A 25-year-old man was in an altercation while smoking “crack” cocaine.
He was punched in his back, the left side of his chest, and his
neck. He was taken to the hospital where no significant injury was
found. The next day, his chest radiograph was re-read and the patient
The patient appeared well, with only mild tenderness at the above-mentioned
areas of injury. He was otherwise asymptomatic.
- What is the cause of the abnormalities seen
in these radiographs (Figure 1)?
- Should you admit this patient to the hospital?
Occasionally, it is unclear whether a patient has sustained a
traumatic injury or has a nontraumatic disorder. The abnormality
in this patient—pneumomediastinum—could potentially
be due to either of the two.
The PA chest radiograph shows linear
air collections adjacent to the mediastinum (heart and aorta)
and an associated fine white line representing the displaced mediastinal
pleura (Figure 2A). In addition, linear air collections extend up
the mediastinal fascial planes into the neck. On the lateral view,
there is air surrounding mediastinal structures, particularly the
aorta (Figure 2B). The lateral cervical spine radiograph, obtained
because the patient had neck pain following trauma, shows air within
the prevertebral soft tissues (Figure 2C).
Initial radiographs—Patient 10.
(A) The PA view shows a thin layer
of air is adjacent to the left and right heart borders and the fine white
line of the raised parietal pleura (white
arrowheads). Air outlines the lateral margin of the descending
aorta (black arrowhead) and tracks into
the soft tissues of the superior mediastinum and base of the neck
(B) On the lateral view, a thin layer
of air outlines the ascending and descending aorta (arrowheads).
(C) The cervical spine radiograph
shows air within the prevertebral soft tissues (arrowheads).
Pneumomediastinum can occur following blunt or penetrating trauma, often, but not always, major
trauma, or can occur “spontaneously,” without
There are three potential sources of mediastinal air: the esophagus,
the tracheobronchial tree, and the lung. Injury to each of these
structures should be suspected in patients with pneumomediastinum.
The clinical scenario usually provides evidence as to which organ
is the site of air leak into the mediastinum.
The most frequent source of mediastinal air is the lung. Pneumomediastinum occurs in
clinical settings associated with alveolar hyperinflation and high intrapulmonary ...