Pneumothorax

Classification

Pathophysiology

• Increasing intrapleural pressure
• Mediastinal shift to the contralateral side
• Compression of mediastinal veins - reduced venous return
• Cardiovascular collapse and death if untreated

Primary Spontaneous Pneumothorax (PSP)

• Classic profile: tall, thin young male in 2nd-4th decade; 3:1 male-to-female ratio
• Incidence ~10/100,000 in men, ~3/100,000 in women
• Etiology: rupture of subpleural blebs (small thin-walled cystic spaces at the lung apex), found at CT or surgery in ~80% of patients
• Risk factors: smoking (10-20x increased risk, dose-dependent), Marfan syndrome, mitral valve prolapse, changes in ambient atmospheric pressure
• Recurrence: ~25% after first episode, typically within 1-2 years; ~50-60% after second; even higher after third

Secondary Spontaneous Pneumothorax (SSP)

• Airway disease: COPD (most common in US), asthma, cystic fibrosis (marker of poor prognosis)
• Infections: Pneumocystis jirovecii pneumonia (HIV), tuberculosis, lung abscess (leading causes in developing countries)
• Interstitial lung disease: sarcoidosis, IPF, lymphangioleiomyomatosis, tuberous sclerosis, pneumoconioses
• Neoplasms: primary lung cancers, pulmonary/pleural metastases
• Connective tissue disease: Marfan syndrome, Ehlers-Danlos, scleroderma, rheumatoid arthritis
• Miscellaneous: pulmonary infarction, endometriosis (catamenial pneumothorax)

Traumatic and Iatrogenic Pneumothorax

Clinical Features

• Ipsilateral pleuritic chest pain - sharp, sudden onset, may evolve to dull ache
• Dyspnea (may be mild in PSP without underlying disease)
• Dry cough (occasional)
• Patients may wait days before seeking care; symptoms can spontaneously improve within 24-72 hours even while pneumothorax persists

• Decreased/absent breath sounds on the affected side
• Hyperresonance to percussion
• Tachycardia (anxiety-driven)
• Subcutaneous emphysema (rare)
• Small-to-moderate pneumothoraces may have no physical signs

• Air hunger, severe dyspnea
• Tachycardia, then hypotension
• Elevated peak airway pressures (ventilated patients)
• Jugular venous distention (may be absent if hypovolemic)
• Hyperresonance on affected side (difficult in a noisy resuscitation area)
• Absent/diminished breath sounds ipsilaterally
• Tracheal deviation away from the affected side (late, not always present)
• Cardiovascular collapse - cardiac arrest if untreated

Treat tension pneumothorax clinically before waiting for a chest X-ray. Absence of tracheal deviation does NOT rule it out. - Tintinalli's Emergency Medicine

Diagnosis

• Presence of pleural sliding (lung sliding sign) excludes pneumothorax at that location
• Absence of sliding (with A-line pattern/"bar code sign" on M-mode = "stratosphere sign") suggests pneumothorax
• Lung point sign (transition from sliding to no-sliding) is highly specific for pneumothorax and can estimate size
• B-lines exclude pneumothorax at that location
• More sensitive than CXR in experienced hands

Management

Simple Pneumothorax - Observation

• Small pneumothorax in a spontaneously breathing, stable patient: observation with repeat CXR in 4-6 hours, drain only if expanding
• This is NOT an option in patients on any form of positive pressure ventilation (PPV), as simple can rapidly progress to tension

Needle Decompression (Tension Pneumothorax)

• Immediate large-bore needle into the 2nd intercostal space, midclavicular line (or 4th-5th ICS, anterior axillary line per updated ATLS)
• Life-saving; follow immediately with tube thoracostomy

Tube Thoracostomy (Chest Drain)

• Indicated for: tension pneumothorax after needle decompression, secondary spontaneous pneumothorax (nearly all patients), ventilated patients, expanding pneumothorax
• Small-bore tubes (24 Fr) or pigtail catheters via Seldinger technique for simple air evacuation
• Connect to water-seal drainage system with suction (~20 cmH₂O for persistent air leaks)
• Wean to water seal only after air leak resolves
• For loculated pneumothoraces: ultrasound- or CT-guided percutaneous drainage

Chemical/Surgical Pleurodesis

• For recurrent PSP or failed lung expansion: thoracoscopy with stapling of blebs + pleurodesis
• Nearly 100% effective in preventing recurrence
• Chemical pleurodesis for patients who refuse or are not candidates for surgery

