Pneumothorax

Pneumothorax is a condition characterized by the accumulation of air in the pleural space, resulting in the partial or complete collapse of the affected lung.

Classification

Pneumothoraces can be classified as follows:

• spontaneous pneumothorax
  • primary spontaneous pneumothorax (PSP): Occurs without underlying lung disease, often in tall, thin, young individuals. PSP is associated with the rupture of subpleural blebs or bullae.
  • secondary spontaneous pneumothorax (SSP): Occurs in patients with pre-existing lung disease, such as COPD, asthma, cystic fibrosis, lung cancer, Pneumocystis pneumonia. Certain connective tissue diseases such as Marfan's syndrome are also a risk factor
• traumatic pneumothorax: results from penetrating or blunt chest trauma, leading to lung injury and pleural air accumulation.
• iatrogenic pneumothorax: occurs as a complication of medical procedures, such as thoracentesis, central venous catheter placement, ventilation, including non-invasive ventilation or lung biopsy.

An important clinical entity is a tension pneumothorax - this describes a severe pneumothorax resulting in the displacement of mediastinal structures that may result in severe respiratory distress and haemodynamic collapse.

Catamenial pneumothorax is the cause of 3-6% of spontaneous pneumothoraces occurring in menstruating women. It is thought to be caused by endometriosis within the thorax.

Clinical features

Symptoms tend to come on suddenly:

• dyspnoea
• chest pain: often pleuritic

Signs

• hyper-resonant lung percussion
• reduced breath sounds
• reduced lung expansion
• tachypnoea
• tachycardia

In tension pneumothorax: