of compaction (hepatization) - a sharp increase in vocal fremitus, the appearance of bronchophony, dull sound during percussion, vesicular breathing is not heard, crepitation disappears, often pleural friction noise. In the phase of resolution - vocal fremitus gradually normalizes, bronchophony disappears, crepitation redux (abundant, sonorous, over a large area), sonorous fine-bubble wheezing appear, bronchial breathing gradually changes to harsh, then vesicular. However, it should be taken into account that the pattern of stages of pneumococcal pneumonia is not always observed, therefore, in different areas of the lung at the same time, different physical data are determined.

In focal pneumococcal pneumonia, physical data are much less demonstrative: dullness of percussion sound over the lesion, crepitation and fine bubbling rales (due to the presence of concomitant focal bronchitis) may be determined (not always).

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Radiographic data

The most characteristic changes are observed in the phase of hepatization (compaction) of the lung tissue. Lobar pneumonia is characterized by intense darkening of the lung lobe. During tomographic examination, against the background of inflammatory infiltration, the bronchi are clearly visible, which reliably distinguishes pneumonia from pulmonary atelectasis. Focal pneumococcal pneumonia is manifested by local compaction (focal shadow).

Laboratory diagnostics of pneumococcal pneumonia

The most demonstrative changes are in the general blood test. As a rule, there is pronounced leukocytosis (the number of leukocytes reaches 20-30 x 10 ⁹ /l), a significant increase in the number of neutrophils, a pronounced shift in the leukocyte formula to the left (up to myelocytes and promyelocytes) are observed. During the height of the disease, eosinophils disappear, the number of lymphocytes and platelets decreases, with the onset of the resolution phase, the number of lymphocytes, eosinophils and platelets normalizes. An increase in ESR is characteristic.

A biochemical blood test reveals signs of an inflammatory process: increased levels of a- and gamma globulins, seromucoid, sialic acids, fibrin, and haptoglobin.

Diagnostic criteria for pneumococcal pneumonia

Pneumococcal pneumonia can be diagnosed based on the following:

• acute onset of the disease with chills, fever, chest pain, shortness of breath, cough;
• characteristic data of physical and radiological examination of the lungs;
• detection of gram-positive lanceolate diplococci forming short chains in sputum preparations stained according to Gram, with at least 10 typical pneumococci (diplococci) being detected in the field of vision. For final proof that the detected streptococci belong to pneumococcus, it is advisable to conduct a swelling reaction of its capsule. This reaction occurs upon the addition of polyvalent pneumococcal antiserum;
• an increase in the titers of antipneumococcal antibodies in paired blood sera of the patient, taken at the onset of the disease and after 10-14 days.

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Treatment of pneumococcal pneumonia

In mild cases of pneumonia, oral bactericidal antibiotics can be used. Phenoxymethylpenicillin, ampicillin (amoxicillin), 1st generation cephalosporins, in case of intolerance to the above-mentioned drugs - erythromycin, less often Biseptol (Groseptol) is used. Treatment with penicillin is also possible.

In cases of moderate to severe pneumonia, the drug of choice is penicillin, which is administered intramuscularly in doses of 1-2 million U every 4 hours. If pneumonia is complicated by pleural empyema, lung abscess, or infective endocarditis, the penicillin dose is doubled for better penetration of the drug into the tissue.

In recent years, a large number of penicillin-resistant strains of pneumococcus have been noted. In this case, cephalosporins should be used, imipenem and vancomycin are also effective.

• Pneumonia - Treatment regimen and nutrition
• Antibacterial drugs for the treatment of pneumonia
• Pathogenetic treatment of pneumonia
• Symptomatic treatment of pneumonia
• Combating complications of acute pneumonia
• Physiotherapy, exercise therapy, breathing exercises for pneumonia
• Sanatorium and resort treatment and rehabilitation for pneumonia