Pneumothorax

A pneumothorax is defined as the presence of air within the pleural space , the potential space between the visceral and parietal pleura ^[5]D. This accumulation of air disrupts the negative pressure required for normal lung expansion, potentially leading to partial or complete lung collapse. While often occurring as a primary event, it is frequently a complication of underlying pulmonary pathology, trauma, or medical intervention ^[3]D[5]D.

Synonyms and Alternate Nomenclature

In clinical practice, several terms are used interchangeably or to describe specific presentations of the condition. Standardized nomenclature is essential for clear communication between clinicians, particularly in emergency and neonatal intensive care settings ^[2]D[6]D.

• Also Called: PTX, collapsed lung, or air in the chest.
• Simple Pneumothorax: A pneumothorax that does not result in significant mediastinal shift or hemodynamic instability ^[5]D.
• Tension Pneumothorax : A life-threatening variant where air enters the pleural space but cannot escape, leading to progressively increasing intrapleural pressure ^[5]D.
• Spontaneous Pneumothorax: A pneumothorax occurring without an external provocative factor, further divided into primary and secondary types ^[3]D.
• Iatrogenic Pneumothorax: A pneumothorax resulting from a medical procedure, such as a biopsy or injection ^[1]D[4]D.

Key Definitions and Clinical Phases

Understanding the progression of a pneumothorax is critical for determining the urgency of intervention. The condition is often described through various phases and clinical states:

• Prodromal/Initial Phase: The period immediately following the initial air leak into the pleural space. In spontaneous cases, this may be associated with the rupture of subpleural blebs or cysts, such as those seen in Birt-Hogg-Dubé syndrome ^[3]D.
• Progressive Phase: The stage where the volume of air in the pleural space increases. This is particularly dangerous in patients receiving positive pressure ventilation (PPV), as the ventilator can exacerbate the air leak and accelerate the transition from a simple to a tension state ^[5]D.
• Nadir: The point of maximal lung collapse and physiological impairment before intervention.
• Tension State: A critical physiological state where expanding air volume and pressure result in obstructive shock ^[5]D. This occurs because the high intrapleural pressure impairs venous return to the heart.
• Plateau: A stable state where the air leak has ceased and the volume of intrapleural air remains constant.
• Recovery Phase: The period following successful intervention (e.g., thoracocentesis or chest drainage) where the lung re-expands and the pleural layers appose ^[6]D.

Classification of Pneumothorax Types

Pneumothorax is classified based on its etiology and the presence or absence of underlying lung disease. Standardized classification systems, such as the Common Terminology for Clinically Adverse Events (CTCAE), are often used to grade the severity of iatrogenic cases ^[4]D.

Spontaneous Pneumothorax and Genetic Predisposition

Spontaneous pneumothorax is categorized into primary (PSP) and secondary (SSP). PSP occurs in individuals without clinically apparent lung disease, while SSP occurs as a complication of an existing condition. A notable cause of SSP is Birt-Hogg-Dubé syndrome (BHDS), an autosomal dominant condition caused by mutations in the folliculin (FLCN) gene ^[3]D.

In BHDS, the development of lung cysts predisposes patients to spontaneous pneumothorax. The FLCN gene encodes a 579-amino acid protein that is highly conserved across species; mutations in this gene have a detection rate of approximately 88% in affected families ^[3]D. This highlights the importance of genetic screening in patients with recurrent or familial spontaneous pneumothorax.

Traumatic and Iatrogenic Classifications

Traumatic pneumothorax results from blunt or penetrating chest injury and is common in both civilian and military environments ^[5]D. Iatrogenic pneumothorax is a subset of traumatic pneumothorax caused by medical procedures. For example, image-guided core needle biopsies for suspected malignant pleural mesothelioma carry a risk of pneumothorax, which must be documented using standardized nomenclature to track procedural safety ^[4]D. Even seemingly minor procedures, such as trigger point injections (TPIs) for headache disorders, carry a theoretical risk of iatrogenic pneumothorax if the needle penetrates the pleura ^[1]D.

Size-Based and Physiological Classifications

While clinical nomenclature often focuses on the mechanism (e.g., traumatic vs. spontaneous), the physiological impact is the primary driver of management . The distinction between a simple and a tension pneumothorax is the most critical classification in emergency medicine ^[5]D.

• Simple: Air is present, but the pressure does not exceed atmospheric pressure throughout the respiratory cycle.
• Tension: A "one-way valve" mechanism allows air to enter the pleural space during inspiration but prevents its egress during expiration. This leads to a rapid rise in pressure, mediastinal shift, and eventual cardiovascular collapse ^[5]D.

Clinicians also utilize chest ultrasound to classify findings based on specific artifacts, such as the presence or absence of "lung sliding," which is a key diagnostic marker in the differential algorithm for acute dyspnea ^[6]D.

Overview

The supplied evidence describes pneumothorax across neonatal, pediatric, spontaneous, secondary, traumatic, procedure-related, postoperative, transplant-associated, and mechanically ventilated populations. The studies are heterogeneous and largely retrospective; therefore, their reported frequencies should not be generalized to the overall population. ^{[176][179][181][184]}

Neonatal and pediatric epidemiology

In a three-center cohort of 58,706 neonates, pneumothorax occurred in 310 infants (0.53%). Prevalence varied substantially by gestational age: 0.39% among infants born at ≥35 weeks, 4.0% at 29–34 weeks, and 4.6% at ≤28 weeks. Most events occurred within the first 24 hours of life, particularly among infants born at ≥35 weeks, in whom 76% of pneumothoraces developed during that period. ^[184]

Among infants born at ≥35 weeks, pneumothorax was associated with male sex, chorioamnionitis, and delivery-room continuous positive airway pressure. In the 29–34-week group, the study also evaluated neonatal respiratory and treatment-related variables, although the supplied abstract does not provide the complete list of associations. The cohort additionally compared rates before and after implementation of bubble CPAP, indicating that respiratory-support practices may influence neonatal risk. ^[184]

For pediatric primary spontaneous pneumothorax (PSP), a multicenter retrospective study included patients aged ≤21 years presenting between 2011 and 2022. It assessed patient characteristics, initial treatment—observation, tube thoracostomy, or operation—and ipsilateral recurrence for up to 5 years using multivariable Cox regression. The supplied abstract confirms that recurrence risk varied according to baseline characteristics and initial management, but does not provide the numerical recurrence estimates or the individual independent predictors. ^[179]

