Infiltrating pulmonary tuberculosis

Introduction to invasive tuberculosis Invasive pulmonary tuberculosis: more common exogenous secondary tuberculosis, that is, caused by repeated tuberculosis infection. A few are tuberculosis bacteria that are latent in the body. When the body's resistance declines, it is propagated, and it is caused by endogenous tuberculosis, and it is also formed by the primary lesion. This type is more common in adults. The lesions are mostly above and below the clavicle. They are flaky or flocculent, and the boundary is blurred. The lesion can be a caseous necrosis, which causes heavier toxic symptoms and becomes a cheeseous (tuberculous) pneumonia. After being wrapped by fiber, it forms a tuberculosis ball. After appropriate treatment of the lesions, the absorption of inflammation is dissipated, leaving a small cheese stove, residual small nodular lesions after calcification, showing fibrous induration lesions or clinical healing. Those who have empty holes can also be reduced or closed by treatment absorption, and there are no closed or no viable bacteria, which is called "open cavity healing." basic knowledge The proportion of illness: 0.10% Susceptible people: no specific population Mode of infection: droplet spread Complications: pneumothorax

Invasive pulmonary tuberculosis

Most of the tuberculosis bacteria that are latent in the lungs are gradually dying when the primary infection is transmitted by blood (hidden bacteremia). Only when the body's immunity is reduced, the combination of latent in the lesion begins to have the opportunity to multiply and form with exudation and A cell-like infiltrate with a different degree of cheese-like lesions called infiltrating tuberculosis (endogenous infection). The primary lesion may also progress directly to infiltrating pulmonary tuberculosis.

In addition, close contact with patients with TB tuberculosis, repeated respiratory infections, but also due to reinfection and invasive pulmonary tuberculosis (exogenous infection), but less common, and no bacteremia. Invasive and multi-adult patients, slow onset, early and small lesions, often no obvious symptoms and signs, often by health check or other reasons for chest X-ray examination. Clinical symptoms depend on the extent of the lesion and the reactivity of the human body. Most of the lesions were above and below the clavicle, and the X-ray showed flaky, floc-like shadows with blurred edges. When the human body is in an allergic state, and a large number of bound bacteria enter the lungs, the lesions are necrotic and liquefied, and then the bronchial spread of the cavity and the lesion is formed.

Invasive pulmonary tuberculosis with large caseous necrotic foci, often acute progression, severe toxicity symptoms, clinically known as cheese-like (or tuberculous) pneumonia. After the cheese-like necrotic area is partially dissipated, a fibrous envelope is formed around it; or the drainage bronchus of the cavity is blocked, and the cheese in the cavity is difficult to be discharged, and it is condensed into a spherical lesion, which is called "tuberculosis ball".

When the lesion is in the stage of inflammatory exudation, cell infiltration, and even caseous necrosis, after appropriate anti-tuberculosis chemotherapy, the inflammation absorption dissipates, leaving a small cheese-like lesion surrounded by fibers, gradually water-drying, and even calcification, becoming a residual knot. A nodular lesion, called a fiber induration lesion or clinical recovery. Effective chemotherapeutic treatment can make the cavity shrink and close, or the hollow tissue defect still exists, and the tuberculosis bacteria in it are nearly completely eliminated, which is called "open cavity healing."

Invasive pulmonary tuberculosis prevention

1. Vaccination with BCG

BCG should be vaccinated in uninfected persons such as neonates, recruits and new trainees with negative serotonin test, young workers in new TB medical units, and adolescents undergoing kidney transplantation.

2, chemoprevention

Selective chemoprevention of infected persons is as follows:

(1) Close contacts of patients with bacteriucin, such as children with positive serotonin test (no BCG), strong positive adolescents.

(2) The children and adolescents were tested positively, and the adult sputum test was strongly positive.

(3) Inactive tuberculosis is one of the following:

1 long-term large amount of glucocorticoids, immunosuppressants, cytotoxic drugs.

2 radiation therapy.

3 before and after gastrectomy.

4 recruits, new students, strong test positive.

5 tuberculosis and HIV double infection, AIDS patients with positive test.

6 Kidney transplant recipients have tuberculosis, or have inactive tuberculosis.

7 diabetes combined with inactive tuberculosis.

8 patients with silicosis (silicosis) who were positive for the test.

For chemoprevention, the isoniazid adult is 0.3g/d, the child is 6-8mg/(ks·d), and the treatment lasts for 6 months.

