New strategies in the management of pneumothorax

Abstract

Pneumothorax arises from pulmonary air leaking into the pleural space. If the air leak has healed, the pneumothorax may not require intervention but will take time to resolve. Procedural management may be warranted, despite resolution of the air leak, depending on patient preference. An ongoing air leak carries a risk of tension pneumothorax and requires intervention. Surgical prevention of recurrent pneumothorax should be considered in cases with a second episode or for patient factors (e.g. occupational risk). This review aims to describe the evidence base for the recent paradigm shift towards individualised management in the treatment of pneumothorax, supported by new guidelines, and the utility of novel diagnostic/management adjuncts such as thoracic ultrasound and digital drainage systems.

Shareable abstract

Newly published guidelines on the management of pneumothorax have a strong emphasis on an individualised approach, offering conservative, ambulatory or surgical management depending on clinical features and patient preference https://bit.ly/4eow23G

Introduction

Pneumothorax is the accumulation of air between the parietal and visceral pleurae [1]. Spontaneous pneumothorax comprises of primary spontaneous pneumothorax (PSP) in the absence of suspected lung disease, and secondary spontaneous pneumothorax (SSP) in those with established underlying lung disease. Pneumothorax occurring in patients >50 years of age with a smoking history is usually categorised as SSP [2].

A breach of the visceral pleura by any means results in air leak from the lung; positive pressure within the pleural space causes the lung to fall away from the chest wall. Often the leak rapidly resolves but the lung may take time to fully re-inflate. Traumatic pneumothorax results from penetrating or non-penetrating chest trauma, while iatrogenic pneumothorax occurs as a consequence of medical intervention, most commonly after transthoracic biopsy or subclavian/jugular venous cannulation.

The recently published British Thoracic Society (BTS) pleural guideline and the joint European Respiratory Society (ERS)/European Association for Cardio-Thoracic Surgery (EACTS)/European Society of Thoracic Surgeons (ESTS) clinical practice guidelines have provided recommendations for the management of spontaneous pneumothorax [2, 3]. These new guidelines represent a dramatic paradigm shift in the management of pneumothorax with a strong emphasis on an individualised and minimally invasive approach. Advances in imaging, interventions and preventative measures are shaping new strategies aimed at reducing recurrence and enhancing overall patient experience.

Epidemiology

PSP predominantly affects young adults. A large study using the English national dataset identified a rate of 11.6 per 100 000 population [4]. There is a notable gender difference, with spontaneous pneumothorax admissions found to be more common among males than females, and age distribution is bimodal with a first peak at age 15–34 years and an increasing incidence beyond 60 years in both males and females [5–7]. The peak incidence of SSP occurs later in life [8]. Pneumothorax rates appear to be increasing [4, 5]. Risk of spontaneous pneumothorax increases dramatically in smokers, by nine-fold in women and 22-fold in men [6].

The incidence of iatrogenic pneumothorax is on the rise, driven by the escalating use of necessary invasive diagnostic and therapeutic procedures in modern healthcare, with incidence proportional to the number of invasive procedures performed and increasing as intensive care modalities advance [7]. The annual incidence of traumatic pneumothorax is estimated to be 81 per 100 000 people with thoracic injury occurring in approximately one fifth of major trauma patients [9].

Aetiology

Traditional understanding of the pathogenesis of PSP centres on the rupture of subpleural blebs/bullae [10]. These emphysema-like changes (ELCs) are areas of hypoattenuation exhibiting thin or imperceptible walls on computed tomography (CT). Bense et al. [11] demonstrated a striking difference in the prevalence of ELCs in nonsmoking individuals with PSP (over 80%), compared to a complete absence in healthy volunteers. A meta-analysis observed that individuals with abnormalities identified on their thoracic CT scans were 2.5 times more likely to suffer a recurrence compared to those without, providing support for a mechanistic link between emphysematous changes and pneumothorax [12]. Emerging evidence from Burn et al. [13] shows that contralateral lung cysts in younger individuals are associated with a higher risk of contralateral recurrences, with no significant association detected in those over 50 years. This suggests that pulmonary cysts and pneumothorax are causally linked, either by cyst rupture leading to pneumothorax or from them sharing a common aetiological mechanism [13].

The exclusive role of ELCs has been challenged as not all patients with spontaneous pneumothorax exhibit macroscopically visible blebs and a minority of blebs are found to have ruptured at thoracoscopy [14]. The correlation between the number of blebs on CT and recurrence risk is inconsistent [15]. An alternative, or perhaps complementary, mechanism is pleural porosity, whereby microscopic pores within the pleura, even in areas appearing macroscopically normal, can permit air leakage. These areas of pleural porosity are characterised by disrupted mesothelial cells on the visceral pleura, replaced by an inflammatory elastofibrotic layer [16].

