Imaging description

Pneumomediastinum occurs in up to 10% of patients following blunt trauma. However, only the minority of patients have an aerodigestive injury. In a recent study of 136 patients with pneumomediastinum identified by CT following blunt thoracic trauma, 27 patients had CT findings suspicious for aerodigestive tract injury, and of these only 10 patients required operative intervention [1]. No patient had a significant injury that was not suggested by the CT. In this same series, only 20 of the 136 cases of pneumomediastinum were identified on radiographs.

Suspicious CT findings of aerodigestive injury when pneumomediastinum is identified in blunt trauma patients include airway irregularity, disruption of the cartilage or tracheal wall (Figure 31.1), focal thickening or indistinctness of the trachea or main bronchi, laryngeal disruption, and concurrent pneumoperitoneum on CT of the abdomen. Massive pneumomediastinum despite adequate tube drainage of pneumothoraces is also considered a suspicious finding for an aerodigestive tract injury. If all these findings are absent, further investigation is likely unwarranted [1].