Primary and secondary spontaneous pneumothorax

Spontaneous pneumothorax is described as a common benign condition in the surgical literature, with rupture of pulmonary bullae identified as the principal mechanism in patients undergoing thoracoscopic treatment. ^[178][185] The available evidence does not provide a population incidence for primary spontaneous pneumothorax. ^[178][185]

Secondary spontaneous pneumothorax (SSP) is represented particularly by chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD). A retrospective surgical cohort included 138 patients undergoing first SSP surgery and compared ILD-associated with COPD-associated SSP after propensity matching. The study examined 3-year overall survival, recurrence-free survival, prolonged air leak, postoperative complications, and mortality, confirming clinically important differences between these underlying disease groups; the supplied abstract does not report all subgroup-specific risk estimates. ^[23]D

Anti-melanoma differentiation-associated gene 5-positive dermatomyositis with ILD is another high-risk context. A large inception cohort from 2014–2023 specifically investigated spontaneous pneumomediastinum and/or pneumothorax, their prognostic value, and predisposing factors using demographic data, pulmonary function tests, high-resolution CT findings, laboratory parameters, and 12-month survival. The supplied abstract establishes an association with unfavorable outcomes but does not list the individual predisposing variables. ^[176]

Patients with pectus excavatum may have congenital apical blebs and an increased risk of spontaneous pneumothorax. After minimally invasive repair of pectus excavatum, the procedure can create a communication between the pleural cavities—a so-called buffalo chest—which may make a subsequent pneumothorax bilateral and potentially life-threatening. ^[11]

Procedure-, treatment-, and hospital-associated risk

CT-guided percutaneous transthoracic lung biopsy carries recognized risks of pneumothorax and chest-tube placement. A 2026 systematic review and meta-analysis evaluated whether normal-saline needle-tract sealing reduces these outcomes compared with usual care; it therefore addresses prevention of iatrogenic pneumothorax rather than baseline spontaneous-pneumothorax epidemiology. ^[177]

Bronchoscopy can also be complicated by pneumothorax. In a retrospective cohort of 216 children undergoing flexible bronchoscopy, pneumothorax was recorded among post-procedure airway complications alongside hypoxemia, bronchospasm, laryngeal edema, and aspiration pneumonia. The study also examined peri-procedural oxygenation and nursing interventions, but the supplied abstract does not provide the pneumothorax-specific incidence or independent predictors. ^[182]

After anatomical lung resection, postoperative air leak is described as one of the most common complications. Randomized studies of segmentectomy, lobectomy, or bilobectomy evaluated pleurodesis and digital drainage strategies in patients who already had postoperative air leaks; these studies inform management of an air leak rather than the incidence of spontaneous pneumothorax. ^[8][9][14]

Pleural-space complications are common after lung transplantation. In a retrospective series of 791 bilateral lung-transplant recipients, 465 (58.8%) underwent a post-transplant intervention—surgical or nonsurgical—for pleural-space complications. The supplied abstract reports shorter median survival among patients requiring intervention, but does not isolate pneumothorax-specific incidence or risk factors. ^[20]D

Mechanical ventilation is an important setting for secondary or iatrogenic pneumothorax. In a retrospective ALS cohort of 131 patients, 95 underwent mechanical ventilation and the study evaluated pneumothorax occurrence, ventilation details, CT findings, independent risk factors, cumulative incidence, and survival. The supplied abstract indicates that pneumothorax affected a subset of ventilated patients and had prognostic implications, but the numerical incidence and specific independent predictors are not available in the provided text. ^[21]D

Trauma and emergency-care context

Traumatic pneumothorax commonly coexists with hemothorax or hemopneumothorax and is frequently treated with tube thoracostomy. A national trauma-database analysis evaluated whether the mortality and length-of-stay risks associated with thoracostomy were driven by iatrogenic complications, emphasizing that the intervention itself can introduce additional harm. ^[181] Prehospital needle thoracostomy is used for suspected tension pneumothorax; a retrospective trauma study examined objective criteria and factors associated with a positive response, including improvement in oxygen saturation. ^[183]C

Among patients with isolated traumatic rib fractures, outpatient chest radiography was studied in adults with at least three fractures or fractures accompanied by hemothorax, pneumothorax, or tube thoracostomy. The investigation focused on abnormal post-discharge imaging and interventions, not population incidence. ^[19]D

Evidence not directly informing pneumothorax epidemiology

The high-flow-versus-standard-oxygen randomized trial enrolled patients with acute hypoxemic respiratory failure defined by PaO₂/FiO₂ ≤200, respiratory rate >25/min, and pulmonary infiltrates; its primary outcomes were 28-day mortality and intubation-related outcomes, not pneumothorax risk. ^[175] Similarly, medical thoracoscopy research focused on re-expansion pulmonary edema after drainage of pleural effusion or pneumothorax, rather than on pneumothorax incidence or etiologic risk factors. ^[22]D Surgical meta-analyses comparing pleurectomy with abrasion and retrospective comparisons of pleurodesis techniques primarily address recurrence prevention and perioperative outcomes after spontaneous pneumothorax has occurred. ^[178][185]

Overview

Pneumothorax results from entry of air into the pleural space, but the initiating mechanism differs among primary spontaneous, secondary spontaneous, traumatic, iatrogenic, and neonatal forms. The available updated evidence supports a multifactorial model involving pleural or lung structural abnormalities, underlying parenchymal disease, external injury, medical procedures, and positive-pressure ventilation. ^{[10][11][12][15][20]D[21]D[23]D[26]D[184]}

Primary spontaneous pneumothorax

Primary spontaneous pneumothorax (PSP) is defined clinically by pneumothorax occurring without recognized underlying lung disease. ^[10] Classical epidemiologic associations include male sex, smoking, tall stature, and low body mass index; a population-based study also investigated whether genetically determined ABO and Rh blood-group phenotypes contribute to susceptibility, reflecting the possibility of additional biological or genetic mechanisms. ^[187] The available study description does not establish a causal blood-group association. ^[187]