Additional techniques, such as fluorescein-enhanced autofluorescence thoracoscopy (FEAT) [17] and infrared thoracoscopy [18], may improve our understanding of the source of air leaks in PSP. Noppen et al. [17], using FEAT, demonstrated areas of subpleural fluorescein accumulation and leakage that were not always associated with visible blebs. Examination of lung tissue from surgery reveals signs of inflammation and small airway damage with a suggestion that matrix metalloproteinases (MMPs) may play a role [19]. MMPs are zinc- and calcium-dependent endopeptidases that can damage the barrier between the pulmonary epithelium and alveoli [20]. Two studies of surgical resection specimens of patients undergoing surgery for PSP demonstrated overexpression of MMPs [20, 21].

Risk factors for pneumothorax include smoking and changes in atmospheric pressure [22]. A Valsalva manoeuvre, for example, during weight lifting or straining, may theoretically precipitate visceral pleural rupture but this remains unproven [23]. The COVID-19 pandemic saw a significant association with pneumothorax as well as pneumomediastinum. This increased incidence probably relates to a combination of risk factors including cystic change in areas of confluent consolidation, barotrauma with mechanical ventilation and reduced healing in the context of immune-modulating treatments, such as tocilizumab [24].

Diagnosis

Pneumothorax typically presents with chest pain and dyspnoea [25]. Sometimes (more commonly in SSP than in PSP) patients may be haemodynamically unstable. Diagnosis requires imaging and pneumothorax is often visible on chest radiography, but chest CT is more sensitive for small pneumothorax [26], and thoracic ultrasonography is emerging as an alternative rapid and accurate modality [27].

The hallmark finding on erect chest radiography is a displaced visceral pleural line, with absent lung markings between it and the chest wall. While pneumothorax appears larger in expiratory views [28], it is reliably diagnosed with inspiratory radiographs alone [29]. Only 50 mL of air in the pleural space is needed for detection of pneumothorax in the upright position [30]. Detection is more difficult on supine chest radiographs, which are frequently obtained in intensive care unit or trauma patients, and the clinician must maintain awareness of signs such as the deep sulcus sign (air in the anterior costophrenic sulcus causing the lateral costophrenic angle to become deeper and more lucent) in order to avoid missing pneumothoraces in supine patients [31]. Several conditions can mimic a pneumothorax on chest radiographs, examples include bullae, herniation of the stomach into the chest and prominent skinfolds in the chest wall. Where diagnostic uncertainty exists, thoracic clinicians should have a low threshold to use a CT scan to distinguish these abnormalities, particularly when intervention is being considered.

Thoracic ultrasound (TUS) has emerged as a valuable tool in the diagnosis of pneumothorax [32], particularly in supine patients [33]. Nonspecific features on TUS are a lack of lung sliding and the absence of “B-lines”, which is useful in ruling out pneumothorax in acutely unwell patients [34, 35], while identification of a “lung point”, the site at which the lung comes into contact with the chest wall, is pathognomonic [36]. When available, TUS in real time post-thoracentesis also allows immediate identification of the presence or absence of an iatrogenic pneumothorax [37].

Numerous prospective case series, primarily within trauma, iatrogenic and critical care settings, have documented the value of TUS in pneumothorax diagnosis. Pooled data from four meta-analyses indicate that ultrasound demonstrates superior sensitivity for pneumothorax detection (78–90%) compared to chest radiography (39–52%), although specificity is similar for both [38].

These findings should be interpreted with caution, as accuracy of ultrasound for pneumothorax detection can be compromised by operator inexperience, the presence of small or loculated pneumothorax, previous pleurodesis, and technical limitations imposed by subcutaneous emphysema or chest wall dressings [39]. Interpretation of absent lung sliding on TUS in particular requires significant caution in patients with COPD, as this sign can occur due to underlying hyperinflation or bullous disease, potentially confounding the diagnosis of pneumothorax [40]. Thoracic CT is the most sensitive modality for determining the presence, size and location of intrapleural air. Observational studies show that CT is more accurate than chest radiography [41, 42] or ultrasonography [43] for the diagnosis of pneumothorax. CT remains the modality of choice when diagnostic doubt exists and offers the added benefit of providing significantly more detail on any underlying parenchymal disease, pneumomediastinum or areas of tethered lung that may impact the chosen site for intercostal chest drain (ICD) placement (figure 1).

