mediastinal emphysema

Last reviewed 01/2018

Air in the mediastinum.

Most common cause is rupture of the alveoli (air then enters the interstitial tissues and tracks to the mediastinum). Causes include:

• raised intrapulmonary pressures e.g. vomiting, asthma, coughing
• positive pressure mechanical ventilation

Other causes include:

• penetrating neck injury
• oesophageal and bronchial rupture

Clinical features:

• may be asymptomatic
• chest pain that is worse on swallowing or breathing
• crunching sound coincident with each heart beat

Chest X-ray:

• air in the upper mediastinum, around the heart, or within the soft tissues of the neck
• pneumothorax in 30% of cases

Treatment:

• treat underlying cause
• treatment with high concentration inspiratory oxygen can hasten resolution