Caseous pneumonia is a severe independent clinical form of pulmonary tuberculosis, which is characterized by rapid progression of specific inflammation, accompanied by destruction of the pulmonary parenchyma and the formation of cavities. The leading clinical signs of the disease are severe intoxication, cough with sputum, respiratory failure. For diagnostic purposes, radiation methods of examination of the chest organs are used, laboratory tests are performed. Etiotropic chemotherapy is prescribed, detoxification agents and immunostimulants are used. According to the indications, surgical treatment is carried out.
A15 A16 A31.0
Caseous pneumonia develops as an independent disease or is a complication of the progressive tuberculosis process. It is common in countries with a high incidence of tuberculosis. Occurs against the background of an immunodeficiency condition. The proportion of caseous inflammation in patients with newly diagnosed pulmonary tuberculosis is 3-15%. Bacterial excretion is observed in 90-95% of cases. Approximately 60% of patients have primary or secondary multidrug resistance to anti-tuberculosis drugs. 30-50% of cases end in death within the first 2-6 weeks of the disease.
Caseous pneumonia causes
The causative agent of the infectious disease is Mycobacterium tuberculosis (bacillus Koch). Caseous pneumonia is formed when a person is massively infected with a highly virulent agent, often resistant to tuberculostatics, or when a tuberculosis infection persisting in the body is activated. Most often, caseous necrosis of the lung tissue complicates the course of disseminated or fibrous-cavernous tuberculosis process. A prerequisite for the occurrence of the disease is pronounced immunosuppression. The risk group for the development of severe forms of tuberculosis infection includes:
- Socially maladapted persons. Includes persons without a fixed place of residence, engaged in vagrancy, refugees. Pronounced secondary immunodeficiency is often observed in patients with alcohol dependence, drug addiction. There is a high probability of infection with drug-resistant tuberculosis and the occurrence of its severe forms in people serving sentences in prisons.
- Medical risk group. Most often, caseous pneumonia is detected and becomes the cause of death in AIDS patients who do not take antiviral drugs and specific chemoprophylaxis. The risk of this pathology is high in patients receiving corticosteroids and cytostatics for a long time, patients with diabetes mellitus.
The disease is formed against the background of a deficiency of immune cells active against infection. Mycobacteria multiply freely, releasing a number of toxic substances. The waste products of microorganisms damage the membrane of immunocompetent cells. A vicious circle is formed – immune disorders worsen, tuberculosis progresses, further depressing the immune system.
Initially, the pathological process is localized within one segment. Microcirculation is disrupted in the affected area. Blood clots form in the vessels feeding the lung tissue. The lack of proper blood supply causes mass cell death – caseous necrosis. Bronchogenic and lymphohematogenic mycobacteria enter neighboring segments, the opposite lung, can be introduced into other organs and tissues. Within 2-3 weeks, common tuberculous pneumonia develops. Pathomorphological examination reveals extensive, often bilateral lung damage with characteristic irregularly shaped decay cavities partially filled with caseous masses. The parietal and visceral pleura are involved in the process. Caseous pleural overlays are formed.
The classification of severe caseous lesion of the pulmonary parenchyma is based on pathomorphological changes in the damaged tissue. Some authors of scientific articles in the field of phthisiology believe that it also reflects the stages of the pathological process. Depending on the damage to certain anatomical structures, the following forms of pneumonia with caseous melting of the lung are distinguished:
- Acinous. A large number of acinuses – structural units of alveolar tissue – are simultaneously involved in the pathological process. Often complicates the course of acute miliary tuberculosis.
- Lobular. The lobules of the lung are affected. Caseous lobular pneumonia is characterized by the presence of numerous, rather large areas of specific necrosis. Sometimes it develops against the background of tuberculosis dissemination.
- Lobarnaya. Inflammation occupies the entire pulmonary lobe. The melting of massive sections of caseose leads to the formation of destruction cavities. Usually occurs as an independent pathology.
Caseous pneumonia symptoms
The disease begins acutely, less often subacute. An increase in temperature to high febrile and hyperthermic values is determined. Fever of the hectic or irregular type with significant fluctuations in daily temperature is accompanied by chills, headache. Symptoms of intoxication are pronounced. Appetite sharply decreases up to complete anorexia. Patients feel significant general weakness, fatigue. Sleep is disturbed. Bothered by torrential night sweats. Sometimes the clinical picture at the onset of the disease resembles the onset of an acute respiratory infection. Patients complain of a runny nose, sore and sore throat, aching joints, moderate fever.
