Pediatric right middle lobe syndrome

　　1. Etiology

　　This condition is not caused by a single factor. Any inflammatory lesion that can cause enlargement of the hilum lymph nodes, compression of the middle lobe of the right lung or the lingular lobe of the left lung bronchus can lead to pneumonia and atelectasis. The etiology of this condition can be nonspecific pneumonia and lymphadenitis, which cause enlargement of the surrounding lymph nodes, blockage of the bronchus, and atelectasis of the middle lobe, or inflammation of the middle lobe itself. In severe cases, it can involve the pleura. Conditions such as bronchial lymphatic tuberculosis and sarcoidosis can also cause this condition. Some scholars propose that bronchial foreign bodies or tumors are not included in this syndrome. In summary, the etiology of middle lobe syndrome can be categorized into three types: tuberculosis (such as primary pulmonary tuberculosis), inflammatory lesions of the middle lobe of the right lung, and others (histoplasmosis, sarcoidosis, etc.). Middle lobe syndrome in children often accompanies asthma, especially during persistent asthma attacks, which may be related to a lack of pulmonary alveolar surface tension factors, the cause of which may be related to changes in pH and oxygen tension, but this requires further confirmation. Middle lobe syndrome in children may be related to genetic factors, as Hartl reported that in a family of five children, three were affected by middle lobe syndrome. Dees reported that in 30 cases of pediatric middle lobe syndrome, there were 9 male and 21 female patients, which is different from the case where more boys than girls are affected by asthma; at the same time, one case of middle lobe syndrome appeared two weeks after birth, and her sister also had difficulty breathing and wheezing in the first month after birth. Examination showed that both sisters had IgA deficiency, thus considering the possibility of genetic factors.

　　2. Pathogenesis

　　1. Anatomical Characteristics

　　The middle lobe of the right lung is prone to atelectasis due to the relatively slender and long bronchus of the middle lobe compared to other bronchi, with its opening located at the junction of the upper and lower lobe pulmonary lymphatic drainage, surrounded by lymph nodes. Therefore, it is susceptible to compression and erosion by enlarged lymph nodes, leading to stenosis and obstruction. The middle lobe bronchus is not only slender and long but also intersects with the right main bronchus at a sharp angle, making it difficult for drainage and prone to obstruction by congenital secretions and mucosal edema. Additionally, due to its smaller size and location between the upper and lower lobes, the middle lobe has relative independence anatomically, but lacks collateral ventilation, making it more prone to atelectasis.

　　2. Inflammation

　　In children with primary pulmonary tuberculosis, enlarged lymph nodes compress the middle lobe bronchus, causing middle lobe syndrome. In addition, enlarged lymph nodes may corrode the bronchus, causing bronchopleural fistula. Caseous tissue and granulation tissue may block the middle lobe bronchus, causing middle lobe syndrome. The syndrome is caused by inflammatory lesions in the right middle lobe itself, where the mucosal inflammation and edema narrow the lumen, filling it with mucus, leukocytes, and debris, obstructing bronchial drainage. The surrounding lymph nodes of the drained bronchus may swell, compressing the bronchus and making obstruction more likely. Obstruction further aggravates infection, causing the lymph nodes to become more enlarged, forming a vicious cycle. Dees reported that in 30 cases of right middle lobe syndrome, 23 cases showed a specific reactive constitution, and laboratory examination results also suggested the presence of infection.

　　3. Pathological staging

　　(1) First stage (atelectasis stage): During this stage, there are symptoms of acute lymphadenitis and middle lobe atelectasis, but there are no symptoms of obstructive pneumonia.

　　(2) Second stage (obstructive pneumonia stage): There is obstructive pneumonia, which forms the initial clinical symptoms of this syndrome. During this period, the X-ray findings are difficult to differentiate from those of general pneumonia.

　　(3) Third stage (recovery or progression stage): If treated properly, the lymph nodes shrink, the drainage is unobstructed, inflammation subsides, obstruction disappears, and atelectasis opens up. If not treated properly, persistent obstruction and recurrent pulmonary parenchymal inflammation may lead to bronchiectasis and chronic fibrosis of lung tissue, and even form lung abscess or empyema.

