Obstructive emphysema refers to the continuous expansion and enlargement of the balloon cavity (including respiratory bronchioles, alveolar ducts, alveolar sacs and alveoli) at the distal end of terminal bronchioles, accompanied by structural destruction of the balloon wall, without obvious fibrosis.
When chronic bronchitis is complicated with emphysema, it is often based on the original symptoms of chronic bronchitis such as cough and expectoration, which leads to the gradual aggravation of dyspnea. In the early days, I felt short of breath only after working, climbing stairs, going uphill or walking quickly. With the development of the lesion, you will feel short of breath when you move on the flat ground. If you feel short of breath in daily life, such as talking, dressing, washing, or even resting, it indicates that emphysema is serious. In addition, there are systemic symptoms such as fatigue, loss of appetite and weight loss. During the acute attack, the respiratory function is further reduced, and every time there are symptoms of hypoxemia and hypercapnia, such as chest tightness, dyspnea, headache, drowsiness and trance. Corresponding symptoms can appear when the right heart fails. See the section on chronic pulmonary heart disease.
Symptoms and signs
1. Symptoms When chronic bronchitis complicated with emphysema, on the basis of the original symptoms of chronic bronchitis, such as cough and expectoration, the dyspnea is gradually aggravated. In the early days, I felt short of breath only after working, climbing stairs, going uphill or walking quickly. With the development of the lesion, you will feel short of breath when you move on the flat ground. If you feel short of breath in daily life, such as talking, dressing, washing, or even resting, it indicates that emphysema is serious. In addition, there are systemic symptoms such as fatigue, loss of appetite and weight loss. During the acute attack, the respiratory function is further reduced, and every time there are symptoms of hypoxemia and hypercapnia, such as chest tightness, dyspnea, headache, drowsiness and trance. Corresponding symptoms can appear when the right heart fails. See the section on chronic pulmonary heart disease.
2. Early signs are generally not obvious. With the development of the disease, patients with severe emphysema can see that the chest diameter increases, the intercostal space is full, the appearance is barrel-shaped, and the respiratory movement is weakened. Palpation tremor weakened or disappeared. Percussion is silent The voiced boundary of the heart becomes narrow or difficult to knock out, and the lower boundary of the lung and the voiced boundary of the liver move down. Auscultation of heart sounds is far away, expiratory phase is prolonged, breathing sounds are generally weakened, and dry and wet rales can be heard in the lungs when complicated with infection. If the heart beats under the sword, the heart sounds are more obvious than those at the apex, suggesting that the right heart may be involved.
3. Classification According to the clinical manifestations of this disease, obstructive emphysema can be divided into two types.
(1) types of emphysema (flat chest type, red asthma type, PP type): emphysema is more serious, but bronchial lesions are relatively mild. It is more common in frail elderly patients with severe dyspnea and no obvious cyanosis. The patient's shoulders are high, his hands support the bed, and his cheeks swell and his lips contract when he exhales. Chest X-ray showed increased transparency of both lungs. Ventilation dysfunction is not as serious as bronchitis, the gas distribution is relatively uniform, the proportion of residual gas to total lung capacity increases, and alveolar ventilation is normal or hyperventilated, so PaO2 _ 2 does not decrease significantly, and PaCO2 _ 2 is normal or decreased.
(2) Bronchitis type (cyanosis type, BB type): Bronchial lesions are serious, mucous membrane swelling and mucous gland hyperplasia are obvious, and emphysema is relatively mild. Patients often have years of history of coughing and expectoration. Obesity, cyanosis, jugular vein dilatation, edema of lower limbs, and moist rales in both lungs. Chest X-ray showed thickening of lung texture, and the signs of emphysema were not obvious. The ventilation function was obviously damaged, the gas distribution was uneven, the functional residual volume and total lung capacity increased, the diffusion function was normal, PaO2 decreased and PaCO2 increased. Elevated hematocrit is easy to develop into right heart failure.
The cause of the disease
1. Chronic bronchitis causes various factors of chronic bronchitis, such as infection, smoking, air pollution, long-term inhalation of occupational dust and harmful gases, allergic factors, etc., which can cause chronic inflammation of the bronchi, make the lumen narrow and partially blocked, make the gas easily enter the alveoli when inhaling, and further close the bronchi when exhaling, resulting in excessive residual gas in the alveoli and excessive inflation of the alveoli. Chronic inflammation can also damage the cartilage tissue of the small wall of the bronchus, so that the bronchus loses its normal stent function. When exhaling, the bronchus is easy to trap, which hinders the gas discharge, leading to excessive accumulation of gas in the alveoli, increased pressure in the alveoli and excessive expansion. In addition, due to the increase of alveolar internal pressure, the capillary of alveolar wall is compressed, the blood supply of lung tissue is reduced, and nutrition is damaged, which can also cause the elasticity of alveolar wall to decrease. Therefore, chronic bronchitis injury is an important cause of obstructive emphysema.
2. Protease-antiprotease imbalance At present, it is believed that some proteolytic enzymes in the body can damage lung tissue, while antiprotease can inhibit proteases such as elastase. Maintaining the balance between protease and anti-protease is an important factor to ensure that the normal structure of lung tissue is not destroyed.
3. Genetic factors The occurrence of emphysema is also related to genetic factors. The α 1-AT in normal human serum is inherited according to autosomal recessive genes.
complication
1. Spontaneous pneumothorax is caused by rupture of subpleural pulmonary bullae and air entering pleural cavity. Patients often suddenly feel chest pain, dyspnea aggravates and cyanosis is obvious. Drums are heard on the affected side. Breathing sounds weaken or disappear, and every tremor weakens. Diagnosis can be made by X-ray examination.
2. On the basis of severe pulmonary dysfunction, patients with obstructive emphysema due to respiratory failure often suffer from some inducement, such as respiratory infection, poor expectoration, improper oxygen therapy, application of sedatives and surgical anesthesia, which often leads to further aggravation of pulmonary dysfunction and respiratory failure.
3. Patients with chronic pulmonary heart disease obstructive emphysema can cause pulmonary hypertension due to destruction of alveolar capillary bed, reduction of gas exchange area, hypoxemia and hypercapnia. When emphysema is further aggravated or repeatedly complicated with respiratory tract infection, and blood gas analysis is gradually deteriorated, pulmonary artery pressure can be obviously increased continuously, and right heart load is aggravated, and then right ventricular hypertrophy or even right heart failure occurs.
Prediction and prevention
Prognosis: Obstructive emphysema is a natural process of slow and progressive decline of ventilation function. When FEV 1 drops below 25% of the expected value, respiratory failure may occur. The 5-year survival rate after the first respiratory failure was only 15% ~ 20%. It is generally estimated that people with FEV 1 > 1.2L can live for 10 years. Those with FEVl of 1.0L will survive for about 5 years. FEVl