INTRODUCTION — Gas in the pleural space is termed pneumothorax. Pneumothorax can be a life-threatening condition that needs prompt attention.
The management of primary spontaneous pneumothorax is discussed in this topic review. The etiology and diagnosis of pneumothorax, and the management of secondary spontaneous pneumothorax are discussed separately. (See "Pneumothorax in adults: Epidemiology and etiology" and "Clinical presentation and diagnosis of pneumothorax" and "Treatment of secondary spontaneous pneumothorax in adults".)
DEFINITION — A spontaneous pneumothorax is considered one that presents in the absence of an external factor. The management strategies of primary spontaneous pneumothorax (PSP; that which presents in the absence of clinical lung disease) and secondary spontaneous pneumothorax (SSP; that which presents as a complication of underlying lung disease) (table 1) differ in their threshold to perform a chest tube thoracostomy and a definitive procedure to prevent recurrence. Thus, following the radiographic identification of pneumothorax, clinicians should quickly estimate the size, assess the degree of symptomatology, and attempt to classify the pneumothorax as primary, secondary, or other (trauma, iatrogenic) so that appropriate therapy can be initiated.
INITIAL MANAGEMENT FOR FIRST EVENT — All patients with primary spontaneous pneumothorax (PSP) should receive resuscitation with a focus on airway stabilization (if indicated) as well as supplemental oxygen which treats hypoxemia (if present) and facilitates absorption of air from the pleural space. Subsequent management is directed at deciding whether air needs to be removed from the pleural space and, if so, by what means; options include observation with or without supplemental oxygen, needle aspiration of intrapleural air, and chest tube or catheter thoracostomy (algorithm 1).
The approach to managing PSP varies widely among institutions and across continents. Our approach expands upon that outlined in published clinical consensus statements and guidelines from The American College of Chest Physicians (ACCP; 2001), British Thoracic Society (BTS; 2010), European Respiratory Society (2015), and the Japanese Association for Chest Surgery (2014) [1-4]. While some experts use a symptom-driven approach and others prefer a size-driven approach, we prefer one that primarily incorporates size and symptoms.
Assessment of size and stability
Definition of size limits — Size assessment for PSP in the United States typically uses a cutoff of 3 cm between the pleural line and the chest wall at the level of the apex on a chest radiograph [2] while in Europe, physicians use a cutoff of 2 cm at the level of the hilum [1,3]. Pneumothorax size estimated by the average intrapleural distance ("Collins method") is more commonly used for research purposes. All approaches are acceptable and have their own advantages and disadvantages; none is perfect. Estimation of size is usually only performed on chest radiography (and less commonly chest computed tomography [CT]). Ultrasonography cannot reliably quantify pneumothorax size; after ultrasound is used to identify a pneumothorax, we believe that chest radiography should be done to estimate the size, although practice may vary considerably and no guidelines are available to facilitate this decision. Further details regarding the assessment of size are provided separately. (See "Clinical presentation and diagnosis of pneumothorax", section on 'Pneumothorax size'.)
Definition of stability — The definition of stability suggested by the ACCP [2] comprises patients with all of the following:
●Respiratory rate <24 breaths per minute
●Heart rate <120 and >60 beats per minute
●Normal blood pressure (not defined)
●Room air oxygen saturation >90 percent
●Ability to speak in whole sentences
All other patients are considered unstable.
Management strategy
Stable patients — Initial management of stable patients who present with PSP depends upon the size of the pneumothorax, associated symptoms, and whether the event is a first or a recurrent event (algorithm 1). Additional factors include the presence of bilateral pneumothorax, concurrent pleural effusion that may need to be drained, and presence of complex loculations.
Small (≤3 cm at apex or ≤2 cm at hilum) — Clinically stable patients (see 'Definition of stability' above) with a first episode of PSP that is small (see 'Definition of size limits' above) should be treated with observation with or without supplemental oxygen and be discharged, if feasible. The rationale for this approach is based upon our experience and data from one trial [5] that suggest many patients in this category improve with this strategy without an invasive procedure for the removal of gas. The administration and period of observation and follow-up for those on observation with or without oxygen are discussed below. (See 'Observation alone' below and 'Supplemental oxygen and observation' below.)
Occasionally, patients with significant symptoms despite the small pneumothorax size should have aspiration or chest tube thoracostomy since these patients are more likely to have worsened symptoms or signs if the pneumothorax should increase. However, a presentation that is disproportionate with the small size is unusual in PSP (because underlying lung disease is absent) and should prompt consideration of an unidentified underlying lung disorder; this should not delay the implementation of therapy. (See 'Tube or catheter thoracostomy' below and "Clinical presentation and diagnosis of pneumothorax", section on 'Patients without a clear cause'.)
Large (>3 cm at apex or >2 cm at hilum) — Options for patients with a first occurrence of PSP that is large include aspiration, chest tube thoracotomy with or without an ambulatory device, or observation. Choosing among these options is dependent upon the severity of symptoms and local expertise. For most patients who are clinically stable (see 'Definition of stability' above) with a first PSP that is large (see 'Definition of size limits' above) needle or catheter aspiration is traditionally the standard of care provided expertise is available, an approach that is supported by most guidelines [1-3]. However, newer approaches that incorporate ambulatory devices or observation are also appropriate in select individuals.
●Aspiration – Aspiration is particularly suitable for patients who are symptomatic (at rest or during ambulation) or need oxygen [1,6,7]. The rationale for this approach is based upon meta-analyses of small randomized trials that report similar recurrence rates at one year with needle aspiration compared with chest tube or catheter thoracostomy and shorter hospital stays, the details of which are discussed below. (See 'Aspiration' below.)
Although some guidelines encourage needle or catheter aspiration [1], they have not been widely followed [8] which may be due to the ease and wide availability with which small-bore intrapleural catheters can be placed for pleural drainage.
