Spontaneous pneumothorax

Spontaneous pneumothorax Spontaneous pneumothorax refers to the rupture of the lung parenchyma or visceral pleura without the influence of exogenous or interventional factors, causing gas to accumulate in the pleural cavity. basic knowledge The proportion of illness: 0.005%-0.007% Susceptible people: no specific population Mode of infection: non-infectious Complications: blood pneumothorax

Spontaneous pneumothorax

(1) Causes of the disease

The etiology of spontaneous pneumothorax has changed with the development of society and medicine. In 1932, the cause of spontaneous pneumothorax reported by Kjaergarrd was mostly subpleural bullae. In the 1950s, tuberculosis became a common cause of spontaneous pneumothorax. Later, with the effective drug treatment and epidemiological control of tuberculosis, the incidence of spontaneous pneumothorax caused by tuberculosis decreased. After the 1980s, with the process of aging of the social population, senile chronic obstructive pulmonary disease The rate of spontaneous pneumothorax caused by emphysema has an increasing trend, and with the emergence of some special social phenomena, spontaneous pneumothorax caused by Pneumocystis carinii infection in patients with acquired immunodeficiency syndrome (AIDS) also has increase.

Spontaneous pneumothorax is divided into: idiopathic pneumothorax and secondary pneumothorax according to the causes of gas spillage into the pleural cavity. Idiopathic pneumothorax is more common in adolescents, and is thin and tall, on X-ray and even under open surgery. In the visceral pleural surface, there are often no clear lesions. Secondary pneumothorax is more common in middle-aged and elderly people. It is often caused by the rupture of the original lesions in the lungs, such as bullae, tuberculosis, lung abscess, lung cancer, etc. The patient's clinical signs and symptoms depend on the underlying cause, the extent of lung collapse, and the presence of underlying lung disease. The common causes of spontaneous pneumothorax are as follows:

Subpleural pulmonary bullous rupture

Spontaneous pneumothorax in adolescents is caused by rupture of the bullae under the pleura of the lungs. The subpleural pulmonary bullae are mostly divided into two types. The subpleural tiny lung bullae (bleb), diameter <1cm, often multiple, can occur At the tip of the lung, at the edge of the interlobular fissure and at the edge of the lower lobe of the lung, such tiny bullae are often caused by inflammation of the bronchial and pulmonary linings, resulting in poor traction and poor ventilation during the formation of scars in the fibrous tissue. Spontaneous pneumothorax caused by blister is not easy to find lesions on X-ray chest or surgery, so it is also called "idiopathic pneumothorax". Subpleural pulmonary bullae are often single, mostly in the tip of the lung, due to the visceral layer. Congenital hypoplasia of the pleura, gradual emergence of bullae, this type of spontaneous pneumothorax is common in adolescents with thin and tall body shape, in addition to the discovery of pulmonary bullae during surgery, often can not find the basic lesions in the lung parenchyma associated with it The spontaneous pneumothorax caused by the rupture of these two types of bullous bulls can be induced during intense activity, coughing, sneezing, or in a quiet state.

2. Follicular emphysema rupture

As a result of chronic obstructive pulmonary disease, the alveolar unit is over-inflated, and alveolar wall destruction occurs for a long time, that is, lobular central emphysema and whole lobular emphysema, alveolar fusion and compression of alveolar septum and pulmonary interstitial formation of massive spleen Swelling, which is characterized by the extremely thin blood vessels and alveolar spaces that are compressed in the large bubbles on the chest X-ray and chest CT slices, so as to differentiate from the giant bullae, when the residual volume of the lung parenchyma is further increased, the pressure Pneumothorax occurs when the pleural rupture of the viscera is too high. Men over 40 years old are more common, often accompanied by chronic cough, long-term smoking history, and history of bronchial asthma.

3. Tuberculosis

In the 1950s, tuberculosis was one of the most important factors causing spontaneous pneumothorax, and its pathogenesis was mainly:

1 The old tuberculous scar contracted, causing the small bronchi to distort and block, forming a localized bullous rupture;

2 The active tuberculosis cavity of the lung is directly ruptured;

3 Indirect pulmonary emphysema caused by tuberculous lesions in the lungs, when the infection, bronchial obstruction, caused the distal alveolar excessive expansion and rupture, in the 1980s, with effective anti-tuberculosis drugs Application, the incidence of tuberculosis was significantly reduced, and the incidence of spontaneous pneumothorax caused by tuberculosis was also significantly reduced. In the case of 95 cases of spontaneous pneumothorax reported by Beg in 1988, tuberculosis accounted for 21%, second only to purulent infection. In recent years, the incidence of tuberculosis has increased, and attention should be paid to the complications of pneumothorax.

4. Other

(1) Infection: Staphylococcal pneumonia and congenital pulmonary cyst secondary rupture after infection is the main cause of spontaneous pneumothorax in children. With the clinical application of various high-efficiency antibiotics, pus pneumothorax caused by rupture of lung abscess is rare. The report of spontaneous pneumothorax caused by fungal infection of the lungs is increasing. The accompanying disease of acquired immunodeficiency syndrome (AIDS) can also cause spontaneous pneumothorax. Beers proves that the pathogenesis may be Extensive pulmonary interstitial inflammation, cystic cellular tissue necrosis of the lungs.

