Risk factors

• pre-existing lung disease: COPD, asthma, cystic fibrosis, lung cancer, Pneumocystis pneumonia
• connective tissue disease: Marfan's syndrome, rheumatoid arthritis
• ventilation, including non-invasive ventilation
• 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

Symptoms tend to come on suddenly. Features include:

• dyspnoea
• chest pain: often pleuritic
• sweating
• tachypnoea
• tachycardia

The British Thoracic Society (BTS) published updated guidelines for the management of spontaneous pneumothorax in 2010. A pneumothorax is termed primary if there is no underlying lung disease and secondary if there is.

Primary pneumothorax

Recommendations include:

• if the rim of air is < 2cm and the patient is not short of breath then discharge should be considered
• otherwise aspiration should be attempted
• if this fails (defined as > 2 cm or still short of breath) then a chest drain should be inserted
• patients should be advised to avoid smoking to reduce the risk of further episodes - the lifetime risk of developing a pneumothorax in healthy smoking men is around 10% compared with around 0.1% in non-smoking men

Secondary pneumothorax

Recommendations include:

• if the patient is > 50 years old and the rim of air is > 2cm and/or the patient is short of breath then a chest drain should be inserted.
• otherwise aspiration should be attempted if the rim of air is between 1-2cm. If aspiration fails (i.e. pneumothorax is still greater then 1cm) a chest drain should be inserted. All patients should be admitted for at least 24 hours
• if the pneumothorax is less the 1cm then the BTS guidelines suggest giving oxygen and admitting for 24 hours
• regarding scuba diving, the BTS guidelines state: 'Diving should be permanently avoided unless the patient has undergone bilateral surgical pleurectomy and has normal lung function and chest CT scan postoperatively.'

Iatrogenic pneumothorax

Recommendations include:

• less likelihood of recurrence than spontaneous pneumothorax
• majority will resolve with observation, if treatment is required then aspiration should be used
• ventilated patients need chest drains, as may some patients with COPD