Pneumothorax

Spontaneous
- Primary (No underlying disease)
- Secondary (Underlying lung disease)
Traumatic
- Non-iatrogenic
- Iatrogenic (barotrauma and procedure related)

Etiology:
- Result of rupture of a pleural “bleb” (congenital defect in the tissue of the alveolar wall)
- More common in tall young men
Incidence:
- 4–40 per 100,000 per year
- Male to Female ratio: 2.5:1
Recurrence:
- 25–50%, usually within the first year
Age Group:
- Typically in their 20s; rare after age 40
Complications:
- Tension pneumothorax in about 1–2% of cases
Risk Factors:
- Smoking (including cannabis): ~90% of cases occur in smokers
- Family History: 25% of cases
- Genetic Conditions:
  - Marfan Syndrome
  - Homocystinuria

Associated Conditions:
- Chronic Obstructive Pulmonary Disease (COPD): 70% of secondary causes
- Asthma
- Tuberculosis and abscess: Most common cause worldwide
- Cystic Fibrosis: Lifetime risk of 8–20%
- AIDS: Risk: 2–6%, typically associated with Pneumocystis jiroveci Pneumonia
- Catamenial Pneumothorax: Related to menstruation, high recurrence with menses
- Other Conditions:
  - Pneumonia
  - Bronchitis
  - Connective Tissue Diseases (Marfan Syndrome, Ehlers-Danlos)
  - Drug use (smoking, vaping)

Presentation: Within 24 hours of onset in 70% of cases
Chest Pain:
- Sudden sharp pain radiating to back or shoulders
- Initial pleuritic pain transitions to steady ache
- Improvement after 24 hours despite persistence of pneumothorax
Dyspnoea:
- Variably present, typically not severe in PSP
- Severe dyspnoea with hypoxia, hypotension, tachycardia indicates tension pneumothorax

General:
- Examination may be unremarkable
- Tachycardia (most common finding)
COPD Patients: Tall, thin males
Affected Side Changes:
- Unilateral absent or decreased breath sounds
- Hyperresonance to percussion
- Decreased tactile fremitus
- Decreased chest wall movement
Tension Pneumothorax Signs:
- Clinically unstable (SBP < 90 mmHg, HR > SBP, RR > 30, SpO2 < 90%)
- Unilateral absent breath sounds
- Hyperresonant chest to percussion
- Cyanosis, respiratory distress, tracheal deviation, neck vein distention

Supine Position:
- Hyperlucency in anteromedial and subpulmonic recesses
- Visualization of visceral pleural
- Deep sulcus sign
Tension Pneumothorax (Radiological):
- Increased volume of hemithorax
- Depressed hemidiaphragm
- Tracheal deviation

Tension Pneumothorax:
- Clinical diagnosis (not imaging)
- Needle Decompression:
  - Immediate intervention, followed by chest tube placement
  - 14 gauge (5 cm) angiocatheter in children, 10 gauge (7.5 cm) in adults
  - Insert over the top of the third rib in the mid-clavicular line
Small Primary Spontaneous Pneumothorax (Mildly Symptomatic):
- Observe in ED, repeat CXR at 4 hours
- Discharge if stable with follow-up x-ray in 24-72 hours
- Supplemental oxygen may hasten lung expansion
Large Spontaneous Primary Pneumothorax:
- Definitions vary (ACP, BTS, Belgian guidelines, Light’s index, Collin’s method)
- Treatment approach based on size and severity

The American College of Chest Physicians (ACCP):
- Apex-cupola distance > 3 cm.
The British Thoracic Society (BTS):
- Interpleural distance at the hilum > 2 cm.

Belgian Guidelines:
- Dehiscence over the entire length of the lateral chest wall.
Light’s Index:
- A calculative approach involving the diameter of the collapsed lung (L) and the diameter of the inner hemithorax at the hilum (H).
- Estimated pneumothorax size = (1 – L³/H³) x 100.
- A pneumothorax size of ≥20% is defined as large.

Collin’s Method (see image below)- A+B+C > 6cm

Chest 2001 (Expert Opinion):
- Recommends small bore “pigtail” catheter for all large pneumothoraces.
British Thoracic Society 2010:
- Conservative management may be appropriate for large pneumothorax.
- Needle aspiration as the first option.
- Small-bore chest tube as the next option.
Belgian Respiratory Society 2005:
- Start with needle aspiration or small-bore chest tube for large pneumothorax.
European Respiratory Society 2015:
- Focus on patient symptoms.
- Observation alone for large, stable pneumothorax.

Large Spontaneous Pneumothorax in Select Patients (age < 50 years, normal vitals, mildly symptomatic, not near/total lung collapse):
- ED Management:
  - Provide supplemental oxygen.
  - Repeat CXR in 4 hours; if stable, discharge with repeat CXR in 24 hours.
- Follow-Up:
  - CXR at 24-72 hours post-ED discharge, then at 1 week, 2 weeks, 4 weeks, 8 weeks, or until complete resolution.
Large Symptomatic Pneumothorax:
- Consider needle aspiration first as an alternative to a chest tube for patients who prefer to avoid chest tubes.

Without Chest Tube:
- CXR at 24-72 hours post-ED discharge.
- Subsequent CXR at 1 week, 2 weeks, 4 weeks, 8 weeks, or until resolution.
With Chest Tube:
- Daily CXR until resolution of air leak and removal of chest tube.
- Only a single view PA CXR is required.
Increasing Symptoms or Pneumothorax Size:
- Return to the Emergency Department for further assessment.

Primary Spontaneous Pneumothorax (First Presentation):
- Often managed non-surgically.
Recurrent Pneumothorax (2 or More Occurrences on Same Side):
- Thoracic surgery consultation is recommended.

Risks Associated with Flying:
- Expansion of Trapped Air: At high altitudes, the decrease in atmospheric pressure can cause expansion of the air trapped in the pleural space, leading to a worsening pneumothorax or recurrence.
- Hypoxia: Reduced cabin pressure and lower oxygen levels can exacerbate respiratory issues.
Recommendations for Air Travel:
- Avoid Air Travel: Patients should avoid flying until complete resolution of the pneumothorax is confirmed by clinical examination and imaging.
- Wait Period: Generally, air travel is not recommended for at least 2-4 weeks after a spontaneous pneumothorax, and only after a follow-up chest X-ray confirms full resolution.
- Medical Clearance: Obtain clearance from a healthcare provider before flying.
- Emergency Precautions: Inform the airline and ensure access to emergency medical care if needed during the flight.