Treatment
Treatment recommendations for pneumothorax vary significantly from guideline to guideline. The treatment methods for pneumothorax include conservative observation and treatment, pleural puncture and aspiration, closed chest drainage, and surgery. The appropriate method of treatment can be selected according to the patient’s symptoms, hemodynamic stability, the size of the pneumothorax, the cause of the pneumothorax, the initial or recurrence, and the effect of initial treatment.
The main differences between the treatment recommendations of different guidelines for primary and secondary pneumothorax are listed below. For example, the evaluation of the size of the pneumothorax varies from guideline to guideline. The British Thoracic Society (BTS) defines the distance between the lateral chest wall and the incisive lung margin >50px as a massive pneumothorax, whereas the American College of Chest Physicians (ACCP) defines the distance between the apex of the pleura and the lung apex >75px as a massive pneumothorax. The BTS guideline evaluation method is better than the ACCP guideline in determining the appropriate patients for closed chest drainage in the “safety triangle”.
1.Primary spontaneous pneumothorax
If the pleural cavity rupture is closed, the air accumulation in the pleural cavity will gradually decrease because the pulmonary capillaries can absorb the air in the pleural cavity by themselves. Studies suggest that conservatively treated patients can absorb 2.2% of the volume of gas in the pleural cavity (the area of pneumothorax on chest X-ray) by themselves every day. High oxygen concentrations are often given to conservatively treated patients because the rate of absorption is 4 times faster with oxygen.
The indications for pleurodesis differ between the 2001 ACCP guidelines, which recommend pleurodesis for massive primary pneumothorax (>50 px), and the 2010 BTS guidelines, which recommend closed chest drainage for such patients, and fine tube puncture drainage for only some massive pneumothorax patients requiring further surgical treatment.
Since the efficacy of large-bore surgical cannula drainage is close to that of fine tube drainage, and because fine tube drainage reduces patient discomfort, both guidelines do not recommend the use of large-bore surgical cannula drainage in patients with primary pneumothorax, and recommend the use of Seldinger puncture for fine tube drainage (Seldinger puncture uses a puncture needle to penetrate and then feed a guidewire, which is withdrawn and fed into the chest cavity along the guidewire to achieve drainage). The purpose of drainage is achieved).
In a prospective randomized trial of 56 patients with massive primary pneumothorax, there was no significant difference in treatment success and recurrence rates between pleurodesis and closed chest drainage, but pleurodesis aspiration significantly reduced the number of days in hospital, and therefore pleurodesis aspiration can be used to treat patients with massive primary pneumothorax.
An early published Cochrane systematic review, although only a single-center randomized controlled study was included, also suggested that pleurodesis and closed-chest drainage both had similar early effects and outcomes after 1 year of treatment, but the former had a lower rate of patient hospitalization.
2.Secondary spontaneous pneumothorax
Secondary pneumothorax often requires more aggressive management due to the number of complications, significant symptoms and impact on cardiopulmonary function, and both the ACCP guidelines and the BTS guidelines therefore recommend hospitalization for all patients with secondary pneumothorax. Patients with secondary pneumothorax can be treated with oxygen, but caution is needed in patients who are prone to CO2 retention.
Although almost all patients eventually require closed chest drainage, the BTS guidelines recommend attempting pleurodesis for small amounts of asymptomatic secondary pneumothorax (1-50 px), but not for ACCP.
In secondary pneumothorax, the pleural rupture is often less likely to close on its own than in primary pneumothorax, so the average hospital stay is longer, and some studies have demonstrated that the average hospital stay in secondary pneumothorax patients is more than 10 days longer than in primary pneumothorax patients.
Pneumothoracic patients who do not close the ruptured pleural cavity for 48h must be seen by a thoracic surgeon and given an individualized treatment plan, with further surgical treatment depending on the risk of recurrence and surgical complications. Some patients who are not suitable for surgical treatment will require longer conservative treatment or less invasive treatment.
3.Negative pressure suction
If the pleural rupture does not heal after closed chest drainage, the air bubbles continue to escape from the water seal bottle, and the lung reopening is incomplete, the addition of negative pressure suction can be considered. Theoretically, negative pressure suction can promote healing of the rupture by increasing gas drainage in the pleural cavity and bringing the dirty pleura into contact with the wall pleura. However, a randomized controlled study of 23 patients with pneumothorax found that negative pressure suction did not increase lung resuscitation rates or reduce hospital length of stay.
Therefore, the BTS guidelines do not recommend the routine use of negative pressure suction in pneumothorax patients, but only in patients with poor pulmonary resuscitation. As part of high-flow low-pressure suction therapy, the negative pressure is generally set at -10 to -500 px H2O. High-flow low-pressure suction reduces air leakage and also prevents a large amount of inhaled gas from entering the chest tube and reducing effective breathing. In addition, it should be noted that the use of negative pressure suction should be avoided in the early stage of closed chest drainage because the lung reopening too quickly can lead to reopening pulmonary edema.
4.Surgical treatment
Both axillary small incision opening and thoracoscopy have been successfully applied in the treatment of recurrent pneumothorax. In a recent randomized controlled study, a total of 66 patients with primary and secondary pneumothorax were enrolled, and a comparison between axillary mini-incision and thoracoscopic treatment showed no significant difference in the postoperative recurrence rate (2.7% vs. 3%) and pain level. However, although thoracoscopic treatment was more time-consuming than small axillary incision open-chest treatment, the postoperative patient satisfaction was higher (based on the use of the affected arm after surgery) and the return to normal life was faster.
