Pneumomediastinum
Pneumomediastinum is air in the mediastinum. The mediastinum is the space in the middle of the chest, between the lungs.
Alternative Names
Mediastinal emphysema
Causes, incidence, and risk factors
Pneumomediastinum is uncommon. The condition can be caused by injury or disease. Most often, it occurs when air leaks from any part of the lung or airways into the mediastinum.
Increased pressure in the lungs or airways may be caused by:
It may also happen after:
Pneumomediastinum also can occur with pneumothorax
or other diseases.
Symptoms
There may be no symptoms. The condition usually causes chest pain behind the breastbone, which may spread to the neck or arms. The pain may be worse when you take a breath or swallow.
Signs and tests
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 that there is air in the mediastinum, and help diagnose a hole in the trachea or esophagus.
Treatment
Often, no treatment is needed because the body will gradually absorb the air. Breathing high concentrations of oxygen may speed up this process.
The doctor may put in a chest tube
if you also have a collapsed lung (pneumothorax). Surgery is needed to repair a hole in the trachea or esophagus.
Expectations (prognosis)
The outlook depends on the disease or events that caused the pneumomediastinum.
Complications
The air may build up and enter the space around the lungs (pleural space), causing the lung to collapse.
More rarely, air may enter the area between the heart and the thin sac that surrounds the heart. This is called a pneumopericardium.
In other rare cases, so much air builds up in the middle of the chest that it pushes on the heart and the great blood vessels, making them unable to work properly.
All of these complications require urgent attention.
Calling your health care provider
Go to the emergency room or call the local emergency number (such as 911) if you have severe chest pain or difficulty breathing.
References
Park DR, Vallieres E. Pneumomediastinum and mediastinitis. In: Mason RJ, Broaddus VC, Martin TR, et al, eds. Textbook of Respiratory Medicine. 5th ed. Philadelphia, Pa: Saunders Elsevier; 2010: chap 77.
Celli BR. Diseases of the diaphragm, chest wall, pleura, and mediastinum. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 99.
Updated: 8/30/2012
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Denis Hadjiliadis, MD, Assistant Professor of Medicine, Division of Pulmonary, Allergy and Critical Care, University of Pennsylvania, Philadelphia, PA. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.