Pneumothorax (pneumothorax) is a condition in which gas enters the pleural cavity and causes pneumatization, called pneumothorax. Mostly due to pulmonary diseases or external forces that rupture the lung tissue and dirty pleura, or rupture the fine emphysema bubble near the surface of the lung, the air in the lung and bronchus escapes into the pleural cavity. Pneumothorax caused by trauma to the chest wall or lung is called traumatic pneumothorax; pneumothorax caused by rupture of lung tissue due to disease is called “spontaneous pneumothorax”, and pneumothorax caused by artificially injecting air into the pleural cavity due to treatment or diagnosis is called “artificial pneumothorax”. Pneumothorax can be divided into closed pneumothorax, open pneumothorax and tension pneumothorax. Spontaneous pneumothorax is mostly seen in young and middle-aged men or those suffering from bronchiectasis, emphysema and tuberculosis. This disease is one of the pulmonary emergencies and can be life-threatening in serious cases, and can be cured by timely treatment.
How to treat different types of pneumothorax?
I. Treatment of spontaneous pneumothorax
The treatment of pneumothorax aims to promote the reopening of the affected lung, eliminate the cause of the disease and reduce recurrence. The basic treatment measures include conservative treatment, exhaust therapy, recurrence prevention measures, surgical treatment and prevention and control of complications, etc.
1.Conservative treatment
Including bed rest, oxygen therapy, as well as analgesia, sedation, cough, laxative, etc. to remove the cause. Weak and poor nutritional status are given appropriate supportive treatment.
(1) Primary pneumothorax with mild symptoms
Patients with small closed spontaneous pneumothorax with mild symptoms only need conservative treatment. Clinical observation is sufficient for more than 80% of patients with pneumothorax volume less than 15%, during which the chance of sustained air leakage is low. Moreover, the recurrence rate of pneumothorax cases under observation alone is lower than that of those who undergo thoracentesis intervention.
(2) Secondary pneumothorax with mild symptoms
Patients with small (<1 cm) secondary pneumothorax or isolated apical pneumothorax without clinical symptoms may be considered for conservative treatment, but hospitalization for observation is recommended.
(3) Symptomatic primary or secondary pneumothorax
These patients are not suitable for conservative treatment and require aggressive treatment, including suctioning or chest tube drainage. Patients with a small amount of pneumothorax (<2 cm) presenting with significant dyspnea may suggest a tension pneumothorax.
2.Exhaustion therapy
(1) Simple suctioning
Suction with a small-bore catheter (14-16G) is comparable to the therapeutic effect of a large-bore (>20F) chest drain, which has the advantage of reducing pain scores and shortening the number of hospital days.
After simple suctioning for secondary pneumothorax, the patient should be admitted for observation for more than 24 h. If there is no improvement, intubation and drainage are required. Simple suctioning has a high failure rate for massive secondary pneumothorax (≥2 cm), especially in patients older than 50 years, and a high recurrence rate, and intubation and drainage should be considered at the outset. Aggressive treatment of the underlying lung disease is also required. Statistical analysis shows a success rate of 30%-80% for simple aspiration therapy. If the total amount of aspirated air is more than 2.5 L, the presence of a persistent air leak with lung reopening is considered less likely, and small catheter cannulation for drainage should be chosen at this time.
More than one-third of patients with primary pneumothorax who fail the initial simple aspiration can be revascularized with a second aspiration. After failure, small catheter cannulation should be considered.
(2) Intercostal cannula drainage
A small chest tube (13F) or a larger tube for closed chest drainage is used as appropriate. One study showed a low success rate of using a small chest catheter (13F) for pneumothorax and recommended a larger catheter, however, later findings did not match this and concluded that a smaller caliber chest catheter was more effective and has not been recommended as the preferred treatment, which requires more experience. The average duration of drainage with a small-bore chest tube drainage system compared to a large-bore chest tube drainage system ranged from 2 to 4 days. No problems with catheter obstruction were found in any of these studies. Chemical pleural fixation can still be performed through the small catheter built-in cannula system. If there is a pleural effusion and a large air leak that exceeds the drainage capacity of a small catheter, then the use of a small catheter is likely to fail, and the choice of a larger catheter is more favorable.
