Background Information

Definitions

Spontaneous pneumothorax: presence of air in the pleural space, between the visceral and parietal pleura, that occurs in the absence of trauma or medical intervention.

Tension pneumothorax is a life-threatening condition characterised by intrapleural pressure rises sufficiently to cause significant hemodynamic compromise, typically due to a one-way valve effect that traps air in the pleural space.

Aetiology

Causes of pneumothorax are classically divided into the following: ^[Ref1][Ref2]

Category	Causes
Spontaneous pneumothorax	Spontaneous pneumothorax occurs spontaneously, without any preceding trauma / medical intervention. Spontaneous pneumothorax can be sub-classified into: Primary spontaneous pneumothorax (PSP): occurs in otherwise healthy individuals without known lung diseases Risk factor: young, tall, thin males Most have subclinical lung abnormalities (e.g. subpleural blebs ur bullae)   Secondary spontaneous pneumothorax (SSP): occurs in individuals with underlying lung disease (e.g. COPD, asthma, cystic fibrosis) OR ≥50 y/o with a significant smoking history These patients’ alveoli are more prone to rupture from chronically increased alveolar pressure or lung tissue necrosis
Traumatic pneumothorax	Penetrating chest trauma (e.g. gunshot wound, stab wound) Blunt chest trauma (e.g. motor vehicle accident)
Iatrogenic pneumothorax	Mechanical ventilation Central venous catheter placement Thoracocentesis Lung biopsy Bronchoscopy

Complication

Acute Complications

• Progression into tension pneumothorax
  • Any type of pneumothorax can evolve into tension pneumothorax, however the risk is greater in traumatic and iatrogenic pneumothorax ^[Ref]
  • Risk is highest in mechanically ventilated patients ^[Ref]
• Persistent air leak / failure of lung re-expansion
• Respiratory failure
• Obstructive shock (mostly seen in tension pneumothorax, where the mediastinal shift compresses the great veins and reduces preload)

Chronic Complications

• Recurrence is common (>50% recurrence risk after 1st episode, higher in the presence of underlying lung disease)
• Persistent air leak and failure of lung re-expansion

Diagnosis

Clinical Features

Symptoms

Sudden onset of:

• Pleuritic chest pain
• Dyspnoea

Signs

Typical respiratory examination findings:

Examination aspect	Typical findings
Chest expansion	↓ on the affected side (due to pain)
Percussion	Hyper-resonant over the affected area
Tactile fremitus	↓  on the affected side
Auscultation	Reduced / absent breath sound over the affected area

Additional findings that suggest tension pneumothorax:

• Haemodynamic instability
• Trachea deviation (away from the affected side) & Distended neck veins
  • Typical signs but have low sensitivity
  • Absence does NOT exclude diagnosis

Investigation and Diagnosis

1st line: chest X-ray

• Typical finding is a visible pleural line with lung markers only visible up to this line, no longer visible beyond the pleural line
• Ultrasound is increasingly used to identify pneumothorax (e.g. in eFAST)

2nd line (if chest X-ray is equivocal): CT chest

Management

Tension Pneumothorax Management

Immediate management: chest decompression with needle decompression or finger thoracostomy

• Latest recommended site: 4th/5th intercostal space, mid-axillary line
• Traditional site: 2nd intercostal space, mid-clavicular line

Definitive management: chest drain insertion (insert a chest drain AFTER initial chest decompression)

Spontaneous Pneumothorax Management

 

Full decision algorithm:

Symptomatic Pneumothorax

Assess for high-risk characteristics:

• Patient factors:
  • ≥ 50 y/o with significant smoking history
  • Presence of underlying lung disease (i.e. secondary pneumothorax)
  • Significant hypoxia
• Pneumothorax factors:
  • Haemodynamic compromise
  • Bilateral pneumothorax
  • Haemopneumothorax

Subsequent action, depends on whether high-risk characteristics are present or not.

High-Risk Characteristics Present

If safe to intervene → chest drain insertion

Subsequent care following chest drain insertion

• Admit as inpatient with daily review
• Remove chest drain when resolved
• Discharge and review as outpatient in 2-4 weeks

No High-Risk Characteristics

If safe to intervene → offer ANY of the following depending on the patient’s main priority

• If it is ‘safe to intervene’ → interventional options (i.e. needle aspiration / ambulatory device / chest drain) are allowed, but not mandatory
• However, if it is NOT ‘safe to intervene’ → interventional options should NOT be carried out

Goal	Management pathway	Description
Patient wishes to avoid procedures	Conservative management	PSP→ review as outpatient every 2-4 days SSP → admit as inpatient and give high-flow oxygen
Rapid symptomatic relief	Needle aspiration	If resolved → discharge and review as outpatient in 2-4 weeks If not resolved → chest drain insertion
If locally available (preferred in PSP	Ambulatory device	Review as outpatient every 2-3 days Remove device when resolved If stable → follow up as outpatient in 2-4 weeks

Asymptomatic Or Minimal Symptoms

Always offer conservative care regardless of pneumothorax size

• If PSP  → discharge and review as outpatient every 2-4 days
• If SSP  → admit as inpatient for a minimum of 24 hours with supplemental oxygen

Post-discharge Advice

• Return to emergency department immediately if further breathlessness develops
• Advise smoking cessation to reduce risk of recurrence
• Patients can only fly 7 days after full resolution confirmed on CXR
• Patients should be advised to permanently avoid diving, unless a definitive preventive strategy has been performed (e.g., surgical pleurectomy)

References

ATLS® Advanced Trauma Life Support® Student Course Manual 10th Edition. 2018 American College of Surgeons.

Original BTS Flowchart