Subcutaneous Emphysema(Archived)

Excerpt

Subcutaneous emphysema is the de novo generation or infiltration of air in the subcutaneous layer of skin. Skin is composed of the epidermis and dermis, with the subcutaneous tissue being beneath the dermis. Air expansion can involve subcutaneous and deep tissues, with the non-extensive subcutaneous spread being less concerning for clinical deterioration. However, the development of subcutaneous emphysema may indicate that air is occupying another deeper area within the body not visible to the unaided eye. Air extravasation in other body cavities and spaces can cause pneumomediastinum, pneumoperitoneum, pneumoretroperitoneum, and pneumothorax. The air travels from these areas along pressure gradients between intra-alveolar and perivascular interstitium, spreading to the head, neck, chest, and abdomen by connecting fascial and anatomic planes. Air will preferentially accumulate in subcutaneous areas with the least amount of tension until the pressure increases enough to dissect along other planes, causing extensive subcutaneous spread which can result in respiratory and cardiovascular collapse.