Secondary pulmonary tuberculosis

Introduction to secondary tuberculosis Secondary tuberculosis is type III tuberculosis, including invasive tuberculosis and chronic fibrovascular tuberculosis in the 1978 tuberculosis classification. M. tuberculosis (hereinafter referred to as tuberculosis) re-propagation of M. tuberculosis in the latent lesions in the body after the initial infection (mostly in childhood), causing re-ignition of the lesion as the main cause of the disease (called endogenous recurrence). It can also be caused by infection with external M. tuberculosis (called exogenous heavy staining). This type can occur at any age after the primary infection, is more common in adults, and is the most common type of adult tuberculosis. Secondary pulmonary tuberculosis distinguishes between exudative pulmonary tuberculosis, proliferative tuberculosis, fibrinous tuberculosis, caseous pneumonia, cavitary tuberculosis, tuberculoma (tumor), chronic fibrovascular tuberculosis, and other pathological and X-ray features. The morphology of secondary pulmonary tuberculosis is rarely single, often multiple forms coexist, mainly one. Due to the implementation of powerful and high-efficiency chemotherapy, pathological and X-ray morphological differentiation is of little significance for treatment, but it still helps the differential diagnosis. Secondary tuberculosis is prone to forminous necrosis and cavities, and there are more bacteria in the epidemiology. basic knowledge The proportion of sickness: 0.01%-0.018% Susceptible people: multiple adults Mode of infection: droplet spread Complications: hemoptysis, spontaneous pneumothorax, respiratory failure, atelectasis

Secondary pulmonary tuberculosis

Cause

1. Endogenous recurrence:

It is the main cause of secondary tuberculosis. Latent lesions are formed in the lungs and outside due to early bacteremia. When the body's resistance is reduced, the recessive tuberculosis lesions can recur and form secondary tuberculosis.

2. Exogenous reinfection:

I have been infected with tuberculosis, and this disease is not a reactivation of the original lesion, but is again infected by tuberculosis.

Pathophysiology

The type of lesion caused by tuberculosis in the body is specific, and its pathological changes are often determined by the state of the body, the intensity of allergic reaction, the local tissue characteristics and the virulence of the pathogen. Tuberculosis is a chronic inflammation with three basic pathological changes: exudation, proliferation and metamorphism. Exudative lesions indicate a large amount of bacterial tissue, strong virulence, strong allergic reaction or pathological changes in the acute development stage. At this time, the vascular permeability of the tissues and organs is increased, and the inflammatory cells and proteins are exuded to the extravascular vessels. In the exudative lesions, a large number of lymphocyte heaps are integrated with lymph node nodules, and tubercle bacilli can be found in the exudate lesions.

Secondary tuberculosis prevention

1. Control the source of infection

Timely discovery and treatment.

2, cut off the route of transmission

Pay attention to window ventilation and pay attention to disinfection.

3. Protect susceptible populations

Inoculate BCG, pay attention to exercise and improve your resistance.

Secondary pulmonary tuberculosis complications Complications, hemoptysis, spontaneous pneumothorax, respiratory failure, atelectasis

1, hemoptysis: when the pulmonary tuberculosis lesions progress, erosive blood may occur when eroding neighboring blood vessels, the amount of blood is different due to the size of the blood vessels involved, the arteries, veins, or capillaries; cavity lesions are more prone to hemoptysis. Older lung lesions can also cause hemoptysis due to secondary bronchiectasis or calcification shedding, traction of the traction foci of the fiber foci.

2, spontaneous pneumothorax: tuberculosis disease lung surface cavity and necrotic tissue can directly break into the pleural cavity, causing spontaneous pneumothorax. Spontaneous pneumothorax can also be produced due to rupture of the bullous bullae.

3, respiratory failure: when the lung lesions are extensive, such as fibrous thick-walled cavities with bronchial dissemination, large pleural thickening, residual lung emphysema emphysema or total pulmonary atelectasis may have difficulty breathing. Most patients present with chronic dyspnea.

4. Secondary bacterial infection in the lung: refers to bacterial or other pathogen infection that occurs on the basis of bronchial-pulmonary structural damage caused by tuberculosis. Tuberculosis, especially in patients with severe tuberculosis, is prone to nosocomial infections due to prolonged hospitalization or combined with respiratory failure in the intensive care unit for certain special treatments such as inhalation therapy and mechanical ventilation. Impaired immunity of the body caused by tuberculosis itself may be a predisposing factor for secondary infection.

5, atelectasis: bronchial lymph node tuberculosis, tracheal, bronchial tuberculosis (including endobronchial congestion, edema, granuloma formation and scar stenosis) can cause atelectasis.

Symptoms of secondary tuberculosis Common symptoms Cough fatigue, cough, weight loss, night sweats, unexplained fever, hemoptysis, hemoptysis, hemoptysis, chest pain, menstrual cycle changes

symptom:

Most patients have symptoms such as fever, cough, and cough. A small number of patients may be asymptomatic or have only mild symptoms, which are found during health checkups.

1, slow onset, cough, cough, may be accompanied by hemoptysis, chest pain, difficulty breathing and other symptoms.

2, fever (low fever after noon), cheese pneumonia, the onset is often sharp, can be high fever at the beginning, after the relaxation of heat with severe tuberculosis symptoms, may be associated with night sweats, fatigue, loss of appetite, weight loss, menstrual disorders.

3, a small number of patients may have allergic manifestations caused by tuberculosis allergies: nodular erythema, herpetic conjunctivitis and tuberculosis rheumatism.

