Management depends upon:

  • Whether the patient is symptomatic
  • Whether the pneumothorax is primary or secondary
  • The size of the pneumothorax on the PA radiograph

The guidance below is based on the BTS guidelines (2023). Different guidelines have been adopted by other international bodies [21].

Symptomatic patients and those admitted for observation should have high-flow oxygen administered (15 L/min via a non re-breathe mask with a reservoir). Inhalation of high concentrations of oxygen reduces the total pressure of gases in pleural capillaries by lowering the partial pressure of nitrogen (Henry’s Law). This increases the pressure gradient between the pleural cavity and pleural capillaries and results in increased absorption of air from the pleural cavity. Compared to breathing room air, a pneumothorax will resolve four times faster if the patient is on high-flow oxygen [11]. For patients with COPD, fixed concentration oxygen should be administered.

Learning bite

A pneumothorax will resolve up to four times faster if high flow oxygen is administered.
Entonox® diffuses into air spaces and can convert an uncomplicated pneumothorax into a tension pneumothorax. It should not be used for analgesia in this setting.