Pneumothorax

Pneumothorax Pneumothorax refers to the entry of gas into the pleural cavity, resulting in a state of accumulation of gas, called pneumothorax. Usually divided into three categories: spontaneous pneumothorax, traumatic pneumothorax and artificial pneumothorax. Spontaneous pneumothorax is caused by lung disease, rupture of lung tissue and visceral pleura, or due to rupture of tiny vesicles and pulmonary bullae near the surface of the lungs, air in the lungs and bronchus into the pleura basic knowledge The proportion of illness: 0.23% Susceptible people: no specific population Mode of infection: non-infectious Complications: blood pneumothorax

Pneumothorax

(1) Causes of the disease

According to the presence or absence of primary disease, spontaneous pneumothorax can be divided into two types: primary and secondary pneumothorax.

The factors that induce pneumothorax are strenuous exercise, coughing, lifting heavy objects or upper arms, lifting weights, and exerting force on stool. When severe coughing or exerting severe stools, the pressure in the alveoli is increased, resulting in the original lesion or defective lung tissue. Rupture causes pneumothorax, using artificial respirator, if the gas supply pressure is too high, pneumothorax may occur. According to statistics, 50% to 60% of cases can not find obvious incentives, and about 6% of patients even sick in bed rest.

1. Primary pneumothorax, also known as idiopathic pneumothorax, refers to the pneumothorax that occurs in healthy people who have not found obvious lesions in the routine X-ray examination of the lungs. It occurs in young people, especially male elders. According to foreign literature It is reported that this pneumothorax accounts for the first place in spontaneous pneumothorax, while the domestic is mainly secondary pneumothorax.

The cause and pathological mechanism of this disease are not yet clear. Most scholars believe that due to the rupture of subpleural microbubbles (bleb) and bullous bullula (bulla), according to histopathological examination of pulmonary bullae in patients with idiopathic pneumothorax Based on the subpleural non-specific inflammatory scars, that is, non-specific inflammation around the bronchioles causes scarring of the pleural and subpleural elastic fibers and collagen fibers, which can reduce the elasticity of the adjacent alveolar walls and cause alveolar rupture. The formation of pulmonary bullae under the pleura, the non-specific inflammation of the bronchiole itself acts as a one-way valve, resulting in emphysema changes in the stroma or alveoli to form a bullous bullae.

Some scholars believe that the congenital hypoplasia of lung tissue is the cause of the formation of bullous bullae, that is, due to the congenital dysplasia of the elastic fiber, and the elasticity is low, the alveolar wall expands to form a large bubble and rupture, Marfan syndrome (a congenital inheritance) Sexual connective tissue lacks disease. Spontaneous pneumothorax is a typical example. There are familial spontaneous pneumothorax reports abroad. Gongs report of 725 cases of spontaneous pneumothorax has 11 family history. Kimura reports that siblings have spontaneous pneumothorax. May mean the existence of genetic factors.

In the etiology of this disease, there are also people who propose "neomembrane theory", collateral ventilatory barrier mechanism, and air pollution theory.

2. Secondary pneumothorax The mechanism of its production is based on other lung diseases, the formation of bullae or direct damage to the pleura, often chronic obstructive emphysema or post-inflammatory fibrous lesions (such as silicosis, chronic tuberculosis, On the basis of diffuse pulmonary interstitial fibrosis, cystic pulmonary fibrosis, etc., bronchiolitis is narrowed and distorted, resulting in a valve mechanism to form a bullous bullae, a swollen emphysema bubble due to nutrition, circulatory disorders and degenerative Degeneration, when coughing, sneezing or increased intrapulmonary pressure, causing pneumothorax caused by rupture of bullae, 179 cases of spontaneous pneumothorax reported by Wu et al., chronic bronchitis complicated with emphysema (38.5%), Followed by tuberculosis accounted for 17.3%, idiopathic pneumothorax was 13.4% (third place), and staphylococcal pneumonia was 12.3% (fourth place), the rest for other reasons.

Suppurative pneumonia caused by Staphylococcus aureus, anaerobic or Gram-negative bacilli, lung abscess lesions ruptured into the thoracic cavity, pus pneumothorax, fungi or parasites such as microbes infecting the pleura, lungs, infiltration or visceral pleural effusion Pneumothorax, bronchopulmonary cyst rupture, etc. can be complicated by pneumothorax. In addition, perforation of adjacent organs such as esophagus breaks into the pleural cavity, and positive pressure artificial ventilation is used. Long-term use of glucocorticoids can also cause pneumothorax.