4. Patients with diabetes, pneumoconiosis, major gastrectomy, chronic renal failure, organ transplantation and bone marrow transplantation, long-term treatment with corticosteroids or immunosuppressants should be alert to the presence of tuberculosis, and the incidence of tuberculosis in HIV-infected patients is high.

Signs:

Long-term chronic consumption can be malnourished and anemia; chest-positive signs vary greatly depending on the size, extent, and complications of lung lesions. When the lung lesions are more extensive, there may be corresponding signs, such as local turbidity, and the local lesions can be heard and bronchoalveolar breath sounds. A large area of infiltrating lesions, caseous pneumonia, and atelectasis can smell tubular breath sounds. The limited small and medium vesicles often indicate that there are holes or concomitant expansion, and the empty breath sounds suggest that there are huge holes.

Secondary tuberculosis examination

First, laboratory inspection

1. Pathogen examination: Positive bacteriological examination is the basis for diagnosis.

2, tuberculin (PPD-G 5U) skin test is an important means to determine whether the body is infected with M. tuberculosis. When the strong positive indicates that the body is in a state of oversensitivity, the incidence is high, which can be used as a reference indicator for clinical diagnosis of tuberculosis.

3. Molecular biological diagnostic methods such as polymerase chain reaction (PCR).

4, serum anti-tuberculosis antibody test.

Second, imaging examination

1, X-ray inspection

X-ray imaging has important reference significance for the diagnosis of tuberculosis.

2, chest CT

Chest CT scans found hidden lesions of the common chest radiograph (pulmonary tip, lung base, posterior, bilateral lung and other lung lesions), understanding the hilar and mediastinal lymphadenopathy and finding a small amount of pleural effusion and a small amount of pneumothorax Important value; enhanced CT can observe the density enhancement of selected parts through different phases, which is helpful for the diagnosis and differential diagnosis of diseases.

Third, bronchoscopy

Fiberoptic bronchoscopy is an important means of diagnosis and identification of respiratory diseases: cases with negative sputum and atypical chest X-ray findings, difficult diagnosis, or suspected bronchial tuberculosis and cases where lung cancer or other malignant lesions cannot be excluded Fiberoptic bronchoscopy examination of brush, lavage fluid, bronchial biopsy, etc.

Diagnosis and diagnosis of secondary pulmonary tuberculosis

diagnosis

1. The patient's medical history and clinical manifestations are still the basis of diagnosis. The medical history should pay attention to the history of tuberculosis exposure, whether there are general symptoms of tuberculosis poisoning and respiratory symptoms that are unhealed. For patients with susceptibility to tuberculosis, such as: the use of immunosuppressive agents, diabetes, silicon deposition, chronic renal failure, major gastrectomy, organ transplantation, should be more vigilant.

2, pathogen examination: tuberculosis test is a specific method for diagnosis, multiple sputum smear is a common method for diagnosis of tuberculosis, but non-tuberculous mycobacterial lung disease its clinical symptoms, X-ray findings and secondary tuberculosis is difficult Differentiate, conditional should be sent to the sputum sputum culture at the same time as sputum smear examination for further strain identification.

3, chest X-ray examination is a necessary means of diagnosis of tuberculosis, secondary tuberculosis chest X-ray showed a variety of mixed forms, often cloud-like or spotted (spotted) nodular, dry lesion density High and uneven, often with translucent areas or voids. The prolongation of the disease can occur at the same time as fibrosis or calcification. The combination of the posterior segment of the upper tip or the dorsal segment of the inferior segment and the X-ray features can provide an important reference for diagnosis.

4, other tests PPD skin test strong positive, serum anti-tuberculosis antibody positive, patient TB tuberculosis DNA PCR ten probe test positive, can be used as a diagnostic reference.

Differential diagnosis

X-ray findings of secondary pulmonary tuberculosis often show multiple forms. When the main manifestations of the lungs are exudative lesions, attention should be paid to the identification of various bacterial and non-bacterial pneumonias. The incidence of streptococcal pneumonia is rapid, the chills are hot, the uniformity of the lungs or lungs is flaky, and the density is light. The transparent area changes rapidly, the white blood cell count increases, and antibiotic treatment is effective. Pulmonary tuberculosis cavity has more inflammatory infiltration around it, or it should be differentiated from lung abscess when there is liquid level. Lung abscess is often acutely ill, showing chills and high fever, a lot of pus sputum, white blood cells increase, and there are often thick inflammation shadows around the cavity. There is a liquid level in the cavity. Thin-walled cavities need to be differentiated from pulmonary cysts and cystic bronchiectasis, and the wall of the chest radiograph is thin and neat. Bronchiectasis can be seen in irregular ring-shaped translucent shadows or brooch-like curls. When the inner wall of cheese cavity is not smooth, it should be differentiated from lung cancer cavity. Nodular tuberculosis, tuberculosis, and atelectasis caused by obstruction of bronchial tuberculosis should be Take care to rule out lung cancer. In order to observe the shape, edge and peripheral burrs of the mass, there were no vacuoles in the nodule. Pulmonary hilar, mediastinal lymphadenopathy and bronchoconstriction, chest radiography and chest CT are often helpful in the identification of lung cancer. Tumor cell examination. Fiberoptic bronchoscopy and lung biopsy are important means of diagnosis. Non-tuberculous mycobacterial lung disease is similar to tuberculosis in clinical symptoms and X-ray findings, and the smear-resistant acid-staining morphology is also difficult to distinguish, and can only be identified based on the identification of strains after culture.

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