FIGURE 1.

a) Secondary spontaneous pneumothorax with tethered lung on computed tomography (CT) of the chest. b) Chest drain inserted using blunt dissection, puncturing the lung. c) CT imaging demonstrated an intraparenchymal intercostal chest drain. d) A second pigtail drain was successfully inserted using ultrasound guidance.

Management

Management of spontaneous pneumothorax

Once a pneumothorax is diagnosed, a number of options are available for management. The decision requires clinical assessment, determination of the presence of ongoing air leak and shared decision making with the patient. Management options include a conservative approach with radiographic follow-up, needle aspiration, chest tube insertion and surgical management.

Conservative management

The first reports of spontaneous pneumothorax are characterised by a non-interventional approach [44]. In the mid-20th century, many clinicians were proponents of conservative management, focusing on keeping patients active and in work with significant success [45]. International guidelines then shifted towards management of pneumothorax dictated by the size (>2 cm at the hilum or >3 cm at the apex) on chest radiography [46]. This approach has long been challenged.

Meta-analyses demonstrated that conservative management is comparable to chest tube drainage in terms of resolution and PSP recurrence, with fewer adverse events [47]. The PSP trial provided prospective evidence that conservative management was non-inferior to intervention for radiographic resolution of moderate-to-large PSP within 8 weeks [48]. Lower 12-month recurrence rates in the conservative management arm (8.8% versus 16.8%) were also shown and 85% of patients in the conservative arm did not require any procedural intervention [48]. It should be noted that the overall recurrence rates were significantly lower than those found in previous epidemiological studies and meta-analyses, suggesting that the study population may not be adequately representative. Decreased length of hospital stay and fewer adverse events are associated with conservative management [47].

Guidelines now advise that conservative management should be considered for the treatment of minimally or asymptomatic PSP in adults [2, 3], regardless of size, once the pneumothorax is radiographically stable (figure 2) [3]. Clinicians should observe patients for 4 h, ensure that they can walk comfortably around the emergency department and facilitate early clinical follow-up [3]. The same approach is not currently recommended in SSP, which results in more significant physiological compromise and increased risk of prolonged/persistent air leak (PAL).

FIGURE 2.

Chest radiograph series demonstrating complete resolution of a large right-sided primary spontaneous pneumothorax managed conservatively.

Benefits and key considerations

Conservative management has the potential for substantial cost savings with shorter hospital stays and reduced readmission rates [48, 49]. Patients treated in the PSP trial experienced improved patient-focused outcomes, including notable decreases in hospitalisation time, days off work, the requirement for chest drains or subsequent surgery, and related pain and complications [48].

Developing institutional follow-up protocols is a critical consideration when aiming for widespread implementation of conservative management, especially since current evidence points to these protocols often being lacking [50, 51]. A survey of emergency medicine, thoracic surgery and respiratory medicine teams found that 21% of responding departments did not have a guideline for spontaneous pneumothorax management or referral procedure for follow-up [52]. The implementation and standardisation of conservative management in spontaneous pneumothorax requires education of all involved specialities with protocols for early follow-up essential to ensure safe application of current evidence [3].

Future research

The PSP trial had significant limitations in generalisability. Participants had low symptom burden and there was a high screening failure rate. The CONSEPT trial addresses this by comparing initial conservative management with standard intervention for patients presenting with a large, symptomatic PSP (www.isrctn.com identifier ISRCTN75384510). These results may strengthen our evidence base for conservative management in PSP with increased applicability in a real-world setting.

Needle aspiration

Current ERS/EACTS/ESTS guidelines advocate for needle aspiration as the preferred initial intervention over ICD insertion for patients presenting with symptomatic PSP, while the BTS guidelines recommend that needle aspiration or tube drainage should be considered if the patient is unsuitable for conservative or ambulatory management [2, 3].

Needle aspiration yields favourable patient-focused outcomes compared with ICD insertion owing to its less invasive nature, which results in better tolerability and reduced pain, including pain-limited breathing [3, 53]. It provides rapid symptomatic relief with shorter length of stay and fewer complications versus ICD [2, 3, 54, 55].

However, it has been shown that needle aspiration has a higher initial failure rate, with a greater need for repeated pleural procedures following needle aspiration [2, 53]. Published evidence regarding the initial success of needle aspiration versus ICD is conflicting, predominantly due to lack of a standard definition and many studies allowing multiple aspirations [3, 53, 55]. Importantly, there was no difference in 1 year recurrence rates between needle aspiration and ICD [56].