　　Recurrent pneumonia or wheezing bronchitis in children can lead to bronchiectasis, chronic fibrosis of lung tissue, and even form lung abscess or empyema; it can also lead to anemia and malnutrition. Or it may be a general term for a category of diseases with specific blockage etiology that needs to be further investigated. Clinical manifestations include recurrent cough, coughing up mucus or purulent sputum, sometimes with hemoptysis or fever, and symptoms of chronic bronchitis or bronchiectasis with infection.

　　Children often start to have recurrent pneumonia from 1 to 2 years old, and generally be diagnosed with middle lobe syndrome at around 4 to 8 years old. Children may have long-term cough, school-age children can cough up mucus sputum, late-stage purulent sputum, and occasionally may cough up blood or stones. Children may repeatedly suffer from pneumonia or wheezing bronchitis, have difficulty breathing, fever, and in severe cases, cyanosis. Physical signs include wheezing sounds, moist rales, dry rales, and the right lung may have reduced breath sounds. A few may have reduced breath sounds in the middle lobe area of the right lung. percussion produces dull sounds. In cases with a long course, weight loss may occur, the chest circumference may increase, and a few may have clubbing of the fingers (toes). This syndrome can occur in children and individuals of any age, often presenting acutely with fever, recurrent hemoptysis, and pneumonia. During the intercritical period, there may be chronic cough and fatigue. During acute attacks, pneumonia signs may be present, and during the intercritical period, there may be signs of bronchiectasis or chronic lung suppuration. Acute onset may be caused by acute inflammation or foreign bodies, while tuberculosis may cause a slow onset. Chest X-ray in the anterior oblique position shows a triangular shadow, the base towards the heart and merging with it, and the tip towards the lung fields. In the right anterior position, the middle lobe shows a uniform or non-uniform dense shadow, with indistinct edges resembling inflammatory lesions.

　　The middle lobe syndrome should meet the following 3 conditions:

　　1, Enlargement of the lymph nodes adjacent to the middle lobe bronchus.

　　2, Bronchial stenosis.

　　3, Middle lobe atelectasis and obstructive pneumonia.

　　For non-specific pneumonia and (or) allergic reactions, use antibiotics, expectorants, antiallergic agents, etc. during the acute attack period to thoroughly cure infections and inflammation; it can prevent middle lobe syndrome. Foods that clear the lungs, such as carrots, pears, mushrooms, soy milk, and honey, etc. Clear lung pears: They can relieve thirst, cool the body, and relieve coughs. One method is to hollow out the inside and fill it with Fritillaria thunbergii, rock sugar, and honey, and then cook it. Another method is to cut the skin into pieces, place them in a bowl, and then steam them. It is best to put rock sugar in the bowl, mix in honey after cooking, and eat it hot for the best effect. The third method is to cut the skin into pieces and cook it with papaya, jujube, and pork bones, which has the effects of clearing lung heat and improving appetite. The fourth method is to soak the silver ear and cook it with pears in cold water, and add goji berries and jujube according to taste. Additionally, the pears can be mashed into pear cake, mixed with rock sugar, and eaten, which can also clear heat and treat coughs.

　　1, White blood cell count

　　The total count of some children increases, and the neutrophil count increases.

　　2, Pathogen examination

　　The bacterial culture of secretions is mostly Streptococcus hemolyticus, Streptococcus pneumoniae, Staphylococcus aureus, Gram-negative bacilli, etc. In the later stage of tuberculosis, it may not be possible to find the tubercle bacillus, and only non-specific bacteria can be seen.

　　3, Tuberculin test

　　Mostly negative.

　　4, Immune test

　　Attention should be paid to exclude Ig deficiency.

　　5, X-ray examination

　　It is of great help in diagnosis.

