Pneumothorax

• Pneumothorax:

  • this occurs when air leaks into a pleural cavity
  • a large pneumothorax can cause the lung to collapse
  • there is no definitive cause of a pneumothorax but it is thought to start from a tear in the lining of the lung
• Pathophysiology of Pneumothorax:

  • in a healthy person, the pleural pressure remains negative, relative to atmospheric pressure throughout the entire respiratory system
  • this cycle of pressure difference between the pulmonary alveoli and the pleural cavity is called transpulmonary pressure, and causes elastic recoil of the lung
  • if negative pressure is not maintained, the lungs will collapse
• Signs and symptoms:

  • dyspnoea (shortness or breath)
  • cyanosis
  • tachycardia
  • tachypnoea
  • distress
  • shunting develops due to the non-ventilated alveoli leading to hyperaemia
• Treatment:

  • if only a small portion of the lung has collapsed, it may re-inflate itself over time
  • large pneumothoraxes require chest drains to allow air to leave and not return