Side impact injury
He landed on his left shoulder, which is swollen, bruised and tender. The skin overlying the injured shoulder feels very puffy to the touch and compresses easily. In addition, he has some leftsided chest cage tenderness. There are no other major injuries or exam findings. Vitals are normal.
An X-ray of the left shoulder is shown. What does it show? What should be the next step?
For Diagnosis see next page
Large subcutaneous air and presumed pneumothorax
This is a very elegant but unusual X-ray finding which fits beautifully with the physical exam. The left shoulder “puffiness” to palpation, as well as the left chest injury, suggests subcutaneous air of an occult pneumothorax. Although you cannot see the pneumothorax well on CXR, the amount of subcutaneous air is sizable and outlines the fibers of the pectoralis muscle!
The next step is a CT scan to further define the injury. This CT scan, taken a few days after the original X-ray, shows the presumed pneumothorax completely re-absorbed, but with a large amount of persistent subcutaneous air (see labelled CT). A single rib fracture is noted. Importantly, there is no evidence of major vascular or airway injury. Classically, the presence of a large amount of subcutaneous emphysema by exam or X-ray is a clue to presence of injury to either the trachea or a major bronchial trunk.
Amazingly, given the amount of subcutaneous air, this fellow was managed without placement of a chest tube (I was stunned). Some people have all the luck.
John Dallara, DO, practices Emergency Medicine in Virginia and North Carolina, and directs the Emergency Medicine PREP Course. www emprepcourse.com