　　6, Bronchography

　　It has certain value for the diagnosis of this disease. It can show the entire middle lobe bronchus and its branches. If the middle lobe bronchus and its branches cannot be filled or are not well-filled, the area occupied by the entire middle lobe bronchus will be significantly reduced, indicating that the middle lobe lung is atelectasis. The contrast examination has certain value for the diagnosis of this syndrome.

　　7, Bronchoscopy

　　It can be found that the middle lobe bronchus orifice is compressed, the mucosa is red and swollen, or there is secretion obstruction. Sometimes, X-ray examination may show slight changes, while bronchoscopy can find obvious abnormalities. It can find and remove foreign bodies, identify secretions, and aspirate them, making it possible for the middle lobe to reinflate.

　　8, Pulmonary function test

　　For children over 6 years old who need surgery and can cooperate, pulmonary function tests can be conducted, including the volume of forceful expiration in 1 second.

　　Foods that clear the lungs, such as carrots, pears, mushrooms, soy milk, and honey, etc. Clear lung pears: They can relieve thirst, cool the body, and relieve coughs. One method is to hollow out the inside and fill it with Fritillaria thunbergii, rock sugar, and honey, and then cook it. Another method is to cut the skin into pieces, place them in a bowl, and then steam them. It is best to put rock sugar in the bowl, mix in honey after cooking, and eat it hot for the best effect. The third method is to cut the skin into pieces and cook it with papaya, jujube, and pork bones, which has the effects of clearing lung heat and improving appetite. The fourth method is to soak the silver ear and cook it with pears in cold water, and add goji berries and jujube according to taste. Additionally, the pears can be mashed into pear cake, mixed with rock sugar, and eaten, which can also clear heat and treat coughs..

　　I. Treatment

　　1. Anti-inflammatory and Symptomatic Treatment

　　For those caused by bacterial infection, sufficient effective antibiotics should be given during the initial acute attack period to achieve the rapid disappearance of bronchial lymphadenitis and lung parenchymal inflammation. For those with specific reaction体质, desensitization treatment should be given. For those with bronchospasm symptoms, antispasmodic and bronchodilator drugs can be used.

　　2. Anti-tuberculosis Treatment

　　For those caused by tuberculosis infection, anti-tuberculosis drugs should be used as soon as possible. The treatment method is the same as that for active primary pulmonary tuberculosis and bronchial tuberculosis. Anti-tuberculosis treatment should be used early and reasonably, which will have a good effect. The longer the course of the disease and the later the treatment, the poorer the effect.

　　3. Bronchoscopy and Aspiration

　　It can improve the bronchial obstruction status, which is both a method of examination and confirmation, and a good treatment method. When performing this operation on children, it must be emphasized that the technology is skilled and the operation is light and skillful, and it must be done steadily, accurately, and quickly.

　　4. Surgical Treatment

　　If the course of the disease is long, and the treatment with anti-inflammatory or anti-tuberculosis drugs has reached several months, as well as bronchial aspiration, etc., and there is no effect, it indicates that irreversible changes have occurred in the middle lobe of the lung parenchyma, and it can be considered to perform middle lobectomy by surgery.

　　II. Prognosis

　　If there are recurrent attacks of pneumonia, wheezing pneumonia, or wheezing bronchitis, etc., about 3 to 5 times or more per year, and the duration is long, attention should be paid to examination. At the same time, the immune function should be tested and the tuberculin test should be performed. If the course of the disease is prolonged and the pneumonia recurs frequently, the middle lobe of the lung tissue is severely damaged, fibrosis and cystic bronchial dilation occur, long-term coughing, sputum or sputum with blood, lung function damage, extended to 2 to 10 years or more, and if not surgically removed, it can cause sepsis and threaten life. Early diagnosis and reasonable treatment can restore the disease, otherwise irreversible changes in lung parenchyma may occur. Early rational use of anti-tuberculosis treatment for primary pulmonary tuberculosis will have a good effect, and the longer the course of the disease and the later the treatment, the poorer the effect. Generally, those with surgical indications should be operated on in time, and the prognosis after surgery is good.