Key Facts

Pressure ulcers (also called pressure injuries or decubitus ulcers) are a significant cause of morbidity, mortality, and healthcare cost. They are largely preventable, making them a key patient safety indicator. Healthcare organisations are measured on pressure ulcer rates.

Epidemiology

• Prevalence: ~10–18% of hospitalised patients; up to 30% in long-term care
• Sacrum: most common site (~30%)
• Heels: second most common (~25%)
• NHS cost: estimated £1.4–£2.1 billion/year in UK
• ~700 deaths/year in UK directly attributed to pressure ulcers

Aetiology

• Sustained pressure: compresses capillaries → tissue ischaemia → necrosis
• Shear forces: layers of tissue slide over each other → disrupts blood supply
• Friction: surface abrasion during repositioning
• Risk factors: immobility, malnutrition, incontinence (moisture), sensory impairment, extremes of age, acute illness, spinal cord injury, peripheral vascular disease

Pathophysiology

• External pressure exceeds capillary closing pressure (~32 mmHg) → tissue ischaemia
• Sustained pressure for >2 hours → irreversible tissue damage
• Tissue layers affected progressively: skin → subcutaneous fat → muscle → bone
• 'Iceberg effect': visible skin damage may underestimate deep tissue destruction
• Reperfusion injury: paradoxical tissue damage when pressure relieved after ischaemia

NPUAP/EPUAP Staging

Stage 1:

• Non-blanchable erythema of intact skin
• Localised area of erythema that does not blanch on pressure
• May be painful, firm, soft, warmer or cooler than adjacent skin
• Difficult to identify in dark skin — look for colour change, temperature, oedema

Stage 2:

• Partial-thickness skin loss involving epidermis and/or dermis
• Presents as shallow open ulcer with red/pink wound bed
• May present as intact or ruptured serum-filled blister

Stage 3:

• Full-thickness skin loss — subcutaneous fat visible
• Bone, tendon, and muscle NOT visible
• Depth varies by anatomical location
• Slough or eschar may be present

Stage 4:

• Full-thickness tissue loss with exposed bone, tendon, or muscle
• Slough or eschar may be present
• Often includes undermining and tunnelling
• Osteomyelitis risk

Unstageable:

• Full-thickness loss with base obscured by slough/eschar — cannot determine depth

Deep tissue injury:

• Purple/maroon localised area of discoloured intact skin or blood-filled blister
• Indicates deep tissue damage that may evolve rapidly

Red Flags

• Signs of infection: increasing pain, warmth, erythema, purulent discharge, fever, sepsis
• Exposed bone → osteomyelitis risk — urgent surgical assessment
• Rapid deterioration despite pressure relief — consider deep tissue injury
• New pressure ulcer in acute hospital — investigate and report as patient safety incident

Bedside

• Risk assessment: Waterlow score (UK standard) or Braden scale — on admission and reassess regularly
• Wound assessment: stage, size (length × width × depth), base, edges, undermining/tunnelling, exudate, odour
• Clinical photography: baseline and serial monitoring
• Pain assessment: pain score

Bloods

• FBC: infection, anaemia
• CRP: infection marker
• Albumin/pre-albumin: nutritional status (hypoalbuminaemia impairs healing)
• HbA1c: diabetes (impairs wound healing)
• Blood cultures: if sepsis suspected

Imaging

• X-ray/MRI: if osteomyelitis suspected (Stage 4 with exposed bone)
• MRI: most sensitive for osteomyelitis

Special Tests

• Wound swab: only if clinical signs of infection (cellulitis, purulence)
• Bone biopsy: gold standard for osteomyelitis diagnosis (if MRI equivocal)
• Nutritional assessment: MUST score (Malnutrition Universal Screening Tool)

Prevention (Most Important)

• Risk assessment: Waterlow score on admission; reassess with any change in condition
• Repositioning: 2-hourly for bed-bound; 30° lateral tilt; use slide sheets to reduce shear
• Pressure-relieving devices: high-specification foam mattress (all at-risk patients); alternating pressure mattress for higher risk
• Skin inspection: daily, especially bony prominences; use mirrors for sacral area
• Moisture management: continence care, barrier creams
• Nutrition: high-protein, high-calorie diet; refer to dietitian; vitamin C and zinc supplementation
• Patient education: self-repositioning where possible, skin checks

Treatment by Stage

Stage 1:

• Pressure relief, repositioning, barrier cream, monitor closely

Stage 2:

• Pressure relief + moist wound healing — hydrocolloid or foam dressings
• Avoid friction during repositioning

Stage 3–4:

• Pressure relief: specialist mattress essential
• Wound care: debridement of necrotic tissue (sharp, autolytic, or larval)
• Dressings: evidence-based wound care — foam, alginate, negative pressure wound therapy (VAC) for large wounds
• Infection management: systemic antibiotics only if cellulitis/sepsis; topical antiseptics (cadexomer iodine) for local infection
• Nutritional support: high-protein, calorie-rich diet; supplements

Surgical

• Flap reconstruction: for Stage 3–4 ulcers not healing with conservative management — plastic surgery referral
• Sharp debridement: removal of necrotic tissue — may need theatre for extensive wounds

Referral Criteria

• Tissue viability nurse: all Stage 2+ pressure ulcers
• Dietitian: nutritional assessment and support
• Plastic surgery: Stage 3–4 ulcers not responding to conservative management
• Orthopaedics/infectious diseases: osteomyelitis
• Safeguarding: consider if pressure ulcer development suggests neglect (institutional or community)

• Stage 1: fully reversible with pressure relief
• Stage 2: usually heals in 2–4 weeks with appropriate care
• Stage 3: may take months; significant morbidity
• Stage 4: prolonged healing; high morbidity/mortality; osteomyelitis risk ~20–30%
• Overall mortality: pressure ulcers associated with 2–4× increased mortality in hospitalised patients
• Prevention is far more effective and cost-effective than treatment
• ~700 deaths/year in UK directly attributed to pressure ulcers

Waterlow Risk Assessment Score

NPUAP/EPUAP Stage Summary