Areas for pressure sores

• Sacrum
• Greater trochanter
• Heel
• Lateral malleolus
• Ischial tuberosity
• Occiput

Pathophysiology

1. Prolonged weight-bearing and mechanical forces act on areas of soft-tissue overlying bony prominences
2. Leads to occusion and tearing of small blood vessles
3. Reduced perfusion leads to ischaemic necrosis 

Approach

• Examine as for ulcers
• Examine the peripheral vascular system (ulcers may be due to pressure necrosis as well as peripheral vascular disease)

Classification of Pressure Sores

1. Stage 1: Abnormal area of skin with erythema that will not blanch - indicates extravasated blood from cutaneous capillary vessels
2. Stage 2: Partial thickness skin loss - shallow abrasion wound
3. Stage 3: Full thickness skin loss with fat at the base of the wound
4. Stage 4: Extensive soft tissue loss through deep fascia, often with underlying muscle necrosis

Completion

1. History for predisposing factors
   • Immobility and prolonged bed rest - cardiopulmonary disease, trauma, neurologicaldisease, bone/joint disease, prolonged operative procedures
   • Conditions that slow wound healing
     1. Metabolic: DM, vitamin deficiencies, trace elements
     2. Drugs: steroids, post-chemotherapy
     3. Underlying disease: tissue hypoxia, peripheral vascular disease, renal failure, jaundice

Treatment

1. Prevention
   • Regular skin inspection
   • Frequent furitning of immobile patients
   • Special mattresses and cushions which redistribute pressure on at-risk areas
2. Non-surgical: optimise tissue perfusion and oxygenation
   • Treat infection as it arises
   • Various topical dressings as required
   • Nutritional support: vitamin C, zinc, multivits
3. Surgical
   • Debridement of dead tissue (often does not require anasthesia and can be performed by tissue viability nurse)
   • Reconstruction using fascial and muscle-containing composite flaps (eg. buttock rotational flaps for sacral sores)