Skin shear is a type of tissue damage that occurs when layers of skin and underlying tissue move in opposite directions. This lateral movement causes damage deeper within the skin than superficial friction injuries. Think of it like a rug sliding across a floor – the rug (skin) moves, but the floor (underlying tissue) stays put, causing damage at the interface.
Understanding Skin Shear
Shear injuries happen when there's a difference in movement between the skin and underlying tissues. This is often caused by factors like:
- Patient movement: A patient shifting in bed, sliding down in a chair, or being moved without proper support.
- Gravity: The downward force of gravity can cause skin to shift over bony prominences.
- Improper positioning: Poor positioning in bed or a chair can increase shear forces.
The damage from shearing isn't always immediately visible. It can affect tissues beneath the skin surface, leading to:
- Pressure ulcers (bedsores): Shearing frequently contributes to the development of pressure ulcers, especially in immobile individuals.
- Deep tissue damage: Shearing injuries can be significant and may not show on the surface, but lead to deep tissue damage.
- Increased risk of infection: Damaged tissue is more susceptible to infection.
Differentiating Shear from Friction
While both shear and friction contribute to skin breakdown, they differ in their mechanisms:
- Shear: Involves the lateral movement of tissue layers relative to each other.
- Friction: Involves the rubbing of one surface against another, typically the epidermis (top layer of skin) against a surface. Friction injuries are more superficial.
The damage caused by shear is often more significant and deeper than friction damage. Both often work together to cause wounds.
Prevention and Treatment
Preventing skin shear is crucial:
- Proper positioning: Regularly repositioning patients to relieve pressure on bony prominences is vital.
- Use of support surfaces: Special mattresses and cushions can help distribute pressure and reduce shear forces.
- Careful patient handling: Proper lifting and transferring techniques are necessary to minimize skin shear.
Treatment focuses on wound care and prevention of further damage:
- Wound dressings: Appropriate dressings are used to protect the wound and promote healing.
- Pressure relief: Continuous pressure relief remains critical.