Recent research challenges the view that needle aspiration is unsuitable for SSP. In a randomised study, needle aspiration was associated with a significantly shorter hospital stay for SSP patients (median of 2.5 days versus 5.5 days for ICD, p=0.049) with higher immediate success rates (59% versus 23% for chest drain, p=0.011) and no serious complications [55]. The SSP population in this study was not well defined and previous studies have demonstrated contradictory outcomes [57]. As such, there is a far wider evidence base for the use of needle aspiration in PSP as opposed to SSP. The joint ERS/EACTS/ESTS clinical practice guideline does not currently advocate for needle aspiration in SSP due to a lack of conclusive evidence [3].

Future research

The clear drawback to needle aspiration over ICD is its lack of efficacy if the air leak is ongoing. Most studies of needle aspiration versus ICD were published prior to updated guidelines, which incorporate new evidence for conservative management. As resolution of air leak likely predicts success in both conservative and needle aspiration management approaches, perhaps those who successfully undergo needle aspiration would have similar outcomes with no intervention at all. A study including all three strategies is required to evaluate for any superiority of needle aspiration over conservative management.

The large, pragmatic, non-inferiority trial, PRINCE-SSP, is ongoing in the UK to compare the effect of needle aspiration versus standard of care on hospital days in SSP [58].

Chest drain management

Current clinical guidelines widely support the view that small-bore chest drains (≤14 F) provide sufficient drainage for the management of pneumothorax [2, 3, 59]. Randomised controlled trial (RCT) results and systematic reviews indicate that small-bore tubes are non-inferior and associated with lower complication rates, shorter drainage duration and shorter hospital stay compared with large-bore chest tubes [60, 61]. If full lung re-expansion is not achieved, some advocate replacing a small-bore tube with a large-bore one to allow greater flow of air and promote pleural apposition, although this remains unproven and there is no high-quality evidence to support this approach.

Underwater seal systems provide a one-way flow and maintain a pressure gradient for air to leave the pleural space. Bubbling can be monitored and graded qualitatively; however, this assessment is susceptible to interobserver variability and lacks the capacity to quantify changes in air leak status over time [62]. Digital drainage systems can monitor intrathoracic pressure changes and air leaks in real time, providing more objective analyses on patients with spontaneous pneumothorax. Digital drainage systems may be of value in determining timing of ICD removal, with studies suggesting that the accurate quantification of air leak and characterisation of air leak patterns over time may lead to a shorter period of drainage and reduced hospital stays [63–66].

Observational studies suggest that an initial air leak exceeding 100 mL·min⁻¹ on day one, as measured by digital drainage, may serve as a predictive marker for subsequent failure of non-surgical management [67].

In patients requiring suction, these portable devices allow patients to ambulate earlier than with wall suction, promoting faster recovery. There remains no definite consensus on the standardised digital suction system in pneumothorax and further studies are needed [68]. Evidence suggests that the enhanced efficiency of these systems in the monitoring and management of air leaks results in decreased overall hospitalisation expenditures [69].

Ambulatory management

The management of spontaneous pneumothorax has traditionally involved hospitalisation with ICD drainage and observation. The prospect of ambulatory care, using portable drainage devices, has gained traction as a means of reducing hospital stay and facilitating transition of care into the outpatient setting. Ambulatory valve management has been shown to reduce the number of procedures, shorten hospital stays and lower overall healthcare costs [51, 70, 71].

The RAMPP trial (Randomised Ambulatory Management of Primary Pneumothorax) was the first large RCT to assess the utility of self-contained ambulatory devices in the management of PSP compared to standard management [72]. In the ambulatory arm, there was a significant reduction in the duration of hospitalisation. However, all 14 serious adverse events occurred in patients who received ambulatory care, eight of which were related to the intervention [72]. There is no significant difference in the rate of hospital readmission, rate of pneumothorax recurrence and the need for repeat pleural procedures or complications following ambulatory management [2].

The efficacy of ambulatory management for stable PSP, irrespective of size, is reflected in its endorsement by most societal guidelines. This consensus underscores the growing acceptance of outpatient strategies for managing PSP, shifting the paradigm towards less invasive and patient-centric approaches but with the caveat that any pathway must have appropriate expertise and resources available for close follow-up. Clinicians must also consider patient factors, such as available support at home and access to urgent acute medical care.