In recent years, secondary pneumothorax caused by certain diseases has gradually attracted people's attention:

1 Lung cancer, especially metastatic lung cancer, with the progress of comprehensive treatment, the survival of patients with lung cancer is gradually prolonged, and the pneumothorax secondary to lung cancer will increase gradually; its incidence accounts for 4% of lung cancer patients (especially more common in the late stage) Small cell lung cancer), the cause of which is: tumor obstruction of the bronchioles, leading to localized emphysema; obstructive pneumonia further develops into pulmonary suppuration, and finally collapses into the thoracic cavity; the tumor itself invades or destroys the visceral pleura,

2 sarcoidosis, mainly in the third stage, the incidence of pneumothorax is 2% to 4%, due to the late fibrosis leading to the formation of subpleural follicles or direct invasion of the pleural membrane due to granulomatous lesions,

3 histiocytosis X: It is reported that the incidence of spontaneous pneumothorax can reach 20% to 43%, which is related to the obvious pulmonary fibrosis in the late stage of the disease, and finally leads to "honeycomb lung" and the formation of bullae.

4 pulmonary lymphangioleiomyomatosis (LAM): According to the literature, about 40% of patients with spontaneous pneumothorax, Taylor reported 32 cases of LAM, 26 cases (81%) developed pneumothorax, the occurrence of this disease and estrogen changes in the body Close relationship, due to bronchial smooth muscle hyperplasia can partially or completely block the airway, causing bullae, lung cysts, and eventually leading to rupture of the pneumothorax,

5 AIDS: the incidence of spontaneous pneumothorax is 2% to 5%. Coker et al reported that the incidence of pneumothorax in 298 cases of AIDS is 4%. The mechanism may be: the disease is easy to invade the pleural lung tissue, and it is easy to concurrently develop K. Pneumocystis pneumonia, which has a destructive effect on the lungs and pleura, leading to pneumothorax; the direct cytotoxic effect of human immunodeficiency virus (HIV) on lung macrophages causes elastase release, resulting in emphysema and formation of large lungs Blisters.

3. Special type of pneumothorax

(1) Menstrual pneumothorax: a recurrent pneumothorax related to the menstrual cycle. The disease was first reported by Maurer in 1958 and officially named as menstrual pneumothorax by Lillington in 1972. The incidence is only female spontaneous pneumothorax. 0.9%, accounting for 5.6% of female pneumothorax patients under 50 years of age.

The cause is mainly related to endometriosis of the lung, pleura or diaphragm. The exact pathogenesis is still unknown, but some theories are proposed to explain the mechanism of the disease:

1 intrathoracic endometriosis theory: the reason is that pneumothorax is closely related to the menstrual cycle; many cases have found endometriosis in the thoracic cavity; the disease is more common on the right side and the endometriosis of the thoracic cavity It is the same; the age of onset is the same in both cases. Because of the presence of endometriosis in the thoracic cavity, endometrial lesions in the bronchioles are congested and swollen during menstruation, causing partial obstruction of the lumen to form a "live flap" effect. , causing distal localized over-inflation leading to rupture of the pleura, but there are also phenomena that cannot be explained: about 75% of patients with open-thoracic surgery due to this disease have not found endometriosis; patients with thoracic endometriosis There are often pleural effusions, menstrual hemoptysis, and menstrual pneumothorax is not accompanied by hemoptysis and pleural effusion, so menstrual pneumothorax caused by endometriosis only represents the cause of partial pneumothorax.

2 Muscle channel rupture theory: From the embryonic development and anatomy and physiology of the diaphragm, the path of gas from the abdominal cavity into the thoracic cavity is: congenital defects of the diaphragm, such as Morgagni and Bochdalek, etc.; normal esophagus, aorta and lower Venous venous rupture; condylar rupture of the diaphragm, such as the rupture of the diaphragmatic ectopic endometrium, the pneumothorax after Meiqi's syndrome and pulmonary tuberculosis treated with pneumoperitoneum has confirmed the existence of a pathway between the thoracic and abdominal cavity, but not seen in men In the case of spontaneous pneumothorax caused by a single diaphragmatic defect, a case of spontaneous pneumothorax with pneumoperitoneum was found abroad, and attempted to prove traffic between the chest and abdomen by radionuclide imaging, but the results are not supported. The data further confirmed the specific pathogenesis of women. During the menstrual period, due to uneven uterine contraction, air may enter the uterine cavity and reach the abdominal cavity through the fallopian tube. At this time, the ectopic endometrial tissue of the occluded diaphragmatic pore is detached. The diaphragmatic channel is temporarily open, and the gas is inhaled from the diaphragmatic hole into the pleural cavity under the action of the chest vacuum suction pump; instead of the menstrual period The liquid embolus closes the cervix and blocks the gas from entering the chest through the genital tract. This theory can explain many clinical signs of the disease. For example, a diagnostic artificial pneumoperitone can induce pneumothorax; after tubal ligation or hysterectomy, pneumothorax can be cured. It is rare to have diaphragmatic endometriosis and defects, only 19%, and many cases still have recurrence after surgically blocking the diaphragmatic channel, so this theory cannot be used to make a comprehensive and reasonable explanation.

