OVERVIEW
Unilateral emphysema is narrowly defined as a lung disease in which the affected lung is able to transmit more X-rays than normal lung tissue due to congenital abnormalities in the development of lung tissue and pulmonary circulation. Some people also refer to obstructive or compensated emphysema, pulmonary pustules, and pneumatocystosis as clear lungs, which can be interpreted as a broad category.
Etiology
1. Congenital lobar emphysema
Although there are congenital lung developmental disorders, there are also cases of acquired bronchial compression, so this disease is also called “neonatal” lobar emphysema or “infantile” lobar emphysema, and it is not appropriate to call it “congenital” lobar emphysema. Lobar emphysema is also called “neonatal” or “infantile” rather than “congenital” emphysema. It is characterized by over-expansion of a lobe or a section of lung tissue, which compresses the normal lung tissue mediastinal organs and the cardiovascular system, and it is one of the common causes of acute respiratory distress in infants and young children.
2. Atopic emphysema (Swyer-James syndrome)
Swyer and James (1953), first reported this disease as a case of a 6-year-old boy. 1954, Macleod reported 9 similar patients in adults, so this disease is also known as Macleods syndrome or M-S-J syndrome. It is only seen in newborns or young children. 1/3 of cases develop immediately after birth, 50% in the first month of life, and only 5% in the first 6 months of life. It is more common in males than females, and is found in the upper lobes of both lungs (the left upper lobe is the most common), followed by the right middle lobe of the lungs, and the lower lobes are less common.
Symptoms
1. The symptoms of congenital emphysema are divided into two types: early onset and late onset. Only 5% of patients develop the disease 6 months after birth, and respiratory distress occurs in half of the patients in the first month after birth. Few people are asymptomatic. Typical early-onset symptoms start from the 4th day to a few weeks after birth, and the symptoms progress very rapidly, manifested by progressive dyspnea, inspiratory and expiratory rales, tachycardia, cyanosis, etc. Signs include: asymmetry of the chest, fullness of the affected side of the thorax, clear sounds on percussion, weakened respiratory sounds, and shifting of the trachea and the healthy side of the mediastinum, which is similar to a pneumothorax. Late onset symptoms were recurrent respiratory infections. Physical examination: the affected side of the thorax is distended, the percussion reaction is enhanced, the respiratory sound is weakened on auscultation, and wheezing or rales may be heard.
2. Atopic emphysema can be seen in children and adults, the clinical manifestations vary in severity, the mild cases may be asymptomatic, while the severe cases may have cough, sputum, dyspnea or recurrent respiratory tract infections and hemoptysis. Physical examination is similar to congenital lobar emphysema.
Examination
1. Radiologic examination
Congenital emphysema can be seen in the upper lobe of the lung, mainly on the left side, and rarely in the lower lobe. It is characterized by increased translucency of single lobe, decreased vascular texture, obvious increase in the volume of the affected lobe, compression and atelectasis of the adjacent healthy lungs, displacement of the healthy side of the mediastinum, downward displacement of the diaphragm, or normal, and the mediastinum can be seen to be shifted to the affected side during inhalation, and then shifted to the healthy side during exhalation. Specific emphysema X-ray shows increased translucency of the affected lung and decreased hilar vascular texture. Bronchography: bronchioles are filled proximally and tiny distally; bronchioles below grade 5-6 are not filled. Fluoroscopy: the affected side of the mediastinum is shifted during inspiration, the mobility of the diaphragm on the affected side is weakened, and the volume of the affected lungs does not change with respiratory movements.
2. Cardiovascular imaging
Congenital emphysema can be seen as abnormal blood vessels or cardiac malformations, radionuclide lung scan can be seen as decreased blood perfusion in the affected lobe, bronchoscopy and bronchography are used to exclude other lesions. Pulmonary arteriography: the affected pulmonary artery is small and the peripheral vasculature is sparse. Radionuclide examination: the perfusion of the affected lung is significantly reduced.
3. Bronchoscopy
Bronchial mucosal congestion, edema, thickening and other acute and chronic inflammatory manifestations.
4. Lung function test
Suggests ventilation dysfunction.
Diagnosis
Combining the clinical manifestations and X-ray examination of unilobar lung with increased translucency, obvious spreading and thinning of vascular texture, pulmonary hyaline membrane disease can be clearly diagnosed. In congenital emphysema, bronchoscopy is indicated in older pediatric patients to exclude endotracheal lesions. Radiographically important features are the presence of vascular texture which can be differentiated from pulmonary pemphigoid.
Treatment
1. Congenital emphysema
Some patients can relieve symptoms by themselves without surgical treatment. If cardiac and pulmonary functions are seriously affected, emergency surgery is often required. Surgery is more dangerous, especially in the period between the start of positive pressure ventilation and the removal of the affected lung, so the chest must be opened and the lung removed as soon as possible. The prognosis is good after removal of the affected lung.
2. Specific emphysema
Conservative treatment is based on antispasmodic and anti-inflammatory, similar to congenital lobar emphysema, with surgical resection if the symptoms are severe, and the prognosis is good.