Air is trapped in the pleural cavity under positive pressure, displacing mediastinal structures and compromising cardiopulmonary function

Aetiology

• Causes include penetrating trauma from road traffic accidents or iatrogenic procedures such as central line insertion or lung biopsy

Pathophysiology

• A tension pneumothorax occurs when air enters the pleural cavity through a one-way valve and cannot escape
• This is a life-threatening medical emergency that can lead to the compression of mediastinal organs if not treated immediately

Clinical features

• Haemodynamic instability: tachypnoea, tachycardia, hypotension, raised JVP
• Tracheal deviation away from the affected side
• Decreased chest expansion
• Increased resonance on percussion
• Decreased breath sounds
• Decreased vocal resonance
• Surgical emphysema

Investigations

• Should be a clinical diagnosis and treated immediately

Management

• Immediate needle decompression with a large-bore needle inserted into the second intercostal space in the midclavicular line
  • Recent guidelines have showed improved success in reaching the thoracic cavity when the fourth or fifth intercostal space mid-axillary line is used instead of the second intercostal space mid-clavicular line in adult patients
  • ATLS now recommends this location for needle decompression in adult patients
• This should be followed by chest drain insertion to reduce the risk of an immediate recurrence of the tension pneumothorax