3Kovarik and other theories: It is believed that the endometrial tissue in the pelvic cavity may spread through the diaphragmatic defect or blood flow, the lymphatic pathway spreads to the subpleural pleura to form a lesion, and it is caused by the leakage of gas in the lung during the menstrual period, resulting in pneumothorax. Japanese scholars report 1 In the case of open thoracic exploration, no abnormalities of the diaphragm were found, and endometrial tissue was found around the ruptured pulmonary bullae, which further supported the theory.

4 elevated levels of prostaglandins (mainly prostaglandin F2a) are associated with menstrual pneumothorax: prostaglandins can regulate the vasomotor function of pulmonary vasculature and bronchial smooth muscle. Rossi believes that this disease is a rise in blood prostaglandin F2a levels during menstruation. Contraction of bronchial smooth muscle, increased pressure in the airway, causing alveolar and pleural rupture to form pneumothorax, and prostaglandin F2a can cause endometrial necrosis, but there is still insufficient evidence.

(2) Pregnancy with pneumothorax: There are many young women in the growth period. The patient has pneumothorax due to each pregnancy. According to the time of pneumothorax, it can be divided into early stage (3 to 5 months of pregnancy) and late stage (8 cases of pregnancy). More than two months, the mechanism of its occurrence is not very clear, some people think that it is related to changes in adrenocortical hormone levels and changes in thoracic compliance. Pneumothorax occurred in early pregnancy, some scholars believe that it is related to the decline of adrenal cortical hormone levels (reported in the literature) Usually, the urinary 17-hydroxysteroid content is 3.25mol/24h (1.18mg/24h), but it drops to 2.125mol/24h (0.77mg/24h) during pregnancy, but it is also considered that the adrenal cortex hyperfunction during pregnancy, thus inhibiting Susceptible repair after connective tissue injury, the spontaneous pneumothorax occurred in the late pregnancy may be related to the lower thoracic compliance and the increase of intrathoracic pressure.

(3) Spontaneous pneumothorax in the elderly: spontaneous pneumothorax in people over 60 years old is called spontaneous pneumothorax in the elderly. In recent years, the incidence of this disease has increased, more men than women, most of which are secondary to chronic lungs. Diseases (about 90%), including chronic obstructive pulmonary disease, the mechanism is not very clear, but may be based on the original chronic lung disease, due to the aging of the body tissues and organs of the elderly, alveoli Reduced elasticity, decreased body resistance, in general activities, even coughing, sneezing and holding breath, stool can cause alveolar rupture leading to pneumothorax.

(two) pathogenesis

With the development of science and technology, especially the further improvement and progress of optical technology and micro camera system and high definition imaging system, VATS (TV thoracoscopy) has been widely used in clinic, because the thoracoscope can be thorough and careful. The entire lung surface lesions were examined and magnified under high-resolution endoscopy and television displays to observe subtle pulmonary pleural lesions. Vanderscheren clinically divided spontaneous pneumothorax according to thoracoscopic alveolar lesions and pleural adhesions. Grade 4: Grade I is idiopathic pneumothorax, no obvious abnormalities in lung tissue under endoscopy; Grade II is pneumothorax with visceral layer, parietal pleural adhesion; Grade III is visceral subpleural vesicle and lung with diameter <2cm Blisters; Class IV has multiple bullae with diameter >2cm. This grading method has clinical practical value for guiding the selection of reasonable treatment methods, such as grade I idiopathic pneumothorax, direct visual observation of near normal appearance, but in recent appearance High-definition endoscopes and TV monitors can be enlarged to reveal pulmonary blisters with a diameter of 1 to 2 mm. They can be directly closed by laser or electric knife through endoscope, or talcum powder can be added. Induction of pleural fixation, grade II can still be directly coagulated by laser or electrocautery, or blocked with fibrin glue, but the adhesive band must be decomposed during surgery. Class III can be directly coagulated with a laser with a diameter of <2cm, but must be added in different ways. Pleural fixation, grade IV is a plurality of giant bullae, can withstand thoracotomy, can be simple bullous resection or pulmonary wedge resection, can not tolerate thoracotomy, then thoracoscopic injection Talc powder (or tetracycline hydrochloride, etc.) for pleurodesis.

