A pressure ulcer, also known as a bedsore or pressure injury, is a localized area of damage to the skin and underlying tissue. This injury forms over a bony prominence due to prolonged pressure, or pressure combined with friction or shear. Pressure restricts blood flow to the affected area, which can lead to tissue damage and tissue death. These injuries are common, especially in individuals with limited mobility, and understanding their severity is important.
Understanding Pressure Ulcer Staging
Healthcare professionals use a classification system for pressure ulcer staging to describe the severity of these wounds. This system helps categorize the extent of tissue damage, ranging from superficial skin changes to deep tissue injury. The National Pressure Injury Advisory Panel (NPIAP) updated this staging system. Staging provides a standardized way to assess the wound, which guides treatment decisions and helps predict the healing outlook.
Characteristics of Stage 4 Pressure Ulcers
A Stage 4 pressure ulcer involves full-thickness skin and tissue loss. This means the injury extends deeply enough to expose underlying structures such as fascia, muscle, tendon, ligament, cartilage, or bone.
Visual characteristics include a deep, open wound that may have a “punched out” appearance. Slough, which is yellow, tan, gray, green, or brown dead tissue, or eschar, which is tan, brown, or black dead tissue, may be present within the wound bed. Undermining and tunneling, where the wound extends beneath the surrounding skin, occur with Stage 4 pressure ulcers. This classification signifies a severe, deep injury requiring comprehensive care.
Characteristics of Unstageable Pressure Ulcers
An unstageable pressure ulcer also involves full-thickness tissue loss, but its actual depth cannot be determined. This is because the wound bed is completely obscured by slough and/or eschar. The presence of this dead tissue prevents healthcare providers from seeing the base of the wound. Therefore, it is impossible to accurately stage the ulcer until this obscuring material is removed. This classification indicates a severe injury, as superficial wounds do not accumulate enough slough or eschar to hide their depth.
Comparing Severity
Both Stage 4 and unstageable pressure ulcers indicate severe tissue loss. In a Stage 4 ulcer, the visible exposure of bone, tendon, or muscle confirms the profound depth of the injury. However, with an unstageable ulcer, the true extent of the damage remains hidden beneath the slough or eschar.
This means an unstageable ulcer could be a Stage 3, where fat is visible, or a Stage 4, with exposed bone or muscle. The uncertainty associated with an unstageable ulcer implies a more extensive or deeper injury than a clearly defined Stage 4. While both are serious, the unstageable classification presents a diagnostic challenge due to the hidden nature of the wound.
Progression and Management Considerations
Once an unstageable pressure ulcer is identified, the slough and/or eschar needs to be removed. This process, known as debridement, allows healthcare professionals to determine the wound’s true depth and stage. After debridement, the wound can then be properly classified, revealing a Stage 3 or Stage 4 pressure ulcer underneath. General principles for managing these severe ulcers include reducing pressure on the affected area through repositioning and specialized support surfaces. Infection control, meticulous wound care, and adequate nutrition are also important components of comprehensive treatment to promote healing.