What is pneumomediastinum?
Pneumomediastinum, also known as mediastinal emphysema, is a condition in which air is present in the mediastinum (the space in the chest between the two lungs). This can be caused by a traumatic injury or in association with pneumothorax or other diseases.
Pneumomediastinum may not be accompanied by any symptoms. Usually, it causes severe chest pain below the sternum, or breastbone, that may radiate to the neck or arms. The pain may be worse with breathing or swallowing.
During a physical examination, the doctor may feel small bubbles of air under the skin of the chest, arms or neck. A chest X-ray or CT scan of the chest may be done to confirm the presence of air in the mediastinum.
Often, no treatment is required as the air is gradually absorbed from the mediastinum. If pneumomediastinum is accompanied by pneumothorax, a chest tube may be placed. Breathing high concentrations of oxygen may allow the air in the mediastinum to be absorbed more quickly.
The outlook depends on the disease or events that caused the pneumomediastinum.