Congenital or developmental apical blebs are an important proposed structural substrate. Patients with pectus excavatum may have congenital apical blebs and are therefore at increased risk of spontaneous pneumothorax; after minimally invasive repair of pectus excavatum (MIRPE), a surgically created communication between the pleural cavities, termed a “buffalo chest,” can make a subsequent pneumothorax bilateral and potentially life-threatening. ^[11] Pediatric PSP recurrence has been examined in a multicenter cohort of patients aged ≤21 years, with recurrence analyzed according to initial observation, tube thoracostomy, or operative treatment; the study was designed to evaluate whether recurrence risk varies with patient characteristics and initial treatment strategy. ^[179]

Smoking is a recognized risk factor for PSP, while vaping has emerged as a reported association. ^[12][187] A 2025 systematic review found that the evidence for vaping-associated pneumothorax consisted primarily of case reports and case series, indicating a rare and incompletely characterized condition rather than proof of population-level causation. ^[12] The review specifically evaluated clinical features, outcomes, and management reported in these cases. ^[12]

Clinical presentation and symptom duration appear more relevant to treatment failure than to the initial cause. In a prospective analysis derived from an ambulatory-management randomized trial, investigators evaluated whether longer symptom duration and higher symptom scores predicted failure of medical treatment, defined by ongoing pneumothorax or prolonged air leak. ^[10] These factors should therefore be regarded as potential modifiers of early management outcome, not established etiologic triggers. ^[10]

Secondary spontaneous pneumothorax

Secondary spontaneous pneumothorax occurs in the setting of recognized lung or systemic disease. Chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD) are clinically important substrates, and a surgical cohort specifically compared recurrence, prolonged air leak, survival, and postoperative complications in ILD-associated versus COPD-associated secondary pneumothorax. ^[23]D Anti-melanoma differentiation-associated gene 5–positive dermatomyositis complicated by ILD is another high-risk context: spontaneous pneumomediastinum and/or pneumothorax was investigated as a prognostic marker and in relation to predisposing clinical, pulmonary-function, laboratory, and high-resolution CT features. ^[176]

In patients with COPD and emphysema, endobronchial valve (EBV) treatment can precipitate pneumothorax because treatment-induced changes in regional ventilation and lung expansion may stress fragile parenchyma. In a Danish nationwide cohort, pneumothorax occurred in 46 of 228 patients (20.2%), with a median onset of 7 hours and median drain duration of 13 days; treatment involving upper lobes was associated with higher risk than treatment involving other lobes. ^[15]

Traumatic and iatrogenic pneumothorax

Blunt or penetrating chest trauma can disrupt the visceral or parietal pleura and may produce pneumothorax, hemothorax, or hemopneumothorax. Thoracostomy is frequently used for these injuries, although a 2026 trauma-database analysis specifically evaluated whether the observed mortality and length-of-stay burden associated with tube thoracostomy might be driven by in-hospital iatrogenic complications. ^[181] In patients with chest trauma and acute respiratory failure, noninvasive ventilation (NIV) may introduce additional barotrauma risk; a multicenter retrospective study assessed NIV failure and pneumothorax development, including pneumothorax occurring after NIV initiation in patients without pneumothorax at baseline. ^[26]D

Medical procedures can directly breach the pleura. CT-guided lung biopsy is a well-established procedural setting for pneumothorax; a 2025 propensity-matched study evaluated whether injecting 1–3 mL of gelatin-sponge slurry into the needle tract could reduce pneumothorax and pulmonary hemorrhage. ^[25]D Bronchoscopy may also be followed by pneumothorax, and a pediatric cohort recorded pneumothorax among post-bronchoscopy airway complications while examining procedural and nursing-related predictors. ^[182] Lung transplantation is another iatrogenic context in which pleural-space complications are common; a cohort of 791 primary bilateral lung-transplant recipients evaluated post-transplant pleural interventions and outcomes. ^[20]D

Ventilator-associated and neonatal pneumothorax

Positive-pressure mechanical ventilation can cause alveolar overdistension, rupture, and air leakage. In patients with amyotrophic lateral sclerosis receiving mechanical ventilation, a retrospective study assessed pneumothorax incidence, clinical risk factors, CT findings, and survival impact. ^[21]D Neonates are particularly vulnerable because of immature lungs, respiratory distress, delivery-related factors, and respiratory support. In a cohort of 58,706 infants, pneumothorax occurred in 0.53% overall, with higher prevalence at lower gestational ages: 4.0% at 29–34 weeks and 4.6% at ≤28 weeks, compared with 0.39% at ≥35 weeks. ^[184] Most cases in term or near-term infants occurred within 24 hours of birth; in the ≥35-week group, associations included male sex, chorioamnionitis, and delivery-room continuous positive airway pressure. ^[184]

Physiologic escalation

Tension pneumothorax is not a separate initiating disease but a dangerous physiologic progression in which pleural pressure compromises venous return and cardiovascular function. A prospective multicenter study measured pleural pressure during chest thoracostomy in newly diagnosed pneumothorax to examine its relationship with tension physiology, pleurodesis, and in-hospital death. ^[42]D Emergency needle decompression is the immediate recommended treatment for tension pneumothorax, followed by intercostal chest-drain placement; a 2025 meta-analysis addressed optimal needle length and decompression site because ATLS and European Trauma Course recommendations differ. ^[37]

Procedure-related consequences and associated complications

Rapid drainage of a large pneumothorax can trigger re-expansion pulmonary oedema, a serious complication associated with rapid re-expansion of previously compressed lung; risk factors after medical thoracoscopy were evaluated in a cohort of 362 patients. ^[22]D Thus, the initiating trigger, underlying lung reserve, positive-pressure exposure, and speed of re-expansion all influence the clinical trajectory, although the cited studies do not establish a single universal mechanism for every pneumothorax. ^{[10][15][20]D[21]D[22]D[23]D[26]D[42]D[184]}

Initial clinical assessment

Pneumothorax should be considered when a patient develops acute chest pain, dyspnea, respiratory distress, or hypoxemia, although the presentation may vary with the cause, size, laterality, underlying lung disease, and ventilatory status. ^[51] In a reported case of bilateral spontaneous pneumothorax associated with SARS-CoV-2 infection, the patient developed sudden-onset chest pain and progressive shortness of breath 17 days after COVID-19 diagnosis, with tachypnea, severe hypoxemia (oxygen saturation 75%), and bilaterally diminished breath sounds. ^[58]C Respiratory difficulty and chest pain were also the presenting complaints in two postoperative pneumothorax cases after orthognathic surgery. ^[193]C