The use of ambulatory care in the management of SSP is not yet endorsed due to evidence of potential harm. A recent RCT (involving 41 SSP patients) aimed to address if an ambulatory care pathway using flutter valves reduced total hospital length of stay compared to chest tube with underwater seal. The ambulatory care group received a flutter valve: either a Pleural Vent if no chest tube was initially present (n=13), or an Atrium Pneumostat (AP) attached to an existing chest tube (n=8). Despite earlier discharge (1 versus 3.5 days) in the ambulatory care group, a higher rate of early treatment failure and readmission resulted in comparable overall in-hospital days. Interestingly, all treatment failures within the ambulatory care group occurred with the smaller bore Pleural Vent and, although not statistically significant, may indicate that smaller catheter diameters are insufficient for managing the higher air leak flow rates characteristic of SSP [73].

Future research

Further prospective studies are warranted to definitively assess the efficacy and safety of ambulatory valve systems in the management of SSP.

Persistent air leak

PAL is defined as ongoing air leak after 2–3 days and is more common in SSP than PSP. Surgery is the optimal management in those fit enough, but PAL presents an ongoing challenge in those deemed unfit for any surgical intervention [2, 74]. In this cohort, potential interventions include observation, application of suction, instillation of an autologous blood patch (ABP) via the ICD, and placement of an endobronchial valve (EBV).

The application of suction provides negative pressure to the drainage system in order to accelerate the removal of air from the pleural space and promote closure of the defect via apposition of the visceral and parietal pleurae [75]. Inconclusive evidence, to date, means that neither the ERS/EACTS/ESTS guideline nor the BTS guideline can give a recommendation for application of suction compared with a chest drain alone and many remain concerned about the risk of further exacerbating the leak through increasing the negative pressure [2, 3, 76]. The RASPER multicentre, open-label, RCT aims to evaluate whether use of early suction can reduce treatment duration for patients with PSP compared with usual care, and to analyse its health economic impact (RASPER; www.isrctn.com ISRCTN18017504).

ABP involves instilling the patient's fresh unheparinised blood (typically 50–100 mL) into their pleural space [77, 78]. Uncertainty remains regarding the optimal amount of blood to be used in ABP, with some studies suggesting that larger volumes may be associated with greater effectiveness. A meta-analysis found no significant difference in effectiveness when comparing the lower dose of 50 mL ABP versus 100 mL [79]. As clamping is contraindicated with ongoing bubbling, the drainage tube can be positioned in an omega loop for at least 2 h to allow air to escape but keep the blood inside the pleural space (figure 3) [80].

FIGURE 3.

The use of an “omega loop” position allows for pleurodesis to be carried out with an ongoing air leak.

ABP is a feasible, safe and inexpensive intervention for PAL, particularly in patients with secondary pneumothorax who are poor surgical candidates [77, 78]. Variability in practice exists however, and larger, multicentre datasets are required to investigate if ABP can shorten hospital stay compared with conservative treatment, to increase knowledge of the efficacy and safety profile, and to identify the optimal protocol [78, 79].

EBVs, which were originally used for lung volume reduction procedures as an alternative to surgery [81], are small valves placed bronchoscopically into the airway. Bronchi leading to the segments suspected of causing the PAL are occluded with a balloon blocker, which also serves as a sizing device. If the air leak diminishes with occlusion, the unidirectional valve supported by a nitinol stent is then placed into the bronchial segment through the working channel of the bronchoscope to prevent air from entering the isolated lung segment [82].

Although studies have shown that the use of EBVs in spontaneous pneumothorax with PAL can be useful to hasten air-leak cessation, it is noted that failures are common, with only ∼20% of patients showing unequivocal benefit [83]. EBVs are not suitable for every patient, particularly if the source of the air leak cannot be localised [83]. Complications of EBVs must be considered, including valve migration, haemoptysis, persistent cough, formation of granulation tissue, adhesions and temporary shunting [84]. Further evaluation by RCT is warranted and the current limited evidence means that the BTS and ERS/EACTS/ESTS guidelines make no recommendation for or against its use in PSP or SSP with PAL [2, 3].

Future research

Current approaches to PAL management in those not fit for surgery are predominantly experimental and the lack of clear evidence to support inclusion in the current guidelines highlights the need for more robust clinical trials evaluating these interventions.

Recurrence prevention

Recurrence following spontaneous pneumothorax is common and is estimated to occur in 25–30% following a single episode of PSP and 13–39% after the first episode of SSP [4, 15]. The BTS guidelines recommend that video-assisted thoracoscopy can be offered for surgical pleurodesis after a first episode of PSP, particularly in, but not limited to, patients in high-risk occupations and patients presenting with a tension pneumothorax or spontaneous haemopneumothorax [2].

