4.3 Skin Integrity, Pressure Injury Prevention & Wound Care
Key Takeaways
- Friction rubs superficial epidermal layers, while shear occurs when skin stays stationary and deeper skeletal structures slide, tearing deep blood vessels.
- Pressure injury stages range from Stage 1 (non-blanchable erythema) and Stage 2 (partial thickness skin loss/blister) to Stage 3 (subcutaneous fat visible) and Stage 4 (exposed muscle/bone).
- Unstageable pressure injuries are obscured by slough or eschar; Deep Tissue Injury presents as persistent non-blanchable deep red, maroon, or purple discoloration.
- Prevent skin breakdown by repositioning bedfast residents every 2 hours (every 15 minutes in wheelchairs), keeping HOB ≤ 30 degrees, and applying barrier creams.
- Float heels by placing pillows length-wise under calves to suspend heels off the mattress, and report all skin changes promptly to the nurse.
Maintaining skin integrity and preventing skin breakdown are vital components of long-term nursing care. The skin is the body's largest organ, serving as the primary barrier against infection, trauma, and fluid loss. Elderly and bedfast residents in nursing facilities are particularly vulnerable to skin breakdown due to thin epidermis, decreased subcutaneous fat, reduced mobility, incontinence, and poor circulation. Certified Nursing Assistants (CNAs) play an indispensable front-line role in protecting resident skin, applying preventive measures, and identifying early skin changes before severe tissue damage occurs.
Anatomy of Skin Breakdown & Mechanical Forces
Skin breakdown occurs when external pressure exceeds the capillary closure pressure of the skin (approximately 32 mmHg) for a prolonged period, depriving local tissues of oxygen and essential nutrients. This localized ischemia leads to tissue hypoxia, cellular death, and ulceration. Two primary mechanical forces exacerbate pressure-induced tissue damage: friction and shear.
| Mechanical Force | Definition & Mechanism | Clinical Example | Primary Damage Site |
|---|---|---|---|
| Friction | The force created when two surfaces rub directly against each other, removing the superficial epidermal layer. | Pulling or dragging a resident across cotton bedsheets during repositioning without using a draw sheet. | Epidermis and upper dermis (superficial skin layer resembling an abrasion or burn). |
| Shear | The force exerted when skin remains stationary against a surface while deeper musculoskeletal structures slide down due to gravity. | Elevating the head of the bed higher than 30 degrees, causing the resident's skeleton to slide down toward the foot of the bed while sacral skin sticks to the linens. | Deep subcutaneous tissue, fascia, and blood vessels (causes stretching and tearing of blood vessels, leading to deep tissue necrosis). |
Pressure Injury Staging System
The National Pressure Injury Advisory Panel (NPIAP) classifies pressure injuries into six distinct stages based on the depth of tissue damage:
1. Stage 1 Pressure Injury: Non-Blanchable Erythema
Intact skin with a localized area of non-blanchable erythema (redness that does not turn white when pressed with a finger). In dark skin tones, discoloration may appear dark red, purple, or blue, and the area may feel warmer, firmer, or softer than surrounding tissue.
2. Stage 2 Pressure Injury: Partial-Thickness Skin Loss
Partial-thickness skin loss with exposed dermis. The wound bed is viable, pink or red, moist, and may present as an intact or ruptured serum-filled blister. Subcutaneous fat, muscle, tendon, ligament, and bone are not visible.
3. Stage 3 Pressure Injury: Full-Thickness Skin Loss
Full-thickness loss of skin in which subcutaneous fat is visible within the ulcer, and granulation tissue and epibole (rolled wound edges) are often present. Slough or eschar may be present. Bone, tendon, muscle, cartilage, and fascia are not exposed.
4. Stage 4 Pressure Injury: Full-Thickness Skin and Tissue Loss
Full-thickness skin and tissue loss with exposed or directly palpable fascia, muscle, tendon, ligament, cartilage, or bone. Slough or eschar may be visible. Epibole, undermining, and tunneling frequently occur.
5. Unstageable Pressure Injury: Obscured Full-Thickness Loss
Full-thickness skin and tissue loss in which the extent of tissue damage within the ulcer cannot be confirmed because it is obscured by slough or eschar. Slough (yellow, tan, gray, green, or brown dead tissue) or eschar (tan, brown, or black leathery necrotic tissue) must be removed by a clinician before the stage can be determined. Note: Stable, dry, adherent eschar on the heels should not be softened or removed.
6. Deep Tissue Injury (DTI): Persistent Non-Blanchable Discoloration
Intact or non-intact skin with localized area of persistent, non-blanchable deep red, maroon, or purple discoloration, or epidermal separation revealing a dark wound bed or blood-filled blister. DTI results from intense or prolonged pressure and shear forces at the bone-muscle interface.
Comprehensive Pressure Injury Prevention Strategies
Prevention of pressure injuries requires systematic, aggressive nursing assistant interventions focused on pressure relief, skin hygiene, and positioning.
Repositioning Protocols & Head-of-Bed Elevation
- Bed Repositioning: Turn and reposition bedfast residents at least every 2 hours around the clock. Utilize a written turning schedule (e.g., 30-degree lateral tilt alternating right side, back, left side).
- Wheelchair Repositioning: Chair-bound residents must shift their weight every 15 minutes (if able) or be repositioned by the CNA at least every 1 hour.
- Head of Bed (HOB) Limitation: Keep the HOB elevated at or below 30 degrees (unless contraindicated by respiratory or feeding tube requirements) to prevent sliding and reduce sacral shearing forces.
Barrier Creams, Moisture Management & Special Support Surfaces
- Moisture Control: Clean skin immediately following episodes of urinary or fecal incontinence using warm water and a mild skin cleanser. Pat dry gently—never rub. Apply a thin layer of moisture barrier cream (containing zinc oxide or petroleum) to protect skin from digestive enzymes and dampness.
- Support Surfaces: Use pressure-relieving foam, gel, or dynamic air mattresses and wheelchair cushions. Never use ring-shaped "donut" cushions, as they constrict blood flow to central tissues.
Floating Heels Procedure
Heels are extremely susceptible to rapid pressure breakdown due to thin subcutaneous tissue over the calcaneus bone. To float the heels, place pillows length-wise under the resident's calves so that the heels are completely suspended in the air off the mattress surface. Ensure pillows do not press against the popliteal space behind the knees.
Observing & Reporting Skin Changes to the Licensed Nurse
CNAs inspect the resident's skin during daily personal care, bathing, and repositioning. CNAs do not perform sterile wound care, apply prescription medicated dressings, or perform surgical debridement. However, CNAs must inspect vulnerable pressure points (sacrum, heels, hips, elbows, ankles, shoulder blades) and immediately report the following findings to the charge nurse:
- Any new redness, warmth, swelling, or discoloration that does not blanch.
- Skin tears, abrasions, blisters, cracks, or open skin areas.
- Drainage, odor, moisture breakdown (maceration) in skin folds or perineum.
- Complaints of localized pain, burning, or tingling over bony prominences.
A nursing assistant observes intact skin over a resident's sacrum that is persistently red and does not turn white when gentle finger pressure is applied. How should this pressure injury be staged?
When repositioning a bedfast resident to prevent sacral shearing forces and skin breakdown, what is the recommended maximum elevation for the head of the bed?
Which intervention should a CNA perform to effectively 'float the heels' of a bedridden resident?