3.Surgical treatment
Surgical treatment should be considered in the following cases.
① ipsilateral recurrence of pneumothorax.
②The first pneumothorax on the opposite side.
(iii) spontaneous pneumothorax occurring on both sides at the same time.
④ persistent air leak or failure to reopen the lung after 5-7 days of intercostal drainage.
⑤ spontaneous hemopneumothorax.
⑥High-risk occupations (such as pilots, drivers, etc.).
⑦ Pregnancy.
The patient’s wishes are also a factor to be considered. Some patients with primary pneumothorax, even if not due to occupational factors, choose surgery after weighing the risk of recurrence against the pros and cons of chronic pain, somatic discomfort, and medical expenses.
(1) Open-heart surgery
To prevent recurrence of pneumothorax, cautery, ligation, or suturing of the concomitant pneumomediastinum at the site of the pleural leak is necessary to close the leak. The postoperative pneumothorax recurrence rate for open-chest surgery is low. The failure rates for ligation/excision of pulmonary blisters, open pleurodesis, and apical or total lung wall pleurodesis are all less than 0.5%. The combined incidence of thoracotomy complications in patients with pneumothorax was 3.7%, mostly sputum retention and postoperative infection. In general, open thoracotomy is performed using unilateral lung ventilation with a lateral thoracotomy for dirty pleurodesis, pneumonectomy, pneumomediastinum ligation, or pleurodesis.
(2) Television-assisted thoracoscopic surgery (VATS)
Compared with surgery, less information is available on VATS for spontaneous pneumothorax. In terms of complications and length of hospital stay, VATS has advantages over open-heart surgery. The complication rate of the least invasive procedure may be similar to that of open-chest surgery, 8-12%. The recurrence rate of pneumothorax after VATS is 5-10%, which is higher than that of open-chest surgery, 1%. Despite the high success rate of thoracoscopic pneumonectomy, pleurodesis, pleurodesis, and surgical pleural fixation, however, there are concerns that VATS performed under local anesthesia with inhaled nitrous oxide may cause progressive unilateral pulmonary ventilation difficulties and may also make it more difficult to examine the entire dirty pleural surface and increase the risk of missed pneumomediastinum.
Some studies suggest that VATS may be more appropriate for young patients with complex or recurrent primary pneumothorax and less appropriate for secondary pneumothorax. For patients with secondary pneumothorax, open-chest surgery with pleural repair is still the currently recommended approach, while VATS should be used as an alternative for patients who cannot tolerate open-chest surgery because of poor lung function.
II. Complications of pneumothorax and its treatment
1.Hemopneumothorax
Pneumothorax bleeding is caused by the tearing of blood vessels in the pleural adhesion zone, and the bleeding can mostly stop by itself after lung reopening. If the bleeding persists and exhaustion, hemostasis and blood transfusion are ineffective, open-chest surgery should be performed to stop the bleeding.
2.Pneumothorax
Caseous pneumonia, necrotizing pneumonia and lung abscess caused by Mycobacterium tuberculosis, Staphylococcus aureus, Mycobacterium pneumoniae, anaerobic bacteria, etc. can be complicated by pneumothorax, which should be urgently drained and exhausted, and effective antibacterial drug treatment (systemic and local) should be selected. Bronchopleural fistulas need to be treated surgically if they persist.
3.Mediastinal emphysema and subcutaneous emphysema
After tension pneumothorax aspiration or closed drainage, subcutaneous emphysema of the chest wall may appear along the pinhole or incision. The high-pressure gas enters the interstitial lung, enters the mediastinum through the pulmonary hilum via the vascular sheath, and then enters the subcutaneous tissue of the neck and the subcutaneous chest and abdomen along the fascia. The chest x-ray shows a transparent band in the subcutaneous and mediastinal area. Subcutaneous emphysema and mediastinal emphysema can be absorbed by themselves with the decompression of gas discharge in the pleural cavity. If the tension of mediastinal emphysema is too high and affects respiration and circulation, suprasternal fossa puncture or incision can be made for exhaustion.
