pneumomediastinum
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