Air in the pleural space — spontaneous, traumatic, iatrogenic, or tension physiology.
Also known as: pneumothorax, tension pneumothorax, PSP, SSP, collapsed lung, primary spontaneous pneumothorax
Overview
Presence of air in the pleural space, causing partial or complete lung collapse. Primary spontaneous pneumothorax (PSP) occurs without underlying lung disease; secondary spontaneous (SSP) is associated with known lung pathology; traumatic and iatrogenic forms arise from chest injury or procedures. Tension pneumothorax is a life-threatening one-way-valve physiology with hemodynamic compromise.
Epidemiology
PSP incidence ~7-18/100,000 males/year, ~1-6/100,000 females/year. Tall, thin young males (15-34) classic. SSP more common in older patients with COPD.
Try two board-style Pneumothorax questions
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Question 1PulmonaryMedium
A 28-year-old man has a second episode of right-sided primary spontaneous pneumothorax. After successful chest tube drainage, which of the following is most appropriate to prevent recurrence?
AContralateral prophylactic pleurodesis
BProlonged chest tube drainage
CVATS with pleurodesis
DObservation alone
EEndobronchial valve placement
Reveal answer & full explanation
Correct answer: C — VATS with pleurodesis
AContralateral prophylactic pleurodesis
BProlonged chest tube drainage
CVATS with pleurodesis✓
DObservation alone
EEndobronchial valve placement
Why VATS with pleurodesis is correct
After a second ipsilateral primary spontaneous pneumothorax, recurrence risk is 50–80%, so definitive intervention is offered.
Video-assisted thoracoscopic surgery (VATS) with mechanical pleurodesis or pleurectomy is the gold standard, with recurrence <5%.
Chemical pleurodesis (talc) is an alternative when surgery is not feasible.
Why the others are wrong
Prolonged chest tube drainage — evacuates air and seals the current leak but creates no pleural symphysis, so the recurrence risk after a second ipsilateral episode is unchanged
Contralateral prophylactic pleurodesis — recurrence prevention is directed at the affected ipsilateral side; treating the unaffected lung is not standard
Observation alone — appropriate after a first small primary pneumothorax, but a second ipsilateral event carries a 50-80% recurrence risk and warrants definitive intervention
Endobronchial valve placement — one-way endobronchial valves can seal a persistent air leak in patients who are poor surgical candidates, usually with secondary pneumothorax or emphysema, but this young man's leak has already closed, and valves create no pleural symphysis, so they do not lower the recurrence risk after a second ipsilateral episode
Question 2PulmonaryMedium
A 28-year-old tall, thin man who smokes presents with sudden right-sided pleuritic chest pain and dyspnea at rest. He had a left primary spontaneous pneumothorax 2 years ago. Pulse is 106/min, respirations are 24/min, blood pressure is 126/78 mm Hg, and SpO₂ is 96% on room air. He pauses mid-sentence to catch his breath, and the trachea is midline. Chest radiograph shows a 25% right pneumothorax. Which of the following is the most appropriate initial management?
AChest tube with talc slurry pleurodesis
BLarge-bore chest tube thoracostomy
CObservation with supplemental oxygen alone
DVideo-assisted thoracoscopic pleurodesis
ENeedle aspiration or small-bore chest tube
Reveal answer & full explanation
Correct answer: E — Needle aspiration or small-bore chest tube
AChest tube with talc slurry pleurodesis
BLarge-bore chest tube thoracostomy
CObservation with supplemental oxygen alone
DVideo-assisted thoracoscopic pleurodesis
ENeedle aspiration or small-bore chest tube✓
Why Needle aspiration or small-bore chest tube is correct
He is breathless at rest, tachypneic, tachycardic and pausing mid-sentence, so this primary spontaneous pneumothorax (PSP) is not minimally symptomatic and the air should be evacuated by needle aspiration (NA) or a small-bore chest tube.
British Thoracic Society (BTS) 2023 guidance (Roberts et al., Thorax) calls drainage of a symptomatic PSP by NA or chest drain the standard of care; size no longer decides whether to intervene, though it affects how safely an intervention can be done.
The 2024 European ERS/EACTS/ESTS guideline (Walker et al., Eur Respir J) strongly recommends NA over chest tube drainage for initial PSP treatment.
Normal blood pressure, preserved saturation and a midline trachea argue against tension physiology.
Smoking increases PSP risk and influences recurrence, so cessation should be advised (BTS 2023).
