Acute hematogenous disseminated pulmonary tuberculosis in children

Brief introduction of acute hematogenous disseminated pulmonary tuberculosis in children Hematogenous disseminated pulmonary tuberculosis is a tuberculosis of Mycobacterium tuberculosis (hereinafter referred to as tuberculosis) once or repeatedly into the blood circulation, causing lung disease and corresponding pathological, pathophysiological changes and clinical manifestations known as hematogenous disseminated tuberculosis, resulting in When the body is covered with multiple organ lesions, it is called hematogenous disseminated tuberculosis. Hematogenous disseminated tuberculosis is a critical tuberculosis that develops from the original tuberculosis and can also be caused by other tuberculosis cheese-like lesions that collapse to the blood source. The disease is more common in children and can occur in adults. With the aging of the population and the prolongation of the life expectancy of the elderly and the rebound of the tuberculosis epidemic, there is an increasing trend in the dissemination of pulmonary tuberculosis in the elderly. basic knowledge The proportion of illness: 0.001% Susceptible people: children Mode of infection: droplet spread Complications: pneumothorax, empyema, hemoptysis

Causes of acute hematogenous disseminated pulmonary tuberculosis in children

As early as 1882, the German bacteriologist Robert Koch (1843-1910) proved that tuberculosis is the pathogen of tuberculosis. Those who are pathogenic to the human body are human tuberculosis and tuberculosis. Mycobacterium tuberculosis has strong resistance. In addition to its acid, alkali and alcohol resistance, it has strong tolerance to cold, heat, dryness, dryness, light and chemicals. Damp heat has a strong bactericidal power against tuberculosis, which can be killed at 65 ° C for 30 min, 70 ° C for 10 min, and 80 ° C for 5 min.

Dry heat sterilization is poor, dry heat 100 ° C takes more than 20 minutes to kill, so dry heat sterilization, temperature needs high, time needs to be long. Tuberculosis in the sputum is killed within 2 hours of direct sunlight, while ultraviolet light takes only 10 minutes. On the contrary, it can survive for several months in the dark, and the tuberculosis bacteria in the sputum can be sterilized by using 5% of carbolic acid (phenol) or 20% bleaching powder for 24 hours. Tuberculosis does not produce endotoxin or exotoxin. Its pathogenicity may be related to the inflammation caused by the proliferation of bacteria in tissue cells, the toxicity of bacterial components and metabolic substances, and the immune damage caused by the body to the bacterial components.

Prevention of acute hematogenous disseminated pulmonary tuberculosis in children

1. Control the source of infection, reduce the chance of infection: tuberculosis smear-positive patients are the main source of tuberculosis in children, early detection and reasonable treatment of smear-positive tuberculosis patients, is a fundamental measure to prevent tuberculosis in children. Infants and young children with active tuberculosis, their family members should be examined in detail (chest, chest, PPD, etc.). Regular physical examinations of primary and child care institutions should be conducted to detect and isolate infection sources in a timely manner, which can effectively reduce the chance of tuberculosis infection in children.

2. Popularization of BCG vaccination: Practice has proved that vaccination with BCG is an effective measure to prevent tuberculosis in children. BCG was invented by French physicians Calmette and Guerin in 1921, so it is also called BCG. In China, it is prescribed to inoculate BCG in the neonatal period. According to the regulations, BCG is inoculated into the upper end of the deltoid muscle of the left upper arm and injected intradermally at a dose of 0.05 mg/time. The scratch method is now rarely used. In 1997, the Ministry of Health notified the cancellation of the BCG relapse plan for 7 and 12 years old. However, if necessary, children who are negative for this age-based test may still be given multiple crops. In the neonatal period, BCG can be injected on the same day as the hepatitis B vaccine.

Contraindications to vaccination with BCG: positive lignin response; patients with eczema or skin disease; recovery period of acute infectious disease (1 month); congenital thymic dysplasia or severe combined immunodeficiency disease.

3. Prophylactic chemotherapy: mainly used for the following subjects:

(1) Infants under the age of 3 have not been vaccinated with BCG and have a positive test.

(2) Close contact with patients with open tuberculosis (multiple family members).

(3) The sputum test has recently changed from negative to positive.

(4) The sputum test is a strong positive responder.

(5) Children with positive serotonin test need to use adrenocortical hormone or other immunosuppressive agents for a longer period of time.

