Subcutaneous emphysema is defined as:

Subcutaneous emphysema is defined as:

• A. Air in the peritoneal cavity
• B. Blood in the pleural space
• C. Air under skin causing crackling feel
• D. Fluid around joints

Answer: (C)

Subcutaneous emphysema is air trapped in the subcutaneous tissues, which you can feel as a crackling, popping sensation under the skin when you palpate it. The description that fits this is air under the skin causing a crackling feel. The other phrases point to different problems: air in the peritoneal cavity is pneumoperitoneum, blood in the pleural space is a hemothorax, and fluid around joints is a joint effusion.

Subcutaneous emphysema is air trapped in the subcutaneous tissues, which you can feel as a crackling, popping sensation under the skin when you palpate it. The description that fits this is air under the skin causing a crackling feel. The other phrases point to different problems: air in the peritoneal cavity is pneumoperitoneum, blood in the pleural space is a hemothorax, and fluid around joints is a joint effusion.