3. Eliminate the source of infection

Sputum smear positive (smear positive) tuberculosis is the main source of infection, eliminating the source of infection is the fundamental countermeasure to control tuberculosis. The initial treatment of smear-positive pulmonary tuberculosis and re-treatment of smear-positive pulmonary tuberculosis is the main target of chemotherapy.

Invasive pulmonary tuberculosis complications Complications

1, pneumothorax

When the lung cavity and 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

Repeated progression and fibrosis of tuberculosis lesions, 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 be gradually cheeseified or even 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 tuberculosis causes 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.

Invasive pulmonary tuberculosis symptoms common symptoms thin hemoptysis with cough and phlegm, low heat, fatigue, sepsis, signs of difficulty breathing

1, pay attention to the inquiry

(1) With or without fever, night sweats, loss of appetite, weight loss, cough, cough, blood stasis or hemoptysis, chest pain, difficulty breathing. Female patients have menstrual disorders or amenorrhea.

(2) Ask about the length of the disease, the onset time, X-ray lesions, sputum examination, diagnosis, treatment medication and program, course of treatment, efficacy, drug side effects.

2, physical examination

Note whether the superficial lymph nodes are swollen or not, and there is no BCG scar on the left upper arm. Whether there is abnormality in the chest, other systems have signs of tuberculosis complications.

Invasive tuberculosis examination

Tuberculosis test

It is the most specific method for the diagnosis of tuberculosis, and tuberculosis is the main basis for the diagnosis of tuberculosis. The smear anti-acid staining microscopy is quick and simple. It is rare in China for atypical mycobacteria. Therefore, acid-fast bacilli should be used, and the diagnosis of tuberculosis can basically be established. The direct smear positive rate is better than the thin smear, which is commonly used at present. Fluorescence microscopy is suitable for rapid inspection of a large number of specimens. Innocent or children will not cough, use morning stomach wash to find tuberculosis, admit that you can also go through the fiber bronchoscope, or find tuberculosis from its sputum juice China. Positive sputum indicates that the lesion is open and contagious.

If the amount of bacteria is more than 100,000 per ml, the direct smear is easy to be positive, and the social infection originates from the small amount of sputum bacteria (less than 10,000 per ml). The culture method is more precise, in addition to understanding the growth and reproduction ability of tuberculosis, and can be used for drug sensitivity test and bacterial type identification. Tuberculosis grows slowly, using modified Roche medium, which usually takes 4-8 weeks to report. Although it is time-consuming, it is accurate and reliable, and its specificity is high. If the smear is negative or the diagnosis is doubtful, the culture is especially important. The culture strain is further used for drug sensitivity determination, which can provide reference for treatment, especially for re-treatment. The specimens were amplified in vitro by polymerase chain reaction (PCR) method, and the microtuberculosis DNA contained in the tube was amplified and detected by electrophoresis. One tuberculosis contains about 1fg of DNA, and 40 tuberculosis bacteria have positive results. The method does not need to be pre-cultured in vitro, has strong specificity, can be reported in 2 days, is fast, simple, and can identify the type of bacteria. The disadvantage is that false positive or false negative may occur.

Film degree exam

Chest X-ray examination can find the location and extent of lesions in the lungs, whether there are holes or voids, and the thickness of the walls. X-rays have different degrees of permeability to various types of tuberculosis lesions. X-ray examination can roughly estimate the pathological nature of tuberculosis lesions, and can detect tuberculosis early, as well as determine the development of the disease and the therapeutic effect, and help determine the treatment plan. It must be pointed out that the lung lesions caused by different causes may present similar X-ray images, so the diagnosis of tuberculosis cannot be easily determined by X-ray examination alone. X-ray film combined with fluoroscopy can improve the accuracy of diagnosis, and can find ribs, mediastinum, diaphragm or cell lesions covered by the heart, and can observe the dynamics of heart, lung and diaphragm.

X-ray findings of tuberculosis include: indurated lesions of fibrous calcification, characterized by high density, sharply defined spots, strips or nodules; invasive lesions, characterized by a cloud-like shadow with a denser density and blurred edges; cheese-like lesions It is characterized by high density, varying shades, and voids with a circular boundary light-transmissive area. Tuberculosis lesions are usually in the upper, unilateral or bilateral sides of the lungs, contributing to longer periods of time, and there are mixed lesions of various natures and signs of intrapulmonary dissemination.

Exudative or exudative proliferative lesions, caseous pneumonia, cheese-like lesions, and cavities (except for purifying cavities) on X-ray films indicate active lesions; proliferative lesions, tightly packed cheese hard knots And fibrous calcification, etc., are inactive lesions. Tuberculosis can still be found in the sputum of active lesions. Because tuberculosis lesions are mostly mixed, activity should still be considered when full proliferation or fiber calcification is not achieved. CT examination of the lungs is helpful for finding small or insidious lesions, understanding the extent of the lesion and identifying the lesions of the lung.

