Unit
- Epidermis: The outermost layer provides a waterproof barrier and contains melanocytes. It is avascular and relies on diffusion from the dermis for nutrients. Damage to this layer increases susceptibility to pressure ulcer formation.
- Dermis: This middle layer houses blood vessels, nerves, and collagen. It supplies oxygen and nutrients to the epidermis. Loss of dermal integrity can lead to deeper tissue injury and delayed healing.
- Hypodermis: Also called subcutaneous tissue, it consists of fat and connective tissue. It acts as a shock absorber and insulates the body. Thinning of this layer in elderly patients increases pressure ulcer risk.
- Pressure effects: Sustained pressure on bony prominences compresses capillaries, restricting blood flow. Ischemia develops within two hours, leading to tissue hypoxia and cell death if unrelieved.
- Shear forces: When skin remains stationary and underlying tissue moves, vessels stretch and kink. This often occurs when a patient slides down in bed, causing deeper tissue damage than pressure alone.
- Friction: Rubbing against surfaces strips the stratum corneum. Common during repositioning or when using improper lift techniques. Friction combined with moisture accelerates skin breakdown.
- Moisture: Incontinence, perspiration, or wound exudate macerates the skin. Prolonged moisture reduces tensile strength and increases friction coefficient, making skin more prone to injury.
- Intrinsic factors: Age, malnutrition, decreased mobility, and chronic conditions like diabetes impair tissue tolerance. Elderly skin has reduced elasticity and slower repair mechanisms.
- Immobility: Patients who cannot reposition themselves independently experience prolonged pressure on tissues. Even with scheduled turning, unrelieved pressure on bony prominences can cause ischemia within hours. Assistive devices like heel boots or pressure-relieving mattresses help reduce risk, but consistent mobility assistance remains critical for prevention.
- Nutritional status: Adequate protein and calories are essential for maintaining skin integrity and supporting wound healing. Deficiencies in vitamins A and C, zinc, and iron can impair collagen synthesis and immune function. Malnourished patients have thinner skin and slower repair, increasing susceptibility to pressure ulcer development and delayed recovery.
- Sensory perception: Reduced ability to feel pain or discomfort prevents patients from sensing prolonged pressure. Conditions like neuropathy, spinal cord injury, or sedation diminish protective responses. These patients rely entirely on caregivers for repositioning and skin checks. Impaired sensation is a major contributor to pressure ulcer formation even with adequate pressure relief.
- Shear reduction strategies: Using lift sheets, slide boards, and proper body mechanics minimizes shear forces during transfers. Keeping the head of the bed at or below 30 degrees when possible reduces sliding. Applying protective dressings over bony prominences can also mitigate shear damage. These techniques require training and consistent application to be effective.
Scope of Practice
Role: Nursing Assistant in Long-Term Care
Within scope:
- Performing daily skin inspections and reporting changes to the charge nurse
- Assisting with repositioning schedules and documenting turns
- Applying moisture barrier creams as directed
- Measuring and documenting risk using the Braden Scale
- Educating patients and families on basic skin care
Outside scope:
- Diagnosing pressure ulcer stages or skin conditions
- Prescribing topical treatments or wound dressings
- Performing debridement or wound cultures
- Adjusting repositioning intervals without instruction
- Interpreting laboratory values related to nutrition
Quick Revision
- The skin has three layers: epidermis, dermis, and hypodermis, each with a protective role.
- Pressure, shear, friction, and moisture are primary external contributors to tissue damage.
- Intrinsic patient factors such as age, nutrition, and mobility affect skin resilience.
- Nursing assistants perform skin inspections and basic prevention tasks under supervision.