According to the rupture of the dirty pleura and its effect on the intrathoracic pressure after its occurrence, spontaneous pneumothorax is divided into the following three types.
I. Closed pneumothorax (simple)
During expiratory lung retraction, or due to the presence of plasma exudate, the rupture of the dirty layer pleura closes by itself and no more air leaks into the pleural cavity.
The intrapleural cavity manometry shows an increase in pressure, and after pumping, the pressure drops and does not rise again, indicating that the rupture no longer leaks air. The residual gas in the pleural cavity will be absorbed by itself, and the pressure in the pleural cavity can maintain the negative pressure, and the lung will be reopened gradually.
Second, tension pneumothorax (high-pressure)
Pleural rupture forms a live valve obstruction, which opens when inhaling and air leaks into the pleural cavity; it closes when exhaling, and the gas in the pleural cavity cannot return to the respiratory tract through the rupture and is discharged out of the body. As a result, more and more gas accumulates in the pleural cavity, forming a high pressure, making the lungs under pressure, breathing difficulties, mediastinum pushed to the healthy side, and circulation is also impaired, requiring emergency exhaust to relieve symptoms.
If the pressure in the pleural cavity on the affected side rises, after pumping to negative pressure, the positive pressure is restored soon, a continuous pleural venting device should be installed.
Third, open pneumothorax (traffic)
Because of the adhesion and pulling between the two layers of pleura, the rupture is continuously opened, and air flows freely in and out of the pleural cavity during inspiration and expiration. The pressure in the pleural cavity on the affected side is 0 up and down, and the pressure does not decrease when observed for several minutes after pumping.
According to the pathogenesis pneumothorax can be divided into the following types.
1, post-traumatic pneumothorax: caused after a sharp object stab wound to the chest.
2, primary pneumothorax: pneumothorax occurring in healthy people without obvious lung lesions, mostly seen in young adults aged 20-40 years old, more common in men
3, secondary pneumothorax: a pneumothorax occurring secondary to various diseases of the lung based on chronic bronchitis, emphysema, tuberculosis, lung cancer, etc.
Primary pneumothorax is usually caused by congenital lung tissue hypoplasia, the presence of small pulmonary blisters or pulmonary blisters under the pleura after breaking the wall, the lesion is often located in the apical part of the lung; secondary pneumothorax is due to the original lung lesion, the formation of subpleural pulmonary blisters rupture or due to the lesion itself directly damage the pleura.
Spontaneous pneumothorax is mostly unilateral, and only about 10% of the patients have bilateral pneumothorax at the same time, while secondary pneumothorax has a great chance of being bilateral at the same time, and patients often have sudden chest pain after pneumothorax, which is sharp and persistent stabbing pain or cutting pain. The severity is closely related to the speed and type of pneumothorax, the degree of lung atrophy and the basic lung function. Unilateral closed pneumothorax, especially in young people with normal lung function, can have no obvious dyspnea, or even 80-90% lung compression or only feel slightly short of breath when moving or going upstairs, while tension pneumothorax or original The elderly with tension pneumothorax or pre-existing obstructive emphysema can have obvious dyspnea, and even when the lung compression is only 20-30%, they have shortness of breath. Irritant dry cough is produced by gas irritation of the pleura, mostly not serious, without sputum or occasionally a small amount of blood sputum, which may come from the site of lung rupture.
Clinical manifestations
Patients often have triggering factors such as holding heavy objects, breath-holding, and strenuous exercise, but there are also cases of pneumothorax occurring during sleep, in which the patient suddenly feels chest pain, shortness of breath, and breath-holding on one side, and may have coughing but little sputum. If the pneumothorax is large or if there is an existing extensive lung disease, the patient often cannot lie down. If the patient lies on his side, he is forced to put the affected side of the pneumothorax on top to reduce shortness of breath. The degree of dyspnea is related to the amount of pneumoperitoneum and the extent of the original intrapulmonary lesion. When there are pleural adhesions and reduced lung function, even a small amount of limited pneumothorax may result in significant chest pain and shortness of breath.
In tension pneumothorax, due to the sudden increase of intrathoracic pressure, the lung is compressed, the mediastinum is displaced, and serious respiratory and circulatory disorders occur, the patient has a tense expression, chest tightness, and even arrhythmia, often struggles to sit up, is irritable, has cyanosis, cold sweat, rapid pulse, deficiency, and even respiratory failure and unconsciousness.
When pneumothorax is complicated by severe asthma or emphysema, symptoms such as shortness of breath and chest tightness are sometimes not easily detected, so it is necessary to compare carefully with the original symptoms and perform chest X-ray. Physical examination shows that the trachea is mostly shifted to the healthy side and there are signs of pneumothorax in the chest.
Signs: If a small amount of air accumulates in the chest, there are often no obvious signs. When there is a large amount of pneumonia, the patient’s chest is full, the rib space is widened, and the respiration is weakened; voice tremor and voice resonance are weakened or disappeared. The trachea and heart are shifted to the healthy side. Percussion on the affected side shows a drum sound. In the case of right-sided pneumothorax, the hepatic turbid boundary may be shifted downward. On auscultation, the breath sounds on the affected side are diminished or absent. If there is liquid pneumothorax, the sound of water vibrating in the chest can be heard. In hemopneumothorax, if there is excessive blood loss, blood pressure may drop and even hemorrhagic shock may occur.