A pressure ulcer is an area of skin and tissue that becomes injured or broken down. Generally, pressure ulcers occur when a person is in a sitting or lying position for too long without shifting his or her weight. The constant pressure against the skin causes a decreased blood supply to that area. Without a blood supply, the area cannot survive and the affected tissue dies.
The most common places for pressure ulcers are over bony prominences (bones close to the skin), such as the elbow, heels, hips, ankles, shoulders, back, and the back of the head.
While it is more common for people to get pressure ulcers if they spend most of their time in bed or use a wheelchair, people who can walk can also get pressure ulcers when they are bedridden as a result of an acute illness or injury.
Pressure ulcers can be caused by four factors, either individually or in combination:
- Pressure: Results in compression of soft tissue between a bony prominence and an external surface, such as a bed. When external pressure exceeds capillary blood pressure, the blood supply from the blood vessels to the muscle and skin tissue is impeded, resulting in tissue breakdown.
- Moisture: Over-hydrates skin, resulting in maceration, which lowers its resistance to mechanical stresses such as pressure or friction.
- Shear: Occurs when adjacent surfaces slide across one another, typically when a patient slides down in bed or chair. The skin remains stationary against the bed linens while the underlying tissue shifts. This causes capillaries to stretch and tear, resulting in reduced blood flow.
- Friction: Caused when the skin is pulled across a coarse surface such as bed linens, washcloths, or incontinence pads. When friction is applied to the skin, the outer protective layer is rubbed away. The soft moist layers of skin are exposed which allow bacteria to enter.
Shear induced tissue trauma
|Under the downward pressure of the user's weight, tissue is compressed in the vertical plane beneath the bony prominences, trapping the skin. As the body moves, mechanical shearing forces are generated along the horizontal plane, causing damage deep within the tissue|
Vulnerable bony prominences
|Without effective shear-reducing intervention, the skin and deep tissues are vulnerable to shear induced trauma at the scapula, sacrum and heels. This is intensified when the head of bed is elevated, pushing the user toward the foot of the bed.|
|Even, rotational shear, caused when the user is pivoted from the lying to sitting position or vice versa is minimized by Shear Transfer Zone technology.|
Factors which increase risk for pressure ulcers include:
Patient risk is assessed on a number of factors standardized in assessments such as the Norton or Braden scales.
- Age -- elderly people are at higher risk
- Inability to move certain parts of the body without assistance, such as with spinal or brain injury patients, and patients with neuromuscular diseases
- Being bedridden or in a wheelchair
- Having a chronic condition, such as diabetes or artery disease, that prevents areas of the body from receiving proper blood flow and nutrition
- Urinary incontinence or bowel incontinence (moisture next to the skin for long periods of time can cause skin irritation that may lead to skin breakdown)
- Fragile skin
- Mental disability from conditions, such as Alzheimer's (some patients may not be capable of taking the proper steps toward prevention and may not seek appropriate treatment when an ulcer has formed)
An estimated 1.3 to 3 million patients in the US have pressure ulcers. Incidence is highest in older patients, especially those who are hospitalized or in long-term care facilities. Aging increases risk, in part because of reduced subcutaneous fat and decreased capillary blood flow. Immobility increases risk further.
The National Pressure Ulcer Advisory Panel (NPUAP) created a process for evaluating pressure sores based on a staging system from Stage I (earliest signs) to Stage IV (worst). Pressure ulcers are graded from Stage I to Stage IV to classify the degree of tissue damage. Pressure ulcers do not necessarily progress from Stage I to Stage IV or heal from Stage IV to Stage I.
- Stage I: A reddened area on the skin that, when pressed, is "non-blanchable" (does not turn white). This indicates that a pressure ulcer is starting to develop. Non-blanchable erythema of intact skin, the heralding lesion of skin ulceration. In individuals with darker skin, discoloration of the skin, warmth, edema, induration, or hardness may also be indicators.
- Stage II: The skin blisters or forms an open sore. The area around the sore may be red and irritated. Partial thickness skin loss involving epidermis, dermis, or both.
- Stage III: The skin breakdown now looks like a crater where there is damage to the tissue below the skin. Full thickness skin loss involving damage to or necrosis of subcutaneous tissue that may extend down to, but not through, underlying fascia. The ulcer presents clinically as a deep crater with or without undermining adjacent tissue.
- Stage IV: The pressure ulcer has become so deep that there is damage to the muscle and bone, and sometimes tendons and joints. Full thickness skin loss with extensive destruction, tissue necrosis, or damage to muscle, bone, or supporting structures (e.g., tendon or joint capsule).
Once a pressure ulcer is identified, certain basic steps must be taken immediately. These include:
- Relieving the pressure to that area. Use pillows, special foam cushions, and sheepskin to help reduce the pressure.
- Treating the sore. Treatment will be based on the stage of the ulcer. Your health care provider will give you specific treatment and care instructions.
- Avoiding further trauma or friction. Powdering the sheets lightly can help decrease friction in bed. (There are many items made specifically for this purpose -- check a medical supplies store.)
- Focusing on improving nutrition and other underlying problems that may affect the healing process.
- If the pressure ulcer is at Stage II or worse, your health care provider will give you specific instructions on how to clean and care for open ulcers, as it is very important to do this properly to prevent infection.
- Keep the area clean and free of dead tissue. Your health care provider will give you specific care directions. Generally, pressure ulcers are rinsed with a salt-water rinse that removes the loose, dead tissue. The sore should be covered with special gauze dressing made for pressure ulcers.
- Do NOT massage the area of the ulcer because massage can cause tissue damage under the skin.
- Donut-shaped or ring-shaped cushions are NOT recommended because they can interfere with the blood flow to that area and cause complications.
Call immediately for emergency medical assistance if
The patient's health care provider should be contacted immediately if there are any signs that the pressure ulcer is getting infected. An infection can lead to serious problems because the infection can spread to the rest of the body. Some of the signs of an infected pressure ulcer include:
- A foul odor from the ulcer
- Redness and tenderness around the area of the ulcer
- The skin close to the ulcer is warm and swollen
If the patient starts running a fever or have other symptoms, such as weakness or confusion, he or she may be developing a systemic infection that can be very serious.
Education of at-risk patients and their families is the most productive way to prevent pressure ulcers. Steps toward prevention include:
- Identifying individuals at high risk for pressure ulcers.
- Ensuring that immobile patients change their position at least every two hours to relieve pressure.
- Using items that can help reduce pressure caused by bed sheets and wheelchairs (e.g., low air-loss mattress system, pillows, cushions, foam padding ).
- Making sure patients eat healthy, well-balanced meals.
- Encouraging daily exercise, including range-of-motion exercises for immobile patients.
- Following good skin care, including inspecting the skin every day and keeping skin clean and dry. Incontinent people need to take extra steps to limit areas of moisture.
Children who are destined to spend years in a chair should be taught at an early age to do push-ups while in the chair and shift their weight often.
Therapy Mattress Systems for preventing and treating Skin Breakdown:
See our Support Surface Primer for more on how each mattress therapy works.
Wound Care Products: Lotions & Creams for Skin Ulcer therapy
Therapeutic Mattress Systems: Group II Sleep Surface Therapy
Wound Care information links