●Chest or catheter thoracostomy with or without an ambulatory device – Many physicians choose this option likely due to the ease with which they can be placed, the lower failure when compared with aspiration, and the ability to use them for continued drainage using a water seal device (requiring hospital admission) or an ambulatory device (allowing select patients to be discharged) [9]. In reality, choosing between needle aspiration and catheter or chest tube thoracostomy with or without an ambulatory device is often dependent upon availability of local expertise, severity of the presentation, and patient preference. For example, needle aspiration is less painful than catheter or tube insertion. However, the initial failure rate is higher with needle aspiration (on average one-third of patients), thereby necessitating a second procedure. Some clinicians choose chest tube or catheter thoracostomy when expertise in aspiration is not available or in patients with bilateral, or very large pneumothoraces (eg, complete collapse, mediastinal shift), severe symptoms, concurrent hemothorax or pleural effusion necessitating drainage, or complex loculated pneumothorax (unusual in PSP). (See 'Tube or catheter thoracostomy' below.)
●Observation – A conservative approach such as observation has been shown to be equivalent to aspiration or chest tube drainage in patients with large PSP [5]. Observation should only be considered as an option in otherwise healthy patients who have mild symptoms, no hemodynamic compromise, no oxygen requirement and who can ambulate comfortably. Before guidelines are updated, this approach can be considered an option but not yet a routine recommendation. Data to support this approach are discussed below. (See 'Supplemental oxygen and observation' below.)
The procedure and follow-up of patients who undergo observation, aspiration, or thoracostomy and the efficacy data to support this approach are discussed below. (See 'Supplemental oxygen and observation' below and 'Aspiration' below and 'Tube or catheter thoracostomy' below and 'Observation alone' below.)
Unstable patients — Patients with PSP who are unstable (see 'Definition of stability' above) or have tension should undergo immediate chest tube thoracostomy. If chest tube thoracostomy is delayed, needle decompression of the pleural space is recommended. Noteworthy is that tension pneumothorax is rare in patients with PSP (due to the absence of underlying lung disease or precipitating cause such as central line insertion or mechanical ventilation) [10,11]. Details of the radiographic appearance of, and needle decompression for, tension pneumothorax are discussed separately. (See "Clinical presentation and diagnosis of pneumothorax", section on 'Pneumothorax appearance and types' and "Initial evaluation and management of blunt thoracic trauma in adults", section on 'Pneumothorax' and "Approach to shock in the adult trauma patient", section on 'Tension pneumothorax' and "Initial evaluation and management of penetrating thoracic trauma in adults", section on 'Role of needle/finger chest decompression'.)
TREATMENT OPTIONS — Options for treating primary spontaneous pneumothorax (PSP) include observation alone, observation with oxygen therapy, simple aspiration, and thoracostomy tube/catheter. The role of video-assisted thoracoscopic surgery (VATS) as primary therapy for PSP is unclear.
Observation alone — Observation alone has been studied in patients with a large pneumothorax. In a trial of 316 patients (14 to 50 years) with large PSP (ie, over 32 percent (figure 1)), patients were randomized to receive either conservative therapy (ie, observation for first four hours) or an intervention (ie, chest tube attached to a water seal for first hour, followed by clamping for four hours if there was no air leak), after which a chest radiograph was obtained [5]. In the conservative group, after four hours, patients underwent an intervention if they had oxygen requirements, severe symptoms not improving with analgesia, symptoms preventing mobilization, evidence of instability, a preference for an intervention, or worsening pneumothorax on chest imaging. Stable patients without enlargement on the chest radiograph who did not receive oxygen and could ambulate comfortably were discharged with follow up instructions. In the interventional group, if after four hours the pneumothorax had resolved, patients were discharged; if the pneumothorax had not resolved, patients were admitted for drainage. By eight weeks, there was no significant difference in the proportion of patients who had successful re-expansion (94.4 percent for conservative group versus 98.5 percent for interventional group; risk difference -4.1 percentage points). The time to symptom resolution was also no different, and patients in the conservative group had fewer recurrences during the first 12 months (8.8 versus 16.8 percent), fewer days in the hospital, fewer days off work, and less need for surgery. The conservative group also had fewer adverse events (8 percent versus 26 percent). Study flaws included significant loss to follow up and at study entry 15 percent of patients in the conservative treatment group needed an intervention. This study suggests that while observation alone is not routinely recommended, a subgroup of young, hemodynamically stable, mildly symptomatic patients with large PSP may benefit from this strategy. Before guidelines are updated, we can recommend this as an option for this subgroup provided outpatient followup is acceptable.
Supplemental oxygen and observation — Supplemental oxygen and observation is generally the strategy used in clinically stable patients with a first episode of PSP that is small and without severe symptoms. The rationale for supplemental oxygen in this population is based upon our experience and data from animal models which report that the rate of resorption of air from the pleural space is increased up to six-fold if humidified 100 percent oxygen is administered [12-14]. (See 'Small (≤3 cm at apex or ≤2 cm at hilum)' above.)
Since patients with PSP have no underlying lung disease, oxygenation is generally within normal limits or low normal; thus, oxygen is administered to promote resorption of air (mostly nitrogen) from the pleural space. However, the optimal target fraction of inspired oxygen (FiO2) or peripheral oxygen saturation (SpO2) is unclear. Many experts will deliver high FiO2 (eg, 100 percent oxygen via a nonrebreather mask) targeting an SpO2 of 100 percent while others administer lower FiO2 (eg, 6 to 10 L via nasal cannulae) to target an SpO2 >96 percent. We generally administer >6 L to target an SpO2 >96 percent. High flow oxygen via nasal cannulae (HFNC) should not be used since a small amount of positive pressure is delivered to the upper airway and could theoretically worsen the pneumothorax. For similar reasons, noninvasive positive pressure should also be avoided. (See "Heated and humidified high-flow nasal oxygen in adults: Practical considerations and potential applications" and "Noninvasive ventilation in adults with acute respiratory failure: Benefits and contraindications".)