High-resolution CT (HRCT) can be offered to patients following an episode of PSP as up to 10% of are due to underlying diffuse cystic lung disease [85]. Multiple potential familial causes of spontaneous pneumothorax have been identified, including Birt–Hogg–Dubé syndrome, Marfan syndrome, vascular/type IV Ehlers–Danlos syndrome, α₁-antitrypsin deficiency, tuberous sclerosis with lymphangioleiomyomatosis, cystic fibrosis, homocystinuria and Loeys–Dietz syndrome among others, with pneumothorax often their heralding manifestation [86]. In cases where a familial predisposition to pneumothorax is suspected, CT imaging is considered an essential component of the standard diagnostic workup. Additionally, seeking consultation from specialists with expertise in inherited pneumothorax syndromes or referral to a dedicated pneumothorax clinic is strongly recommended [2].

Evaluation for catamenial pneumothorax is warranted in young women with recurrent pneumothorax. This condition often remains unrecognised, despite surgical findings identifying it in as many as 25% of women managed surgically for recurrent spontaneous pneumothorax [87]. A multidisciplinary team approach is essential when managing recurrence prevention for catamenial pneumothorax, a strategy that may include the use of targeted hormonal therapies [88].

Lifestyle modification

The greatest risk for recurrence of spontaneous pneumothorax is within the first year [59]. All patients should, therefore, be followed up by a respiratory physician to ensure complete resolution and optimise any underlying lung disease. Lifestyle advice regarding issues such as air travel should be reinforced (patients can fly 7 days after a chest radiograph confirming complete resolution, in order to exclude early recurrence) [2]. The risk of recurrence with possible later need for surgical intervention should be discussed. Smoking cessation can lead to a four-fold reduction in PSP recurrence [15]; therefore, physicians must strongly advocate that cessation is central to recurrence prevention [89]. Scuba diving with pressurised gas tanks should be discouraged permanently unless a definitive prevention strategy has been performed such as surgical pleurectomy [90].

Additional risk factors for recurrence of spontaneous pneumothorax include younger age, female sex, decreased body mass index, increased height and radiological evidence of underlying lung abnormalities [15].

Chemical pleurodesis

Chemical pleurodesis is intra-pleural instillation of an inflammation-inducing substance, resulting in the development of adhesions and pleural sclerosis [91]. More commonly used in patients with symptomatic malignant pleural effusions (MPE), pleurodesis can also be used for recurrence prevention in spontaneous pneumothorax [92]. A meta-analysis by Xia et al. [93] revealed a significant superiority for talc over other sclerosants in overall success rates.

Talc slurry pleurodesis involves the instillation of a talc suspension into the pleural space mixed in normal saline via an ICD. The most common complications of talc slurry are pain and fever, demonstrative of the significant induced inflammation [94]. It is important to note that the pain with talc instillation can be dramatic in the context of an otherwise normal pleural membrane (e.g. no malignant infiltration). Talc slurry pleurodesis can be particularly effective for patients with SSP who are unable to undergo a surgical procedure [95].

Talc poudrage involves the administration of dry-insufflating fine-powdered talc directly into the pleural cavity during thoracoscopy, theoretically providing a broader coverage of the pleura. This technique facilitates increased contact between smaller talc particles and pleural surfaces, and is thought to be more effective than talc slurry for pneumothorax, primarily due to the higher probability of reaching the apical lung area [96]. An RCT looking at medical thoracoscopy for PSP found that 5-year recurrence rates post-talc poudrage were 5.1% versus 34% in the drainage alone group, and concluded that thoracoscopic pleurodesis is a cost-effective approach [97]. Patient choice after a discussion of the risks and benefits should inform the final decision as thoracoscopy is inevitably more invasive [98]. The most common adverse events of thoracoscopic talc poudrage include pain with higher requirements for opioid analgesics, fever, residual pneumothorax and infections, with a higher incidence of complications in comparison to talc slurry pleurodesis [99, 100].

Thoracic surgery

A meta-analysis of RCTs revealed that early surgical intervention for pneumothorax significantly reduced the likelihood of recurrence compared with chest tube drainage [3]. The presence of blebs/bullae on CT after a first episode of PSP as an indication for elective surgery to prevent recurrence is controversial. Large blebs (≥2 cm) are particularly associated with higher recurrence [101, 102], with the caveat that not all blebs can be definitely detected by HRCT and not all PSP cases are explained by blebs [103]. In recent years, there has been growing advocacy for the use of HRCT at the first presentation of spontaneous pneumothorax and application of a CT-based lung dystrophy severity score to risk stratify patients more likely to need surgery [104, 105]. Further research is warranted into this area as, with recurrence rates estimated at approximately one in four patients in spontaneous pneumothorax [106], a blanket approach of surgical management for all patients during their initial spontaneous pneumothorax episode could lead to substantial over-treatment. Indications for surgical advice are well established and outlined in table 1 [29, 59, 107, 108].

