Pressure Ulcer Stage 4

Stage 4 pressure ulcer is full thickness skin and tissue loss with exposed or palpable fascia, muscle, tendon, ligament, cartilage or bone. Slough or eschar, undermining and tunnelling are frequent.

• Common over sacrum, ischial tuberosities, greater trochanters and heels.
• Osteomyelitis and sepsis are major complications and mortality is high in frail patients.

Deep cavity with visible or probeable bone or tendon, necrotic tissue, heavy exudate, odour, surrounding erythema or cellulitis.

• Fever, tachycardia and malaise suggest sepsis; painless in neuropathic patients.
• Differential diagnosis: necrotising soft tissue infection, malignant ulcer (Marjolin), pyoderma gangrenosum, tuberculous or fungal ulcer, vasculitic ulcer, calciphylaxis, diabetic foot ulcer.
• Complications: osteomyelitis, septic arthritis, bacteraemia and sepsis, fistulae to bowel or urethra, anaemia, hypoalbuminaemia, protein loss, amyloidosis, heterotopic ossification, squamous cell carcinoma in chronic wounds, death.

Clinical and imaging assessment.

• Measure and document depth, undermining, tunnelling, bone exposure, probe to bone; photograph.
• Full blood count, CRP, ESR (over 70 mm/h supports osteomyelitis), glucose, urea, creatinine, albumin, blood cultures if febrile.
• MRI of the area or plain radiograph; bone biopsy for culture and histology when osteomyelitis is suspected; biopsy of chronic edge lesions for malignancy.
• HIV and diabetes screening.

Combine pressure relief, debridement, antibiotics for bone infection, nutrition and surgical reconstruction.

• Supportive: bed rest off the affected area with air fluidised or alternating pressure surface, 30 degree side lying position every 2 hours, heel suspension, high protein diet (1.5 g/kg/day) with energy 35 kcal/kg/day, zinc and vitamin C when deficient, transfuse for symptomatic anaemia, manage incontinence, glycaemic control, treat spasticity.
• Pharmacological: analgesia with paracetamol 1 g four times daily plus morphine 2.5 to 10 mg orally every 4 hours as needed; for osteomyelitis or severe infection give ceftriaxone 2 g IV daily plus metronidazole 500 mg IV every 8 hours (or piperacillin tazobactam 4.5 g IV every 8 hours) and add vancomycin 15 to 20 mg/kg IV every 12 hours where MRSA is likely, then adjust by bone culture, with a total of 6 weeks. Tetanus toxoid if indicated.
• Procedures: surgical debridement of all necrotic and infected tissue and infected bone; negative pressure therapy to prepare the bed; flap reconstruction (myocutaneous or fasciocutaneous) once clean and nutrition is optimal; faecal diversion by colostomy for contaminated sacral wounds; amputation for limb threatening heel osteomyelitis.
• Special groups: spinal cord injury, specialist plastic surgery and strict pressure protocols after surgery; elderly, nutrition and delirium prevention; HIV, antiretroviral therapy and screen for tuberculosis of bone; palliative, comfort and odour control with metronidazole 0.8 percent gel and charcoal dressings.
• Red flags: sepsis, spreading cellulitis, crepitus, exposed bone, new fistula, haemorrhage, unexplained fever, non healing after 4 weeks.
• Follow-up: weekly wound review; ESR and CRP every 2 weeks during antibiotics; review for flap viability; lifelong risk management and seating assessment.