Some scholars according to pulmonary bullae or combined with spontaneous pneumothorax for thoracotomy and histological examination, the bullous bullous is divided into 3 types: type I: a parenchyma cyst, almost no communication with the bronchus, basically belongs to the extra-pulmonary nature, single Cavity, no trabeculae in the cavity, the diameter is usually a few centimeters, sometimes up to 15 ~ 25cm, the common X-ray chest is obvious, and the formation of tensional bullous emphysema, the surgical treatment of this type of large bubble, the best treatment effect Type II: The large vesicle is of medium diameter and fibrotic thick wall. It is located deep in the lung parenchyma and belongs to the large sac in the lung. The large vesicle is separated by many intervals. Only the surface part is visible under the thoracoscope. Type II pulmonary bullae, patients can be asymptomatic, X-ray chest radiographs can also be non-existent, but spontaneous pneumothorax is caused when the big bubble ruptures, ruptured large bubbles can generally be seen under thoracoscopy, type III: large Pulmonary bullae, and not only in one lung lobe, there are multiple trabeculae in the vesicle, and extensive communication with the bronchus, this type is the most common cause of diffuse bullous emphysema, and once it is ruptured, it forms a spontaneous pneumothorax. Incidence rate Mortality rates are high.

In 1980, Ohata et al reported 253 cases of 334 spontaneous pneumothorax patients undergoing thoracotomy, of which 126 were histological light microscopy and 60 cases of emphysema were divided into three types based on scanning electron microscopy: Reid type I, Reid type II and giant bullae, Reid type I is characterized by excessive expansion of lung tissue to form large bubbles, narrow neck and clear boundaries between the entire lung structure; pleural thinning at the large bubble, surface mesothelium The cells are sparsely distributed, and some areas are even completely lacking, so that the collagen fibers are exposed to the outside, and small pores or fissures of several micrometers can be seen. The base of the large bubble is flat, composed of amorphous substances, scattered with small ovals. Hole, microscopic observation of the small hole caused by air leakage during surgery, electron microscopy found that there is no complete mesothelial cells around the small hole, there is no cell material on the inner surface of the large bubble, but instead of the wavy collagen fiber bundle, Reid II type is characterized by large lung The blister is shallow; the neck is wide, and the boundary between the whole lung tissue is unclear. Electron microscopy shows that the pleural surface mesothelial cells in the large vesicle are relatively intact, and short microvilli are seen, but there are still areas. Without mesothelial cell coverage, like the Reid I type large bubble, the deteriorated alveoli are exposed to the cavity of the large bubble; the alveolar structure is relatively normal, and the Cohn hole is visible, and the huge large bubble is large, occupying 1/ of the unilateral chest cavity. 3 or more, the large bubble wall is thin and translucent. The surface of the large bubble is almost normal, and there are normal size mesothelial cells and thick and short microvilli and normal alveolar structures. Therefore, the author further clarifies according to the pathology of pneumothorax. Its pathogenesis suggests that the formation of spontaneous pneumothorax does not have to be based on the rupture of large vesicles, but may be due to the rare or complete lack of pleural mesothelial cells (such as Reid type I), in the case of increased intrapulmonary pressure, air It is caused by the rupture of the large vesicle wall into the pleural cavity, which emphasizes that pleural mesothelial cells play an important role in the occurrence of spontaneous pneumothorax.

Pneumothorax prevention

Cold weather will aggravate the inflammation of the respiratory tract. Multiple alveolar ruptures form a large alveolar tract. 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 severe respiratory diseases in the winter. Special attention should be paid.

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

Pneumothorax complications Complications

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

(1) Hemopharonic chest (hemopneumothorax) spontaneous pneumothorax caused by tearing of blood vessels in the pleural adhesion zone, rapid onset, except for chest tightness, shortness of breath, chest pain continued to increase, accompanied by dizziness, pale complexion, fine veins Speed, hypotension, etc., a large number of signs of pleural effusion in a short period of time, X-ray showed a liquid-vapor level, and thoracic puncture was 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 pulmonary dilation are: traction of the pleural adhesion zone, which keeps the pleural septum open; the hiatus passes through the cyst or lung tissue, forming the bronchopleural fistula. The visceral pleural surface is cellulose-stable, mechanized, restricting the expansion of the lungs; the bronchial lumen lesions cause complete obstruction, so that the collapsed lungs cannot be re-inflated.

In addition, it can also be complicated by pneumothorax and bronchopleural palsy. If it is not treated in time, it can cause acute progressive respiration and death from circulatory failure due to lung atrophy and mediastinal pressure displacement.

