Pressure Injuries (Bedsores): Causes, Staging, Prevention, and Treatment

What Are Pressure Injuries?

Pressure injuries (pressure ulcers or bedsores) are localized damage to skin and/or underlying soft tissue, usually over a bony prominence, caused by sustained pressure (often combined with shear and friction). They result from impaired perfusion exceeding tissue tolerance.

Pathophysiology

• Pressure: Compresses capillaries → ischemia → reperfusion injury → necrosis. Critical closing pressure ~32 mmHg.
• Shear: Parallel forces (sliding down in bed) → vessel stretching/occlusion → deeper tissue damage.
• Friction: Rubbing → epidermal loss → increases susceptibility.
• Microclimate: Moisture (sweat, urine, wound exudate) → maceration, increased friction, increased bacterial growth.

Risk Factors (Braden Scale Domains)

• Immobility or limited activity
• Sensory impairment (neuropathy, spinal cord injury)
• Moisture (incontinence, diaphoresis)
• Nutrition (protein <1.25 g/kg, low albumin, dehydration)
• Age (thin skin, reduced perfusion)
• Comorbidities: diabetes, peripheral arterial disease, cardiovascular disease, dementia, malignancy
• Medications: steroids, vasopressors, sedatives

Staging (NPUAP/EPUAP)

Stage	Description
Stage 1	Non-blanchable erythema of intact skin (darker skin: persistent red/blue/purple)
Stage 2	Partial-thickness skin loss (epidermis ± dermis); pink/red viable wound bed; no slough or eschar
Stage 3	Full-thickness skin loss; adipose visible; no muscle, tendon, or bone exposed; may have slough or eschar
Stage 4	Full-thickness skin and tissue loss; muscle, tendon, bone exposed
Unstageable	Obscured full-thickness loss by slough or eschar
Deep Tissue Pressure Injury (DTPI)	Intact or non-intact skin with persistent non-blanchable deep red, maroon, or purple discoloration—deep tissue damage

Prevention (Standard of Care)

• Repositioning: Every 2 hours (bed), every 1 hour (chair); 30° lateral tilt; avoid direct trochanter pressure.
• Support surfaces: High-spec foam, alternating pressure, low-air-loss, immersion/immersion.
• Skin care: Clean and dry promptly; pH-balanced cleansers; barrier creams for incontinence.
• Nutrition: 30–35 kcal/kg, 1.25–1.5 g/kg protein, micronutrients (vitamin C, zinc, arginine).
• Monitoring: Daily skin assessment; document stage, location, size, exudate.

Treatment by Stage

• Stage 1: Offload, protect, monitor.
• Stage 2: Hydrocolloid, foam, silicone dressings; maintain moist wound healing.
• Stage 3/4: Debride (sharp, enzymatic, autolytic); advanced dressings (alginate, hydrogel, NPWT); surgical consult for flap/closure.
• Infection: Topical antimicrobial (silver, honey) for local; systemic antibiotics for spreading cellulitis or sepsis.
• Pain management: Pre-procedural analgesia; topical lidocaine.

Quality and Reporting

Hospital-acquired pressure injuries (HAPIs) are nurse-sensitive quality indicators. CMS non-payment for Stage 3/4 HAPIs. Root cause analysis for each case.