What is a Tension Collapsed Lung?

While some kind of traumatic event usually causes the collapse of a lung or pneumothorax), something as simple and seemingly harmless as coughing hard can cause the same condition. Traumatic or spontaneous causes can, in rare instances, lead to a tension pneumothorax. Usually associated with chest pain (often localized to one side or the other) and sudden shortness of breath, a collapsed lung will not heal without medical intervention and in some cases—especially when it affects both lungs—can be deadly.

Pneumothorax

• A lung collapse caused by air accumulating in the pleural space between the lining of the lung and the pleura, the sac-like structure surrounding the lungs, is a pneumothorax (pneumo meaning “air” and thorax meaning “in the chest”).

Causes of Pneumothorax

• A pneumothorax can result from trauma, usually a bullet or knife wound, or it can happen spontaneously when a leak develops in the exterior wall of the lung or the smaller airways (bronchi or bronchioles). When the lung injury results in the formation of a flap of lung tissue that acts as a one-way valve, allowing air to seep out of the lungs and into the pleural space upon inhalation but not letting the escaped air back into the lungs, it is a tension pneumothorax, the rarest type of this condition. With each successive breath, more air gathers in the pleural space, compressing the lung, until the victim cannot expand the affected lung at all.

Hemothorax

• Sometimes an injury to a major blood vessel in the chest cavity will cause blood to pool around one or both lungs, compressing them and ultimately leading to collapse. This is a hemothorax ("hemo" meaning “blood”). The pooled blood may accumulate in the pleural space or outside the pleura in the thoracic cavity. Many hemothoraces qualify as “tension” when they compress the lungs to the point where they cannot inflate.

Progression

• Both the tension pneumothorax and hemothorax will lead to a gradual and steady pressure against one or both lungs. More commonly, a pneumothorax will affect one lung as the pleural space surrounding an individual lung will trap the air and keep it from affecting the other lung, but with a hemothorax, blood often pools freely outside the pleura and will distribute to both sides eventually.

Effects

• If left untreated, the steadily increasing pressure against one or both lungs will lead to respiratory insufficiency, where the lungs cannot take in enough oxygen or expel enough carbon dioxide (CO2) to meet the body’s cellular needs. As the condition progresses, it can lead to respiratory failure, the complete inability of the lungs to exchange oxygen and CO2; cardiovascular collapse, sudden succession of blood flow; and death.

Treatment

• The most common emergency treatment for a tension pneumothorax is a needle thoracentesis, the insertion of a needle through the chest wall and into the pleural space. The pressure within the tension pneumothorax forces air to escape the pleural space. Long-term treatment includes the use of a chest tube, a plastic tube inserted between two ribs into the pleural space and attached to suction, to evacuate all residual air from the pleural space. Because hemothoraces almost always result from rupturea of major blood vessels either due to weakening of the vascular wall or trauma, surgery is necessary to stop the bleeding, and an inserted chest tube will draw any remaining blood from the pleural space post-operatively.