History should define the timing and abruptness of symptoms and actively identify precipitating contexts, including trauma, recent procedures, general anesthesia, mechanical ventilation, thoracic surgery, and remote-location anesthesia. ^{[51][57]C[61]D[62]D} Primary spontaneous pneumothorax is defined as pleural air occurring without trauma or known lung disease; therefore, a history suggesting established pulmonary disease or an iatrogenic or traumatic event should prompt consideration of an alternative classification. ^[51] Important disease-specific contexts include mechanical ventilation in amyotrophic lateral sclerosis, in which pneumothorax is a recognized complication; idiopathic pulmonary fibrosis, in which pneumothorax occurred in 18.3% (30/164) of one retrospective cohort; COVID-19 infection; and thoracic endometriosis. ^{[21]D[52][54][191]}

The history should also identify prior thoracic operations and chest-wall procedures. Minimally invasive repair of pectus excavatum can create an iatrogenic communication between the pleural cavities (“buffalo chest”), and congenital apical blebs in these patients may increase the risk of bilateral spontaneous pneumothorax. ^[11] Following CT-guided pulmonary nodule localization, pneumothorax was the most frequent reported complication in one cohort, occurring in 34.3% (60/175) patients; this procedural history is therefore clinically relevant when symptoms arise afterward. ^[189]

Examination

Assess respiratory distress and oxygenation promptly, with particular attention to tachypnea, hypoxemia, and the distribution of breath-sound abnormalities. ^{[48][58]C[62]D[72]C} Breath sounds may be diminished over the affected region, but auscultation is subjective and can be difficult in noisy or operationally challenging environments such as helicopter emergency medical services. ^[48][72]C A respiratory-sound visualization system demonstrated regional respiratory-sound differences in reported cases of pneumothorax and pleural effusion, supporting the concept that abnormalities may be localized rather than uniformly distributed. ^[72]C

Clinical examination alone may be insufficient to exclude pneumothorax. In prehospital care, conventional auscultation can be particularly challenging, and thoracic point-of-care ultrasound (POCUS) has been evaluated as a visual alternative; the relevant systematic review assessed diagnostic accuracy and practicality in helicopter and prehospital settings. ^[48] A separate study specifically evaluated whether emergency physicians’ field clinical assessment could identify blunt traumatic pneumothorax requiring early decompression, reflecting the need to combine examination findings with the patient’s physiology and mechanism rather than relying on a single sign. ^[62]D

Look for evidence of an immediately dangerous presentation, including severe hypoxemia, marked respiratory distress, or bilateral involvement. ^[58]C Bilateral pneumothorax may occur in association with SARS-CoV-2 infection and can be life-threatening. ^[58]C Bilateral disease is also a particular concern after pectus excavatum repair when a pleural communication is present. ^[11] In mechanically ventilated patients, especially those with amyotrophic lateral sclerosis, new respiratory deterioration should raise suspicion for pneumothorax because clinical manifestations may occur in the setting of ventilator-associated barotrauma. ^[21]D

Examination in special and procedural settings

In children with traumatic occult pneumothorax, the defining feature is that pneumothorax is absent on chest radiography but visible on CT; consequently, a reassuring initial chest radiograph does not necessarily exclude pleural air after trauma. ^[61]D Similarly, patients with normal vital signs and atraumatic chest pain represent a diagnostic group in which the clinical utility and yield of routine chest radiography remain under investigation. ^[180]

Anesthesia may obscure the usual clinical presentation. During pediatric cardiac MRI, repeated apnea, limited visual access to the patient, specialized MRI-compatible ventilation equipment, and anesthesia-related barotrauma contributed to delayed recognition of a major pneumothorax; the report emphasizes that early symptoms may be masked in remote or technically constrained environments. ^[57]C Postoperative patients may present primarily with pain or respiratory difficulty, as illustrated after orthognathic surgery and after thoracoscopic surgery for primary spontaneous pneumothorax. ^{[193]C[50][188]C}

Integrating examination with imaging

Physical findings should be interpreted alongside the clinical setting and imaging rather than used in isolation. The French-speaking multidisciplinary guideline defines a large primary spontaneous pneumothorax radiographically as a visible rim extending along the entire axillary line between the lung margin and chest wall, with a width of ≥2 cm at the hilum. ^[51] CT may detect pneumothorax not seen on chest radiography, as demonstrated by the definition of traumatic occult pneumothorax in pediatric trauma. ^[61]D In suspected COVID-19-associated pneumothorax, chest radiography identified a large bilateral pneumothorax after the patient presented with severe hypoxemia and bilaterally reduced breath sounds. ^[58]C

Finally, distinguish acute pneumothorax symptoms from pain related to thoracic intervention. After single-port VATS for primary spontaneous pneumothorax, postoperative incision-site pain was prospectively assessed during rest and coughing at 3 and 6 hours and later follow-up; the study compared serratus anterior plane block with intercostal nerve block. ^[50] A subsequent systematic review evaluated postoperative analgesic strategies after VATS for spontaneous pneumothorax and noted that enhanced-recovery protocols increasingly use less invasive regional techniques, although high-quality evidence remains limited. ^[188]C

Overview

Pneumothorax should be distinguished from other causes of acute pleuritic chest pain, dyspnea, unilateral thoracic hyperlucency, or apparent pleural air. The differential is particularly important before invasive treatment when the patient is hemodynamically stable, because several structural abnormalities can mimic pneumothorax or tension pneumothorax and may worsen with inappropriate drainage. Chest radiography and lung ultrasonography can detect pneumothorax, whereas computed tomography (CT) is useful for confirming the diagnosis, identifying its cause, and characterizing mimics. ^[78]D

In patients with atraumatic chest pain and normal vital signs, chest radiography is commonly used during emergency evaluation, although the diagnostic yield and prevalence of clinically relevant radiographic findings remain important considerations. A large retrospective propensity-matched TriNetX analysis was designed to compare patients who did and did not undergo chest radiography, using 20 years of data from approximately 130 million patients. ^[180] The major life-threatening alternatives in emergency-department patients with atraumatic chest pain include acute coronary syndrome, pulmonary embolism, thoracic aortic dissection, esophageal rupture, pericardial tamponade, ruptured aortic aneurysm, and pneumothorax. ^[194]D