Observation while on supplemental oxygen should last about four to six hours, after which a chest radiograph should be performed:
●If the radiograph demonstrates no progression or an improvement in pneumothorax size, reliable patients with ready access to emergency medical services can be discharged home off oxygen with instructions to return if symptoms worsen. For patients requiring admission, oxygen should be continued as long as the patient is in the hospital and has a pneumothorax. Regardless of the patient's disposition, a repeat chest radiograph is typically performed 12 to 48 hours later:
•If the pneumothorax is resolved, patients should be followed up in an outpatient setting within two to four weeks with a repeat chest radiograph and be given instructions to be evaluated in an acute care setting should symptoms recur.
•If the pneumothorax fails to improve or worsens, then the pleural air should be removed via catheter or chest tube thoracostomy, although some clinicians repeat the aspiration. Choosing among these is at the discretion of the clinician. (See 'Tube or catheter thoracostomy' below.)
●If the radiograph demonstrates worsening of the pneumothorax, the patient should have a chest tube thoracostomy placed and be admitted. (See 'Tube or catheter thoracostomy' below.)
Aspiration — Aspiration is generally performed in clinically stable patients with a large PSP in facilities with expertise. (See 'Large (>3 cm at apex or >2 cm at hilum)' above.)
We perform catheter rather than needle aspiration using equipment available in most commercial thoracentesis kits since needle aspiration alone may increase the risk of perforating the visceral pleural membrane and perpetuate the pneumothorax. The procedure is typically performed blindly, although ultrasound guidance may be used. Similar to the procedure described for thoracentesis, an 8 to 9 French (Fr) catheter is threaded over an introducer needle into the pleural space generally in the second intercostal space at the mid-clavicular line; the catheter is attached to a three-way stopcock. Once the operator observes that air can be aspirated (ie, demonstrates access to the pleural space), the catheter is threaded deeper into the pleural space, and then the needle is withdrawn. Once the catheter is in place, air is manually aspirated using a syringe (typically 60 cc syringe) attached to the stopcock. Aspiration should continue until resistance is met or 4 L of air has been removed. While BTS guidelines suggest that no more than 2.5 liters should be withdrawn, our experience suggests that up to 4 L may be withdrawn; volumes >4 L suggest that a persistent air leak is present and that further expansion of the lung is unlikely.
●Once resistance is felt during aspiration and no more air can be aspirated, this usually indicates lung re-expansion. In this situation, two equally acceptable approaches exist, which are at the discretion of the clinician [15]:
•The stopcock should be closed and the indwelling catheter secured to the chest wall. A chest radiograph should be obtained four hours later:
-If the lung fully expanded and symptoms have improved, the catheter can be removed. Following an additional two hours of observation, another chest radiograph should be performed. If the lung remains expanded on this chest radiograph, the patient can be discharged with appropriate clinical and radiographic follow up within 24 to 48 hours [16]. If not, a chest tube or catheter thoracostomy should be placed. (See 'Tube or catheter thoracostomy' below.)
-If the lung has not expanded fully or the radiograph demonstrates worsening of the pneumothorax, then a chest tube thoracostomy should be placed. (See 'Tube or catheter thoracostomy' below.)
•The catheter can be left in place and attached to a Heimlich (ie, one-way) valve (picture 1). The patient can then be discharged with clinical and radiographic follow-up within one to two days [2,17,18]. If follow-up imaging demonstrates recurrence, then a chest tube or catheter thoracostomy should be placed. (See 'Tube or catheter thoracostomy' below.)
●If there is no resistance after 4 L of air has been aspirated and/or the lung has not adequately expanded on imaging, it is assumed that there is a persistent air leak, and a chest tube or catheter thoracostomy should be placed. Consideration should be given to a preventive measure as soon as is feasible. (See 'Tube or catheter thoracostomy' below and "Pneumothorax: Definitive management and prevention of recurrence".)
Studies that support aspiration in patients with a first PSP rather than tube or catheter thoracostomy (small- or large-bore) are largely observational or small randomized trials that report efficacy rates ranging from 30 to 80 percent, shorter hospital stays, and fewer complications with aspiration [1,9,19-32]. As examples:
●One meta-analysis of six studies (435 patients) reported that compared with tube thoracostomy without an ambulatory device, simple aspiration was associated with a shorter hospital stay (mean difference -1.66 days, 95% CI -2.28 to 1.04) and a lower adverse event rate; however, aspiration was associated with lower rates of immediate success (risk ratio [RR] 0.78, 95% CI 0.69-0.89) although the success rates at one year were the same in both interventions (RR 1.07, 95% CI 0.96-1.18) [26]. However, this meta-analysis is limited since most of the included trials were small.
●Another 2018 network meta-analysis of 29 randomized trials (4262 patients) similarly reported that in patients with a first episode of PSP there was no difference in the recurrence rate when tube thoracostomy without an ambulatory device or aspiration was used but aspiration was associated with fewer hospital days [31].