PSP-Specific Guidance

• Asymptomatic or minimally symptomatic: conservative management / outpatient observation is an option for low-risk patients
• Recurrent pneumothorax or failed expansion: thoracoscopy with bleb stapling + pleurodesis

SSP-Specific Guidance

• Nearly all need tube drainage
• Many require thoracoscopy/thoracotomy with bleb stapling + surgical pleurodesis
• Cystic fibrosis-related pneumothorax carries poor prognosis; management is complex

Return to Sports

Special Situations

Chest X-Ray of Pneumothorax

The Key Radiographic Sign: Visceral Pleural Line

"The outer margin of the visceral pleura separated from the parietal pleura by a lucent space devoid of pulmonary vessels." - Fishman's Pulmonary Diseases

CXR Appearances by Position

Upright (Erect) Patient

• A visible pleural line in the upper hemithorax
• Absent vascular markings beyond that line
• Increased lucency (blacker) in the peripheral zone

• Murray & Nadel's Textbook of Respiratory Medicine

• Murray & Nadel's Textbook of Respiratory Medicine

Supine Patient (ICU/Trauma)

Tension Pneumothorax on CXR

Do NOT wait for CXR to treat tension pneumothorax - treat clinically first.

• Complete or near-complete lung collapse on affected side
• Mediastinal shift away from the affected side
• Tracheal deviation to the contralateral side
• Diaphragmatic depression (flattened or inverted hemidiaphragm on affected side)
• Widened intercostal spaces on the affected side

How to Distinguish Pleural Line from Artifacts

• Skinfold
• Edge of scapula
• Clothing/tubing artifact
• Avascular bullae or thin-walled cysts (inner margin concave, not convex toward chest wall)
• A bulla with a pleural adhesion can form a straight line mimicking a pneumothorax

Expiratory Films

Sizing on CXR

• BTS method: distance from lung edge to chest wall at the hilum level - ≥2 cm = large pneumothorax
• Most clinicians estimate based on the amount of air at the apex and laterally
• CT is more accurate for volume estimation but rarely needed just for sizing

Sensitivity Comparison

Management of Pneumothorax

Step 1 - Identify the Type

A. Tension Pneumothorax - Immediate Action

1. Needle Decompression (emergency first step)

• Insert a large-bore needle (14-16G) into the pleural space
• Sites (either is acceptable per evidence):
  • 2nd intercostal space, midclavicular line (2nd ICS MCL) - traditional ATLS site
  • 4th/5th intercostal space, anterior axillary line (4-5th ICS AAL) - ATLS alternate / ETC preferred
• A 2025 meta-analysis (PMID 40383767) found a 32.84% failure rate for needle penetration into the pleural cavity with standard cannulas. A 7 cm needle is recommended to reduce failure. For left-sided tension pneumothorax, the 2nd ICS MCL is safer to avoid cardiac injury.
• Follow immediately with tube thoracostomy - needle decompression is a bridge only

2. Tube Thoracostomy

• Definitive treatment after needle decompression
• Connect to water-seal drainage system with suction

B. Primary Spontaneous Pneumothorax (PSP)

Small + Clinically Stable (< 2 cm on BTS / < 3 cm ACCP from apex)

• Observation + 100% supplemental oxygen via non-rebreather mask
  • Intrinsic resorption rate: 1-2% per day on room air
  • Supplemental O₂ accelerates resorption ~4-fold (O₂ absorbed 60x faster than N₂)
• Observe in ED for at least 4 hours; repeat CXR before discharge to confirm no worsening
• Discharge with strict return precautions + follow-up in 24-48 hours
• 2024 ERS/EACTS/ESTS guidelines: conditional recommendation for conservative care of minimally symptomatic, clinically stable PSP patients

Large (> 2-3 cm) OR Symptomatic OR Expanding

• 2024 ERS/EACTS/ESTS guidelines (PMID 38806203) make a strong recommendation for needle aspiration over chest tube drain as the initial treatment for PSP
• Technique:
  • Thoracentesis kit (8 Fr catheter / 18G needle + three-way stopcock)
  • Insert at 2nd ICS MCL or 4th-5th ICS anterior axillary line under local anaesthesia
  • Aspirate with large syringe until resistance met; then remove catheter
  • If > 2.5 L aspirated, suggests continuing air leak - proceed to tube
• More likely to succeed if: patient < 50 years, volume aspirated < 2.5 L
• No significant difference in immediate success between aspiration and tube drainage in RCTs (see table)