A first contralateral pneumothorax warrants referral to consider elective surgery once the acute episode is treated (BTS 2023).
Why the others are wrong
Observation with supplemental oxygen alone — Observation suits an asymptomatic or minimally symptomatic PSP, whatever its size (BTS 2023, conditional); ERS/EACTS/ESTS 2024 conditionally recommends it for minimally symptomatic, clinically stable PSP. Choosing it means judging by the 25% size and 96% saturation; symptoms, not size, decide whether to evacuate the air, and he is breathless at rest, tachypneic and pausing mid-sentence.
Chest tube with talc slurry pleurodesis — The chest tube would relieve the pneumothorax, but BTS 2023 says chemical pleurodesis can be considered to prevent recurrence of secondary spontaneous pneumothorax, including at a first episode in high-risk patients such as those with severe COPD (conditional). For a young man with a first contralateral PSP, prevention means considering elective surgery after the acute episode (anchoring on the recurrence and folding prevention into the acute step).
Video-assisted thoracoscopic pleurodesis — Elective surgery is the right idea for a first contralateral episode, but surgery at presentation is considered when recurrence prevention is deemed important, eg, tension pneumothorax or a high-risk occupation (BTS 2023, conditional), or when the patient prioritizes preventing recurrence (ERS/EACTS/ESTS 2024, conditional). The stem gives none of these, so he first needs the pneumothorax relieved, then elective surgical referral (right idea, wrong step, anchored on the recurrence history).
Large-bore chest tube thoracostomy — drainage is needed, so the traditional large tube is tempting, but for PSP large-bore drains offer no advantage over needle aspiration or a small-bore drain and cause more pain, so current guidance favors the smaller options; large-bore tubes are kept for problems such as hemothorax (the trap is outdated teaching about tube size).
Additional high-yield points
Ambulatory one-way-valve devices (a purpose-made device or a Heimlich valve attached to a chest drain) should be considered for initial PSP treatment in adults with good support, at centers with expertise and follow-up facilities (BTS 2023, conditional); ERS/EACTS/ESTS 2024 also conditionally recommends ambulatory management.
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Traumatic: blunt or penetrating chest trauma, rib fracture
Iatrogenic: central line placement, thoracentesis, lung biopsy, mechanical ventilation (barotrauma), CPR
Catamenial (rare): pleural endometriosis, recurs with menses
Pathophysiology
Disruption of visceral pleura (rupture of subpleural bleb in PSP) allows air to enter pleural space → loss of negative intrapleural pressure → ipsilateral lung collapse. Tension physiology occurs when a one-way valve traps air with each breath, increasing intrathoracic pressure, displacing mediastinum, compressing venous return → obstructive shock.
Clinical presentation
Symptoms
Sudden ipsilateral pleuritic chest pain and dyspnea
PSP often during rest or sleep; may be mild and self-limited
Severe distress in SSP (limited reserve) and tension PTX
Anxiety, diaphoresis
Signs / physical exam
Decreased or absent breath sounds on affected side
Hyperresonance to percussion
Decreased tactile fremitus
Tachycardia, tachypnea, hypoxia
Tension PTX: hypotension, tracheal deviation (away from PTX, late finding), distended neck veins, contralateral mediastinal shift
Classic findings
Sudden unilateral pleuritic pain + decreased breath sounds + hyperresonance in tall, thin young man = primary spontaneous pneumothorax until proven otherwise.
Aortic dissection — Tearing pain, BP differential, widened mediastinum on CXR
Large bulla mimicking pneumothorax — Pre-existing imaging important; CT can distinguish — avoid chest tube if bulla
Massive hemothorax — Trauma with shock and absent breath sounds, but DULL to percussion with usually flat neck veins (hypovolemia); initial chest tube output >1500 mL
Diagnostic workup
Diagnostic criteria
Confirmed by imaging in stable patient. Tension PTX is a CLINICAL diagnosis (hypotension, absent breath sounds, distended neck veins) requiring immediate decompression.
