Describe the key characteristics of Stage I–IV pressure injuries, including unstageable and suspected deep tissue injury.

• A. Stage I: nonblanchable erythema of intact skin; Stage II: partial-thickness loss with exposed dermis; Stage III: full-thickness loss with visible subcutaneous tissue; Stage IV: full-thickness loss with exposed bone, tendon, or muscle; Unstageable: depth obscured by slough/eschar; Suspected Deep Tissue Injury: intact skin with nonblanchable deep red or maroon discoloration.
• B. Stage I: shallow skin loss; Stage II: dermis exposed; Stage III: no tissue loss; Stage IV: only surface epidermis affected.
• C. Stage I: full-thickness loss; Stage II: superficial partial; Stage III: full-thickness with bone; Stage IV: nothing.
• D. Stage I: noninfected; Stage II: mild infection; Stage III: moderate; Stage IV: severe.

Answer: (A)

This question tests how pressure injuries are classified by depth of tissue loss and special cases for unclear depth. The stages progress from superficial changes to full-thickness loss, with two important exceptions: unstageable injuries and suspected deep tissue injury.

Stage I is nonblanchable erythema of intact skin, meaning redness that does not fade when pressed and the skin is not broken yet. That signals early tissue threat without a break in the skin barrier.

Stage II involves partial-thickness loss with exposed dermis. The wound bed is not full thickness; you can see a shallow open ulcer and pink/red wound bed, but the epidermis is affected and the dermis is exposed.

Stage III is full-thickness loss with visible subcutaneous tissue. Here the damage extends through the epidermis and dermis into subcutaneous tissue, but it does not expose bone, tendon, or muscle yet.

Stage IV is full-thickness loss with exposed bone, tendon, or muscle. The injury extends deeply into supporting structures, often with exposed tissues and potential damage to underlying structures.

Unstageable injuries are those where the depth cannot be determined because the wound bed is obscured by slough or eschar. Until the slough or eschar is removed and depth is revealed, the exact stage cannot be assigned.

Suspected deep tissue injury describes intact skin with nonblanchable deep red or maroon discoloration, or a localized area that feels firm, mushy, or painful, indicating underlying tissue damage even though the surface appears intact.

This description matches the standard definitions for all stages, including unstageable and suspected deep tissue injury.