Pneumothorax Symptoms Common symptoms Chronic pleural pleural shock Dyspnea alveolar rupture pleural thickening dry cough pleural adhesions breath sounds weakened chest pain

1. Symptoms The severity of pneumothorax depends on the speed of onset, the degree of compression of the lungs and the condition of the primary lung disease. The typical symptoms are sudden chest pain, followed by chest tightness and difficulty breathing, and may have irritating cough. Chest pain is often acupuncture or knife cutting, the duration is very short, irritating dry cough is caused by gas stimulation of the pleura, most of the onset of sudden onset, large amount of pneumothorax, or with the original lesions of the lungs, the air is obvious, Some patients have severe cough before the pneumothorax, exerting force to breathe stools or lifting heavy objects, but many patients develop symptoms during normal activities or quiet rest. Young healthy people have little discomfort in moderate pneumothorax, sometimes patients only Physical examination or routine chest fluoroscopy is only found; elderly people with emphysema, even if the lungs are less than 10% compressed, can cause significant breathing difficulties.

Patients with tension pneumothorax often show high mental tension, fear, irritability, shortness of breath, suffocation, cyanosis, sweating, and a weak and rapid pulse, decreased blood pressure, cold skin and other shock states, and even unconsciousness, coma, If not rescued in time, it often leads to death.

Patients with pneumothorax generally have no fever, increased white blood cell count or increased erythrocyte sedimentation rate. If these manifestations are present, the original pulmonary infection (tuberculosis or suppurative) activity or complications (such as exudative pleurisy or empyema) are often suggested. ).

A few patients may have bilateral pneumothorax, which accounts for 2% to 9.2% of spontaneous pneumothorax, or even 20%. For those over 20 years old, the ratio of male to female is 3:1, with dyspnea as a prominent performance, followed by For chest pain and cough, the incidence of bilateral sporadic spontaneous pneumothorax (ie, the first side followed by bilateral pneumothorax) was higher than that of bilateral spontaneous pneumothorax, which was 83.9%.

Part of pneumothorax patients with mediastinal emphysema, dyspnea is more serious, often with obvious cyanosis, less common is the pleural adhesion band or pleural vascular tear in the pneumothorax occurs to produce blood pneumothorax, if the amount of bleeding, can be expressed For signs of paleness, cold sweat, weak pulse, and decreased blood pressure, most patients have only a small amount of bleeding.

When asthma patients are in persistent state of asthma, if the condition continues to deteriorate after active treatment, consideration should be given to whether or not pneumothorax is complicated. Conversely, patients with pneumothorax sometimes have asthma-like symptoms, and the air is acute, and even the lungs are full of wheezing. The pleural cavity is decompressed, and the air rush and wheezing sound disappear.

2. Signs Depending on the amount of gas and whether it is accompanied by pleural effusion, a small amount of pneumothorax is not obvious, especially in patients with emphysema, the percussion response is also enhanced, it is difficult to determine the pneumothorax, but the auscultation of respiratory sounds is of great significance. In patients with emphysema and pneumothorax, although the breath sounds on both sides are weakened, the weakening of the pneumothorax is more obvious than that of the contralateral side. Even if the amount of pneumothorax is small, this change is important. Therefore, it is very important to carefully compare the breath sounds on both sides. Auscultation is more sensitive than percussion, so the combination of percussion and auscultation should be used, with special attention to the slight changes in contrast and contrast.

If the amount of pneumothorax is above 30%, the thoracic side of the diseased side is full, the intercostal space is bulging, the respiratory movement is weakened, the percussion is drum sound, the heart or liver dull area disappears, the speech tremor and the breath sound are weakened or disappeared, and the trachea can be made when the pneumothorax is large. And the mediastinum shift to the healthy side, tension pneumothorax can be seen on the disease side of the thoracic bulging and increased blood pressure (may be related to severe hypoxia, blood pressure quickly returned to normal after exhaust).

A small amount of pneumothorax on the left side, sometimes a special cracking sound can be heard at the left heart. Obviously, the patient can detect it himself. The Hamman sign is called, the rupture sound is consistent with the heartbeat, and the patient can hear more clearly when exhaling in the left lateral position. This kind of "sound" pneumothorax is often a small amount of pneumothorax. It is difficult to detect other common signs in the clinic. Therefore, it is one of the basis for diagnosing a small amount of pneumothorax on the left side. The mechanism of this sound may be caused by sudden gas leakage during cardiac contraction. Movement, caused by sudden contact and separation of the two layers of pleura, this sign is also an important sign for the diagnosis of mediastinal emphysema.

A small amount of pleural effusion is often caused by air irritating pleural effusion, but it may also cause blood pneumothorax caused by pneumothorax caused by pneumothorax, a small amount of fluid, physical examination is difficult to find, can only be found from chest X-ray examination, pneumothorax combined with a large number With effusion, the chest can simultaneously detect the signs of gas accumulation and effusion, and shake the chest to have a water sound.

