Pressure Injury Prevention and Staging

Pressure injuries are one of the most common — and most preventable — complications in immobile or chronically ill patients. This note reviews how they form, where they appear, how to stage them, and the nursing interventions that prevent them, with a focus on high-yield exam concepts.

Definition

• A pressure injury is localized damage to the skin and underlying soft tissue caused by sustained pressure, usually over a bony prominence.
• Pressure injuries are largely preventable with proper nursing care.
• Prevention matters because pressure injuries cause pain, increase infection risk, prolong hospital stays, and are linked to poor patient outcomes.

Risk Factors

• Patient factors: advanced age, immobility, incontinence, poor nutrition, dehydration
• Medical factors: decreased sensation, altered mental status, diabetes, vascular disease
• External factors: friction, shear, moisture, pressure from medical devices

How the External Forces Cause Damage

• Sustained pressure compresses blood vessels, reducing blood flow and causing tissue ischemia and cell death.
• Friction removes the outer protective layer of skin when the patient rubs against bedding.
• Shear occurs when skin stays in place while deeper tissues move, stretching and tearing blood vessels. Common when the head of the bed is elevated and the patient slides down.
• Moisture from incontinence or sweating softens skin and increases vulnerability to breakdown.
• Medical devices (oxygen tubing, nasal cannulas, casts, IV lines) can cause injuries on the ears, nose, heels, and other sites.

Common Pressure Injury Sites

• Supine: occiput, scapulae, elbows, sacrum, coccyx, heels
• Side-lying: ears, shoulder, greater trochanter, medial knees, medial ankles
• Prone: forehead, chin, breasts, iliac crests, knees, toes
• Sitting: ischial tuberosities, sacrum, coccyx, heels

The sacrum and coccyx are the most common sites in supine patients, with heels as the second most common. In sitting patients, the ischial tuberosities bear the most weight and are at highest risk.

Pressure Injury Staging

• Stage 1: Intact skin with non-blanchable erythema. Press the red area; if it does not turn white, it is Stage 1.
• Stage 2: Partial-thickness skin loss. Shallow ulcer with a red-pink wound bed; no slough; no visible fat.
• Stage 3: Full-thickness skin loss with visible subcutaneous fat. Bone and muscle are not visible; undermining may be present.
• Stage 4: Full-thickness tissue loss with visible muscle, bone, or tendon.
• Unstageable: Full-thickness loss with the base covered by slough (yellow, tan) or eschar (black, brown). Depth cannot be determined until the covering is removed.
• Deep tissue injury (DTI): Purple or maroon localized area, or a blood-filled blister, indicating damage beneath intact or non-intact skin.

Prevention Interventions

Repositioning

• Reposition immobile patients at least every 2 hours, rotating between supine, left side-lying, and right side-lying.
• For patients in chairs, reposition every hour; encourage self–weight shifting every 15 minutes if able.
• Use pillows, foam wedges, and positioning devices to offload bony prominences. Place a pillow between the knees when side-lying.
• Lift the patient during repositioning — do not drag or slide across sheets (prevents shear and friction).

Support Surfaces

• Use pressure-redistributing mattresses (foam, air, or alternating pressure) for high-risk patients.
• Use heel offloading devices to elevate heels completely off the bed. Place pillows under the calves, not under the heels.
• Use gel or foam cushions for patients in chairs.
• Do not use donut-shaped cushions — they reduce blood flow and worsen pressure.

Skin Care

• Inspect the skin daily, especially over bony prominences and under medical devices.
• Clean skin with mild, pH-balanced cleansers. Avoid hot water and harsh soaps.
• Apply moisturizer to dry skin and barrier creams to protect skin in incontinent patients.
• Change wet or soiled linens immediately.

Nutrition and Hydration

• Ensure adequate calories and protein — pressure injuries heal poorly in malnourished patients.
• Provide vitamin C, zinc, and arginine supplementation when indicated.
• Encourage adequate fluid intake.

Common Exam Traps

• Do not massage reddened areas over bony prominences — massage can damage underlying tissue.
• Do not use donut-shaped cushions — they reduce blood flow.
• Do not drag or slide the patient during repositioning — use a lift sheet or friction-reducing device.
• Do not document a Stage 1 injury as just a "red area" — use correct staging terminology.

Key Takeaways

• Pressure injuries result from sustained pressure, friction, shear, and moisture; the most common sites are the sacrum, heels, coccyx, and ischial tuberosities.
• Staging: Stage 1 = non-blanchable redness; Stage 2 = partial-thickness; Stage 3 = fat visible; Stage 4 = muscle/bone visible; unstageable = slough/eschar covers the base; DTI = purple/maroon area or blood-filled blister.
• Reposition bed-bound patients every 2 hours and chair-bound patients every hour; lift rather than drag to prevent shear.
• Use pressure-redistributing mattresses and heel offloading devices; place pillows under calves, not heels.
• Never massage reddened areas, use donut cushions, or drag the patient across sheets.
• Keep skin clean, dry, and moisturized; optimize nutrition, protein, and hydration to support healing.