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A pneumothorax is a collection of air between the outside surface of the lung and the inside surface of the chest wall. These two surfaces are lined with a smooth membrane called pleura and normally are in contact with each other, but they can become separated when air, fluid or blood collects between them.

Causes of pneumothorax

A pneumothorax can occur whenever the surface of the lung is ruptured, allowing air to exit from the lung into the pleural space. It can occur when some injury punctures the chest wall, allowing outside air to enter the pleural space. A spontaneous pneumothorax occurs without chest trauma, and is usually due to the rupture of a small cyst on the lung surface. Such cysts may occur without any associated lung disease, or they can develop due to a variety of underlying lung disorders, emphysema being the most common.

Symptoms of pneumothorax

The major symptoms of a spontaneous pneumothorax are:

  • the sudden onset of chest pain
  • and/or shortness of breath

A physician may suspect that a pneumothorax is present after examining the patient and learning his/her symptoms, but the most accurate diagnostic test is a chest X-ray, which will show air collected around the outside surface of the lung.

Treatment of pneumothorax

A pneumothorax usually does not require emergency treatment unless so much air collects in the chest that the heart and major blood vessels are compressed; this condition, called a tension pneumothorax, requires prompt removal of air from the pleural space. When the pneumothorax is not the tension variety, its treatment will depend on its size, the patient's symptoms, whether it is a recurrent problem and whether the hole in the lung or chest wall has sealed itself.

Treatment options include:
  • simple observation — waiting for the air in the pleural space to be absorbed by the blood stream
  • removal of the air through a tube that is inserted through the chest wall into the pleural space (the tube may be removed immediately after the air has been aspirated, or it may be left in place attached to a drainage system for several days)
  • surgical procedures — generally reserved for recurrent pneumothorax
Preventing another pneumothorax (do not scuba dive)

Persons who have had one pneumothorax have an increased risk of a recurrence. Because of this increased risk and because a pneumothorax which occurs during scuba diving may enlarge to a dangerous size as the diver ascends, persons who have had a pneumothorax should avoid scuba diving.

Spontaneous pneumothorax

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.

Spontaneous pneumothorax is seven times more likely to occur in males than females. Male smokers have 22 times the likelihood of spontaneous pneumothorax compared to non-smoking males. Female smokers have a nine times increase in the likelihood 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. Without treatment same side recurrence rates are as high as 30% at six months and up to 50% at two years.

Treatment of spontaneous pneumothorax

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 when 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 recommended for recurrent episodes.

Preventing another spontaneous pneumothorax

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

Catamenial pneumothorax

Catamenial pneumothorax is a rare condition where women experience pneumothorax at the onset of their menstrual period.

Catamenial pneumothorax generally affects women in their thirties and forties. Women with catamenial pneumothorax often report monthly chest pain, shortness of breath, dizziness and fatigue. Some women with catamenial pneumothorax have experienced multiple lung collapses over several years. Many of these women have also been diagnosed with pelvic endometriosis (a condition where the endometrium, the tissue that lines your uterus, grows in other places in your pelvis).