TABLE 1.

Indications for surgical referral in patients with spontaneous pneumothorax

Recurrent ipsilateral PSP

First contralateral PSP

Simultaneous bilateral spontaneous pneumothorax

Presentation with tension pneumothorax

Significant spontaneous haemopneumothorax

Persistent air leak

Professions at risk (e.g. pilots, drivers)

Pregnancy

Confirmed underlying DCLD

PSP: primary spontaneous pneumothorax; DCLD: diffuse cystic lung disease.

While the current indications for surgical management are well defined, the optimal approach is yet to be fully established and in the elective setting the management strategy for prevention of spontaneous pneumothorax will depend on available expertise, operative risk and patient preference [108].

Thoracic surgery for pneumothorax typically involves two main approaches: 1) resection of lung parenchyma where blebs/bullae are located, to address the current air leak and prevent recurrence, and 2) surgical pleurodesis (mechanical or chemical) and/or pleurectomy. The BTS guidelines suggest that surgical pleurodesis and/or bullectomy should be considered for the treatment of spontaneous pneumothorax in adults [2]. The joint ERS/EACTS/ESTS taskforce assessed evidence for bullectomy with additional pleurodesis and bullectomy alone and was unable to identify a difference in outcomes [3]. These European guidelines made a conditional recommendation that early surgical intervention should be offered as part of the initial treatment of PSP in patients who prioritise recurrence prevention. They have not made the same recommendation for SSP due to the lack of compelling evidence [3].

Future research

Controversy over which is the important intervention (the bullectomy or the pleurodesis) persists. Comparison of different surgical techniques is necessary to clarify whether resection of the ELCs, creation of pleural symphysis or the combination of both is optimal for recurrence prevention.

Iatrogenic and traumatic pneumothorax

In general, iatrogenic pneumothorax tends to resolve rapidly and intervention may not be required [2]. Options to treat iatrogenic pneumothorax are the same as those for PSP and SSP; however, there is little literature available to guide practice, with neither iatrogenic nor traumatic pneumothorax included in the current BTS or ERS/EACTS/ESTS guideline updates.

The incidence of pneumothorax in patients undergoing transthoracic needle biopsy (TTNB) is 25.6% [109]. In one RCT, central venous cannulation resulted in pneumothorax requiring chest tube insertion in 1.5% of subclavian vein insertions and 0.5% of jugular vein insertions [110]. Sundaralingam et al. [111] reviewed the literature surrounding complications of pleural procedures and found that iatrogenic pneumothorax occurs in ∼3% following thoracocentesis (3.3%, 95% CI 3.2–3.4%), but was much less common (0.3%, 95% CI 0.2–0.4%) when the procedure was ultrasound guided.

Risk factors for the development of biopsy-related pneumothorax, including COPD, lesion size, number of pleural punctures and need to cross the fissure, should be considered in the pre-procedure evaluation to minimise incidence [112]. The balance of benefit against risk for TTNB should be assessed using recent pulmonary function tests and a multidisciplinary team assessment if forced expiratory volume in 1 s (FEV₁) is <35% predicted [46, 113]. Some centres advocate instillation of a prophylactic ABP or saline via the co-axial system once sampling is complete to prevent air leak [114, 115]. Manual aspiration of air from the pleural space after moderate or large pneumothorax on CT post-biopsy has demonstrated up to 93% complete resolution [116].

Traumatic pneumothorax, usually identified in the emergency department, has traditionally been managed with large-bore ICD insertion. This approach is newly challenged by recent literature demonstrating small-bore/pigtail catheters as equally efficacious alternatives [117].

The Advanced Trauma Life Support protocol now supports the efficacy of lung ultrasound for diagnosis and more conservative approaches including smaller catheters or even observation, particularly in patients with small pneumothorax [118]. Ultimately, this shift is favourable in reducing length of stay, development of complications and pain in the trauma patient [117].

Evaluation of the conservative management model in patients presenting with SSP, traumatic pneumothorax and iatrogenic pneumothorax is required. The CoMiTED trial looks to determine if initial conservative management is non-inferior to standard invasive management for patients presenting to the Emergency Department with significant traumatic pneumothoraces where the clinician is uncertain if a drain is immediately necessary. The primary outcome of this trial will look to establish if there is a need for one or more subsequent emergency pleural interventions within 30 days of randomisation [119].