Third, other types of rare pneumothorax
1.Pneumothorax combined with pregnancy
Although the incidence of pneumothorax in women is lower than that in men, pneumothorax in women of childbearing age is not uncommon. The recurrence rate of pneumothorax during pregnancy and delivery is high, thus posing a potential hazard to the mother and fetus. Early literature recommended aggressive treatment modalities, such as prolonged chest drainage, thoracotomy, or early termination of pregnancy. In recent years, a change in opinion has been observed, suggesting that conservative treatment modalities can be equally effective. If the mother is not in respiratory distress, the fetus is not in discomfort, and the pneumothorax is <2 cm then it can be temporarily observed. If there is a persistent air leak then chest tube drainage is recommended. A less invasive television-assisted thoracoscopic procedure (VATS) can be chosen after delivery to avoid recurrence in subsequent pregnancies.
To avoid recurrence of pneumothorax during spontaneous delivery and cesarean section, the safest way is to induce the fetus before full term using forceps or suction under epidural anesthesia. If a cesarean section must be chosen, needle anesthesia is more appropriate.
2.Catamenial pneumothorax (CPTX)
It is a special type of spontaneous pneumothorax, clinically characterized by recurrent episodes of spontaneous pneumothorax in women during the menstrual cycle, the pathogenesis of which is still unclear and may be related to endometriosis and diaphragmatic foramen ovale. It predominantly occurs on the right side, but it also occurs on the left side or bilaterally. Patients often have a combination of endometriosis in the pelvic, thoracic, and abdominal cavities and the presence of a small diaphragmatic foramen ovale. Spontaneous shedding of ectopic endometrium in the diaphragm and/or pleura and lungs, which occurs during the menstrual cycle, causing spontaneous pneumothorax is the main cause of CPTX. In addition, uneven contractions during menstruation induce gas to enter the uterine cavity and enter the abdominal cavity via the fallopian tubes, at which time the ectopic endometrium occluding the diaphragmatic micropores is shed, the diaphragmatic channels open, and gas enters the thoracic cavity and develops.
The treatment of menstrual pneumothorax requires the collaboration of respiratory, thoracic and obstetrician-gynecologists. The treatment is achieved by changing the patient’s menstrual cycle to avoid the occurrence of endometrial shedding. This method is indicated for older patients who do not need to have children. Surgical treatment is the best option for adolescent patients with clear CPTX endometriosis site, poor results of medical treatment, tension pneumothorax, those with significant pleural thickening to pulmonary expansion insufficiency, and those between 10 and 19 years of age. The options are simple diaphragmatic notch repair, partial diaphragmatic or pleurodesis, partial lung resection with folded sutures, or simple sutures. For women who are not of childbearing age, gynecological surgery including tubal ligation, partial oophorectomy, and hysterectomy may also be an option. Surgical resection can reduce the recurrence rate of pneumothorax to less than 2%, and the most accurate treatment is open-heart surgery plus gynecological surgery (especially hysterectomy), which is almost recurrence-free.
3.AIDS combined with pneumothorax
More than 5% of AIDS patients are combined with pneumothorax, and 40% of patients are bilateral pneumothorax. Nearly 25% of patients with spontaneous pneumothorax are combined with AIDS. Pneumosporidiosis (Pneumocystis carinii pneumonia) is the most important risk factor for the development of pneumothorax in patients with AIDS, with imaging manifestations such as cysts, pulmonary bullae or pulmonary blisters. Studies have shown that pentoxifylline aerosol prophylaxis is an independent risk factor for the development of pneumothorax. In addition, the application of systemic glucocorticoids is also a risk factor for the development of this group of patients.
Patients with AIDS who develop Pneumocystis carinii infection combined with pneumothorax are often characterized by persistent air leakage, difficulty in treatment, recurrence and high mortality. Moreover, the more immunosuppressed the patient is, and the lower the CD4 count, the worse the outcome of pneumothorax treatment. Treatment methods include closed chest drainage, pleurodesis or partial pleurodesis. It is often difficult to treat pneumothorax with suction alone.