●In contrast, another study has reported lower rates of hospital stay in patients treated with drainage using a chest tube or catheter attached to an ambulatory device, allowing the patients to be discharged [9]. In that study, 236 patients were randomly assigned to ambulatory care (a small bore catheter attached to a one-way valve, allowing discharge and ambulation) or standard care (aspiration with a 14 to 16 gauge cannula followed by the insertion of a chest tube, if aspiration was ineffective). Included patients were young (16 to 55 years of age; mean 30 years), had symptoms, were clinically stable, and had no evidence of underlying lung disease. In the ambulatory arm, patients were observed for one to two hours and if a chest radiograph showed no progression, the patients were discharged provided they had no oxygen requirements and were clinically stable, mobile, able to self-care, and lived with a responsible individual at home. All other patients were admitted. Patients in the standard care arm were also observed for one to two hours following aspiration and were discharged if chest radiography showed sufficient lung re-expansion; if lung re-expansion was insufficient, a chest tube was placed and patients were admitted. The ambulatory strategy resulted in a lower length of stay (median difference two days, 95% CI 1-3) but patients had a higher rate of adverse events that were mostly device- or pneumothorax-related (eg, enlarging pneumothorax, device dislodgement or blockage; 55 versus 39 percent). Although the ambulatory strategy was associated with a lower rate of recurrence at seven days (7 versus 19 percent), the recurrence rate at 12 months was no different (24 versus 28 percent) and surgical referral rate was similar (28 versus 22 percent). However, the lower-than-expected rate of aspiration in the aspiration group (68 percent) may have introduced bias that favored the ambulatory strategy.
Tube or catheter thoracostomy — Clinically stable patients with PSP who fail observation or aspiration, patients who are unstable due to pneumothorax, and patients with recurrent PSP should have a tube or catheter thoracostomy placed to water seal and be admitted. The rationale for this strategy is based upon the assumed high likelihood of clinical worsening and the higher risk of recurrence in these subgroups. These data are discussed in more detail above. (See 'Aspiration' above.)
Thoracostomy is also appropriate in centers without expertise for aspiration as well as in patients with bilateral or very large pneumothoraces (eg, complete collapse), severe symptoms, concurrent hemothorax or pleural effusion necessitating drainage, complex loculated pneumothorax (unusual in PSP). (See 'Unstable patients' above and 'Large (>3 cm at apex or >2 cm at hilum)' above.)
Initial thoracostomy management — Chest tube thoracostomy refers to the insertion of a standard chest tube, while catheter thoracostomy refers to the insertion of a catheter (eg, pigtail catheter) (figure 2). Choosing among them is often at the discretion of the clinician and available expertise. However, small-bore catheters are being increasingly used since they are easy to place, less painful, and as effective for the drainage of air as tube thoracostomy. While both can be placed blindly, ultrasound or other imaging modalities (eg, fluoroscopy, computed tomography [CT]) are frequently used to guide chest catheter placement, particularly, when the pneumothorax is loculated. However, if the patient has impending respiratory failure or hemodynamic instability due to pneumothorax, tube thoracostomy without image guidance should be performed immediately.
●Technique for insertion – The technique of insertion of each type of thoracostomy tube is described separately. (See "Thoracostomy tubes and catheters: Placement techniques and complications".)
●Size – In most patients with PSP, a small-bore chest tube (≤22 Fr) or chest catheter (≤14 Fr) is placed [18,23,33-35]. In most cases, a small caliber tube or catheter is sufficient for the drainage of air in patients with PSP. It is unusual in this population that an indication for a large-bore chest tube (eg, 22 to 28 Fr) is present unless the patient is unstable with tension pneumothorax, concomitant drainage of viscous pleural fluid (eg, empyema) or blood is needed, or small-bore catheter drainage is insufficient.
One systematic review that compared small-bore pigtail catheters with large-bore chest tubes in patients with both PSP and secondary spontaneous pneumothorax (SSP) reported that the success rate was similar in both groups (80 versus 83 percent) but pigtail catheters had a lower complication rate (odds ratio 0.49) and shorter drainage duration (mean difference -1.51 days) and hospital stay (mean difference -2.54 days) [36]. (See "Thoracostomy tubes and catheters: Indications and tube selection in adults and children" and "Treatment of secondary spontaneous pneumothorax in adults", section on 'Tube or catheter thoracostomy'.)
●Suction – For the majority of patients, suction is not initially applied and the tube or catheter is connected to a water seal device only [1]. If the lung fails to re-expand within the subsequent 24 to 48 hours, worsens despite chest tube drainage, or develops a persistent air leak, low wall suction can be applied and, in some cases, a second drainage device may be needed.
If suction is applied, we generally start with low rates of -10 cm H2O and increase to -20 cm H2O using a high pressure-low volume system; other forms of suction using high pressure-high volume or low pressure-high volume systems should be avoided [1].
There are few data to support this strategy. However, lung re-expansion is achieved in 70 percent of patients within 72 hours without suction in most cases [18,37]. In theory, avoiding suction may also help reduce the risk of re-expansion pulmonary edema. In addition, prolonged use of suction may lead to a delay in definitive management by prolonging air flow through the leak, thereby slowing down the natural healing of a ruptured bleb. Digital devices to quantify the size of the air leak have been described but are not typically routine [38]. Further details regarding suctioning are described below. (See 'Follow-up thoracostomy management (one to five days)' below and "Alveolopleural fistula and prolonged air leak in adults", section on 'Quantifying the air leak' and "Large volume (therapeutic) thoracentesis: Procedure and complications", section on 'Re-expansion pulmonary edema'.)
Follow-up thoracostomy management (one to five days) — For patients with a first PSP in whom a catheter or chest tube has been placed, follow-up over the subsequent one to five days usually involves daily bedside assessment for symptoms, for the presence of an air leak, and for complications of the catheter or chest tube (eg, blockage, pain, bleeding). Daily imaging with chest radiography is not always necessary, although frequent imaging is typically performed to assess the degree of lung expansion. Imaging should also be obtained when symptoms worsen to evaluate for worsening pneumothorax on the ipsilateral side or development of a new pneumothorax on the contralateral side as well as for tube thoracostomy position. While some data suggest that measuring the leak size with digital manometry to identify those with large leaks predicts treatment failure and a longer hospital stay, this is not routine at most centers [39]. Further imaging and management strategies depend upon whether the air leak has sealed or is persistent. (See 'Sealed air leak' below and 'Prolonged air leak' below.)