Radiographic and structural mimics

Giant pulmonary bullae and bullous emphysema. Giant bullae may occupy a substantial portion of a hemithorax and resemble a large or tension pneumothorax. In one reported case, air occupied approximately 40% of the right chest cavity, with incomplete expansion of the right lung; chest drainage produced no symptomatic improvement, and thoracoscopy established the diagnosis of a giant pulmonary bulla. CT review identified distinguishing features between the bulla and pneumothorax. ^[85]C Bullous emphysema is also a recognized pneumothorax mimic on lung ultrasonography. A prospective multicenter study of CT-confirmed bullous emphysema evaluated a standardized 14-region ultrasound examination and the diagnostic performance of individual and combined sonographic signs for bullae. ^[76]

Pseudotension pneumothorax. Conditions reported to be misdiagnosed as tension pneumothorax include diaphragmatic hernia, giant pulmonary bullae, cystic lung lesions, and pulmonary hydatid cyst. In a review of 45 misdiagnosed cases, diaphragmatic hernia accounted for 27 cases (60.0%), giant bullae for 9, cystic lesions for 8, and hydatid cyst for 1; 77.8% of cases had been incorrectly treated as tension pneumothorax. ^[43]D These findings support urgent but deliberate image review when the clinical presentation, radiographic appearance, or response to decompression is atypical. ^[43]D

Extrapleural air collection. Air in the extrapleural space can mimic pleural air. In a CT-based study, a “web appearance,” reflecting web-like linear septa within the air collection, was assessed as a potential distinguishing feature; other relevant findings included pneumomediastinum and dependent distribution of air. ^[195]C

Diaphragmatic and thoracic abnormalities. A radiolucent hemithorax with acute chest pain and dyspnea may reflect a nonpleural process, including diaphragmatic hernia, rather than pneumothorax. Diaphragmatic hernia was the most frequent pseudotension-pneumothorax mimic in the reviewed series. ^[43]D Multimodality imaging is useful because pleural, pulmonary, diaphragmatic, and extrapleural abnormalities can produce overlapping radiographic appearances. ^[78]D

Disease-associated alternatives and secondary causes

Pulmonary infection and inflammatory lung disease. Pneumothorax or pneumomediastinum may complicate severe viral pneumonia. In a hospitalized COVID-19 cohort of 6,528 patients, 9 developed spontaneous pneumothorax and/or pneumomediastinum, including cases of pneumothorax alone, pneumomediastinum alone, and combined pneumothorax, pneumomediastinum, and subcutaneous emphysema. ^[196]C Case reports also describe massive spontaneous pneumothorax as an uncommon presentation of severe COVID-19 pneumonia, including in patients who were not mechanically ventilated. ^[96]C A young adult with acute respiratory distress syndrome (ARDS) and pneumothorax illustrates that acute febrile respiratory disease with air-leak complications may be mistaken for isolated spontaneous pneumothorax. ^[86]C

Thoracic endometriosis syndrome. In reproductive-age patients, particularly when symptoms are temporally related to menstruation, thoracic endometriosis should be considered. The syndrome includes catamenial pneumothorax, catamenial hemothorax, catamenial hemoptysis, and thoracic endometriosis-associated lung nodules. Initial evaluation generally uses chest radiography and CT; a dedicated MRI protocol may further characterize diaphragmatic or thoracic lesions. ^[77]D

Vaping-associated pneumothorax. Vaping-associated spontaneous pneumothorax is a described entity in adolescents and should be considered in patients who vape nicotine or cannabis. Bilateral pneumothorax has been reported in a previously healthy 15-year-old who used cannabis concentrate exclusively and had vaped for only 6 months. ^[83]C

Malignancy and airway obstruction. Recurrent pneumothorax can rarely accompany malignant pleural disease. A case of malignant pleural mesothelioma involved recurrent bilateral pneumothoraces despite the absence of typical pleural thickening, nodules, or asbestos bodies at initial assessment. ^[95]C An obstructing endobronchial lesion should also be considered when pneumothorax is accompanied by lobar atelectasis. In an adult, an aspirated airway foreign body mimicked an enhancing endobronchial tumor and caused right upper-lobe atelectasis with pneumothorax; CT and bronchoscopy established the diagnosis. ^[97]C

Iatrogenic and cardiopulmonary mimics

After recent procedures, chest pain or dyspnea may result from complications other than pneumothorax. Pacemaker lead perforation can cause pericardial effusion and should be included in the differential of post-implantation symptoms. ^[87]C Conversely, a chest tube inserted for confirmed pneumothorax can itself cause serious complications: a left-sided tube after blunt trauma compressed the left anterior descending coronary artery, producing iatrogenic ST-segment elevation myocardial infarction that resolved after immediate tube withdrawal. ^[41]C Persistent or complex pneumothorax after endobronchial valve placement may require evaluation for an alternative or additional mechanism; ventilation SPECT/CT with 99mTc-DTPA was used in one such patient with severe chronic obstructive pulmonary disease. ^[84]C

General supportive management

Management should be individualized according to pneumothorax type, symptoms, physiological stability, lung re-expansion, air-leak persistence, underlying disease, and procedural risk. The 2024 joint ERS/EACTS/ESTS guideline used systematic searches, meta-analysis where feasible, GRADE certainty assessment, and an Evidence-to-Decision framework to address 12 key questions in adults with spontaneous pneumothorax. ^[101][102] Evidence from the supplied studies is heterogeneous, ranging from guideline evidence and randomized trials to retrospective cohorts, observational series, and case reports; therefore, interventions supported mainly by lower-certainty studies should be reserved for appropriately selected patients and specialist settings. ^{[101][102][104][106][118]D[119]D[202]C[203]C}

Chest drainage, suction, and removal

When drainage is required, the objective is evacuation of pleural air, restoration of lung expansion, and monitoring for ongoing air leak. In a prospective cohort of adults with post-procedural pneumothorax, catheter drainage connected to a vacuum bottle, drainage set, three-way stopcock, and digital pressure gauge was evaluated for pneumothoraces larger than 15%; the study specifically addressed the safety and efficacy of this approach rather than establishing universal indications for catheter drainage. ^[107] In thoracic trauma requiring an intercostal drain, a prospective randomized trial of 70 patients evaluated negative pleural suction as a strategy to shorten drain duration; the supplied abstract identifies duration of intercostal drainage as the principal outcome, but does not provide the numerical results. ^[103]