Conclusion

Recent years have seen a paradigm shift in the management of pneumothorax, moving from a uniform, intervention-driven approach to a more personalised, patient-centred model characterised by a more conservative strategy as reflected in updated clinical guidelines. This evolution is underpinned by a deeper understanding of the condition's pathophysiology and advancements in diagnostic and therapeutic modalities. However, further rigorous research remains essential to define optimal treatment strategies for specific patient subgroups and to identify individuals most likely to benefit from recurrence prevention measures.

Key points

• Pneumothorax intervention should not be determined based on radiological size but rather patient physiology, preferences and determination of ongoing air leak.

• Conservative management in selected patients is frequently successful, and associated with reduced hospitalisation, improved quality of life and reduced risk of recurrence.

• TUS can be an important adjunct in diagnosing pneumothorax, particularly post-trauma or in remote situations with limited access to radiography.

Self-evaluation questions

1. What is the recommended first-line treatment for a small, asymptomatic PSP in a haemodynamically stable patient?

   1. Immediate chest drain insertion
   2. Needle aspiration
   3. Observation with follow-up imaging
   4. Video-assisted thoracoscopic surgery
   5. Chest drain insertion and application of suction
2. Which of the following criteria indicates that conservative management with early discharge is not appropriate?

   1. Minimal or no symptoms
   2. Normal blood pressure, heart rate and peripheral oxygen saturation >94%
   3. Stable pneumothorax on chest radiography at 4 h
   4. Lives alone in a rural location 90 min from the hospital
   5. Has short-interval follow-up organised
3. A 22-year-old male presents with a first episode of PSP. A repeat chest radiograph did not demonstrate any increase in size and he was physiologically stable. He was conservatively managed. On review in the respiratory clinic 2 weeks later, the pneumothorax has radiologically resolved. His mother had a pneumothorax aged 32 years and has a history of a renal tumour. He has plans to fly to Bali in this week. What do you inform him about his future risk?

   1. He has a 5–10% chance of recurrence and can fly. He does not require further follow-up.
   2. He has a 25–30% risk of recurrence and should be screened for underlying cystic lung disease given his family history. He can fly 1 week after confirmed resolution of the pneumothorax.
   3. He has a 75% chance of recurrence and should be referred for video-assisted thoracoscopic surgery pleurodesis.
   4. He has a 25–30% chance of recurrence and cannot fly until a definitive procedure has been performed.
4. A 68-year-old female with severe COPD (Global Initiative for Chronic Obstructive Lung Disease group D, FEV₁ 35% predicted) presents with her second episode of right-sided SSP. A 14F chest drain is inserted, connected to a digital drainage system. After 5 days, the lung is fully expanded, but the digital monitor shows a PAL consistently measuring 40–60 mL·min⁻¹, with no significant downward trend. The patient is clinically stable but remains hospitalised due to the drain. She is deemed a very high-risk candidate for surgery. Considering the patient's high surgical risk and PAL, which management strategy is most appropriate at this stage, according to current best practice principles?

   1. Continue conservative management with the current chest drain indefinitely, monitoring for spontaneous resolution.
   2. Apply continuous high negative pressure suction (−20 cmH₂O) via the digital drain system to force leak closure.
   3. Proceed directly to open thoracotomy and pleurectomy as the most definitive treatment, despite the high risk.
   4. Discuss and potentially proceed with minimally invasive options such as chemical pleurodesis, ABP pleurodesis or EBV placement if anatomically suitable.
   5. Remove the chest drain and discharge with ambulatory follow-up, accepting the PAL as chronic.
5. A 35-year-old male, an active scuba diver, experienced a first episode of left-sided PSP managed with a chest drain 6 months ago. He is asymptomatic, a nonsmoker and a follow-up HRCT chest shows several small (<1 cm) apical blebs. He wishes to return to diving. What is the most appropriate recommendation regarding fitness to dive and further management for this patient according to current diving medicine and respiratory guidelines?

   1. He can return to diving immediately as the pneumothorax has resolved and small blebs are common incidental findings.
   2. Return to diving is permitted after 12 months if a repeat HRCT shows resolution of the apical blebs.
   3. Chemical pleurodesis via a chest drain should be performed, followed by a 6-month waiting period before considering a return to diving.
   4. A definitive surgical procedure is strongly recommended, followed by assessment for fitness to dive according to specific regulatory standards.
   5. Permanent disqualification from scuba diving is mandatory after any episode of spontaneous pneumothorax.

Suggested answers

1. c.

2. d.

3. b.

4. d.

5. d.