9.3 Skin Integrity, Pressure Injury Staging & Prevention

Skin Integrity, Pressure Injury Staging & Prevention

Skin is the human body's largest organ, serving as the first line of defense against pathogenic invasion, fluid loss, and thermal injury. In elderly and chronically ill residents, aging skin becomes thinner, less elastic, drier, and more vulnerable to mechanical trauma due to decreased subcutaneous fat and diminished capillary perfusion. A pressure injury (formerly termed pressure ulcer, decubitus ulcer, or bed sore) represents localized damage to the skin and underlying soft tissue, usually over a bony prominence. Pressure injuries are painful, costly, and can lead to life-threatening systemic sepsis. Because virtually all pressure injuries are preventable through vigilant nursing care, mastering skin integrity protocols is one of the most critical responsibilities of an Arizona nursing assistant.

---

1. Pathogenesis of Pressure Injuries: Pressure, Shear, Friction & Moisture

Pressure injuries develop when external mechanical forces exceed the capillary closing pressure (approximately 32 mmHg), cutting off microvascular blood supply and resulting in local tissue ischemia, hypoxia, cellular necrosis, and tissue death.

+-----------------------------------------------------------------------------+
|                      THE FOUR PATHOGENIC FORCES                             |
|                                                                             |
|   1. SUSTAINED PRESSURE: Unrelieved force compressing skin & soft tissue    |
|      against a bone and an external surface (bed/chair), collapsing         |
|      capillaries and depriving tissues of oxygen and nutrients.             |
|                                                                             |
|   2. SHEAR FORCES: Mechanical force exerted when skin remains stationary    |
|      against bed sheets while underlying skeletal bone slides downward      |
|      (e.g., resident sliding down in bed when head is elevated), stretching |
|      and tearing deep microvascular blood vessels.                          |
|                                                                             |
|   3. FRICTION: Mechanical scraping of the epidermal skin layer against an   |
|      external surface (e.g., dragging heels or elbows across bed sheets),   |
|      causing superficial abrasions and epidermal stripping.                 |
|                                                                             |
|   4. MOISTURE / MACERATION: Constant contact with urine, liquid feces,      |
|      wound drainage, or heavy perspiration softens and weakens epidermal    |
|      keratin, making skin highly susceptible to erosion and infection.      |
+-----------------------------------------------------------------------------+

Clinical Risk Assessment Tools:

Licensed nurses use validated risk assessment scales—most commonly the Braden Scale for Predicting Pressure Sore Risk (scoring 6 subscales: Sensory Perception, Moisture, Activity, Mobility, Nutrition, and Friction/Shear; lower scores indicate higher risk) or the Norton Scale. CNAs must know which residents are flagged as high risk to deliver targeted preventive interventions.

---

2. Anatomical Pressure Points & Vulnerable Bony Prominences

Pressure injuries occur predominantly where bony skeletons lie close to the skin surface with minimal protective adipose tissue or muscle padding.

+-----------------------------------------------------------------------------+
|                   ANATOMICAL PRESSURE POINTS BY BODY POSITION               |
|                                                                             |
|   SUPINE POSITION (Lying on Back):                                          |
|   - Occiput (Back of Head)        - Scapulae (Shoulder Blades)              |
|   - Spinous Processes (Spine)     - Elbows (Olecranon)                      |
|   - Sacrum & Coccyx (Tailbone)    - Calcaneus (Heels)                       |
|                                                                             |
|   LATERAL POSITION (Lying on Side):                                         |
|   - Ear Cartilage                 - Acromion Process (Shoulder)             |
|   - Ribs & Lateral Torso          - Greater Trochanter (Hip)                |
|   - Medial & Lateral Knee Condyles- Medial & Lateral Malleolus (Ankles)     |
|                                                                             |
|   SEATED POSITION (Wheelchair / Chair):                                     |
|   - Ischial Tuberosities (Sit Bones) - Sacrum & Coccyx                      |
|   - Scapular Inferior Angles         - Posterior Knees (Popliteal)          |
|   - Plantar / Posterior Heels        - Soles of Feet                        |
+-----------------------------------------------------------------------------+

---

3. NPIAP Pressure Injury Staging System (2016/2019 Guidelines)

The National Pressure Injury Advisory Panel (NPIAP) establishes the definitive clinical staging classification. CNAs must recognize these stages to document findings accurately and report worsening skin conditions immediately to the nurse.