For patients with a recurrent PSP, the chest tube/catheter generally remains in place while provisions are being made for the patients to undergo a definitive procedure to prevent recurrence, the details of which are provided separately. (See "Pneumothorax: Definitive management and prevention of recurrence".)
Sealed air leak — Most pneumothoraces in patients with a first episode of PSP resolve with the initial management strategies outlined above (see 'Management strategy' above). Once the air leak has resolved, a chest radiograph should be performed to confirm that the lung has fully expanded.
●Sealed air leak and lung fully expanded – Once the air leak has sealed and the lung is fully expanded, we clamp the chest tube/catheter for an additional 4 to 12 hours. Clamping the chest prevents inapparent drainage of small amounts of air through the water seal and thus allows recognition of small leaks that would otherwise be missed. Some experts prefer not to clamp the chest tube because this might lead to the development of a tension pneumothorax. However, tension pneumothorax is rare in PSP. Nonetheless, certain precautions should be followed after clamping a chest tube, as for example to keep the clamp outside the bedclothes and visible, instructing the bedside nurse about releasing it if the patient becomes hemodynamically unstable or otherwise symptomatic, and obtaining and examining the chest radiograph after a set period (4 to 12 hours). If the pneumothorax has not recurred, the chest tube can be removed and the patients can be discharged:
•The chest tube can be removed if the pneumothorax has not recurred and the patient can be discharged unless an indication for a definitive procedure is present. Details of the technique for removal and indications for a definitive procedure are provided separately. (See 'Indications for definitive procedure after first event' below and "Thoracostomy tubes and catheters: Management and removal", section on 'Removal technique'.)
•If the pneumothorax recurs, then the chest tube is unclamped and the process is repeated. At this point options include:
-Continue with tube or catheter drainage to water seal for another 24 to 48 hours. Some experts prefer to avoid suctioning for a few more days, under the premise that suctioning encourages the flow of air through the defect and prevents closure. Data to support the latter strategy are largely derived from postsurgical patients and is described separately. (See "Alveolopleural fistula and prolonged air leak in adults", section on 'General supportive care (drainage of air)' and 'Initial thoracostomy management' above.)
-The application of suction to increase pleural apposition and facilitate closure of the air leak. Suction strategies are described above. (See 'Initial thoracostomy management' above.)
-Occasionally, a second chest tube is required for patients in whom the lung does not fully expand or those with loculations, although this is rarely needed for patients with PSP.
●Sealed air leak and lung not fully expanded – If there is no air leak and the lung has not fully expanded, blockage of the chest tube or chest tube malposition should be considered. Under these circumstances the chest tube/catheter should be flushed and if patent, chest CT may be obtained to examine tube position. Rarely this phenomenon is due to pneumothorax ex vacuo. (See "Diagnosis and management of pleural causes of nonexpandable lung".)
Prolonged air leak — A small proportion of patients with a first episode of PSP develop a prolonged (also known as persistent) air leak (PAL). An air leak is considered prolonged if it continues for five days or longer, although varying definitions exist in the literature ranging from three to seven days. Of course, one should check that the leak is not coming from the drainage chamber, from the tubing or from around the chest tube at the skin entry site; this is classically done by clamping the tube at different locations to isolate the site of the leak. These patients require a more aggressive approach for defect closure since the longer an air leak persists, the less likely it becomes that the leak will close spontaneously and the more likely that a definitive intervention (eg, blebectomy and pleurodesis) will be required [1,40]. The approach varies among experts and depends upon factors including the degree of lung expansion, local expertise, and patient values and preferences. A multidisciplinary approach that also includes a pulmonary specialist and a thoracic surgeon is recommended. Our approach is below.
Patients with ≥90 percent lung re-expansion — For patients with a persistent air leak, whose lung is at least 90 percent expanded, we prefer ambulatory drainage devices or continued chest tube drainage in those not suitable for an ambulatory device. Other options include nonsurgical pleurodesis (eg, blood patch), or VATS repair of the defect with pleurodesis. Choosing among these is at the discretion of the clinician as well as local expertise and patient preference since there are no data to support one as superior to the other.
●Continued chest tube drainage with an ambulatory drainage device – Many experts prefer ambulatory drainage devices (table 2) based upon the rationale that the leak is small and likely to seal spontaneously without an intervention; in addition, our experience indicates that continued time with conservative therapy often ensures successful closure and allows rapid discharge of the patient with subsequent outpatient management. Ambulatory drainage should continue for about four or five days but longer, if necessary (eg, up to one week). For those not suited to an ambulatory device (eg, poor follow-up care), continued inpatient therapy with chest tube/catheter drainage is appropriate. Resolution of the leak has been described with conservative management after as long as 14 days [1,41]. Choosing among available ambulatory devices is outlined on the table (table 2) and is discussed separately. (See "Alveolopleural fistula and prolonged air leak in adults", section on 'Ambulatory drainage devices'.)
●Pleurodesis – Pleurodesis is an alternative for patients who prefer to achieve a more rapid and definitive resolution or for those who fail conservative therapy with ambulatory devices or continued chest tube thoracostomy. In general, surgical pleurodesis (typically VATS) may be preferred for patients who desire procedures with high success rates. Nonsurgical techniques for pleurodesis including an autologous blood patch are reserved for patients who are not candidates for surgery or favor less invasive techniques. These definitive measures are discussed separately. (See "Pneumothorax: Definitive management and prevention of recurrence", section on 'Definitive measures' and "Alveolopleural fistula and prolonged air leak in adults", section on 'Nonsurgical pleural procedures' and "Chemical pleurodesis", section on 'Technique' and "Talc pleurodesis".)
