Spontaneous pneumothorax is a collection of air or gas in the chest that causes the lung to collapse in the absence of a traumatic injury to the chest or lung. A primary spontaneous pneumothorax usually occurs at rest.

The major symptom is sudden chest pain with breathlessness. The pain may be either dull or sharp or stabbing. It begins suddenly and is worsened by breathing deeply or by coughing. Rapid respiratory rate and abnormal breathing movement for example, splinting of ribs with breathing (by bending over or holding the chest) and little chest wall motion when breathing

Spontaneous pneumothorax is seven times more likely to occur in males than females. Male smokers have 22 times the rate of spontaneous pneumothorax compared to nonsmoking males. Female smokers have a 9 times increase in the rate of a spontaneous pneumothorax compared to nonsmoking females . A spontaneous pneumothorax is most likely to occur during the fall or winter months. There are between 800 and 900 cases a year in Canada.

Usually, the rupture of a small bleb or bullae (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.

If left untreated, recurrence rates of a spontaneous pneumothorax are high. Same side recurrence rates as high as 30% at six months and up to 50% at 2 years, without treatment have been reported.

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.

Aspiration of air, through a catheter to a vacuum bottle, may re-expand the lung.

The placement of a chest tube between the ribs into the pleural space allows the evacuation of air from the pleural space, when simple aspiration is not successful, or the pneumothorax is large. Re-expansion of the lung may take several days with the chest tube left in place. Hospitalization is required for chest tube management.

Surgery may be indicated for recurrent episodes.

Patients should discontinue smoking and avoid high altitudes, scuba diving, or flying in unpressurized aircraft to prevent the recurrence of pneumothorax.