+-----------------------------------------------------------------------------+
|                     NPIAP PRESSURE INJURY STAGING MATRIX                    |
|                                                                             |
|   STAGE 1: Intact skin with NON-BLANCHABLE ERYTHEMA (redness does not fade).|
|   STAGE 2: Partial-thickness skin loss with EXPOSED DERMIS; pink/red moist  |
|            wound bed or intact/ruptured SERUM BLISTER. No fat visible.      |
|   STAGE 3: Full-thickness skin loss; ADIPOSE (FAT) VISIBLE; slough/eschar   |
|            may be present; undermining/tunneling possible. No bone/muscle.  |
|   STAGE 4: Full-thickness skin & tissue loss with EXPOSED BONE, TENDON, or  |
|            MUSCLE; undermining, tunneling, and epibole common.              |
|   UNSTAGEABLE: Full-thickness tissue loss obscured by SLOUGH (yellow/tan)   |
|            or ESCHAR (black/brown). Extent of depth cannot be determined.   |
|   DEEP TISSUE PRESSURE INJURY (DTPI): Persistent non-blanchable DEEP RED,   |
|            MAROON, or PURPLE discoloration of intact/non-intact skin.       |
+-----------------------------------------------------------------------------+

Detailed Staging Breakdown:

1. Stage 1 Pressure Injury: Non-Blanchable Erythema of Intact Skin

• Clinical Presentation: Intact skin with a localized area of persistent redness (erythema) that does not blanch (does not turn pale/white when pressed firmly with a gloved finger).
• Characteristics: The area may be painful, firm, soft, warmer, or cooler compared to surrounding tissue.
• Darkly Pigmented Skin: In residents with dark skin tones, blanching may not be visible. The CNA must inspect for persistent localized discoloration (purple, blue, or deep red hues), localized skin warmth or coolness, localized edema (swelling), or underlying induration/hardness.

2. Stage 2 Pressure Injury: Partial-Thickness Skin Loss with Exposed Dermis

• Clinical Presentation: Shallow, open ulcer with a viable, moist, pink or red wound bed. There is no visible subcutaneous fat, and no slough, eschar, or granulation tissue.
• Blister Presentation: Stage 2 also includes an intact or ruptured serum-filled blister caused by pressure. (Blood-filled blisters are classified as DTPI).

3. Stage 3 Pressure Injury: Full-Thickness Skin Loss

• Clinical Presentation: Full-thickness loss of skin in which subcutaneous adipose (fat) tissue is clearly visible within the ulcer.
• Characteristics: Granulation tissue (beefy red healing tissue) and epibole (rolled wound edges) are frequently present. Slough (yellow, tan, green, or brown dead tissue) and eschar (black/brown crust) may be visible but do not obscure the depth of tissue loss. Undermining and tunneling may occur.
• Key Distinction: Bone, tendon, and muscle are NOT visible or directly palpable.

4. Stage 4 Pressure Injury: Full-Thickness Skin and Tissue Loss

• Clinical Presentation: Extensive full-thickness tissue destruction with directly exposed or palpable bone, cartilage, tendon, ligament, or skeletal muscle.
• Characteristics: Slough and eschar may be present; epibole, extensive undermining, and deep sinus tracts/tunneling are common. Carries severe risk of osteomyelitis (bone infection) and systemic sepsis.

5. Unstageable Pressure Injury: Obscured Full-Thickness Skin and Tissue Loss

• Clinical Presentation: Full-thickness skin and tissue loss in which the actual depth and base of the ulcer cannot be confirmed because it is completely covered and obscured by slough or eschar.
• Clinical Rule on Stable Heel Eschar: If eschar on the heel is dry, adherent, intact, and without erythema or fluctuance, it acts as the body's natural biological cover and should NOT be softened, debrided, or removed.

6. Deep Tissue Pressure Injury (DTPI): Persistent Non-Blanchable Deep Red, Maroon, or Purple Discoloration

• Pathophysiology: Results from intense or prolonged pressure and shear forces at the bone-muscle interface deep beneath the skin surface.
• Clinical Presentation: Intact or non-intact skin with localized, persistent deep red, maroon, or purple discoloration, or epidermal separation revealing a dark wound bed or blood-filled blister.

---

4. Evidence-Based Prevention Protocols & CNA Interventions

Because nursing assistants provide direct, hourly bedside care, they are the front line of pressure injury prevention.

