A condition called pneumothorax generally occurs when air fills the pleural cavity. This is a space formed by a double membrane, the pleura, that sits between the chest wall and the lungs; it is normally filled with fluid so the dual layers can move against each other during breathing. The pathophysiology of pneumothorax involves the filling of the pleural cavity with air or other type of gas. Pressure in the area can interfere with lung function and in some cases the organ can collapse. The condition can occur spontaneously, because of disease, or as the result of an injury.
Tissue can rupture spontaneously around the lungs, causing gas to escape into the space around them. This pathophysiology of the pneumothorax sometimes happens in healthy people, typically in males from 20 to 40 years old. It does not have to occur because of disease or trauma. Other spontaneous forms of pneumothorax result from structural changes caused by diseases such as emphysema. Alveoli, the structures where oxygen normally enters the blood, can be damaged, and this sometimes causes air to escape into the chest cavity.
The pleural cavity is sometimes ruptured during diagnostic tests, as well as when medical therapies are performed. Patients with tuberculosis were at one time treated with induced pneumothorax, while the lung disease itself can lead to a buildup of air in the plural space. Impact with the chest wall, or penetration of the pleura layers by an object, can cause damage to the chest. Often, surgeons implant a tube into the chest to drain the excess gas.
Pressure in the pleural cavity because of trapped air can also displace other structures, such as the lungs and heart. Called tension pneumothorax, the condition should generally be identified promptly because it can be life threatening. Most hospitals and other emergency medical facilities are prepared to recognize the pathophysiology of pneumothorax and treat the problem, because the condition can be so dangerous.
The symptoms of pneumothorax often include chest pain and a cough. A physical examination typically involves looking for a restriction of lung expansion during inhalation, as well as distinctive sounds inside the chest or when one speaks. The trachea, or windpipe, can also be pushed away from the side the air builds up in. Many times, the pneumothorax involves a small pocket of air which can go away within two weeks. Larger pockets often require a tube to be inserted until the leak stops, or major surgery may be performed to fix the problem.