Clinical manifestations of traumatic pneumothorax: in the history of chest trauma, traumatic symptoms and signs, mainly manifested as sudden chest pain, difficulty breathing, occasionally a small amount of hemoptysis, followed by signs of pneumothorax and X-ray findings, if concurrent with hemothorax, There is a manifestation of pleural effusion and internal bleeding.

Pneumothorax examination

1. Blood gas analysis : It shows that PaO2 is decreased, and the arterial-alveolar oxygen partial pressure difference is increased.

2. X-ray performance The most reliable method for diagnosing pneumothorax, showing the degree of lung compression, lung condition, presence or absence of pleural adhesions, pleural effusion and mediastinal shift.

The typical X-ray of the pneumothorax is a thin-lined shadow with a convex curved shape, which is the boundary line between the lung tissue and the gas in the pleural cavity. The line is a compressed lung tissue. The lung texture is not seen outside the line, and the transillumination is obviously increased. When the pneumothorax is extended to the lower part, the rib angle is sharp, and a small amount of gas is often confined to the tip of the lung, which is often covered by the bone. When the patient exhales deeply, the atrophic lung is further reduced, the density is increased, and the external gas is transmitted. The area is in sharp contrast, thus showing the pneumothorax band. The localized pneumothorax is easy to be missed in the posterior anterior X-ray examination. It is necessary to rotate the body position under X-ray to see the pneumothorax. When a large number of pneumothorax is seen, the lungs are compressed and gathered. The hilar area is spherically shaded. If there is lesion or pleural adhesion in the lung, it is lobulated or irregularly shadowed. A large number of pneumothorax or tension pneumothorax shows mediastinum and the heart moves to the healthy side. When pneumothorax is combined with pleural effusion, Then there is a liquid-gas surface, and the liquid level is also changed when the position is changed under the fluoroscopy. If there is a light-transmitting belt around the heart, the mediastinal emphysema should be considered.

According to the chest X-ray, the degree of lung collapse after pneumothorax can be roughly calculated, which has certain significance for clinical treatment. Kircher has proposed a simple calculation method.

Obviously, this formula is only an approximate calculation method. When this method is used, when the width of the airway in the thoracic cavity 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 airway in the thoracic cavity is equivalent to the disease When the lateral thoracic width is 1/3, the lung is compressed by about 50%. When the width of the thoracic cavity is equivalent to 1/2 of the width of the affected thorax, the lung is compressed by about 75%. The above values are different due to individual differences in the thorax shape. Patients can have some differences.

3. CT and MRI findings CT examination of the chest: the basic CT findings of pneumothorax are very low-density gas shadows in the pleural cavity, accompanied by varying degrees of compression and atrophy changes in the lung tissue, generally in the low window position of the lung window Observation, the diagnosis of pneumothorax with a very small amount of gas and the localized pneumothorax mainly located in the anterior middle pleural cavity, X-ray film can be missed, and there is no image overlap on CT, the diagnosis is very easy, most scholars believe that trauma patients In particular, for mechanical respirator ventilation, CT scans should be performed on the CT images of the upper abdomen and lower chest for the observation of a small amount of pneumothorax; CT can also identify pneumothorax and mediastinal emphysema located next to the mediastinum. Pulmonary air sacs, in patients with extensive subcutaneous emphysema, CT examination often found the presence of X-ray plain negative pneumothorax.

The CT findings of pneumothorax vary with the type of pneumothorax, the amount of gas, and the pleural and lung diseases. The gas-free pleural cavity has no lung texture, the density is the same as air, and the inner edge is the visceral pleura. When the pleural adhesions are in the shape of a half-moon, the pleural cavity is irregular when it is stuck. Sometimes the cord-like adhesion fibers are visible. If the effusion or hemorrhage is accompanied by gas-liquid level, the mediastinum is often biased to the healthy side. In severe cases, mediastinal fistula may occur, and the texture of the healthy lung tissue is thickened due to compensatory pulmonary congestion.

MRI examination of the chest: Pneumothorax shows a low signal on MRI. If the amount of gas is small, the compression of lung tissue is not obvious, it is low signal, sometimes it may be missed. There is a lot of gas in the thoracic cavity, and the lung tissue is obviously compressed, showing medium signal. Agglomerate, mediastinal biased to the healthy side, easy to diagnose, such as with pleural effusion, it is gas-liquid level, effusion showed a lower signal on MRI, MRI is very sensitive to the accompanying pleural hemorrhage, on MRI-weighted images High signal.

