Medical Terminology for Pressure Injury Closure
The medical term for the process of a pressure injury closing is epithelialization, which refers to the growth of new epithelial tissue over the wound bed during the proliferation phase of wound healing. 1
Understanding Epithelialization in Pressure Injury Healing
Epithelialization is a critical component of the wound healing process that occurs during the proliferation phase. This phase follows the initial hemostasis and inflammation phases and precedes the final remodeling phase 2. During epithelialization:
- Keratinocytes (epidermal cells) migrate from the wound edges toward the center
- New epithelial cells form to cover the exposed wound surface
- The process creates a protective barrier between the external environment and the healing tissues beneath
Epithelialization typically occurs after or alongside granulation, which is the formation of connective tissue and blood vessels that fill the wound space 3. However, in some cases, epithelialization may occur without significant granulation tissue formation, particularly in superficial wounds 3.
Wound Healing Phases in Pressure Injuries
The healing of pressure injuries follows a sequential process:
- Hemostasis: Formation of fibrin clot to stop bleeding
- Inflammation: Removal of debris and bacteria, bringing nutrients to the wound area
- Proliferation: Key phase including:
- Granulation: Formation of new connective tissue and blood vessels
- Epithelialization: Growth of new epithelial cells over the wound surface
- Contraction: Wound edges pull together to reduce wound size
- Remodeling: Maturation of new tissue and scar formation 2
Factors Affecting Epithelialization in Pressure Injuries
Several factors can influence the epithelialization process:
- Wound bed preparation: Proper debridement removes necrotic tissue and biofilm that can impede epithelialization 4
- Moisture balance: Optimal moisture levels support epithelialization; hydrogel and hydrocolloid dressings can maintain this balance 4
- Nutrition: Protein supplementation (1.25-1.5 g/kg/day) and micronutrients (vitamins B6, B12, C, D, zinc, folate) enhance epithelialization 5
- Growth factors: Epidermal growth factor (EGF) promotes keratinocyte migration and proliferation 6
- Wound pH: Maintaining a slightly acidic pH (4-6) supports epithelialization 4
Clinical Assessment of Epithelialization
When monitoring for epithelialization in pressure injuries, look for:
- Pink or light red tissue at wound edges advancing toward the center
- Decrease in wound size measurements
- Reduction in wound depth
- Smooth, shiny appearance of new tissue
- Decreased exudate production as the wound closes 5
Supporting Epithelialization in Clinical Practice
To promote epithelialization in pressure injuries:
- Maintain moist wound environment: Use appropriate dressings such as hydrocolloid or foam dressings for stage 2 injuries 4
- Debridement: Remove necrotic tissue that can impede epithelial cell migration 4
- Negative Pressure Wound Therapy (NPWT): Can be used to promote granulation tissue formation, which supports subsequent epithelialization in deeper wounds 4
- Nutritional support: Ensure adequate protein and micronutrient intake 5
- Pressure redistribution: Continue pressure relief measures to prevent further injury and support healing 5
Special Considerations
In some cases, particularly with stage IV pressure injuries, epithelialization may occur through alternative pathways:
- Recent case reports suggest that epithelialization can sometimes occur without typical granulation tissue formation in full-thickness wounds 3
- This represents an alternative wound healing pathway where epithelialization proceeds independently of robust granulation 3
Understanding the process of epithelialization is essential for properly documenting wound healing progress and selecting appropriate interventions to support this critical phase of pressure injury closure.