After surgery for spontaneous pneumothorax, early drain removal may reduce pain and length of stay in selected patients. A prospective randomized study compared postoperative drainage with no postoperative chest tube after bullectomy for spontaneous pneumothorax, specifically because chest tubes can cause pain and prolong hospitalization; the supplied abstract does not provide the comparative outcome data. ^[105] A pediatric prospective observational consortium study evaluated pleural-drain use after resectional lung surgery, including wedge resection and lobectomy, and characterized intraoperative air-leak testing; patients undergoing surgery for spontaneous pneumothorax or trauma were excluded, limiting direct applicability to pneumothorax care. ^[116]D A retrospective multicentre study published in 2026 compared removal after cessation of air leakage for less than 8 hours with conservative removal after 1–2 days following surgical pleurodesis for primary spontaneous pneumothorax; it was designed to assess whether progressive management improves recovery without increasing recurrence risk. ^[197]

Persistent air leak

Persistent air leak (PAL) requires continued assessment of lung expansion, drain function, clinical stability, and suitability for definitive intervention. In a pediatric intensive-care cohort, PAL was defined as continuous air leak for more than 48 hours; it complicated 38 of 788 PICU pneumothorax admissions, with 36 children included in the final analysis after exclusions. ^[118]D The reported population included pneumothoraces secondary to multiple lung pathologies, so these findings should not be assumed to represent uncomplicated primary spontaneous pneumothorax. ^[118]D

Conservative treatment for PAL consists of observation when appropriate, continued chest-tube drainage, and pleurodesis. The European expert-panel recommendations state that guidelines recommend surgical evaluation when the leak does not respond after 3–5 days, while endobronchial valves (EBVs) may be considered when surgery is infeasible, high risk, or unsuccessful. ^[202]C Bronchial-valve evidence remains predominantly observational: a 2024 systematic review and meta-analysis included 28 observational studies involving 2,472 participants and assessed success as complete leak resolution or chest-drain removal without further procedures. ^[104] The supplied abstract does not report the pooled success estimate, so a precise expected response rate cannot be stated from the available reference information. ^[104]

Multicentre and national observational experience has examined EBVs for PAL, including patients with emphysema and other underlying causes; the Korean 10-year experience evaluated real-world effectiveness and safety, while the European case series developed expert best-practice recommendations. ^[202]C[203]C EBVs have also been reported for PAL complicating severe COVID-19, particularly in patients considered poor candidates for invasive thoracic surgery, with reported use to support liberation from ventilation. ^[110]C Functional pneumonectomy using multiple intrabronchial valves has been described in a 10-patient series involving patients who failed traditional therapies; 17 procedures and 82 valve placements were performed, with a median of 8 valves per procedure. ^[126]C These valve approaches require bronchoscopic localization and specialist expertise, and the cited evidence does not establish superiority over surgery or pleurodesis. ^{[104][110]C[126]C[202]C[203]C}

Pleurodesis and blood-patch strategies

Autologous blood patch pleurodesis is a potential low-cost option for PAL when surgery is unsuitable or as an adjunct to chest-tube management. In a pediatric retrospective series, 10 patients underwent 17 blood patches; the median duration of PAL before the first patch was 7.5 days (interquartile range, 7–10 days), and 6 patients underwent a second patch. ^[119]D The underlying procedures included blebectomy for spontaneous pneumothorax, lung biopsy, malignant-tumour resection, and empyema treatment, so the evidence is not specific to primary spontaneous pneumothorax. ^[119]D Thoracoscopic blood-patch instillation has been reported in two patients with secondary spontaneous pneumothorax and PAL lasting more than 7 days, allowing direct visualization of the leak and targeted instillation; this evidence is limited to a case series and systematic review. ^[106]

OK-432 pleurodesis has been retrospectively evaluated after lung resection in patients with idiopathic interstitial pneumonia. Among 361 patients receiving postoperative pleurodesis, 67 had idiopathic interstitial pneumonia; the study assessed initial success, complications, and predictors of grade II or greater complications, but its population was lung-cancer surgery rather than spontaneous pneumothorax. ^[199]

Recurrence prevention and escalation

The role and timing of surgery after a first primary spontaneous pneumothorax remain debated. A systematic review using GRADE evaluated video-assisted thoracoscopic surgery versus conservative treatment, including recurrence, complications, hospital stay, and drainage duration; conventional guidance generally reserves surgery for persistent air leak, hemopneumothorax, bilateral pneumothorax, or occupations at risk, although emerging studies have challenged this approach. ^[198] Retrospective studies have evaluated predictors of failed chest-tube drainage in a first episode requiring tube insertion and factors associated with failure of non-operative management in children with large primary spontaneous pneumothorax; these studies support risk-stratified escalation but do not provide a universal threshold for surgery. ^[201]C[204]C

Chest-tube-free postoperative pathways may be safe in selected operations, but evidence is procedure- and population-specific. Immediate tube removal after anterior vertebral tethering in 257 pediatric patients was retrospectively assessed against published complication rates for tube retention and was reported as well tolerated without increased pulmonary complications; this is indirect evidence and should not be generalized automatically to pneumothorax surgery. ^[200]

Initial management of primary spontaneous pneumothorax

The randomized multicenter trial by Marx et al. evaluated first-line simple aspiration versus chest-tube drainage in adults aged 18–50 years with a complete primary spontaneous pneumothorax. In this open-label noninferiority trial, 402 patients were recruited from 31 French hospitals; 200 underwent aspiration and 202 received chest-tube drainage. The primary outcome was lung expansion at 24 hours, with tolerance and adverse events as secondary outcomes. ^[138] This trial directly addresses whether aspiration can replace drainage as initial treatment in selected patients with complete primary spontaneous pneumothorax. ^[138]

The Randomised Ambulatory Management of Primary Pneumothorax dataset was used by Raza et al. to examine predictors of treatment failure, defined as ongoing pneumothorax with prolonged air leak. The investigators assessed symptom duration, symptom scores, treatment allocation, vital signs, and other clinical factors, reflecting the continuing need to identify patients unlikely to succeed with conservative or ambulatory management. ^[10]

