Pressure Injury

Pressure injury is localised damage to the skin and underlying tissue, usually over a bony prominence, resulting from sustained pressure or pressure combined with shear. It is a preventable complication of immobility.

• Risk factors: immobility, neurological injury, sensory loss, malnutrition, incontinence, moisture, advanced age, critical illness, diabetes, peripheral vascular disease, dehydration, low albumin, hospitalisation, poor nursing.
• Common sites: sacrum, heels, ischial tuberosities, greater trochanter, occiput, elbows, malleoli.

Range of severity from non blanching erythema of intact skin to deep ulcers exposing muscle and bone, often with necrosis, odour and exudate.

• Staging: stage 1 intact non blanching erythema; stage 2 partial thickness loss; stage 3 full thickness skin loss; stage 4 full thickness with exposed muscle, tendon or bone; unstageable (slough or eschar obscuring depth); deep tissue injury (persistent purple or maroon discolouration).
• Differential diagnosis: moisture associated skin damage, diabetic and venous or arterial ulcers, skin tears, incontinence dermatitis, pyoderma gangrenosum, vasculitis, calciphylaxis, skin cancer.
• Complications: infection, cellulitis, osteomyelitis, sepsis, fistulae, anaemia, hypoalbuminaemia, chronic wounds, amputation, malignant transformation (Marjolin ulcer), death.

Clinical staging and risk assessment (Braden score of 18 or less indicates risk).

• Measure size and depth, document tissue type, exudate, odour and surrounding skin; photographs.
• Full blood count, CRP, albumin, glucose, renal function; wound swab or tissue culture only if infection suspected.
• Plain radiograph, MRI or bone biopsy for suspected osteomyelitis.
• Nutritional assessment.

Relieve pressure, support healing, treat infection and prevent recurrence.

• Supportive: pressure redistribution (alternating pressure air mattress or high specification foam), reposition every 2 hours using 30 degree side lying position, avoid sitting more than 1 hour at a time, heel suspension, keep head of bed under 30 degrees unless needed, manage moisture and incontinence, avoid massage over bony prominences, nutrition with 30 to 35 kcal/kg/day energy and 1.25 to 1.5 g/kg/day protein, adequate hydration, correct anaemia, optimise glycaemic control.
• Pharmacological: paracetamol 1 g before dressing changes, opioid (morphine 2.5 to 5 mg orally) if severe; topical lidocaine 2 percent gel; antibiotics only for clinical infection: amoxicillin clavulanate 625 mg three times daily for 7 days for cellulitis; osteomyelitis requires 6 weeks of targeted therapy; tetanus toxoid if indicated.
• Procedures: moist wound dressing (hydrocolloid, foam, alginate, hydrogel) chosen by wound bed; sharp or autolytic debridement of slough and necrosis (avoid dry stable heel eschar); negative pressure wound therapy for deep wounds; surgical flap reconstruction for clean stage 3 or 4 wounds in suitable patients; faecal diversion by colostomy for refractory perineal wounds with soiling.
• Special groups: spinal cord injury, specialist seating and education; elderly, full geriatric review and nutrition; paediatrics, device related injuries at tubes and splints; palliative patients, comfort focused care and soft surfaces.
• Red flags: fever, spreading erythema, crepitus, foul smelling exudate, exposed bone, sepsis, non healing wound at 2 weeks, new necrosis.
• Follow-up: wound review weekly with measurement; risk reassessment daily in hospital; educate carers.