Spontaneous pneumothorax

Definition

Spontaneous pneumothorax is a collection of air or gas in the chest that causes the lung to collapse (see also pneumothorax) in the absence of a traumatic injury to the chest or lung.

Causes, incidence, and risk factors

A primary spontaneous pneumothorax occurs in a person with no known lung disease. It affects between 8,000 and 9,000 persons in the USA each year, usually tall, thin men between 20 and 40 years old.

Usually, the rupture of a small bleb or bulla (an air- or fluid-filled sac in the lung) causes primary spontaneous pneumothorax. Secondary spontaneous pneumothorax occurs in the setting of known lung disease, most often Chronic obstructive pulmonary disease (COPD).

Other lung diseases commonly associated with spontaneous pneumothorax include: Tuberculosis, Pneumonia, Asthma, cystic fibrosis, lung cancer, and certain forms of interstitial lung disease.

Symptoms

• Sudden chest pain or chest tightness
  o Dull or sharp or stabbing
  o Worsened by breathing deeply or by coughing
  
• Shortness of breath
  
• Rapid respiratory rate
  
• Abnormal breathing movement
  o Splinting (bending over or holding the chest to protect against pain)
  o Restricting chest wall motion when breathing (protection against pain)
  
• Cough
  

Note: The symptoms often begin suddenly, and may occur during rest or sleep.

Signs and tests

Listening to the chest with a stethoscope (auscultation) during a physical examination reveals decreased breath sounds.

Tests performed include:

• A Chest x-ray
  
• Arterial blood gases
  

Treatment
The objective of treatment is to remove the air from the pleural space, allowing the lung to re-expand. Small pneumothoraces may resolve on their own.