Final answer:
A bedbound patient with a pressure injury covered by slough or eschar should be categorized as 'Unstageable' for treatment purposes, as the actual depth of tissue damage cannot be determined without debridement.
Step-by-step explanation:
When an advanced practice registered nurse (APRN) is caring for a bedbound patient with an area of skin tissue obscured by slough or eschar over the left greater trochanter, the correct staging for this pressure injury would be 'Unstageable'. According to the National Pressure Ulcer Advisory Panel (NPUAP), a pressure injury that is covered by slough or eschar in the wound bed cannot be accurately staged because the depth of tissue damage is not visible. Therefore, the tissue must be debrided to determine the stage properly. Treatment typically involves removing the necrotized tissue to prevent infection and aid healing.