+-----------------------------------------------------------------------------+
|                   PRESSURE INJURY PREVENTION PROTOCOLS                      |
|                                                                             |
|   [SCHEDULED REPOSITIONING] -> Turn bed residents Q2H; chair residents Q1H  |
|                                (Teach chair weight shifts every 15 min).    |
|   [HEEL FLOATING] -----------> Suspend heels completely using calf pillows; |
|                                zero contact between heels & mattress.       |
|   [MOISTURE CONTROL] --------> Prompt incontinence cleansing; apply barrier |
|                                cream (zinc/dimethicone); PAT skin dry.      |
|   [NEVER MASSAGE RED AREAS] -> Massaging reddened bony spots destroys       |
|                                fragile, ischemic microcapillaries.          |
|   [ELIMINATE SHEAR/FRICTION]-> Use lift sheets (2 people); keep head of     |
|                                bed <= 30° except during eating.             |
|   [SUPPORT SURFACES] --------> Ensure alternating air mattresses & dynamic  |
|                                wheelchair cushions are properly inflated.   |
+-----------------------------------------------------------------------------+

Core Prevention Guidelines for CNAs:

1. Repositioning Schedules:
   • Bedbound Residents: Reposition at least every two hours (Q2H), alternating between left 30-degree lateral, supine, and right 30-degree lateral positions.
   • Chairbound Residents: Reposition at least every one hour (Q1H). Teach cognitive residents to perform independent weight shifts (pushing up on armrests or leaning side-to-side) every 15 minutes.
2. The Heel-Floating Protocol: Heels (calcaneus) are the second most common site for pressure injuries. Resting heels directly on a standard mattress—even a specialty mattress—causes breakdown. Technique: Place a pillow lengthwise or crosswise beneath the resident's calves (from below the knees to just above the ankles) so that the heels are completely suspended in the air (floating) with zero contact with the bed surface.
3. Moisture Management & Perineal Care:
   • Cleanse skin promptly following every episode of urinary or fecal incontinence using warm water and pH-balanced, no-rinse skin cleansers.
   • Pat skin dry gently with a soft towel; never rub vigorously.
   • Apply a protective moisture barrier ointment or cream (containing zinc oxide, petrolatum, or dimethicone) to shield fragile perianal skin from enzymatic excoriation.
   • Use breathable, moisture-wicking underpads (chux); avoid layering multiple disposable pads under the resident, which traps heat and moisture.
4. Never Massage Reddened Bony Prominences:
   • If you observe a reddened area over a bony prominence (e.g., sacrum or trochanter), NEVER massage or vigorously rub the area. Massage compresses already ischemic tissues, shearing microscopic blood vessels and accelerating tissue necrosis.
5. Reducing Shear & Friction:
   • Keep the head of the bed elevated no higher than 30 degrees (Semi-Fowler's), except during meals and medication administration. Elevating the head above 30 degrees causes the skeletal pelvis to slide downward, generating severe shear on the sacrum.
   • Always use a friction-reducing draw sheet or slide board and two caregivers to lift and reposition residents up in bed—never drag a resident across bed linens.
6. Nutritional & Hydration Support: Adequate dietary protein, calories, fluids, Vitamin C, and zinc are essential for collagen synthesis and tissue perfusion. Report residents who eat less than 50–75% of meals to the charge nurse and registered dietitian.

---

5. Skin Observation, Documentation & Reporting Standards

CNAs must perform a continuous skin assessment during every personal care encounter (morning care, bathing, peri-care, dressing, and repositioning).

What to Observe and Report Immediately:

• Any new redness that does not fade (non-blanchable erythema).
• Blisters, skin tears, abrasions, cracks, or open sores.
• Areas of localized skin warmth, coolness, hardness (induration), or swelling (edema).
• Complaints of burning, tingling, numbness, or localized pain over any bony prominence.
• Moisture breakdown, maceration, or fungal rashes (satellite lesions) in skin folds (groin, axillae, under breasts, abdominal pannus).
• Foul odor, drainage, or changes in existing wound dressings.

[!IMPORTANT] Scope of Practice Boundary: Nursing assistants observe, protect, and report. CNAs do not diagnose pressure injury stages, perform surgical debridement, or apply prescription medicated wound treatments unless specifically permitted under state-certified medication technician rules. Always report new skin abnormalities to the charge nurse immediately.