Patients with <90 percent lung re-expansion — For patients who have a PAL and whose lung is less than 90 percent expanded, the preferred procedure is VATS pleurodesis with repair of the defect. Nonsurgical pleurodesis or conservative management with ambulatory devices, or chest tube drainage is an option for those who are not candidates for or are unwilling to undergo surgery. (See "Pneumothorax: Definitive management and prevention of recurrence", section on 'Surgical candidates (VATS)' and "Overview of minimally invasive thoracic surgery".)
Endobronchial valves are not generally used for the treatment of PSP but can be used for the treatment of PALs from other causes, the details of which are discussed separately. (See "Alveolopleural fistula and prolonged air leak in adults", section on 'Evaluation and management'.)
Video-assisted thoracostomy — The role of VATS as primary therapy for PSP is unclear. A randomized trial studied recurrence rates in those who received a chest thoracostomy tube compared with those undergoing VATS with bleb resection and mechanical pleurodesis [42]. VATS was more effective at reducing recurrence rates when bullae ≥1 cm were noticed on chest computed tomography. In a meta-analysis of four studies (two randomized trials and two observation series), VATS resulted in lower rates of recurrence and duration of hospitalization, compared with chest tube drainage alone (odds ratio for recurrence: 0.15, 95% CI 0.07-0.33) [43]. In contrast, a network meta-analysis reported that, in patients with a first episode of PSP, there was no difference in the recurrence rate when VATS, tube thoracostomy, or aspiration was used [31]. Further study is required before VATS can become routine in patients with PSP.
INITIAL MANAGEMENT FOR RECURRENT EVENT — For patients with previous primary spontaneous pneumothorax (PSP) who recur with either ipsilateral or contralateral pneumothorax, we suggest chest tube thoracostomy with a small-bore tube (table 3) followed by a definitive procedure to prevent pneumothorax during the same hospital admission. Although some patients could potentially be managed with less aggressive options (eg, oxygen and observation, aspiration), the risk of recurrence is considered high enough to justify an approach which is similar to that performed in patients with secondary pneumothorax. (See 'Tube or catheter thoracostomy' above and "Treatment of secondary spontaneous pneumothorax in adults" and "Pneumothorax: Definitive management and prevention of recurrence".)
INDICATIONS FOR DEFINITIVE PROCEDURE AFTER FIRST EVENT — Unlike those with secondary spontaneous pneumothorax (SSP), most patients after a first episode of primary spontaneous pneumothorax (PSP), do not need to undergo a definitive procedure, because the likelihood of a recurrence is considered low (see "Pneumothorax: Definitive management and prevention of recurrence", section on 'Primary spontaneous pneumothorax') and prolonged (persistent) air leaks (PALs) are unusual. Following initial treatment of a first episode of PSP, a decision to treat with a definitive procedure (eg, pleurodesis with blebectomy) to prevent recurrence needs to be made. Although practice varies widely, there is general consensus among experts that a small population of patients with a first episode of PSP should be selected to undergo a definitive procedure including (algorithm 2):
●Patients with a PAL (see 'Prolonged air leak' above)
●Patients with a high-risk occupation (eg, airline pilot, deep sea diver) or hobby (eg, scuba diving)
●Patients with large, bilateral, or life-threatening PSP in whom tube thoracostomy was required for management
Other less well established indications include:
●Patients undergoing thoracoscopy for an alternate indication (eg, hemothorax, lung biopsy)
●Patients with a significant number of cysts or blebs on imaging (although the exact number is not defined)
●Patients with a strong desire to avoid recurrence
●Patients with significant symptoms or hemodynamic consequences during their first PSP
The rationale for a definitive procedure in these patients is based upon the assumption that, among patients with PSP, the risk of recurrence and risk of harm from recurrence is greatest in these subgroups, approaching that of patients with SSP (see "Pneumothorax: Definitive management and prevention of recurrence", section on 'Incidence of recurrence'). Data to support these indications, however, are sparse. In one small study of 214 patients with PSP (>2 cm from the pleural line to the chest wall), at one year, chemical pleurodesis with minocycline was more effective at preventing recurrence than no pleurodesis (29 versus 50 percent) [44]. Future studies should focus on defining which patients with PSP are at the highest risk of recurrence so that a targeted preventative intervention may be performed selectively.
Some experts also choose to perform a definitive procedure in patients with first PSP who have another indication for thoracoscopy. For example, such patients could include those with PSP who require a diagnostic lung biopsy (eg, if catamenial pneumothorax is suspected) or those with hemopneumothorax where frank blood needs to be removed. In these circumstances, some surgeons choose to perform a definitive procedure (eg, abrasion and/or blebectomy) at the time of surgery because the additional risk is considered relatively low.
Further discussion regarding recurrence rates and the type of definitive procedures available to prevent recurrence is provided separately. (See "Pneumothorax: Definitive management and prevention of recurrence".)
OUTPATIENT FOLLOW-UP — Following resolution of a pneumothorax, whether spontaneously, with a thoracostomy or with an ambulatory device, or after a definitive procedure, patients should be evaluated in about two to four weeks as an outpatient for clinical and radiologic evaluation. In the intervening period they are instructed to return to the hospital if they develop symptoms of chest pain or dyspnea, since recurrence is greatest during the first month after presentation.
During that evaluation, we suggest the following:
●Radiologic evaluation – Chest radiography is obtained to ensure continued full expansion of the lung. Chest computed tomography (CT) is generally not required unless the pneumothorax was loculated or complex, or a previously unidentified underlying lung disorder is suspected.
●Clinical evaluation – Patients should be assessed for chest pain or dyspnea that would suggest recurrence or post pleurodesis pain. Patients with secondary spontaneous pneumothorax (SSP; ie that due to underlying lung disease) should be evaluated for control of their underlying lung disease. Patients with primary spontaneous pneumothorax (PSP) should be reassessed for any potential diagnoses missed during the initial evaluation. If a previously unidentified underlying lung process is discovered, then patients should be treated as if they have SSP and electively undergo a definitive procedure, should they be agreeable to it. Further details regarding post-diagnosis evaluation for patients with PSP and treatment of SSP are provided separately. (See "Clinical presentation and diagnosis of pneumothorax", section on 'Postdiagnosis evaluation' and "Treatment of secondary spontaneous pneumothorax in adults".)
