How might undermining or tunneling appear in a pressure ulcer?

Undermining or tunneling in a pressure ulcer is a critical aspect of its assessment and management. It primarily occurs as a complication of full-thickness tissue loss, where the ulcer extends deeply through the skin layers and may even involve underlying structures such as muscle or bone.

In this context, undermining refers to a situation where there is a cavity or channel forming beneath the edges of the ulcer, creating a 'lip' that may not be visible on the surface. Tunneling, on the other hand, indicates that the ulcer extends in a linear fashion beneath the skin. Both conditions signify a more advanced stage of injury, demonstrating that the wound is not only affecting superficial tissues but has reached greater depths.

In contrast, healthy tissue migration, superficial skin injury, or indications of good blood flow do not typically correspond with the presence of undermining or tunneling, as these features are associated with a more severe and compromised state of the wound. Thus, recognizing these characteristics is crucial for accurate diagnosis and tailoring appropriate treatment strategies for pressure ulcers.