Pneumomediastinum can be classified into traumatic, inflammatory, and spontaneous types, with the latter often caused by rupture of pulmonary emphysema into the mediastinum.

bubble_chart Auxiliary Examination

X-ray examination reveals an air-filled band shadow adjacent to the mediastinum on the chest film, with subcutaneous emphysema visible in the imaging.

bubble_chart Diagnosis

1. Medical history:
   1. Tracheal or esophageal rupture after injury allows gas to enter the mediastinum; neck or chest trauma can also cause mediastinal emphysema.
   2. A history of obstructive pulmonary disease, with mediastinal emphysema occurring after rupture of a pulmonary bulla.
   3. Performing pneumoperitoneum or other abdominal insufflation may allow gas to enter the mediastinum through defects in the thoracoabdominal membrane, leading to mediastinal emphysema.
   4. Presence of a neck drainage tube, where intrathoracic negative pressure draws air along the drainage tract, causing mediastinal emphysema.
2. Symptoms: Most patients are anxious, but dyspnea is not severe.
3. Sign: In cases with subcutaneous emphysema, crepitus is palpable under the skin, more pronounced in the neck and upper chest.

bubble_chart Treatment Measures

1. The primary focus is on treating the underlying disease, and subcutaneous decompression is usually unnecessary. However, in cases of tension pneumothorax, a transverse incision can be made above the sternal notch to relieve gas pressure.
2. Antibiotics should be administered to prevent and treat pulmonary infections.
3. Maintain airway patency by using nebulized inhalation and promptly clearing respiratory secretions.