Describe stage 2, stage 3, and stage 4 pressure injuries in terms of tissue involvement and depth.

• A. Stage 2: partial-thickness loss with exposed dermis; Stage 3: full-thickness loss with visible subcutaneous tissue; Stage 4: full-thickness loss with exposed bone, tendon, or muscle; may include undermining or tunneling.
• B. Stage 2: full-thickness; Stage 3: partial-thickness; Stage 4: no tissue loss.
• C. Stage 2: no tissue loss; Stage 3: partial-thickness; Stage 4: partial.
• D. Stage 2: partial-thickness; Stage 3: no tissue loss; Stage 4: full-thickness with bone exposure.

Answer: (A)

Pressure injuries are staged by depth of tissue involvement, from partial-thickness to full-thickness. Stage 2 is partial-thickness loss with involvement of the epidermis and part of the dermis, resulting in a shallow, pink/red, moist wound bed; the dermis is exposed but deeper structures are not involved. Stage 3 is full-thickness loss with tissue loss through the dermis into subcutaneous tissue; fat may be visible, but bone, tendon, and muscle are not exposed. Stage 4 is full-thickness loss with exposure of bone, tendon, or muscle; undermining or tunneling is common. This progression reflects increasing depth and involvement of deeper structures.