Tuberculin test

The tuberculin test (abbreviated as a nodule) test is a reference indicator for the diagnosis of tuberculosis infection.

Old knot (OT) is a metabolite of tuberculosis, which is made from tuberculosis bacteria grown in liquid culture and contains mainly tuberculosis proteins. The OT antigen is impure and may cause a non-specific reaction. For census in the crowd, 0.1:50 (51U) of OT dilution of 1:2000 can be used for intradermal injection on the flexion of the left forearm. The diameter of the skin induration is measured after 48-72 hours. If it is less than 5mm, it is negative, 5-9mm. It is weakly positive (indicating tuberculosis or Mycobacterium tuberculosis infection), 10-19mm is a positive reaction, and more than 20mm or localized blisters and necrosis are strongly positive reactions.

The pure protein derivative (PPD) of the nodule is refined from the tuberculosis protein extracted from the old knot filtrate, which is a pure knot and does not produce a non-specific reaction. The commonly used PPD-RT23 in the world has replaced OT. China has made PPD (PPD-C) from human tuberculosis and BCG-PPD from BCG. It has good purity and has been widely used in clinical diagnosis. Intradermal injection of 0.1ml (5IU) induration with an average diameter of 5bm is positive. reaction. The sputum test can cause a systemic reaction in addition to causing a local skin reaction. The clinical diagnosis usually uses 51U. If there is no response, 5IU can be used after one week (the effect of enhancing the production of the nodule). If it is still negative, the tuberculosis infection can be roughly excluded.

The lignin test is still one of the commonly used methods in the comprehensive diagnosis of tuberculosis, which helps to determine whether there is tuberculosis infection. If it is strongly positive, it is often expressed as active tuberculosis. The diagnostic value of the sputum test for infants and young children is greater than that of adults. The younger the age, the lower the infection rate. The strong positive responders under 3 years old should be regarded as newly infected active tuberculosis, and it is necessary to treat them. If the sputum reaction increases from <10 mm to more than 100 mm within 2 years and increases by 6 mm or more, a new infection can be considered. In the case of a negative test of the nodule test, in addition to the absence of tuberculosis infection, the following should be considered.

It takes 4-8 weeks after tuberculosis infection to establish a sufficient allergy, and the lignin test can be negative before the allergic reaction occurs. The use of immunosuppressive drugs such as glucocorticoids, or malnutrition, measles, whooping cough, 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.

Other inspection

The blood picture of tuberculosis patients usually does not change, and severe pathology often has secondary anemia. Acute miliary tuberculosis has a decrease in the total number of white blood cells or a leukemia-like reaction. Increased blood is common in active tuberculosis, but it has no specific diagnostic value. Normal erythrocyte sedimentation cannot exclude active tuberculosis. When the patient is innocent or sputum negative and needs to be differentiated from other diseases, the specific antibody in the serum of the patient is detected by enzyme-linked immunosorbent assay (ELISA), which may provide a reference for the diagnosis of extrapulmonary tuberculosis. Fiberoptic bronchoscopy has important diagnostic value for the discovery of endobronchial tuberculosis, understanding of tumors, secretions, unblocking or pathogens and exfoliated cells, and biopsy. Superficial lymph node biopsy helps differential diagnosis of tuberculosis.

In recent years, molecular biology and genetic engineering techniques have been applied to detect and identify tuberculosis bacteria in clinical specimens by non-culture methods, and to demonstrate their sensitivity, rapidity, and specificity, such as accounting probes and chromosome fingerprinting.

Diagnostic identification of invasive pulmonary tuberculosis

Differential diagnosis

First, lung cancer

Central type of lung cancer often has blood in the sputum, with shadows near the hilar, similar to hilar lymph node tuberculosis. Peripheral lung cancer can be spherical, lobulated, and need to be differentiated from tuberculosis. Lung cancer is more common in tobacco over 40 years old. Men often have no obvious toxic symptoms, more irritating cough, chest pain and progressive weight loss. X-ray chest radiograph shows satellite lesions around the tuberculosis ball, calcification, and the edge of the cancer lesion often has notch, burr, chest CT scan It is often helpful to identify the two. In the central type of lung cancer, the CT findings of the bronchial soft tissue density are attached to one side to thicken the bronchial wall, the contour of the mass is irregular, the lung segment and the lobes of the lung are irregularly narrow, and the mediastinal lymph nodes are enlarged. Combined with tubercle bacillus, exfoliated cell examination and fiberoptic bronchoscopy and biopsy, etc., can often identify in time, lung cancer and tuberculosis coexist, also need to pay attention to find that it is difficult to completely eliminate lung cancer in clinical, combined with specific circumstances, if necessary Consider a thoracotomy to avoid delays in treatment.