●Smoking – Patients should be advised to stop smoking cigarettes as well as other tobacco products, marijuana, and illicit drugs. Although poorly studied, the strong association between smoking and pneumothorax suggests that smoking cessation may help prevent recurrent pneumothoraces [45]. In addition, smoking, in one retrospective study, has been shown to predict a higher recurrence rate in those who undergo pleurodesis [46]. (See "Overview of smoking cessation management in adults".)
●Inquiry into familial history/genetics – For some patients, a spontaneous pneumothorax can be the first indication of a genetic predisposition [47]. Birt-Hogg-Dubé syndrome, Marfan syndrome, lymphangioleiomyomatosis, alpha-1 antitrypsin deficiency can all present with pneumothorax. Thus, consideration of family history, suggestive physical findings and/or chest CT may lead to a referral to a geneticist and potential benefits of surveillance for other extrapulmonary complications for the patient and for family members. If not done earlier, a workup of possible familial associations would be valuable at this time.
●Air travel – An acute pneumothorax is an absolute contraindication for air travel. After therapy, the optimal time for avoiding air travel is unknown but patients are typically advised not to travel by air for about two weeks, although that may be over conservative; however, it likely depends upon the type of treatment the patient received (eg, simple aspiration, tube thoracostomy, chemical or mechanical pleurodesis) and the estimated risk of recurrence. Air travel and pneumothorax is discussed in greater detail separately. (See "Pneumothorax and air travel".)
●Deep sea diving – Patients should be advised to avoid scuba diving. Experts suggest that diving be permanently avoided unless the patient has undergone bilateral surgical pleurectomy and has normal lung function and CT scan. (See "Pneumothorax and air travel" and "Complications of SCUBA diving".)
●Exercise – Exercise can be gradually reintroduced two weeks after treatment, but introduction of contact sports, heavy weightlifting, or extreme forms of exercise may warrant longer periods of avoidance.
SPECIAL POPULATIONS — Management of special populations of patients with pneumothorax are discussed separately:
●Patients with pneumothorax due to underlying lung disease (ie, secondary spontaneous pneumothorax) (see "Treatment of secondary spontaneous pneumothorax in adults")
●Patients with pneumothorax who are pregnant (see "Treatment of secondary spontaneous pneumothorax in adults", section on 'Pneumothorax and pregnancy')
●Patients with iatrogenic pneumothorax (see "Treatment of secondary spontaneous pneumothorax in adults", section on 'Other pneumothorax types')
●Patients with pneumothorax due to trauma (see "Initial evaluation and management of blunt thoracic trauma in adults", section on 'Pneumothorax')
●Patients with pneumothorax due to miscellaneous causes (eg, exercise, anorexia) (see "Treatment of secondary spontaneous pneumothorax in adults", section on 'Other pneumothorax types')
SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Pneumothorax".)
INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5th to 6th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10th to 12th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.
Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)
●Basics topic (see "Patient education: Pneumothorax (collapsed lung) (The Basics)")
SUMMARY AND RECOMMENDATIONS
●Assessment of symptoms and size – Following the diagnosis of primary spontaneous pneumothorax (PSP; ie, presents without underlying lung disorder), clinicians should quickly estimate the size and assess the degree of symptomatology, so that appropriate management can be instituted. Following resuscitation (if indicated) and supplemental oxygen, subsequent management is directed at deciding whether air needs to be removed from the pleural space and, if so, by what means. Although approaches vary widely, we prefer one that primarily incorporates size and symptoms (algorithm 1). (See 'Initial management for first event' above.)
•Large – A pneumothorax is considered large in the United States if there is more than 3 cm between the pleural line and the chest wall at the apex on a chest radiograph, while in Europe, a pneumothorax is considered large if there is more than 2 cm between the pleural line and the chest wall at the level of the hilum.
•Small – A small pneumothorax is one that is ≤3 cm from the chest wall at the apex or ≤2 cm from chest wall at the hilum. (See 'Definition of stability' above and 'Definition of size limits' above.)
•Stability – A stable patient is one who can speak in full sentences and who has a respiratory rate <24 breaths per minute, heart rate <120 and >60 beats per minute, normal blood pressure, and room air oxygen saturation >90 percent. All other patients are considered unstable. (See 'Definition of stability' above and 'Definition of size limits' above.)
●Management of a clinically stable patient with a first episode of PSP in whom the pneumothorax is small – For most patients who are clinically stable with a first episode of PSP in whom the pneumothorax is small (≤3 cm from the chest wall at the apex or ≤2 cm from chest wall at the hilum), we suggest observation with or without oxygen rather than aspiration or chest tube/catheter insertion (Grade 2C). The rationale for this approach is based upon our experience and data that suggest many patients in this category improve with this strategy without an invasive procedure for the removal of gas. Rarely, a chest tube or catheter thoracostomy is warranted in severely symptomatic patients. (See 'Small (≤3 cm at apex or ≤2 cm at hilum)' above and 'Observation alone' above and 'Supplemental oxygen and observation' above.)
•Observation with or without oxygen should last four to six hours. After that time, if a repeat chest radiograph demonstrates improvement or excludes progression of the pneumothorax and the patient has access to emergency medical services, the patient can be discharged home.
•Patients who demonstrate worsening of the pneumothorax on repeat imaging, should have a chest tube thoracostomy placed and be admitted.