Pneumothorax diagnosis

diagnosis

According to clinical symptoms, signs and X-ray findings, it is not difficult to diagnose the disease. Obstructive emphysema with spontaneous pneumothorax is often confused with its original symptoms and signs. It is necessary to make a diagnosis by X-ray examination.

The diagnosis of pneumothorax types (closed, open, and tension) can be determined by clinical presentation and intrapleural pressure measurement.

Menstrual pneumothorax and pregnancy with pneumothorax need to be diagnosed by medical history and related examinations. The clinical features of menstrual pneumothorax are:

1 The vast majority of lesions are on the right side, and 35 of a group of 37 patients reported on the right side;

2 The onset is closely related to the menstrual cycle. Most of the symptoms occur within 72 hours before menstruation and 72 hours after the onset of menstruation, but most of them are at 48 hours; repeated with the menstrual cycle;

3 non-menstrual period does not occur;

4 patients with pregnancy or the application of inhibition of ovulation drugs, can prevent the occurrence of this disease;

5 open chest or laparotomy, can be found in the chest, diaphragm and pelvic endometriosis, pregnancy combined with pneumothorax features:

1 more common to young women;

2 spontaneous pneumothorax repeated with each pregnancy;

3 non-pregnancy does not occur.

It is difficult to determine the subpleural bullae and bullae by conventional X-ray examination. The diagnosis rate of chest radiograph is only about 20%. To further define the presence, size and number of lung bullae, the following examination methods can be used:

1. The measurement of the gas component pressure in the pleural cavity helps to identify whether the rupture port is closed. Usually, the gas in the pleural cavity is extracted for analysis. If PO2>6.67kPa (50mmHg) and PCO2<5.33kPa (40mmHg), it should be suspected of persistence. The bronchial pleural fistula; on the contrary, PO2 <5.33 kPa (40 mmHg) and PCO2>6 kPa (45 mmHg), suggesting that the bronchopleural fistula has healed roughly. Qian et al analyzed the pleural gas of 107 patients with spontaneous pneumothorax and confirmed the closure. Pneumothorax has a PO2 <5.33 kPa (40 mmHg) and PCO2 is usually >5.33 kPa (40 mmHg), and its PCO2/PO2 is >1. Patients with open pneumothorax have persistent bronchial pleural fistula, and there are gas and alveolar gas in the thoracic cavity. Traffic, so PO2 is often >13.33kPa (100mmHg), and PCO2<5.33kPa (40mmHg), its PCO2/PO2 are <1, patients with tension pneumothorax continue to enter the pleural cavity due to gas, therefore, PO2 is often >5.33kPa (40mmHg) , PCO2 <5.33kPa (40mmHg), if the patient's PaCO2 is higher, the PCO2 of the gas in the pleural cavity is correspondingly increased, and the PCO2/PO2 ratio is necessarily >0.4, but <1, therefore, the combined application of pleural gas PO2, PCO2 and The PCO2/PO2 ratio has three indicators, which are more important for judging the type of pneumothorax.

2. Pleural angiography is a special diagnostic technique for injecting contrast agent into the pleural cavity and observing the anatomical structure of the pleural cavity and the corresponding lung disease site under X-ray. It is helpful for the diagnosis and differential diagnosis of pleural lesions.

(1) Method: preoperative local anesthetic drug and iodine contrast agent allergy test, without pneumothorax, use artificial gas chest or syringe to inject 300 ~ 500ml air into the pleural cavity, on the basis of pneumothorax, use 60% iodine Peptide glucamine or 60% diatrizoate 20 ~ 80ml, or 76% uragrafin (including diatom sodium and diatom sodium) 40 ~ 60ml, which is mixed with 2ml of 2% lidocaine, surely no bubbles in the contrast agent After that, the pleural effusion is slowly injected into the pleural cavity, and then the patient is rotated 360 degrees, so that the contrast agent is evenly distributed throughout the pleural cavity, and then the pleural cavity at different postures is observed under X-ray fluoroscopy, and separately taken. The observation position under fluoroscopy includes:

1 supine position: head high position, horizontal position, head low position;

2 prone position: head high position, horizontal position, head low position;

3 standing position: left, right anterior oblique and lateral position, the attachment image of the contrast agent at the lesion.