Trauma and chest-tube suction

Evidence on suction after tube thoracostomy for thoracic trauma remains heterogeneous. Priyadarshi et al. conducted a prospective randomized trial at a level 1 trauma center involving 70 thoracic-trauma patients with intercostal drains, comparing low-pressure negative pleural suction with conventional drainage. The principal aim was to determine whether negative suction could reduce intercostal-drain duration. ^[103] Arora et al. similarly randomized patients with blunt or penetrating thoracic trauma in a single-center open-label trial comparing slow negative suction with conventional drainage; the study emphasized the absence of consensus regarding post-insertion suction in trauma. ^[132]

These studies should be interpreted as trauma-specific evidence and not automatically extrapolated to postoperative air-leak management, where digital drainage systems and different pressure strategies have been studied. ^[103][132]

Postoperative air leak and digital drainage

In a multicenter randomized trial after segmentectomy or lobectomy, Takamochi et al. compared physiologic digital-drainage pressure of −8 cm H₂O with −15 cm H₂O in patients with moderate air leaks quantified at 100–1000 mL/min. Among 2379 registered patients, 93 received the −8 cm H₂O strategy and 106 received −15 cm H₂O. Prolonged air leak occurred in 67.7% and 60.4%, respectively, without a statistically significant difference (P = .303). ^[9]

Maxwell et al. randomized patients undergoing minimally invasive pulmonary resection to standard digital suction of −20 cm H₂O or low suction of −8 cm H₂O, using a single 24-Fr Blake drain. Planned tube removal required drainage of ≤450 mL/24 h and air leak of ≤20 mL/min over 6 hours; the study evaluated air-leak duration, tube duration, hospital stay, and the effectiveness of a single drain. ^[14]

Li et al. conducted a single-center randomized noninferiority trial in 95 patients with prolonged air leak after pulmonary surgery. Tube clamping and removal were compared at a low air-flow threshold of 0–20 mL/min versus a higher threshold of 60–80 mL/min, with continuous clinical, imaging, and laboratory monitoring and tube reinsertion when required. ^[135]

Skrzypczak et al. compared intrapleural 40% glucose solution with autologous blood-patch pleurodesis for postoperative air leak after anatomical lung resection, including segmentectomy, lobectomy, or bilobectomy. This prospective randomized study enrolled patients between November 2023 and December 2024 and evaluated the effectiveness of the two pleurodesis strategies. ^[8] Nicotra et al. assessed a polymeric hydrogel matrix after thoracoscopic lung segmentectomy in patients with moderate intraoperative alveolar air leaks. Sixty of 109 screened patients were randomized to hydrogel matrix or standard care, with outcomes including air leak, chest-drain duration, hospital stay, and cost-effectiveness. ^[208]

Thoracoscopy and diagnostic procedures

Wang et al. performed a multicenter randomized noninferiority trial in patients with minimal or absent pleural effusion, comparing medical thoracoscopy with versus without prior artificial pneumothorax. The primary question was whether the nonartificial-pneumothorax approach was noninferior for pleural-access success; the trial addressed guideline recommendations favoring artificial pneumothorax despite prior single-arm evidence suggesting shorter procedures and fewer complications without it. ^[131]

For CT-guided lung biopsy, Dheur et al. randomized 266 patients to gelatin sponge slurry or saline track sealing after a coaxial-needle biopsy traversing aerated lung. The groups included 132 patients receiving gelatin sponge slurry and 134 receiving saline; the primary purpose was to determine whether track sealing reduced postbiopsy pneumothorax. ^[141]

Transbronchial cryobiopsy evidence concerns diagnostic sampling rather than treatment of an established pneumothorax. Bian et al. randomized 224 patients with suspected interstitial lung disease to 1.1-mm versus 1.9-mm cryoprobes, assessing multidisciplinary diagnostic yield, specimen quality, complications, and probe-related mechanical effects. ^[133] Ravaglia et al. randomized 60 patients with diffuse parenchymal lung disease to 1.7-mm versus 1.9-mm probes, evaluating pathological and multidisciplinary diagnostic yield, sample size, and complications; reported pathological diagnostic yield was 100% with the 1.9-mm probe and 93.3% with the 1.7-mm probe. ^[137] The FROSTBITE-2 trial randomized 500 adults at nine US centers to evaluate a 1.1-mm cryoprobe versus conventional forceps for transbronchial biopsy of lung nodules or masses, transplant-related indications, or diffuse parenchymal lung disease; the rationale was that cryobiopsy may provide larger, less-crushed specimens. ^[206]

Respiratory support and prevention of iatrogenic pneumothorax

In acute hypoxemic respiratory failure, Frat et al. randomized 1116 patients meeting a PaO₂/FiO₂ ratio of ≤200, respiratory rate >25/min, and pulmonary infiltrates to high-flow oxygen or standard oxygen. The primary outcome was death by day 28, with intubation and mortality forming the central clinical questions. ^[175] In preterm infants receiving aerosolized calfactant, Kaluarachchi et al. compared low CPAP of 4–7 cm H₂O with high CPAP of 8–10 cm H₂O. CPAP failure and pneumothorax did not differ between groups, and adjusted odds of CPAP failure were not significantly different (OR 0.61; 95% CI 0.29–1.24). ^[134]

For prevention of procedure-related pneumothorax during cardiac-device implantation, the ZEROFLUOROAXI randomized trial compared ultrasound-guided axillary venous access with standard fluoroscopic access. Ultrasound provides direct needle visualization and was evaluated for feasibility, radiation reduction, and periprocedural safety in pacemaker and implantable-cardioverter-defibrillator implantation. ^[136]

Education and simulation

Leon et al. randomized 45 first-year surgery residents to immersive virtual-reality instruction delivered through a head-mounted display or traditional classroom didactics. Both groups subsequently performed chest-tube insertion on a high-fidelity task trainer, with technical acquisition measured using a validated ten-item objective assessment. ^[205] Hassan et al. randomized third-year medical students to a gamified mobile application (LuluRad; n=60) or script-based learning (n=66) for pneumothorax detection on chest radiographs. In the app group, diagnostic accuracy increased from 50.8% to 65.0% (P=.015), while sensitivity increased; the trial’s primary endpoint was the between-group change in pre/post accuracy, with specificity as an additional endpoint. ^[207]