●Management of a clinically stable patient with a first episode of PSP in whom the pneumothorax is large – For most patients who are clinically stable with a first episode of PSP in whom the pneumothorax is large (>3 cm from the chest wall at the apex, >2 cm from the chest wall at the hilum), we suggest drainage with aspiration via a needle or catheter (Grade 2C). This recommendation is based upon the observation that the success of pleural aspiration is sufficiently high enough to warrant its trial before progressing to options that, although more likely to succeed immediately, are also more likely to have adverse effects. (See 'Large (>3 cm at apex or >2 cm at hilum)' above and 'Aspiration' above.)
•A chest tube or catheter should be inserted if aspiration fails to re-expand the lung or expertise is not available; other indications for catheter or tube thoracostomy may include bilateral pneumothorax, complete collapse with mediastinal shift, severe symptoms, concurrent hemothorax, a pleural effusion necessitating drainage, or complex loculated pneumothorax (unusual in PSP). (See 'Large (>3 cm at apex or >2 cm at hilum)' above and 'Tube or catheter thoracostomy' above.)
•Two additional options include chest tube or catheter with an ambulatory device attached or observation with or without oxygen. These options are only appropriate if the patient is young (eg, <55 years old), has mild symptoms, is clinically stable, and is readily available to receive outpatient follow-up; such patients should be well-informed and agree to this approach and not have any travel or scuba diving plans. (See 'Large (>3 cm at apex or >2 cm at hilum)' above and 'Supplemental oxygen and observation' above and 'Aspiration' above.)
●Management recurrent PSP – For patients with recurrent PSP, we suggest that a chest tube or catheter thoracostomy be placed rather than aspiration (Grade 2C). This approach is based upon the success rate of thoracostomy and the likely need for a definitive intervention to prevent recurrence. (See 'Initial management for recurrent event' above.)
●Management unstable patients – Clinically unstable patients should undergo immediate chest tube thoracostomy. If chest tube insertion is delayed, needle decompression should be performed. (See 'Unstable patients' above and "Initial evaluation and management of blunt thoracic trauma in adults", section on 'Pneumothorax' and "Approach to shock in the adult trauma patient", section on 'Tension pneumothorax'.)
●Thoracostomy management – For patients in whom a chest tube or catheter thoracostomy is indicated, a small-bore catheter (≤14 French [Fr]) or tube (≤22 Fr) is generally preferred over large-bore tubes (24 to 28 Fr), unless patients are unstable, have concomitant empyema or hemothorax, or fail small-bore drainage.
•In general, suction is not initially applied, and the tube or catheter is connected to a water seal device.
•If the lung fails to re-expand within the subsequent 24 to 48 hours, worsens, or a prolonged (persistent) air leak (PAL) develops, low wall suction can be applied, and, in some cases, the catheter can be replaced by a larger tube or a second drainage device may be needed. (See 'Initial thoracostomy management' above.)
●Follow-up – Most pneumothoraces in patients with PSP resolve with these initial management strategies. (See 'Follow-up thoracostomy management (one to five days)' above.)
•Sealed air leak – For those in whom the air leak has sealed and the lung is fully expanded, the tube/catheter can be removed, and the patients can be discharged unless a definitive intervention is indicated. (See 'Sealed air leak' above and "Thoracostomy tubes and catheters: Management and removal", section on 'Removal'.)
•Persistent PAL and ≥90 percent expanded – If a PAL persists beyond five days and the lung is at least 90 percent expanded, we prefer ambulatory drainage devices and continued chest tube drainage in those not suitable for an ambulatory device; other options include nonsurgical pleurodesis (eg, blood patch) or video-assisted thoracoscopic surgery (VATS) repair of the defect with pleurodesis. Choosing among these is at the discretion of the clinician as well as local expertise and patient preference since there are no data to support one as superior to the other. (See 'Patients with ≥90 percent lung re-expansion' above.)
•Persistent PAL and <90 percent expanded – For patients who have a PAL and whose lung is <90 percent expanded, the preferred procedure is VATS pleurodesis. Nonsurgical pleurodesis or conservative management with ambulatory devices or chest tube drainage is an option for those who are not candidates for or are unwilling to undergo surgery. (See 'Patients with <90 percent lung re-expansion' above.)
●Indications for a procedure for recurrence prevention – In most patients with a first episode of PSP, we suggest that a definitive procedure not be performed, because recurrence is considered low and PALs are unusual (Grade 2C). However, a small percentage of patients need a preventive intervention (algorithm 2), typically VATS resection of blebs with pleurodesis. (See 'Indications for definitive procedure after first event' above and "Pneumothorax: Definitive management and prevention of recurrence".)
These include patients with the following:
•Prolonged air leaks not responsive to therapy
•A high-risk occupation or hobby (eg, airline pilot, deep sea diver)
•Large, bilateral, or life-threatening PSP in whom tube thoracostomy was required for management
•A high burden of cysts
•A desire to avoid recurrence
•Another indication for thoracoscopy (eg, hemothorax, lung biopsy)
●Outpatient follow-up – Following treatment, patients should be evaluated in about two to four weeks as an outpatient. Patients should be instructed to return to the hospital with symptoms of chest pain or dyspnea because recurrence is greatest during the first month after presentation. Chest radiography is performed to ensure continued full expansion of the lung. Patients should be reassessed for any potential diagnoses missed during the initial evaluation and, if an etiology is discovered, treated as if they had secondary pneumothorax. Patients should be advised to stop smoking cigarettes as well as other tobacco products, marijuana, and illicit drugs and to avoid air travel, scuba diving, and exercise for a limited period. (See 'Outpatient follow-up' above.)
●Special populations – Patients with underlying lung disease, patients who are pregnant, and patients with pneumothorax due to other causes need special consideration. (See 'Special populations' above and "Treatment of secondary spontaneous pneumothorax in adults".)
ACKNOWLEDGMENT — The UpToDate editorial staff acknowledges Richard W Light, MD, now deceased, who contributed to earlier versions of this topic review.