(2) Results: In 1990, domestic Yu et al performed pleural angiography on 25 patients with spontaneous pneumothorax, showing that the diagnosis rate of bullous bullae reached 100%; the angiographic image showed cystic translucent or cystic bulging images. Round, 0.5 to 10 cm in diameter, single or multiple clusters, clusters of grapes, and the diagnostic rate of spontaneous X-ray for spontaneous pneumothorax bullae is only 12% to 20%, and Liu et al. Pleural pleural effusion was performed in patients with pneumothorax. 11 cases of bullous bullous, 1 case of simple pleural adhesion, 2 cases of adhesion and bullous bullae, 2 cases of bullous bullous with a small amount of pleural effusion, 1 case of pneumothorax rupture, 1 case of large lung 2 cases of blistering pulsation, and confirmed the location of the lesion, 22 cases of idiopathic pneumothorax reported abroad, only 6 cases of subpleural bullae or bullae were found by chest radiograph, 10 cases were suspicious, but use this In the examination, 22 cases were confirmed to have subpleural pulmonary bullae and pulmonary bullae.

(3) Adverse reactions: There are few adverse reactions in this method. A few cases have mild chest pain. Some patients have mild to moderate fever. Generally, symptomatic treatment can be relieved. The contrast agent injected into the pleural cavity is mostly 3 to 6 days. Excreted from the urine.

3. Inhalation of radionuclide for the diagnosis of spontaneous pneumothorax leakage method In 1991, Xu et al reported that acupuncture or surgery was used to make an artificial pneumothorax model for 9 dogs, and ultrasonic atomization inhaled 99mTc-sodium phytate aerosol. Then, the GCA90- camera was used for lung scan. Two closed pneumothorax dogs showed pneumothorax-like lung shadow reduction, crescent-shaped radioactive defects in the thoracic cavity, and 7 traffic-type pneumothorax dogs. A total of 13 leaky ports were displayed, and The rupture of the lung specimens is consistent. This method is still in the experimental research stage and has the advantages of non-invasive examination, which needs further research and clinical application.

4. Thoracoscopic surgery is an important means of diagnosis and treatment of pleural diseases. In order to find the cause of spontaneous pneumothorax, and to guide the selection of reasonable treatment methods, thoracoscopy is the most ideal, usually under local anesthesia with a single-cavity thoracoscope directly Comprehensive examination of the pleural cavity, camera or biopsy of the lesion, or injection of drugs and surgery, thoracoscopy for the diagnosis of spontaneous pneumothorax is more than 90%, Weissberg for thoracoscopy of 200 patients with persistent or recurrent pneumothorax For pleural examination, 65% were found to be subpleural bullae or bullae, 15% blocked adhesion due to adhesion, and 10% of lungs could not be re-expanded due to pulmonary fibrosis, pulmonary inflammation, obstructive pulmonary disease. Zhang and pleural thickening (due to long-term fixed pneumothorax), 10% found no abnormalities, 21 cases of spontaneous pneumothorax reported abroad, 6 cases of single bullae, 9 cases of multiple pulmonary bullae by thoracoscopic examination; 2 cases were negative, 1 case was found after thoracotomy, and 4 cases were diagnosed as tuberculosis, Marfan syndrome, malignant histiocytosis and menstrual pneumothorax. In a hospital in China, 50 patients with spontaneous pneumothorax were treated. Endoscopy; 35 cases of subpleural bullae or bullae were found, adhesions prevented 10 cases of lung recruitment; 13 cases underwent biopsy under direct vision, showing 12 cases of non-specific inflammation and 1 case of tuberculosis, with a total diagnosis rate of 92%. The test method is simple, safe, high diagnostic rate, good treatment effect, postoperative complications are transient fever and subcutaneous emphysema, and the incidence is low. The spontaneous pneumothorax can be graded according to the results of thoracoscopy to guide the treatment. .

Differential diagnosis

1. Pneumothorax, especially localized or wrapped pneumothorax should be distinguished from giant bullous bullae: both are similar in symptoms, signs and chest X-rays, but careful examination does have different points:

1 Giant lung bullous disease has a long history and symptoms are slower; while the history of pneumothorax is short, symptoms often occur suddenly.

2 The bullous cavity of the lung is round or ovoid, located in the lung field, and the pneumothorax is a band-shaped gas shadow, located in the chest outside the pleural cavity.

3 The upper part of the lung can be seen to sag downwards, and the outer lung tissue extends upwards under the lower edge, while the upper chest wrapped pneumothorax is inclined outwards and downward.

4 If the bullae are in the lower lobe, the ribs are round and blunt, and the compressed lung tissue and/or pleura are visible near the chest wall. There is no fluid plane in the air cavity, and the sulcus angle of the pneumothorax patient can be seen in the liquid level;

5 After a long period of observation, the size of the lung bullae rarely changed, and the shape of the pneumothorax became smaller at any time and finally disappeared.

2. Pneumothorax should be differentiated from myocardial infarction, pulmonary infarction, septum, bronchial asthma, bronchopulmonary cyst and hernia, chronic obstructive emphysema and other diseases: according to medical history, symptoms, signs, combined with chest X-ray, ECG and related examinations can Make an identification.

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