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Pressure Injuries: Delving Into the Layers

Janis Harrison, RN, BSN, CWOCN, CFCN

My husband once compared my diagnosis process to electrical troubleshooting. They start with the battery that creates the power. Once it's determined the battery is 'good' they examine or continue the diagnosis by focusing on each step that should exist after finding the battery is 'good'.

The NPIAP is my 'good battery'. By following the pressure injury definitions they set, I can trust my diagnosis process is launched from firm ground and furthermore, I know the documentation and communication we use is clear.Revisiting specific definitions is important and another method I use to keep my practice sharp.

In wound care, we use medical jargon that is sometimes so specific that the layperson can get lost in what we are saying. By revisiting definitions, I find my communication on the topic is more consistent and even more important than that, it is accurate.

Pressure injuries become more complicated and difficult to heal as we delve deeper into the tissue layers.

Many Stage 1 and 2 injuries do not typically need to be seen by a wound specialist while stage 3 and beyond should be consulted by a Certified Wound Nurse or Wound Specialist before the patients' condition worsens.

Stage 3 Pressure Injury

Full-thickness skin loss

Full-thickness loss of skin, in which adipose (fat) tissue is visible and granulation tissue and epibole (rolled wound edges) are often present.. Slough and/or eschar may be visible.

The depth of tissue damage varies by anatomical location; areas of significant adiposity can develop deep wounds. Undermining and tunneling may occur. Fascia, muscle tendon, ligament, cartilage and/or bone are not exposed. If slough or eschar obscures the extent of tissue loss this is an Unstageable Pressure Injury.

A Stage 3 Pressure Injury can respond well to collagen in the wound base.

Keep in mind that the dressings need to touch the wound base. If the wound requires debridement, consider a surgical consult. Watch for signs and symptoms of infection and consider support surfaces to help off-load any pressure.

Stage 4 Pressure Injury

Full-thickness skin and tissue loss

Full-thickness skin and tissue loss with exposed or directly palpable fascia, muscle, tendon, ligament, cartilage or bone in the ulcer. Slough and/or eschar may be visible.

Epibole, undermining and/or tunneling often occur. Depth depends on anatomical location. If slough or eschar obscures the extent of tissue loss this is an Unstageable Pressure Injury.

A surgical consult is necessary as Stage 4 injuries can result in patient demise. A support service is necessary.

Unstageable Pressure Injury

Obscured full-thickness skin and tissue loss

Full-thickness skin and tissue loss in which the extent of tissue damage within the ulcer cannot be confirmed because it is obscured by slough or eschar. If slough or eschar is removed, a Stage 3 or Stage 4 pressure injury will be revealed. Stable eschar on the heel or ischemic limb should not be softened or removed.

Deep Tissue Pressure Injury

Persistent non-blanchable deep red, maroon or purple discoloration or epidermal separation revealing a dark wound bed or blood filled blister.

Pain and temperature change often precede skin color changes.

Discoloration may appear differently in darkly pigmented skin. This injury results from intense and/or prolonged pressure and shear forces at the bone-muscle interface. This injury results from intense and/or prolonged pressure and shear forces at the bone-muscle interface. The wound may evolve rapidly to reveal the actual extent of tissue injury, or may resolve without tissue loss. If necrotic tissue, subcutaneous tissue, granulation tissue, fascia, muscle or other underlying structures are visible, this indicates a full thickness pressure injury (Unstageable, Stage 3 or Stage 4). Do not use DTPI to describe vascular, traumatic, neuropathic, or dermatologic conditions.

Additional pressure injury definitions:

Medical Device Related Pressure Injury: This describes an etiology. Medical device related pressure injuries result from the use of devices designed and applied for diagnostic or therapeutic purposes. The resultant pressure injury generally conforms to the pattern or shape of the device. The injury should be staged using the staging system.

Mucosal Membrane Pressure Injury: Mucosal membrane pressure injury is found on mucous membranes with a history of a medical device in use at the location of the injury. Due to the anatomy of the tissue these injuries cannot be staged.

The National Pressure Injury Advisory Panel is a multidisciplinary group of experts in pressure injury. The NPIAP serves as the authoritative voice for improved patient outcomes in pressure injury prevention and treatment through public policy, education and research. Contact NPIAP at The definitions they provides are clear and consistent.

There are many treatment modalities to help us with wound healing. Remember the dry wound needs to be moistened and the wet wound needs to be dried to moist. If there is depth to the wound be sure to fill the hole.

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