(2) malignant tumor: a cancerous cavity close to the visceral pleura rupture into the pleural cavity can cause pneumothorax, lung cancer causes distal bronchial obstruction to form localized emphysema and then rupture, especially metastatic sarcoma can lead to pneumothorax, in children, pneumothorax It can be the first manifestation of osteosarcoma lung metastasis.

(3) Spontaneous pneumothorax during menstruation: Maurer et al. reported spontaneous pneumothorax during menstruation in 1968. In 1972, Lillingto et al named this pneumothorax as menstrual pneumothorax, and the 30- to 40-year-old population was the peak of onset, 90%. Occurred on the right side, often occurs within 48 to 72 hours after the start of menstruation, the reasons may be: menstrual period PGF2 level increased, leading to alveolar rupture; menstrual period cervical mucus thrombosis lack, air through the cervix, fallopian tube and transverse pupil into the pleura Cavity; endometriosis of the pleura or lung.

(4) Pneumothorax in patients with acquired immunodeficiency syndrome: The spontaneous pneumothorax of patients with acquired immunodeficiency syndrome usually occurs on the basis of Pneumocystis carinii pneumonia (PCP), and about 6% of patients with PCP AIDS Pneumothorax occurs, Pneumocystis carinii causes necrotizing pneumonia with diffuse subpleural bullae, pneumothorax is often bilateral, stubborn, easy to relapse, long leaks, recurrence rate after conservative treatment is as high as 65%, about 1/3 Patients with concurrent or non-simultaneous pneumothorax, AIDS patients with PCP, if combined with pneumothorax, hospital mortality rate is as high as 50%, in patients requiring ventilatory support, the mortality rate is close to 90%.

(two) pathogenesis

The occurrence of pneumothorax is related to the sudden increase of intrapulmonary pressure in the lesion. Generally speaking, the pressure required to cause normal alveolar rupture is 7.8 to 13.7 kPa, while the lesions of alveolar and pulmonary bullae can withstand much less pressure than normal alveoli. , so it is easy to rupture, especially in the following situations: pneumothorax is prone to occur:

1 severe cough, increased abdominal pressure;

2 respiratory tract infection caused local tracheal obstruction, the gas can only enter the distal alveolar, and the discharge is not smooth, so that the blocked alveolar pressure in the distal end is increased;

3 asthma status;

4 mechanical ventilation, continuous positive pressure in the trachea, exceeding the pressure limit of the diseased alveoli;

5 Some physical activities suddenly force, suddenly change position, yawn and so on.

Spontaneous pneumothorax prevention

Prevent primary disease. Cold weather will aggravate the inflammation of the respiratory tract. Multiple alveolar ruptures form a large pulmonary vesicle. When the lung vesicles rupture, it is easy to punch the lungs out of a hole, causing gas to leak into the chest cavity and form a pneumothorax. Elderly patients with long-term severe respiratory illness should pay special attention in winter.

Patients with recurrent pneumothorax should be treated with pleurodesis. Traumatic pneumothorax treatment can generally be carried out according to the principle of spontaneous pneumothorax treatment, but should emphasize timely diagnosis, active rescue, prevent complications and prevent recurrence.

Spontaneous pneumothorax complications Complications

The main complications were pus and pneumothorax, blood pneumothorax, and chronic pneumothorax. In recent years, the aseptic operation of thoracic surgery and the timely use of antibiotics, pneumothorax and pus pneumothorax have been rare.

(a) Hemopharonic (hemopneumothorax) spontaneous pneumothorax caused by tearing of blood vessels in the pleural adhesion zone. Sudden onset, in addition to chest tightness, shortness of breath, chest pain continued to increase, accompanied by dizziness, pale, pulse speed, hypotension and so on. A large number of signs of pleural effusion appeared in a short period of time, and the X-ray showed a liquid-vapor level. Thoracentesis is whole blood.

(2) Chronic pneumothorax (chronic pneumothorax) refers to those who do not absorb the pneumothorax for more than 3 months. The factors of incomplete lung expansion are: traction of pleural adhesion zone, continuous opening of pleural cavity; formation of bronchial pleural fistula through the cyst or lung tissue; cellulose deposition on the visceral pleural surface, mechanization, restricting lung expansion; bronchial lumen The internal lesion causes complete obstruction, so that the collapsed lung cannot be reinflated.

In addition, it can also be combined with pneumothorax and bronchopleural fistula. Failure to treat in time may result in acute progressive respiration and circulatory failure due to lung atrophy and mediastinal pressure displacement.

Spontaneous pneumothorax symptoms Common symptoms Palpitation, sternal pain, chest tightness, difficulty breathing, chest pain, smoking, chest pain, chest pain after eating

1. Difficulty breathing Patients have difficulty breathing during pneumothorax, the severity of which is related to the course of the attack, the degree of compression of the lungs and the original state of lung function. In young patients with normal respiratory function, there is no obvious difficulty in breathing. Even if the lungs are compressed by >80%, they can only feel chest tightness during activities. In elderly patients with chronic obstructive emphysema, the lungs are slightly compressed and have obvious dyspnea, acute pneumothorax. Symptoms may be more pronounced, while chronic pneumothorax, contralateral lungs can be compensatory swelling, and clinical symptoms may be mild.