• If aspiration fails or is not feasible
• Pigtail catheters (Seldinger technique) have outcomes similar to small-bore tubes
• Complications: kinking, malposition, occlusion by blood/clot, failure with large air leak

• A recent RCT showed conservative management is non-inferior to drainage in uncomplicated moderate-large PSP, with a lower rate of serious adverse events
• Same RCT: conservatively managed patients had lower recurrence at 1 year than those receiving aspiration/drain - suggesting slow re-expansion may improve healing
• 2024 ERS guidelines also give a conditional recommendation for ambulatory management

• A Heimlich valve attached to a small chest tube allows outpatient treatment
• Significantly reduced hospital stay (median 0 days vs. 4 days; P < 0.0001) vs. standard care
• Higher readmission rate but fewer total pleural procedures

C. Secondary Spontaneous Pneumothorax (SSP)

• Nearly all patients require tube thoracostomy - observation is rarely appropriate
• SSP carries higher physiological risk (limited pulmonary reserve) and higher recurrence risk
• Many will require thoracoscopy/thoracotomy + bleb stapling + pleurodesis
• Patients unfit for surgery (severe COPD, end-stage ILD): chemical pleurodesis or blood patch via the chest drain

D. Traumatic and Iatrogenic Pneumothorax

• Iatrogenic (post-thoracentesis, central line, needle biopsy): most managed with supplemental O₂ alone or simple aspiration; tube drain if these fail
• Traumatic (penetrating or blunt): usually requires tube drainage unless very small
• Hemopneumothorax: two tubes - one superior (air), one inferior (blood)
• Patients on PPV: drain all pneumothoraces regardless of size - risk of rapid progression to tension

E. Chest Tube Management Details

• Connect to a water-seal chamber drainage system
• Suction (20 cmH₂O): for persistent air leaks; suction not recommended by 2024 ERS guidelines routinely, but may help if lung not re-expanding
  • Risk: rapid re-expansion pulmonary oedema (RPE); increased airflow through visceral defect may enlarge it
• When to wean: place on water seal only after air leak resolves
• When to remove: if no pneumothorax on CXR after water seal; or after 4-hour clamp trial + normal repeat film
  • A 4-hour clamp is preferred over direct removal: easier to unclamp than to replace if pneumothorax recurs
• Loculated pneumothoraces: drain under ultrasound or CT guidance

F. Prevention of Recurrence - Pleurodesis and Surgery

Indications for Definitive Intervention

• 2nd or subsequent ipsilateral pneumothorax (recurrence rate ~50-60% after 2nd episode)
• Contralateral or synchronous bilateral pneumothorax
• Persistent air leak (PAL > 5-7 days)
• Occupation at risk (airline pilots, commercial divers) - even after 1st episode
• Failure of lung to expand with drain
• Patient preference after 1st PSP (shared decision-making)

Video-Assisted Thoracoscopic Surgery (VATS) - Gold Standard

• VATS with bleb/bulla stapling + mechanical or talc pleurodesis
• Recurrence prevention rate: ~95-100% (nearly 100% after surgical pleurodesis) - Harrison's 22E
• 2024 ERS guidelines: conditional recommendation for early surgical intervention for initial PSP in patients who prioritise recurrence prevention
• RCT data: VATS after 1st PSP showed 13% recurrence vs. 34% conservative management (Olesen et al.)

Medical (Chemical) Pleurodesis

• Agents: graded talc (most effective; 70-80% success), tetracycline, minocycline, autologous blood
• Instilled via chest tube or at thoracoscopy
• Preferred for patients who refuse or are not surgical candidates
• 2024 ERS guidelines: conditional recommendation for autologous blood patch in SSP patients with persistent air leak

Key Point on Suction vs. Seal

G. Special Situations

Quick Summary Algorithm

Pneumothorax confirmed
        |
 Tension signs? → YES → Needle decompression 2nd ICS MCL (7cm needle) → Tube drain
        |
       NO
        |
    On PPV? → YES → Tube drain (all sizes)
        |
       NO
        |
    Secondary (underlying lung disease)?
        YES → Tube drain ± surgery/pleurodesis
        |
       NO (PSP)
        |
    Small + stable? → YES → O₂ + Observe 4h → Discharge + follow-up 24-48h
        |
    Large / symptomatic? → Needle aspiration (1st line, 2024 ERS) → if fails → Small-bore tube
        |
    Recurrent / PAL / failed? → VATS + pleurodesis