pressure ulcers

Pressure ulcers are areas of soft tissue that are compressed due to pressure/ force, causing impaired circulation which leads to different stages of ulceration (1 being mild and 4 being severe). The patches of area become discoloured, painful and can sometimes lead to ulceration. Reasons for pressure ulcers range from immobility, increased age and undernutrition.

Epidemiology

Globally, the incidence of pressure ulcers ranges between 0-72% in healthcare settings [1]
In the UK, over 700, 000 people are affected by pressure ulcers each year [2]
Most prevalent in long-term acute care facilities (hospitals that manage serious medical conditions that require intense, specialised treatment) with 23-27%
Known to affect around 3 million people in the US
Overall prevalence of pressure ulcers in hospitalised patients has been found to be between 5-15% [3]

Source: DermNetNZ.org

Pressure Sores
Large well bordered sore on the heel

Source: Waikato District Health Board; DermNetNZ.org

Pressure sore
A deep full thickness in the sacral (lower back) extending to the bone

Causes [4]

Constant pressure or friction applied to one area of the body- causing blood to stop flowing normally leading to skin break down
Being unable to move around and staying in one position for a long time.
Being bedridden or in a wheelchair increases the risk of pressure sores

Pathophysiology [5]
- Medical students
  - Many factors contribute to the development of pressure ulcers, but pressure leading to ischemia and necrosis is the common final result.
    - It is a result from constant pressure which is enough to impair local blood flow to soft tissue for an extended period.
      - External pressure must be greater than the arterial capillary pressure (32 mm Hg) to impair inflow for an extended time
      - External pressure must be greater than the venous capillary closing pressure (8-12 mm Hg) to impede the return of flow for an extended time.
    - Tissues are capable of withstanding enormous pressures for brief periods, but prolonged exposure with pressure above capillary rates can lead to tissue necrosis and ulceration.
      - The superﬁcial dermis can tolerate ischemia for 2 to 8 hours before breakdown occurs.
      - Deeper muscle, connective tissue, and fat tissues tolerate pressures for 2 hours or less (speculated to be due to the increased need for oxygen and higher metabolic requirements).
    - Often there is signiﬁcant damage to underlying tissues while the epidermis and dermis remain intact.
    - By the time ulceration is present through the skin level, significant damage of underlying muscle may already have occurred, making the overall shape of the ulcer an inverted cone
    - Friction caused by skin rubbing against surfaces like clothing or bedding can also lead to the development of ulcers by contributing to breaks in the superficial layers of the skin.
    - Moisture can cause ulcers and worsens existing ulcers via tissue breakdown and maceration
- Patients
  - Many factors contribute to the development of pressure ulcers, but pressure leading to ischemia (lack of oxygen supply) and necrosis (tissue death) is the common final result.
    - It is a result from constant pressure which is enough to stop local blood flow to soft tissue for an extended period.
      - External pressure must be greater than the arterial capillary (artery) pressure (32 mm Hg) to impair inflow for an extended time
      - External pressure must be greater than the venous (veins) capillary closing pressure (8-12 mm Hg) to stop the return of flow for an extended time.
    - Tissues are capable of withstanding enormous pressures for brief periods, but prolonged exposure with pressure above capillary rates can lead to tissue necrosis and ulceration (forming ulcers)
      - The superﬁcial dermis (layer of skin closest to the surface) can tolerate ischemia for 2 to 8 hours before breakdown occurs.
      - Deeper muscle, connective tissue (tissues that attaches other tissue), and fat tissues tolerate pressures for 2 hours or less
    - Often there is signiﬁcant damage to underlying tissues while the epidermis (top layer of skin) and dermis (middle layer of skin) remain intact.
    - By the time ulceration is present through the skin level, significant damage of underlying muscle may already have occurred, making the overall shape of the ulcer an inverted cone
    - Friction caused by skin rubbing against surfaces like clothing or bedding can also lead to the development of ulcers by contributing to breaks in the superficial layers of the skin.
    - Moisture can cause ulcers and worsens existing ulcers via tissue breakdown and maceration (to soften tissues after death by soaking)

Pressure sores

Skin of the buttocks area is broken down seen in an immobile patient

Risk factors [6]
- Reduced mobility
- Nutritional deficiency
- Conditions such as diabetes and peripheral vascular disease that causes poor blood flow to sites of pressure
- Older age
- Poor posture or deformity

Presentations [7]
- Can be stages 1-4:
  - Stage 1- mild injury with intact skin and redness (without white discolouration under pressure). Dark skin can fail to present the injury. The areas of injury are warmer, cooler, softer and firmer than non-affected tissue
  - Stage 2- more deep injury with a red/pink base and loss of epidermis (layer of skin) causing erosions or blisters
  - Stage 3- ulcer formation with full skin loss that extends to the fascia (a couple of skin layers deep) which are crater like in appearance
  - Stage 4- severe injury with full-thickness loss of the skin layers, including the destruction of the skin, tissue death and damage to muscles, tendons, bones.
- Deep tissue pressure injury- intact/non-intact skin to the area of damage due to pressure or force applied to the skin. This presents with dark/maroon discolouration and blood-filled sacs (bullae)
- Medical device pressure injury- caused by casts or splints that lead to the injury fitting the pattern of the device
Investigations [8]