Labs
Most cases require no specific labs; obtain ABG/SpO2 to assess oxygenation
Consider underlying disease workup if SSP
Imaging
Upright PA chest radiograph — visceral pleural line with absent lung markings peripheral to it
Standard inspiratory erect film is adequate (expiratory films add no diagnostic yield); lateral decubitus view, ultrasound, or CT can detect small or occult pneumothoraces
Bedside lung ultrasound — high sensitivity (absent lung sliding, lung point pathognomonic) for trauma/critical care
CT chest — gold standard for size/quantification, occult PTX, underlying lung disease characterization
DO NOT delay decompression for imaging if tension PTX suspected clinically
Diagnostic algorithm
flowchart TD
A[Suspected pneumothorax] --> B{Hemodynamic<br/>compromise?}
B -->|Yes| C[TENSION PTX<br/>Needle decompress<br/>4-5th ICS AAL/MAL]
C --> D[Tube thoracostomy]
B -->|No| E[CXR / ultrasound]
E --> F{Size and<br/>symptoms}
F -->|Small PSP<br/>asymptomatic| G[Observe + O2<br/>± outpatient]
F -->|Large PSP<br/>or symptomatic| H[Aspiration or<br/>small-bore chest tube]
F -->|SSP| I[Chest tube<br/>+ admit]
G --> J[Recurrence?]
H --> J
I --> J
J -->|2nd event or<br/>persistent leak| K[VATS + pleurodesis]
Management algorithm for spontaneous and tension pneumothorax.
Treatment
First-line
Tension pneumothorax (CLINICAL DIAGNOSIS): immediate needle decompression (14-16 gauge angiocatheter) at 4th-5th intercostal space, anterior or mid-axillary line (preferred over the historical 2nd intercostal space midclavicular line per ATLS 10th edition) — followed by definitive tube thoracostomy
Open pneumothorax (sucking chest wound): apply three-sided occlusive dressing; convert to tube thoracostomy
Small PSP (<2-3 cm or <30%, asymptomatic): observation, supplemental high-flow O2 (accelerates reabsorption ~4× — nitrogen washout), serial CXR; outpatient if reliable
Large or symptomatic PSP: needle aspiration OR small-bore chest tube (8-14 Fr pigtail catheter), with similar success; BTS 2023 bases management on symptoms rather than size, so a stable, minimally symptomatic large PSP may instead be observed (conservative care was non-inferior in Brown, NEJM 2020)
SSP: chest tube (small-bore) for almost all — even small SSPs poorly tolerated; admit
Traumatic PTX: tube thoracostomy (28-32 Fr if hemopneumothorax); some occult traumatic PTX on CT can be observed if asymptomatic and not on positive-pressure ventilation
Second-line / adjunct
Persistent air leak (>3-5 days) or recurrent PSP: VATS bullectomy + mechanical or chemical pleurodesis (talc poudrage)
Indications for surgical/pleurodesis intervention: second ipsilateral PTX, first contralateral PTX, bilateral PTX, persistent air leak, hemothorax, occupation (pilot, diver) after first event
Smoking cessation strongly reduces recurrence
Avoid air travel for 2-3 weeks after resolution; SCUBA diving lifetime contraindication unless surgical pleurodesis
Complications
Tension pneumothorax with obstructive shock and cardiac arrest
Persistent air leak, bronchopleural fistula
Re-expansion pulmonary edema (rapid evacuation of large/chronic PTX)
Recurrence — 30-50% after first PSP without intervention
Hemopneumothorax from torn pleural adhesion
PANCE pearls
Tension pneumothorax is a CLINICAL diagnosis; never delay decompression for a CXR — needle decompress immediately, then tube thoracostomy.
ATLS now recommends needle decompression at 4th-5th intercostal space anterior or mid-axillary line (thinner chest wall) rather than the older 2nd ICS midclavicular site.
High-flow oxygen accelerates PSP reabsorption ~4-fold via nitrogen washout — use even in observation cases.
Beware re-expansion pulmonary edema after rapid drainage of large/chronic PTX or pleural effusion — for effusions, drain slowly (about 1.5 L at a time) and stop if cough or chest tightness; for pneumothorax, avoid early suction and never clamp a bubbling chest drain (risk of tension).
Recurrence after first PSP is 30-50%; recurrence after a second event approaches 80% — pleurodesis indicated after the second event (or first contralateral, bilateral, or persistent air leak).
References
BTS 2023 — British Thoracic Society Guideline for pleural disease (Roberts et al., Thorax 2023;78(Suppl 3):s1-s42)
ACCP — Management of Spontaneous Pneumothorax: An American College of Chest Physicians Delphi Consensus Statement (Baumann et al., Chest 2001)
PSP Trial — Conservative vs Interventional Treatment for Spontaneous Pneumothorax (Brown et al., NEJM 2020)
ATLS 10th Edition — Advanced Trauma Life Support, 10th Ed., American College of Surgeons Committee on Trauma (2018)
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