5.Pleural fixation
Injection of sclerosing agents such as tetracyclines and talcum powder via the chest tube, as well as wiping the wall pleura with gauze or injecting sclerosing agents during surgery, can induce aseptic pleural inflammation and cause adhesion of the dirty layer and wall pleura, thus eliminating the pleural cavity gap, and the method is called pleural fixation. Injection of sclerosing agent via the chest tube is chemical pleural fixation, while via surgery is surgical pleural fixation. To avoid local pain caused by pleural inflammation, pleural fixation requires adequate pleural anesthesia and analgesia.
A randomized controlled study from Taiwan included 214 patients with primary pneumothorax to evaluate the effect of pleural fixation with minocycline, all of whom were treated with or without pleural fixation according to a randomized control principle with chest drainage via a fine tube. The results showed that the 1-year recurrence rate of patients treated with pleural fixation was 29.2%, which was significantly lower than that of the control group (49.1%).
However, pleural fixation has been questioned to some extent. One study showed a 1-year recurrence rate of 33% in patients without pleural fixation, which was lower than the 49.1% rate in the control group described above, and pleural fixation required a two-day hospital stay. An early small sample randomized controlled study compared the recurrence rate of closed chest drainage alone (control group) with the addition of pleural fixation with tetracycline or talcum powder. After a mean follow-up period of 4.6 years, the recurrence rate was found to be 8% in the pleural fixation group compared to 36% in the control group.
Because surgery significantly reduced the postoperative recurrence rate in patients with pneumothorax to only 3%, which is lower than the reported recurrence rate suggested by pleural fixation, the BTS guidelines consider chemical pleural fixation only for patients with persistent air leaks who are not candidates for surgical treatment and do not recommend it as the treatment of choice.
New treatment methods
1. Conservative treatment
The BTS guidelines recommend conservative treatment for small amounts of pneumothorax (distance between the lateral chest wall and the lung margin <50px< span="">) without significant symptoms of chest tightness and shortness of breath, or for large amounts of pneumothorax with mild symptoms. In a randomized controlled study currently underway in Australia, pulmonary reopening, clinical symptoms, complications, and recurrence were compared after 8 weeks of conservative treatment (discharge after clinical observation of stable disease) and standard treatment (pleural puncture and aspiration and closed chest drainage if necessary) in patients with massive pneumothorax treated by different modalities.
2. Quantification of air leakage
Compared with the traditional water seal bottle, the new digital chest closed drainage system can quantify the air leakage in pneumothorax patients. The system is mainly used for the management of long-term pulmonary air leakage after thoracic surgery, and also for the early classification of pneumothorax patients, distinguishing those who are prone to persistent air leakage from those who have better results with closed chest drainage.
3.Endobronchial valve
Endobronchial valves are mainly used for non-surgical volume reduction in patients with emphysema and for the treatment of persistent air leaks in patients with pneumothorax. A transbronchoscopic placement of a segmental or subsegmental bronchial placement with a unidirectional valve collapses the distal lung, reducing air entry into the distal lung tissue without affecting gas exhalation.
A previous study reported the use of a unidirectional bronchial valve to treat 40 patients with persistent air leak, 25 of whom had spontaneous pneumothorax. 93% (n=37) of the patients had a reduction or disappearance of air leak, and 48% (n=19) had a complete disappearance of air leak. At present, as a non-surgical treatment, bronchial flap can be applied to patients with pneumothorax who have poor results with traditional conservative treatment, but further prospective trials are needed to prove it.
4.Autologous blood transfusion
One study reported the application of intrapleural autologous blood transfusion to treat 44 patients with advanced COPD, secondary pneumothorax, and persistent air leak after 7 days of closed chest drainage, and this method successfully reduced the air leak rate on the 13th day after treatment. The effect was better.
Intra-thoracic autologous blood transfusion also had some complications, with 14% of patients developing hypothermia, but the temperature returned to normal quickly after antibiotic treatment. This study suggests that intrathoracic autologous blood transfusion may be an effective alternative to chemical pleural fixation for patients at greater risk for surgical treatment.
5. Ambulatory treatment
The Heimlich unidirectional valve can replace the water-sealed bottle connected to a closed chest drain, providing a convenient daytime outpatient treatment option for patients with pneumothorax, which has good application prospects. In a randomized controlled trial of 48 patients with primary pneumothorax, all patients were seen in the emergency room and treated with either a Heimlich unidirectional valve or thoracentesis aspiration.
The results showed no significant difference in hospitalization rates between the two, 44% (n=11) and 61% (n=14), respectively. At initial follow-up, 24% (n=6) of Heimilich unidirectional valve-treated patients had complete lung recovery, whereas only 4% (n=1) of patients treated with thoracentesis aspiration had complete lung recovery, and patients tolerated both approaches easily. patients treated with Heimilich unidirectional valve had their chest tubes removed at an average of 3.5 days.
A systematic evaluation (n=1235) evaluated the effectiveness of Heimlich unidirectional valve therapy, and although the systematic evaluation included data from a large number of nonrandomized controlled trials and may be subject to bias, the results showed an overall success rate of 85.8% for Hemilich unidirectional valve therapy, including 77.9% for patients treated on an outpatient basis.
Hemilich unidirectional valve treatment reduced the hospitalization rate and complication rate, with a complication rate of 1.7%. Further randomized controlled trials with large samples are needed to evaluate the value of the Heimlich unidirectional valve in the treatment of pneumothorax.