Current international guidance

The principal contemporary resource is the joint ERS/EACTS/ESTS clinical practice guideline on adults with spontaneous pneumothorax, published in parallel in the European Respiratory Journal and the European Journal of Cardio-Thoracic Surgery in 2024. The multidisciplinary Task Force addressed 12 key clinical questions, searched MEDLINE and Embase, synthesised evidence with meta-analysis when possible, rated certainty using GRADE, and used an Evidence-to-Decision framework to determine the direction and strength of recommendations. ^[101][102] The guideline should be preferred for current adult spontaneous-pneumothorax decision-making over older society documents, while recognising that recommendations are based on the certainty and availability of evidence for each individual question. ^[101][102]

The French-speaking multidisciplinary guideline for primary spontaneous pneumothorax (PSP) was published in 2023 and endorsed by respiratory, emergency-medicine, intensive-care, anaesthesia, and thoracic-cardiovascular-surgery societies. It used literature review, GRADE assessment, and consensus involving experts, patients, and organisers; only proposals with strong agreement were retained. It defines a large PSP as a visible pleural rim along the entire axillary line and ≥2 cm at the hilum. ^[51]

The German S3 guideline, developed by the German Society for Thoracic Surgery with pulmonary, radiological, and internal-medicine societies, covers spontaneous and post-interventional pneumothorax. Its development was moderated by the German Association of Scientific Medical Societies; the spontaneous-pneumothorax literature search covered publications from 2008 onward, whereas the post-interventional search covered evidence from 1960 onward, with Oxford Centre for Evidence-Based Medicine levels assigned to relevant studies. ^[159][162]

Spanish guidance includes the SEPAR diagnostic and treatment update and the SECT clinical practice guideline. The SEPAR document classifies spontaneous pneumothorax as partial, complete, or complete with total lung collapse and introduced simple aspiration in an outpatient setting as an option for uncomplicated primary spontaneous pneumothorax, with reported results comparable to conventional drainage. ^[161] The SECT guideline formulated PICO questions and used the GRADE framework for evidence quality and recommendations. ^[163]

Special populations and clinical contexts

The Cystic Fibrosis Foundation guideline addresses pneumothorax and haemoptysis as pulmonary complications of cystic fibrosis. It was produced by the Foundation’s Pulmonary Therapies Committee, which noted that insufficient evidence existed for fully evidence-based recommendations in some areas. ^[153]

Pregnancy requires individualised multidisciplinary planning because evidence is limited. A systematic review identified 87 reported cases of spontaneous pneumothorax during pregnancy and found no strong evidence base for treatment during pregnancy or labour; the review collected gestational, pulmonary, management, maternal, fetal, and obstetric outcomes to formulate proposed recommendations. ^[160]

For children, paediatric-specific guidance has historically been limited. A multicentre retrospective case series from Australia and New Zealand evaluated 219 episodes in 162 children, including PSP and secondary spontaneous pneumothorax, specifically examining management patterns and aspiration outcomes because adult guidance could not be assumed to apply directly to paediatric patients. ^[166]C

Pneumothorax is a recognised complication of bronchoscopic one-way-valve therapy for advanced emphysema. The 2020 expert statement reports a prevalence of up to approximately 34% after treatment and emphasises timely, skilled management so that the therapeutic benefits of valve treatment can be preserved after pneumothorax resolution. ^[158]

Diagnosis, emergency care, and procedure-related resources

The prehospital chest-injury consensus statement from the Royal College of Surgeons of Edinburgh addresses assessment, diagnosis, and intervention for life-threatening chest trauma. It stresses that interventions should reflect the practitioner’s training, experience, and competence. ^[155]

Neonatal lung ultrasound is presented as a rapid diagnostic tool for pneumothorax. The neonatal guideline explains the relevance of A-lines, B-lines, and the lung point, and describes ultrasound-based rule-in and rule-out criteria intended to reduce radiation exposure. ^[164]

The Swedish clinical guideline on central venous catheterisation is relevant to iatrogenic pneumothorax prevention and management because it addresses safe CVC practice. It was developed through literature retrieval from PubMed and the Cochrane databases, multidisciplinary task-force review, consensus meetings, and Oxford evidence grading. ^[157]

Post-interventional pneumothorax is specifically included in the German S3 guideline. Contemporary procedural literature also illustrates the importance of monitoring: in a 2025 prospective multicentre TARGET study of robotic-assisted bronchoscopy for 8–50 mm peripheral pulmonary lesions, pneumothorax requiring intervention was one of the prespecified primary safety outcomes. ^[29]D A 2026 retrospective CT-guided pulmonary-nodule-localisation cohort reported pneumothorax in 34.3% (60/175) patients and defined pneumothorax using a visible visceral pleural line on CT with lung compression of ≥10%. ^[189]

Transport, classification, and implementation resources

Air travel guidance for patients with stable respiratory disease summarises British Thoracic Society recommendations concerning the hypobaric cabin environment. Commercial cabin altitude may reach approximately 8,000 feet, equivalent to about 0.75 atmospheres, and assessment should identify patients who may require in-flight supplemental oxygen. ^[165]

Older classification systems are not interchangeable. A comparative study evaluated BTS, ACCP, Belgian Society of Pulmonology, and Collins volumetric approaches to PSP size classification and highlighted the need for international consensus because the same pneumothorax may be assigned to different size categories depending on the method used. ^[170]D

Implementation should not be assumed from guideline availability alone. An audit of adherence to the BTS 2003 spontaneous-pneumothorax guideline found substantial deviations in initial practice; after a targeted educational intervention and provision of an online guideline link, a prospective re-audit was performed to assess change. ^[209]

Practical use of this resource set

Use the 2024 ERS/EACTS/ESTS guideline as the primary adult framework, supplement it with the French, German, Spanish, CF, pregnancy, paediatric, neonatal, valve-therapy, prehospital, CVC, and air-travel resources when relevant, and document the clinical context, pneumothorax classification method, patient stability, underlying lung disease, and local expertise. ^{[101][102][51][159][162][161][163][153][160][166]C[158][155][164][157][165][170]D}