2. Chest pain often occurs in the pneumothorax at that time, sudden sharp tingling and knife cut pain, regardless of the degree of sudden rupture of the bullae and compression of the lungs, may be related to increased intrapleural pressure, wall pleural stretch, pain The site is not certain, it can be confined to the chest, but also to the shoulders, back, upper abdomen, when there is obvious mediastinal emphysema, there may be sustained post-sternal pain, pain is the most common complaint of pneumothorax patients, and in mild pneumothorax May be the only symptom.

3. Irritant cough Spontaneous pneumothorax occasionally irritating cough.

4. Other symptoms When the pneumothorax is combined with the blood pneumothorax, if the amount of bleeding is high, the patient will have palpitations, low blood pressure, and cold limbs.

Spontaneous pneumothorax examination

X-ray inspection

It is the most reliable method for diagnosing pneumothorax. It can show the degree of lung collapse, lung condition, presence or absence of pleural adhesions, pleural effusion and mediastinal shift, etc. The pleural effusion zone on the chest image shows a uniform translucent area without lung texture. The inner side is a curved linear lung edge parallel to the chest wall. A small amount of gas is often confined to the upper part of the chest, which is often covered by bones. At this time, the paralyzed patient exhales deeply, making the collapsed lungs shrink, the density is increased, and the outside The air-transparent area forms a sharper contrast, which shows the pneumothorax. When the pneumothorax is large, the affected lung is compressed, and the lungs are scattered in the hilar area. Some patients can see the lungs on the chest X-ray. Bullae; in the presence of blood pneumothorax, the liquid-vapor plane is visible; when there is an adhesive band in the chest, the collapsed lung loses its uniform compression to the hilum, showing irregular compression or lung compression on the X-ray image. It is lobulated; the affected side of the diaphragm is obviously moved down, the trachea and the heart are displaced to the healthy side; when mediastinal emphysema is combined, mediastinal and subcutaneous gas is visible. According to the X-ray image, the degree of compression of the lung after pneumothorax can be roughly calculated. This is the clinical office The qi chest has a certain guiding significance, Kircher proposed a simple calculation method:

According to the above formula, it can be estimated that when the width of the gas-filled zone is equivalent to 1/4 of the width of the thoracic side of the affected side, the lung is compressed by about 35%; when the width of the gas-filled zone in the chest is equivalent to 1/3 of the width of the affected thorax, the lung is Compression is 50%; when the width of the gas in the chest is equivalent to 1/2 of the width of the thoracic side of the affected side, the lung is compressed by 65%. According to the amount of pneumothorax, the pneumothorax can be divided into 3 categories: a small amount of pneumothorax (<20%) , medium volume pneumothorax (20% to 40%), a large number of pneumothorax (> 40%).

2. Chest CT scan

Can clearly show the extent of pleural effusion and the amount of gas, the degree of compression of the lungs, in some patients can see the presence of lung bullae, and chest CT can also show how much pleural effusion, especially for the pole A small amount of gas pneumothorax and a localized pneumothorax mainly located in the anterior middle pleural cavity.

Spontaneous pneumothorax diagnosis

According to the clinical manifestations combined with X-ray and CT examination is not difficult to diagnose.

Differential diagnosis

1. Pneumothorax of repeated recurrent episodes of pulmonary bullae, due to adhesions in the chest, pneumothorax is easy to form a localized package. At this time, it is easy to be confused with tension tuberculosis on X-ray films. Pneumothorax often has a history of sudden onset. Tension-induced pulmonary bullae is a long-term recurrent chest tightness. The tension of the pulmonary bullae on the X-ray image shows the fine line of the bullous bullae at the edge of the chest wall, especially at the rib angle. The identification of pneumothorax and tension tuberculosis It is very important that misdiagnosis of tension tuberculosis as a pneumothorax and placement of a chest drainage tube can easily cause serious pathophysiological changes.

2. Bronchial rupture It should be said that bronchial rupture is one of the causes of traumatic tension pneumothorax. Bronchial rupture often has a history of traumatic chest injury. The trauma is characterized by a sudden stop during the acceleration process, and a tension pneumothorax caused by bronchial rupture. Chest drainage tube often has persistent overflow, and the "lung sag sign" can be seen on the chest X-ray, that is, the upper edge of the collapsed lung is lower than the hilar level, and the general cause of pneumothorax, the lung collapse is toward the hilum. of.

3. Acute pulmonary embolism may have symptoms such as dyspnea in the clinic, and often accompanied by fever, hemoptysis, shock, increased white blood cell count, etc., generally have a history of venous thrombosis of repeated lower extremities or a long history of bed rest, no X-ray image Pneumothorax sign.

4. Other chest pain, dyspnea and other symptoms should be differentiated from myocardial infarction, pleurisy, acute abdomen and so on.

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