CNA Certification (Written Exam)Restorative SkillsHard
A resident frequently slides down in bed, requiring frequent repositioning. This constant sliding increases their risk of pressure injuries. Which type of pressure injury cause is most directly associated with this sliding motion?
- AMoisture
- BFriction
- CShearing
- DImpact
Show answer & explanationAnswer & explanation
Correct answer: C. Shearing
Shearing occurs when the skin remains stationary while the underlying tissues and bones move, typically when a resident slides down in bed. This stretches and damages blood vessels, leading to tissue ischemia and pressure injury formation. Friction is the rubbing of skin against a surface, which can cause abrasions, but shearing is the more significant and deeper tissue damage associated with sliding.
Why the other options are wrong
- A. Moisture can contribute to skin breakdown (maceration) but is not the direct cause of injury from sliding down in bed.
- B. Friction is the rubbing of skin against a surface. While some friction occurs, the primary damaging force from sliding down in bed, where skin sticks and underlying tissue pulls, is shearing.
- D. Impact refers to a sudden force or blow, which is not directly related to sliding down in bed.
Shearing vs. Friction
Shearing is internal tissue damage from skin staying put while underlying bone/muscle moves (e.g., sliding). Friction is external damage from rubbing against a surface.
- Shearing: skin stationary, underlying tissue moves.
- Friction: skin rubs against surface.
- Both contribute to pressure injuries, but shearing causes deeper damage from sliding.
Memory trick: Pressure, friction, shear, moisture's near.