A pressure injury is localized damage to the skin and underlying soft tissue, usually over a bony prominence or related to a medical device. It results from intense or prolonged pressure, or pressure combined with shear. The term "pressure ulcer" has been replaced by "pressure injury" (NPIAP, 2016) because early stages may have intact skin.

Mechanism

• Sustained pressure greater than capillary pressure compresses small vessels → ischemia → cell death; relieving pressure causes further reperfusion injury
• Muscle and fat are more vulnerable than skin, so damage often starts deep near the bone and appears on the surface later ("cone-shaped" injury)
• Shear — deeper tissue slides while skin stays fixed (e.g., sliding down in bed with the head raised) → stretches and tears vessels
• Friction — skin rubbing against a surface; mainly causes superficial injury and increases susceptibility
• Moisture (incontinence, sweat, exudate) softens skin and increases friction damage

Extrinsic factors: pressure, shear, friction, moisture, microclimate (heat), devices. Intrinsic factors: immobility, reduced sensory perception (spinal cord injury, sedation, neuropathy), malnutrition and dehydration, poor perfusion (shock, vasopressors, peripheral artery disease), advanced age, diabetes, anemia, edema, fever.

Common sites by position

Skin inspection — head-to-toe on admission, at least daily, and with any change in condition; look under and around devices.

• Blanch test: press a reddened area; blanchable redness that fades is reactive; non-blanchable redness indicates stage 1 injury
• Check temperature, firmness or bogginess, edema, pain
• In darker skin tones, redness may not be visible — look for color change (purple, bluish, darker), warmth or coolness, induration, and ask about pain; use good lighting
• Differentiate from moisture-associated skin damage (incontinence-associated dermatitis: diffuse, shiny, irregular, in skin folds and perineum, top-down) and skin tears

NPIAP staging

Staging rules

• Stage is based on the deepest tissue visible — not on the size, cause, or pressure intensity
• Never reverse-stage: a healing stage 3 is documented as a "healing stage 3," not stage 2
• Stage 2 is not used for skin tears, tape injuries, incontinence-associated dermatitis, or burns
• The 2025 International Pressure Injury Guideline (4th edition, EPUAP/NPIAP/PPPIA) keeps this classification without substantive conceptual change

Risk assessment tools

Braden does not include vital signs, mood, or age — risk tools support but do not replace clinical judgment.

Healing tools: PUSH tool (surface area, exudate amount, tissue type) and Bates-Jensen (see Topic 24). Measure length × width × depth weekly and document undermining and tunneling.

Other tests: nutrition screening (weight loss, intake), albumin and prealbumin with caution, probe-to-bone and imaging for osteomyelitis in stage 4 wounds.

Prevention bundle

• Risk assessment and skin inspection
• Pressure-redistributing support surfaces: high-specification foam mattresses for at-risk clients; alternating-pressure or low-air-loss surfaces for high risk or existing injury; pressure-redistributing chair cushions
• Prophylactic multilayer silicone foam dressings over the sacrum and heels in high-risk clients (e.g., ICU)
• Nutrition: screen and treat malnutrition; adults with or at risk of pressure injury commonly need about 30–35 kcal/kg/day and 1.25–1.5 g protein/kg/day if not contraindicated (kidney disease), plus adequate fluids; dietitian referral
• Manage moisture and incontinence; control fever and perfusion where possible

Treatment by stage

Topical antibiotics are not routinely applied to pressure injuries; use systemic antibiotics only for spreading or systemic infection. Clean with saline or a noncytotoxic wound cleanser; avoid hydrogen peroxide.

Listed in priority order.

1. Assess risk with the Braden Scale on admission, per policy (often every shift in acute care), and with any change in condition; inspect all skin and devices
2. Relieve and redistribute pressure
   • Reposition on an individualized schedule based on risk, tissue tolerance, and support surface — traditionally at least every 2 hours in bed
   • Use the 30-degree lateral tilt (alternating right, back, left) instead of a 90-degree side-lying position that loads the trochanter
   • Keep the head of the bed at 30 degrees or lower when safe, to limit shear (exceptions: tube feeding, respiratory needs)
   • Float heels with a pillow under the calves or heel-suspension boots; knees slightly flexed
   • Do not position the client on an existing pressure injury or reddened area
   • Seated clients: limit sitting time for high-risk clients; teach weight shifts about every 15 minutes for those who can; reposition dependent clients at least every hour; use a pressure-redistributing cushion
   • Never use ring (donut) cushions — they compress circulation around the ring
3. Reduce shear and friction: use lift sheets, slide sheets, or mechanical lifts — lift, do not drag; use a trapeze if appropriate; knee gatch before raising the head of the bed
4. Skin care
   • Do not massage bony prominences or reddened skin — it damages fragile tissue
   • Cleanse promptly after incontinence with a pH-balanced cleanser; apply barrier creams; use breathable pads (avoid layers of linen)
   • Moisturize dry skin; avoid hot water and vigorous rubbing
5. Medical devices: correct size; pad under tubes and masks; reposition devices and check skin under them at least twice daily; remove as soon as possible
6. Nutrition and hydration: record intake, offer high-protein snacks and supplements, weigh regularly
7. Wound care per stage; measure and document weekly; report deterioration
8. Pain management — premedicate before repositioning or dressing changes
9. Documentation: risk score, skin findings, stage, measurements, interventions, response. Admission skin assessment establishes whether an injury was present on admission

• Change position often; use the prescribed mattress or cushion; avoid donut cushions
• Check the skin daily (mirror or caregiver), especially the sacrum, hips, heels, and under devices; report redness that does not fade after 30 minutes or a blister
• Keep skin clean and dry; manage incontinence promptly
• Eat enough protein and calories and drink fluids unless restricted
• Wheelchair users: shift weight or do pressure relief lifts every 15 minutes if able
• Teach caregivers safe turning without dragging

• Main causes: pressure + shear; friction and moisture add risk
• Most common sites: sacrum/coccyx and heels; ischial tuberosities when sitting
• Stage 1 = intact skin, non-blanchable erythema; Stage 2 = partial thickness, exposed dermis, or serum blister
• Stage 3 = fat visible; Stage 4 = bone, tendon, muscle exposed or palpable
• Unstageable = base covered by slough or eschar; DTPI = purple or maroon intact skin or blood blister
• Never reverse-stage
• Braden: 6 subscales (sensory, moisture, activity, mobility, nutrition, friction/shear); 6–23; lower = higher risk; 18 or below = at risk
• Reposition on an individualized schedule (traditionally every 2 hours); 30-degree tilt; HOB 30 degrees or lower; float heels
• No massage of reddened areas; no donut cushions; lift, do not drag
• Protein about 1.25–1.5 g/kg/day
• Do not debride stable dry heel eschar
• Pressure relief is the foundation of prevention and treatment