Clinical examination which looks at the appearance of the patient and features of pressure ulcers
Blood tests can be carried out to suggest osteomyelitis (an infection of the bone) using erythematous sedimentation rate and white blood cell count.
Serum glucose can be used to exclude diabetes
Deep tissue biopsy (taking a sample of skin from the deeper layers of the skin) to diagnose infection
An MRI scan used when bones are involved- does not confirm pressure injury

Differential diagnosis [6]
- Diabetic foot ulcer
- Damage to the skin caused by moisture
- Osteomyelitis- infection of the bone
- Malignancy on the skin
- Peripheral arterial disease- affecting the arteries of the hands/feet
- Venous ulcers- sores formed in the skin

Pressure sores

Well defined superficial (on the skin) pressure ulcer in a red, circular lesion

Management [7]

Medical students
- Lifestyle changes
  - Pressure reduction is crucial for managing pressure injuries and involves careful positioning, protective devices, and support surfaces.
  - Repositioning of the patient is vital, with written schedules to direct and document repositioning.
    - Bedridden patients should be turned every 2 hours and positioned at a 30° angle to the mattress when on their side.
    - Patients in chairs should be repositioned every hour.
  - Protective padding, such as pillows and foam wedges, can be used to reduce pressure on vulnerable areas.
  - Support surfaces, either static or dynamic, can help reduce pressure and shearing forces.
    - Static surfaces include air, foam, gel, and water overlays and mattresses
    - Dynamic surfaces include alternating-air, low-air-loss, and air-fluidized mattresses.
- Medications
  - Pain management is essential, and nonsteroidal anti-inflammatory drugs or acetaminophen can be used for mild-to-moderate pain.
  - Friction reduction using barrier protectants like petroleum jelly can be helpful, particularly for patients using personal protective equipment.
  - Appropriate wound care involves cleaning, debridement, and dressings.
    - Cleaning is done with normal saline or irrigation at sufficient pressures.
    - Debridement is necessary to remove necrotic tissue and can be done mechanically, surgically, or using autolytic or enzymatic methods.
  - Dressings should protect the wound and facilitate healing.
    - Different types of dressings are used depending on the stage of the pressure injury and the amount of exudate.
Patients
- Lifestyle changes
  - Pressure reduction is crucial for managing pressure injuries and involves careful positioning, protective devices, and support surfaces.
  - Repositioning of the patient is vital, with written schedules to direct and document repositioning.
    - Bedridden (remains in bed) patients should be turned every 2 hours and positioned at a 30° angle to the mattress when on their side.
    - Patients in chairs should be repositioned every hour.
  - Protective padding, such as pillows and foam wedges, can be used to reduce pressure on vulnerable areas.
  - Support surfaces, either static (still) or dynamic (moving), can help reduce pressure and shearing forces (a mechanical force that acts internally on the skin tissue in a direction parallel to the body's surface)
    - Static surfaces include air, foam, gel, and water overlays and mattresses
    - Dynamic surfaces include alternating-air, low-air-loss, and air-fluidized mattresses.
- Medications
  - Pain management is essential, and non-steroidal anti-inflammatory drugs or acetaminophen (pain relief drug) can be used for mild-to-moderate pain.
  - Friction reduction using barrier protectants like petroleum jelly can be helpful, particularly for patients using personal protective equipment.
  - Appropriate wound care involves cleaning, debridement (the removal of damaged tissue from a wound), and dressings.
    - Cleaning is done with normal saline (solution of salt in water) or irrigation (flushing with water) at sufficient pressures.
    - Debridement is necessary to remove necrotic tissue and can be done mechanically, surgically, or using autolytic (known as self digestion through enzymes- proteins that cause a chemical change in the body) or enzymatic (usages of enzymes) methods.
  - Dressings should protect the wound and facilitate healing.
    - Different types of dressings are used depending on the stage of the pressure injury and the amount of exudate (fluid leakage from blood vessels into tissues).

Complications [8]
- Cellulitis- infection of the tissue
- Blood poisoning- infection from the ulcers can spread to other parts of the body as well as the blood
- Bone and joint infections from ulcer formation
- Necrotising fasciitis (tissue death) that can be very serious- caused by bacteria such as Group A streptococci
- Gas gangrene- serious conditions that cause the ulcer to become infected with clostridium bacteria

Source: Waikato District Health Board; DermNetNZ

Pressure sores
A small pressure ulcer with slough (dead tissue) over the ulcer

Source: DermNetNZ.org

Pressure sores
Chronic (long term) pressure ulcers formed due to a lack of movement and anaesthesia (drug used to numb) due to the congential (from birth) condition, spina bifida

Myths
- Pressure injuries can be prevented if you turn every two hours
- Pressure ulcers are only found in cases of patients in care homes
- Pressure ulcers are inevitable in elderly and for those with poor nutrition [9,10]
Questions to ask your doctor
- What is the best way to take care of pressure ulcers?
- How often do pressure sores need to be looked at?
- What positions are advised to prevent ulcers forming?
- How do I get support for the maintenance of pressure ulcers?
- How long will treatment take to be effective in managing the symptoms of pressure ulcers?
Support
- NICE guidelines
- NHS Inform
- Skill for Care