The drug used for chemoprevention is mainly isoniazid, the dose is 10mg/(kg·d), and the course of treatment is 6-9 months. Newborn children under 6 years of age with new tuberculosis and neonates born with tuberculosis should be treated with isoniazid regardless of the outcome of the test. The dose is the same as above. After 3 months of treatment, the sputum test was performed. If it was positive, the isoniazid was continued for 9 months. If the sputum test was negative (<5 mm), the isoniazid was stopped.

Anti-HIV-positive children with a history of tuberculosis should receive isoniazid for 12 months regardless of the outcome of the nodule test.

If the tuberculosis patient contacted by children is resistant to isoniazid, the chemotherapeutic drug should be changed to rifampicin, 15mg/(kg·d), 6-9 months; if it is resistant to isoniazid and resistant to rifampicin, It is recommended to give pyrazinamide plus ofloxacin for 6 to 9 months, or pyrazinamide plus ethambutol for 6 to 9 months.

Acute hematogenous disseminated pulmonary tuberculosis complications in children Complications, pneumothorax, hemoptysis

1. Pneumothorax: When the cavity in the lungs and the cheese-like lesions are close to the pleural area, it can cause tuberculous pus. Miliary tuberculosis can cause bilateral spontaneous pneumothorax.

2. Endobronchial stenosis: caused by endobronchial lesions.

3. Bronchiectasis: Pulmonary tuberculosis lesions repeatedly progress and fibrosis, resulting in the destruction of the normal structure of the bronchus in the lungs, can cause secondary bronchiectasis, often repeated hemoptysis. Often located in the upper lobe, called dry branch expansion. Can cause fatal hemoptysis.

4. Empyema: The pleural effusion of exudative pleurisy, if not treated in time, can gradually be cheeseified or even become purulent, becoming tuberculous empyema. It is the result of the progression of cardiovascular and cavitary lung tuberculosis infection, often occurring after pneumothorax, accompanied by failure and loss of resistance to infection.

5. Pulmonary aspergillosis: common in tuberculosis. Hemoptysis is the leading cause of death in this disease.

6. Chronic pulmonary heart disease: severe pulmonary tuberculosis caused by extensive destruction of lung tissue. Chronic fibrovascular tuberculosis or one-sided lung damage, complicated by emphysema, bullous bullae, can cause spontaneous pneumothorax, can also lead to chronic heart disease, and even cardiopulmonary failure. In the primary infection, tuberculosis is distributed along with the blood, and is lurking in other organs. Once the human immunity is extremely weak, tuberculosis of the organ can be produced, and lymph nodes, meninges, bones, and genitourinary tuberculosis are common. AIDS is prone to secondary tuberculosis or non-tuberculous mycobacterial infections. In some developed countries, the tuberculosis epidemic has been significantly reduced, but due to the AIDS epidemic, Pneumocystis carinii, cytomegalovirus infection and tuberculosis patients have increased. In developing countries, the main complication of human immunodeficiency virus (HIV) infection and AIDS patients is tuberculosis infection, which is common in the old obsolete tuberculosis (endogenous recurrence). At the same time, suffering from tuberculosis and AIDS, its diagnosis is difficult, the curative effect is poor, and the mortality rate is high.

Acute hematogenous disseminated pulmonary tuberculosis symptoms in children Common symptoms: fatigue, night sweats, weight loss, fever, cough, and sputum... Mycobacterium tuberculosis blood line disseminated, heat retention, relaxation, heat, difference, drape, heart bloating

Acute hematogenous disseminated pulmonary tuberculosis is a sepsis caused by tuberculosis. It has an acute onset and often has obvious symptoms of tuberculosis. Often for high fever, heat retention or relaxation heat type, some patients have night sweats, weight loss, fatigue, anorexia, general malaise, respiratory symptoms often cough, cough, some patients have hemoptysis, chest pain and other performance. Gastrointestinal symptoms are anorexia, bloating, diarrhea, constipation, etc. In addition, female patients still have amenorrhea and other manifestations. When combined with tuberculous meningitis, there are symptoms of high intracranial pressure and meningeal irritation such as headache and vomiting. In severe cases, there may be changes in sleepiness such as lethargy and coma. Chronic or subacute hematogenous disseminated pulmonary tuberculosis has a slow onset and prolonged course. Clinical symptoms can show fever, night sweats, fatigue, tuberculosis symptoms are more acute, respiratory symptoms may be more obvious.

Examination of acute hematogenous disseminated pulmonary tuberculosis in children

(1) X-ray chest radiograph: early diffuse mesh-like shadow, small nodular shadows appear after two weeks of onset, the size and shape are basically the same, the two lungs are widely distributed, most of the acute hematogenous disseminated pulmonary tuberculosis is typical of "three Uniform, that is, miliary nodules of uniform size, density, and distribution, partially accompanied by patchy, strip-like, and/or hollow shadows.

