Pressure injuries are localized areas of damage to the skin and/or underlying soft tissue, resulting from sustained pressure or pressure combined with shear. These injuries can manifest as intact skin or an open ulcer and may cause pain. They represent a significant health concern, particularly for individuals with limited mobility.
What Are Pressure Injuries?
Pressure injuries develop when sustained pressure on the skin reduces blood flow to tissues, depriving them of oxygen and nutrients. This can lead to tissue damage and cell death within hours. Friction and shear forces, where skin rubs against a surface or layers slide over each other, also contribute.
These injuries commonly occur over bony prominences where soft tissue offers less padding, such as the sacrum, heels, hips, and elbows. Healthcare professionals classify the severity of skin-related pressure injuries using staging systems. Organizations like the National Pressure Injury Advisory Panel (NPIAP) and the European Pressure Ulcer Advisory Panel (EPUAP) provide standardized classifications based on the extent of tissue damage.
The Nature of Mucosal Membranes
Mucosal membranes are moist tissue layers that line various internal cavities and organs, including the oral cavity, nasal passages, gastrointestinal, and genitourinary tracts. Unlike skin, which has a protective outer layer of keratinized epithelium, most mucosal membranes are composed of non-keratinized stratified squamous epithelium. This structural difference, along with their consistently moist environment, makes mucosal tissues distinct from skin. Mucosal membranes serve as a primary barrier between the body’s internal environment and the external world, playing a role in protection, absorption, and secretion.
Staging Mucosal Membrane Injuries
Standard staging systems, such as those for skin pressure injuries by the NPIAP and EPUAP, are not applicable to mucosal membrane pressure injuries. This is due to fundamental anatomical differences between mucosal tissue and skin. Mucosal membranes lack the distinct layers found in skin, making it challenging to accurately assess the depth of tissue loss.
For instance, non-blanchable erythema, a key indicator for a Stage 1 skin pressure injury, is not visible on mucous membranes because of their underlying color and moist nature. Additionally, soft blood clots that form on injured mucosal surfaces can resemble slough, which typically indicates deeper tissue loss in skin wounds. The NPIAP explicitly states that pressure injuries on mucosal surfaces should not be staged using the standard system and should instead be labeled as “mucosal pressure injury” without an assigned stage.
Describing Mucosal Membrane Injuries
Since a numerical stage cannot be applied, healthcare professionals describe mucosal membrane pressure injuries using detailed characteristics. This approach provides a comprehensive picture for effective communication and care planning. Key descriptive elements include the precise location, its size (length, width, depth), and color.
Observations about the presence and type of exudate, any signs of infection, and the suspected cause of the injury are also important. Many mucosal pressure injuries are related to medical devices, such as endotracheal tubes, oxygen cannulas, or urinary catheters, which exert pressure on these delicate tissues. Detailed documentation ensures accurate assessment and management.