Shearing in bed refers to a type of force that occurs between the skin and underlying tissues when someone is lying in a bed, often leading to tissue damage.
Understanding Shearing Force
Shearing is a specific type of force that acts parallel to a surface, rather than perpendicular (like direct pressure). In the context of the body, shearing wounds occur when forces moving in opposite directions are applied to tissues in the body. This happens when layers of tissue slide over each other.
How Shearing Happens in Bed
When a person is in bed, particularly if they are not moving frequently or are being repositioned incorrectly, shearing can occur. According to the reference, this can happen when the skin is stuck to a surface, such as a bed, while gravity forces the body downward on the bed.
Here's a breakdown of the process:
- Skin Friction: The skin's surface (e.g., on the back, heels, or buttocks) has friction with the bed sheet or mattress.
- Body Movement/Gravity: As the body slides down the bed slightly due to gravity (e.g., when the head of the bed is elevated) or is pulled during repositioning, the skin remains relatively stuck due to friction.
- Tissue Distortion: Because the skin is held in place while the underlying bone and muscle continue to move with the rest of the body, the tissue layers between the skin and bone are stretched and distorted. This is the shearing action.
Imagine pushing a deck of cards sideways – the top cards slide over the bottom ones. Shearing in the body is similar, but it involves skin, fat, muscle, and bone.
Why is Shearing a Concern?
This stretching and distortion of tissues can damage small blood vessels and nerve endings, reducing blood flow to the area. Reduced blood flow makes the tissue more vulnerable and can lead to the development of pressure injuries, also known as bedsores or pressure ulcers. Shearing often occurs alongside pressure, compounding the risk of skin breakdown.
Key scenarios in bed where shearing is common include:
- Sitting up in bed with the head elevated, causing the body to slide down.
- Being pulled up or across the bed instead of lifted.
- Slouching in bed.
Minimizing shearing forces is a crucial part of preventing skin breakdown for individuals who are confined to bed.