(2) Pulmonary CT: Acute hematogenous disseminated pulmonary tuberculosis is characterized by miliary nodules of 1-3 mm in diameter, density and uniform distribution, while subacute and chronic patients exhibit 3-7 mm in size and density mainly in the upper lung field. And unevenly distributed nodules. The boundaries of the nodules are mostly clear, but there are also blurred boundaries; the nodules are randomly distributed in the lobules, interlobular septa, and subpleural. In some patients, CT showed patchy, fibrous cord-like and/or hollow shadows, with mediastinal and/or hilar lymphadenopathy, with varying degrees of pleural effusion or pleural thickening.

(3) Sputum tuberculosis smear or culture: sputum smear or culture positive is the gold standard for the diagnosis of tuberculosis. However, the positive rate of sputum in blood-borne disseminated tuberculosis is only about 30%. Moreover, the positive bacteria are affected by many factors, such as improper selection of sputum specimens, fewer sputum examinations, intermittent bacterial drainage, and drainage bronchial obstruction. Fiberoptic bronchoscopy can directly scan or biopsy from the surrounding lesions, thus improving the basis of bacteriological diagnosis.

(4) The lignin test: it is an auxiliary diagnostic method in the comprehensive diagnosis of tuberculosis. Patients with strong positive reactions within 3 years of age should be considered as active tuberculosis with newly infected. In addition to no tuberculosis infection, the negative test of the nodule test should consider the following situation: It takes 4-8 weeks after the tuberculosis infection to establish a sufficient allergic reaction, and the test may be negative before the allergic reaction occurs. The use of immunosuppressive drugs such as glucocorticoids, or malnutrition, etc., can also temporarily disappear. Severe tuberculosis and various critically ill patients do not respond to the nodules, or only weakly positive, and are related to the temporary suppression of human immunity and allergic reactions. When the condition improves, it can be converted into a positive reaction. Other factors such as lymphocyte immune system defects (such as septicemia, lymphoma, sarcoidosis, AIDS, etc.) are also often negative for the former or elderly.

(V) IFN- release assay in vitro: Mycobacterium tuberculosis can activate the body's immune system after infection, producing effector T lymphocytes and memory T lymphocytes against M. tuberculosis, when these specific T lymphocytes are again When encountering M. tuberculosis antigen, it can be activated to secrete cytokines (such as IFN-). Therefore, detection of IFN- in whole blood or body fluids of patients after stimulation with specific antigens contributes to the diagnosis of sputum tuberculosis.

(6) Other tests: including blood routine, Mycobacterium tuberculosis TaqMan-PCR, PPD skin test, anti-tuberculosis antibody, erythrocyte sedimentation rate, etc., have certain reference significance for diagnosis.

Diagnosis and diagnosis of acute hematogenous disseminated pulmonary tuberculosis in children

1. Susceptible population: Patients with low immune function such as diabetes, connective tissue disease, childbirth, long-term use of hormones or anticancer drugs, organ transplantation and other patients have predisposing factors.

2. Clinical manifestations of tuberculosis, chills, high fever, night sweats, weakness, respiratory symptoms and signs.

3. Some patients have manifestations of meningeal irritation, hepatosplenomegaly, and leukemia-like reactions.

4.x chest radiographs show typical miliary shadows in both lungs. Thoracic CT acute hematogenous disseminated pulmonary tuberculosis is characterized by miliary nodules of 1-3 mm in diameter, density and uniform distribution; while subacute and chronic patients exhibit 3-7 mm size, density and uneven distribution of the above-mentioned lung fields. Nodule. The boundaries of the nodules are mostly clear, but there are also blurred boundaries; the nodules are randomly distributed in the lobules, interlobular septa, and subpleural.

5. Mycobacterium tuberculosis is still the gold standard for diagnosis, but the positive rate of sputum is not high. For sputum negative patients combined with erythrocyte sedimentation, blood image changes, blood IFN- in vitro release test, TB-PCR, TB-Ab, LAMIgG, PPDIgG and other immunological examination, fiberoptic bronchoscopy (brushing, clamping, lavage) Biopsy includes lymph node biopsy, fiberoptic bronchoscopy lung biopsy, liver and bone marrow biopsy, and diagnostic anti-tuberculosis treatment reactions that are clinically diagnosable.

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