Important signs of caseous lung damage are cough and shortness of breath. At the beginning of the disease, the cough is dry, a small amount of mucosal sputum is separated with difficulty. Often bronchial secretions acquire a rusty color. After 1-2 weeks, the cough becomes productive. Non-specific microflora joins the caseous inflammation, which causes the release of yellow-green purulent sputum. The manifestations of the febrile syndrome change, episodes of remission with normal or subfebrile body temperature are noted. At the same time, the general condition of the patient worsens. Often during this period of time, an admixture of blood in the sputum is detected.
Pronounced shortness of breath worries the patient already in the first days of the disease. It appears with little physical exertion and increases even more as the pathology progresses. Breathing difficulties are accompanied by pain syndrome. Minor chest pains become intense when the pleura is involved in the inflammation process. The patient is noticeably losing weight. Pulmonary heart failure is gradually increasing.
Caseous pneumonia in the acute period is often complicated by hemoptysis or pulmonary bleeding. Massive infection against the background of immunodeficiency often leads to an infectious and toxic shock at the first stage of the disease. Sometimes spontaneous pneumothorax occurs. During the regression period, against the background of conservative therapy, caseous lobar pneumonia transforms into fibrous-cavernous pulmonary tuberculosis. Cavities are formed from different-sized cavities of destruction. Fatal outcome occurs when the patient does not seek medical help in time, there is no treatment, severe immunosuppression. The main causes of death are acute respiratory and circulatory insufficiency, massive pulmonary hemorrhage, infectious and toxic shock.
It is difficult to diagnose a caseous lesion of the lung during the first week, since the disease proceeds under the mask of croup pneumonia, influenza or septic condition. The presence of tuberculosis of any localization or contact with a bacillary patient in the anamnesis makes it possible to suspect a specific process. When examining the patient, attention is drawn to the pallor of the skin with a feverish blush on the cheeks, cyanosis of the lips. The final diagnosis is made on the basis of:
- Physical data. With percussion, the dulling of the pulmonary sound in the infiltration projection is determined. Bronchial respiration is auscultatively listened to, which may be amphoric over a large decay cavity. There are numerous wet different-caliber wheezes.
- Methods of radiation diagnostics. Lobar caseous pneumonia on the lung x-ray is a massive shading of the lobe of the lung with forming cavities of decay and displacement of the mediastinum in the affected side. The presence of bronchogenic foci of dropout in the affected and opposite lungs is characteristic. With lobular and acinous caseosis, multiple foci of infiltration with a tendency to merge and decay are revealed.
- Blood test. In the study of peripheral blood, leukocytosis, a rod-shaped shift of the leukocyte formula, lymphopenia is observed. Acute phase indicators increase, hypoalbuminemia is detected. An increased protein content in the urine is determined.
- Sputum studies. The detection of mycobacteria in the sputum of the patient is possible only in the second week of the disease. A simple bacterioscopy according to Zil-Nielsen is performed, crops are sown on liquid and solid media, express diagnostic methods are used. Sensitivity to tuberculostatics is being clarified. The presence of tubercle bacillus in the sputum confirms the diagnosis.
Skin immunodiagnostic tests (Mantoux test, Diaskintest) are not informative enough to diagnose the caseous process due to a violation of the immune response. The result of the study is usually negative or weakly positive. In the presence of a severe immunosuppressive condition, quantiferon and tubinferon tests may not respond to tuberculosis infection.
Treatment for caseous pneumonia
After diagnosis, the disease is treated by a phthisiologist. Etiotropic therapy with tuberculostatic drugs is prescribed taking into account the resistance of mycobacteria to drugs. The treatment is two-stage. The intensive phase of chemotherapy is carried out in a specialized hospital. Detoxification agents, antihypoxants, immunostimulants, corticosteroid hormones are used. The patient’s diet should be balanced, high-calorie. In the presence of multiple or giant single destruction cavities, the question of surgical intervention is considered. In the absence of contraindications, lung resection is performed. Treatment with anti-tuberculosis drugs in the continuation phase is carried out for a long time (up to 24 months) on an outpatient basis under the supervision of medical workers.
Prognosis and prevention
The prognosis for pneumonia of a specific nature is always serious. The disease regresses with the formation of dense foci in about 25% of cases. This healing process is the outcome of acinous or lobular inflammation. Caseous lobitis is transformed into chronic fibrous-cavernous or cirrhotic pulmonary tuberculosis. The long course of tuberculosis infection gradually leads to the formation of a pulmonary heart, the occurrence of amyloidosis and disability of the patient. Specific prevention of severe forms of tuberculosis is carried out by vaccinating children with BCG vaccine in a maternity period. Non-specific measures include compliance with a healthy lifestyle, proper nutrition, timely preventive X-ray and fluorographic examinations. HIV-infected patients are prescribed preventive treatment with tuberculostatics.