Pressure sores (DERM) Flashcards
Define pressure sores.
Localised damage to the skin and underlying soft tissue usually over a bony prominence, or related to a medical/other device
Why do pressure sores happen?
Constant pressure limits blood flow to the skin leading to tissue damage
How do pressure sores occur on lying?
- mean capillary pressure normally 25mmHg
- when lying down, pressure increases due to compression, especially on contact points (heel, sacrum, greater trochanters) to 100mmHg
- –> sores form on prolonged lying >4h with mean capillary pressure >100mmHg
- occlusion of capillaries –> hypoxia of neighbouring tissues –> necrosis of surrounding skin, muscle, vessels –> ulcers
What are some risk factors for pressure sores? (6)
- immobility
- recent surgery/intensive care stay
- diabetes
- malnutrition
- sensory impairment
- older age
Who/where are pressure sores most common in?
Hospitals and elderly population
How do we screen for patients at risk of pressure sores?
Waterlow score - takes BMI, nutritional status, skin type, mobility and continence into account
What are the majority of pressure sores?
- majority are superficial ulcers
- deep ulcers form with prolonged occlusion –> extensive necrosis of wedge-shaped tissue which can separate from bony prominences
What are the clinical features of pressure sores? (6)
- location - over bony prominences, typically sacrum or heel
- focal area of non-blanching erythema or purple/maroon localised area of discoloured skin
- evidence of decreased skin perfusion (increased CRT)
- painful (unlike neuropathic ulcers = painless), firm, mushy, boggy –> early stage of tissue damage
- signs of infection - purulent drainage, foul smell, localised tenderness and warmth
- use of non-pressure-relieving support surface
What can occur in advanced stages of pressure sores?
There may be full-thickness skin loss, in which adipose (fat) is visible in the ulcer
What are the 4 stages of pressure sores?
- stage 1: non-blanchable erythema of intact skin
- stage 2: loss of dermis +/- epidermis; superficial ulcer
- stage 3: loss of all skin layers (full thickness)
- stage 4: extensive destruction, tissue necrosis, or damage to muscle, bone or supporting structures
How are pressure sores diagnosed?
Clinical diagnosis
What predisposing factors can we evaluate for pressure sores? (3)
- blood glucose (DM if elevated)
- HbA1c
- serum albumin (malnutrition)
How do we check for infection in pressure sores?
Raised WCC and CRP
If ESR/WCC elevated –> osteomyelitis
What are some differential diagnoses for pressure sores? (6)
- moisture-associated dermatitis
- venous ulcers (near ankles + skin staining)
- arterial ulcers (feet, heels or toes, painful at night, skin white and shiny)
- diabetic neuropathy
- pyoderma gangrenosum (edge of ulcer purple and undermined, associated with other conditions)
- osteomyelitis (bone pain, tenderness, swelling, PMH)
What is the first-line management of pressure sores? (4)
- pressure relief over affected areas
- repositioning - frequent position changes (every 2h) for immobile patients, depends on level of activity/mobility
- moist wound environment - encourages ulcer healing
- ensure good nutrition
