CNA Certification (Written Exam)Restorative SkillsMedium
A resident frequently slides down in their wheelchair, requiring constant repositioning. This situation puts the resident at high risk for which type of pressure injury development?
- ADeep tissue injury
- BIschemic injury
- CFriction injury
- DShearing injury
Show answer & explanationAnswer & explanation
Correct answer: D. Shearing injury
Shearing occurs when skin stays in one place while underlying tissue and bone move, causing stretching and tearing of blood vessels. Sliding down in a wheelchair is a classic example of this, as the skin on the buttocks and sacrum remains somewhat stationary against the chair while the body's weight pulls the underlying tissues downwards.
Why the other options are wrong
- A. Deep tissue injury (DTI) is a specific type of pressure injury that often presents as purple or maroon discoloration, but 'shearing' describes the *mechanism* of injury in this scenario leading to DTI or other stages of pressure injury.
- B. Ischemic injury refers to tissue damage due to lack of blood flow, which can lead to pressure injuries but isn't the direct mechanism described by sliding.
- C. Friction injury occurs when two surfaces rub against each other, causing skin abrasion. While some friction may be present, shearing is the predominant and more damaging force in this scenario.
Shearing Force
Shearing is a force that causes layers of skin to slide over each other, or the skin to stay put while underlying tissue moves. It stretches and tears blood vessels, increasing pressure injury risk.
- Often caused by sliding down in bed or chair.
- Damages deeper tissues and blood vessels.
- Different from friction, which is surface rubbing.
Memory trick: Shear tears deep, friction rubs surface.