Second, pneumonia

Typical pneumococcal pneumonia is indistinguishable from invasive pulmonary tuberculosis, and infiltrating pulmonary tuberculosis, which progresses faster, expands into the entire lobe, forming caseous pneumonia, which is easily misdiagnosed as pneumococcal pneumonia. The former has a rapid onset, high fever, chills, chest pain. With urgency, cough and rust, sputum X-ray signs are often limited to one leaf, antibiotic treatment is effective, caseous pneumonia is more symptoms of tuberculosis, slow onset, cough yellow mucus, X-ray signs are located in the upper right lobe It can affect the tip of the right upper lobe, and the posterior segment is cloud-like, with uneven density. It can appear as a worm-like cavity. It is effective for anti-tuberculosis treatment, and it is easy to find tuberculosis.

Symptoms of inflammation on the X-ray with mild cough, hypothermia mycoplasma pneumonia, viral pneumonia or hypersensitivity pneumonitis (eosinophilic pulmonary infiltrates), similar to early invasive pulmonary tuberculosis, for such cases that are difficult to identify at one time, Should not be eager to anti-tuberculosis treatment, mycoplasmal pneumonia usually in a short period of time (2 to 3 weeks) can easily dispel the allergic pneumonia in the lung infiltration shadow is often migratory, blood eosinophilia.

Third, lung abscess

Lung abscess cavity is more common in the lower lobe of the lung. The inflammation around the abscess is more serious. There is often a fluid level in the cavity. The tuberculosis cavity occurs mostly in the upper lobe of the lung. The cavity wall is thin, and there are few liquid levels in the hole. Lung abscess is more acute, high fever, a lot of purulent sputum, no tuberculosis in the sputum, but there are many other bacteria, the total number of white blood cells and neutrophils, antibiotic treatment is effective, chronic fibrovascular tuberculosis combined with infection Confused with chronic lung abscess, the latter is negative for tuberculosis.

Fourth, bronchiectasis

Chronic cough, sputum and repeated hemoptysis need to be differentiated from chronic fibroblastic tuberculosis, but bronchiectasis is negative for tuberculosis, no abnormalities in X-ray chest radiographs or only local lung texture thickening or curling shadows, CT Help to confirm the diagnosis.

Fifth, chronic bronchitis

The symptoms of chronic bronchitis in the elderly are similar to those of chronic fibrovascular tuberculosis. In recent years, the incidence of tuberculosis in the elderly has increased. It is necessary to carefully identify the two, and timely X-ray examination can help to confirm the diagnosis.

Sixth, other febrile diseases

Various types of tuberculosis often have different types of fever, so tuberculosis is often one of the main causes of clinical fever. Unexplained typhoid fever, sepsis, leukemia, mediastinal lymphoma and sarcoidosis are similar to tuberculosis. Typhoid fever has high fever and blood. Decreased white blood cell count and liver and spleen in clinical manifestations, easy to be confused with acute miliary tuberculosis, but typhoid fever type is often missed fever, relatively slow pulse, skin rose rash, serum typhoid agglutination test positive, blood, fecal typhoid culture positive Septicemia onset, chills and relaxation heat, white blood cells and neutrophils, often have recent skin infections, history of squeezing or urinary tract, history of biliary tract infection, common skin defects, near the course of the disease Migratory lesions or septic shock, blood or bone marrow culture can be found in pathogenic bacteria, acute miliary tuberculosis has fever, hepatosplenomegaly, specific X-ray manifestations appear several weeks after onset, occasionally bloody leukemia-like reactions or monocytes Abnormal increase, need to be differentiated from leukemia, the latter has obvious bleeding tendency, bone marrow smear and dynamic X-ray chest radiograph follow-up can help establish diagnosis, adult Tracheal lymphadenopathy often manifests as fever and hilar lymphadenopathy, and should be differentiated from sarcoidosis, mediastinal lymphoma, tuberculosis patients with positive test, anti-tuberculosis treatment and lymphoma development, often liver and spleen and superficial Lymph node enlargement, diagnosis often depends on biopsy, sarcoidosis usually does not fever, hilar lymphadenopathy is mostly bilateral, nodules test negative, glucocorticoid therapy is effective, if necessary, biopsy should be performed to confirm the diagnosis.

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