Caseous pneumonia

Caseous pneumonia is one of the most severe forms of pulmonary tuberculosis. It is characterized by a pronounced caseous-necrotic component of tubercular inflammation, rapid progression and the formation of multiple cavities of decay. It can arise as an independent disease in a previously healthy person or as a complication of another form of pulmonary tuberculosis. There are two clinical forms of caseous pneumonia; lobar and lobular. Lobar caseous pneumonia usually develops as an independent clinical-anatomical form of tuberculosis, and lobular complicates other forms of pulmonary tuberculosis more often.

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Epidemiology of caseous pneumonia

Against the backdrop of social and economic shocks, frequent disorganization in the work of the TB service, the number of patients with this form of tuberculosis has increased. Caseous pneumonia was again included in the Russian clinical classification of tuberculosis. In recent years, casein pneumonia is observed in 3-5% of newly diagnosed tuberculosis patients. Adults from medical and social risk groups associated with the danger of development of immunodeficiency (HIV-infected, alcoholics, socially maladjusted persons, and also long-term treated with glucocorticoids, cytostatic drugs, etc.) are the most susceptible to the disease of caseous pneumonia. An important factor that increases the risk of developing caseous pneumonia, consider the infection of a person with highly virulent, resistant to drugs mycobacteria tuberculosis.

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Pathogenesis and pathological anatomy of caseous pneumonia

The emergence of caseous pneumonia is associated with an intensive multiplication of mycobacteria in the lung tissue, which occurs against a background of pronounced immunodeficiency. Metabolic failure of phagocytic cells and lymphocytes. The pathological increase in the apoptosis of cells participating in the immune response is considered the main pathogenetic factor in the development of caseous pneumonia.

The initial stage of caseous pneumonia (acinous, acinosis-lobular, draining lobular) is characterized by mass death of cells in the affected area and the formation of an extensive zone of caseous necrosis. The pathological process quickly passes into the next, more widespread and irreversible stage. Casey foci and foci are formed in the adjacent pulmonary tissue, merging with each other. Mycobacteria penetrate the lumen of small bronchi, lymphatic and blood vessels. Their spread and progression of caseous changes within 2-3 weeks lead to a widespread lung injury. Morphological peculiarity of caseous pneumonia is considered to be a sharp predominance of caseo-necrotic changes over other specific changes in the pulmonary tissue.

In the mechanism of decay of the lung tissue, the damaging effect of the products of the vital activity of the pathogen causing cytolysis of macrophages and the entry of light lysosomal enzymes, prostaglandins and TNF-α into the tissue are of great importance. The decay of the lung tissue is facilitated by significant disturbances in the microcirculation. Caused by necrotic vasculitis. Melting of caseous masses leads to the formation of multiple cavities of various sizes - acute caverns. A destructive process in the lung is accompanied by a temporary increase in the partial tension of oxygen in the affected area, which creates optimal conditions for intensive multiplication of mycobacteria.

Without treatment, caseous pneumonia often leads to death. The cause of death is pulmonary-cardiac insufficiency, which develops against the background of destruction of the lung tissue and pronounced intoxication.

With the timely begun complex treatment, rapid progression of the process can be stopped. Gradual organization of fibrinous masses determines the appearance of areas of carnification: the cavity is transformed into fibrous cavities, caseous necrotic foci are encapsulated. So caseous pneumonia, in which changes in the lungs are largely irreversible, is transformed into fibro-cavernous tuberculosis of the lungs.

Symptoms of caseous pneumonia

A typical caseous pneumonia develops sharply. In the initial stage, when caseous necrotic masses are formed in the affected area, an intoxication syndrome (fever, chills, weakness, severe sweating, a sharp deterioration in appetite) is expressed, dyspnea, cough, mostly dry, sometimes with a small amount of difficultly separated sputum.

After the melting of the caseous necrotic masses and the formation in the lung of multiple cavities of decay, the severity of bronchopulmonary-pleural syndrome sharply increases. The cough becomes wet, with more sputum. Patients are concerned about chest pain. An impurity of blood may appear in the sputum. Dyspnea increases, acrocyanosis develops. Mark a hectic fever of the wrong type, often the development of cachexia.

In the physical examination of the affected lungs, the shortening of the percussion sound is detected, the weakened bronchial breathing, wet, finely bubbling rales are heard. After the formation of cavities of decay, rales become sonorous, numerous, medium- and large-bubbly. They note the appearance of tachycardia and an accent tone II over the pulmonary artery. Often observed increase in the liver.

Radiographic picture of caseous pneumonia

In radiographic examination of chest organs, common gross changes are found. In patients with lobar caseous pneumonia, a darkening of all or most of the lobe of the lung is determined, initially homogeneous. As the disease progresses, areas of enlightenment of irregular bay-shaped form with fuzzy contours appear. On CT ("air bronchography") in the condensed lobe of the lung, the lumens of the enlarged medium and large bronchi can be clearly discernible. In the future, as the caseous mass is rejected, the cavities acquire the characteristic features of a cavern with a gradually forming wall. In the adjacent segments and in the other lungs, foci of bronchogenic dropout are often seen. The affected portion of the lung decreases as a result of loss of elasticity.

In case of lobular caseous pneumonia, large focal shadows and small foci with a diameter of about 1.5 cm are visible on the roentgenogram in a direct projection. The shadows have irregular shape, medium or high intensity, fuzzy contours. When tomography in the lungs reveal multiple cavities of decay).

Treatment of caseous pneumonia

Treatment of caseous pneumonia is carried out with the help of antituberculous drugs.