Decubitus Ulcer (Bedsore)

How a decubitus ulcer forms

"Decubitus" comes from the Latin for lying down. When skin and fat are squeezed between bone and a mattress or chair, small blood vessels close and tissue starves of oxygen. Damage can start within 2 hours of unrelieved pressure, and in very frail people even sooner. Two other forces add to it:

• Shear: the skin stays still while the bone slides, for example when someone slips down in bed with the head raised. This tears small vessels deep under the surface.
• Friction and moisture: rubbing on sheets and skin soaked by sweat, urine or stool weaken the surface.

Because the deepest tissue (muscle near the bone) is most vulnerable, a small sore on the surface can hide a much larger area of damage beneath. Clinicians now often call these pressure injuries. Our pressure ulcers page covers the same condition with a focus on caregivers.

Who is at risk

• People confined to bed or a wheelchair, including after surgery or a hip fracture
• Spinal cord injury and other causes of paralysis, where people cannot feel pressure building
• Advanced dementia, stroke and coma
• Malnutrition, weight loss and dehydration
• Urinary or fecal incontinence
• Diabetes, peripheral artery disease and smoking, which reduce blood flow
• Older age, with thinner, less elastic skin
• Medical devices pressing on skin: oxygen tubing, casts, catheters, splints

Hospitals use risk scores such as the Braden scale to decide who needs extra protection.

Decubitus ulcer stages

The National Pressure Injury Advisory Panel stages are used across the US.

Ulcers are not "reverse staged" as they heal. A healing stage 4 ulcer is still called a healing stage 4 ulcer.

Symptoms

• a red, purple or darkened patch over a bony area that stays after pressure is removed
• skin that feels warmer, cooler, firmer or softer than the skin around it
• pain or tenderness, though people with nerve damage may feel nothing
• blisters, open sores or a crater
• drainage, a bad smell, or black or yellow tissue in deeper sores

The commonest site is the sacrum (the bony area above the buttocks) in people lying down, and the ischial tuberosities (sit bones) in wheelchair users. Heels are the second most common site.

What serious condition can a decubitus ulcer cause?

Deep ulcers can lead to life-threatening problems:

• Sepsis: bacteria from the wound enter the bloodstream. Sepsis causes fever, confusion, low blood pressure and organ failure, and pressure ulcers are a recognized source of it in nursing home residents.
• Osteomyelitis: infection spreads to the bone under a stage 4 sore. Osteomyelitis needs weeks of antibiotics and often surgery to remove infected bone.
• Cellulitis: spreading skin infection, with warmth, redness and swelling. See cellulitis.
• Septic arthritis: infection of a nearby joint, such as the hip.
• Necrotizing soft tissue infection: rare, rapidly spreading and life-threatening.
• Squamous cell carcinoma: a rare skin cancer (Marjolin ulcer) that can develop in a wound that has not healed for many years.

Large ulcers also leak protein and fluid, worsening malnutrition, and cause pain, depression and long hospital stays.

Diagnosis

Pressure ulcers are diagnosed by examining the skin. The care team measures length, width and depth, checks for tunneling, and photographs the wound to track progress. If infection is suspected, they may take tissue samples or blood cultures. When bone is visible or can be touched with a probe, or a sore will not heal, an MRI or bone biopsy can confirm osteomyelitis. Blood tests check nutrition (albumin, blood count) and blood sugar.

Treatment

Take the pressure off

Nothing heals while the pressure continues.

• Reposition at least every 2 hours in bed and every hour in a chair, or more often for high-risk people.
• Use pressure-redistributing mattresses (foam, air or alternating-pressure) and cushions.
• Keep the head of the bed at 30 degrees or less, unless medically needed, to reduce shear.
• Float the heels off the bed with a pillow under the calves or a heel boot.
• Do not use donut-shaped cushions, which concentrate pressure around the ring.

Wound care

• clean the wound with saline at each dressing change
• keep the ulcer base moist with dressings such as hydrocolloids, foams, alginates or hydrogels, chosen by depth and drainage
• remove dead tissue (debridement) by sharp, surgical, enzymatic or dressing-based methods. Dry, stable black eschar on the heel is often left alone
• negative-pressure (vacuum) wound therapy for some deep wounds

Support healing

• enough calories and protein, often with supplements and a dietitian's advice
• control of blood sugar
• managing incontinence and protecting the skin with barrier creams
• pain relief before dressing changes

Infection and surgery

Antibiotics are used for cellulitis, bone infection or sepsis, not for colonized wounds that look clean. Large stage 3 and 4 ulcers may need surgical closure with a muscle or skin flap once the person is well nourished and infection is controlled.

Outlook

Stage 1 sores can resolve within a few days once pressure is relieved. Stage 2 ulcers usually heal in 1 to 3 weeks. Stage 3 and 4 ulcers can take months, and some never fully heal, especially in people who remain immobile or are at the end of life. Healed areas stay weaker and are prone to break down again.

Prevention

• check the whole skin, especially bony areas, at least once a day
• reposition on a schedule and use the 30-degree side-lying position
• use specialist mattresses and cushions for anyone at high risk
• keep skin clean and dry and moisturize dry skin. Do not massage red areas
• lift rather than drag when moving someone in bed
• treat malnutrition and dehydration
• wheelchair users should shift their weight every 15 to 30 minutes

Frequently asked questions

Decubitus ulcers may result in what serious condition?

Deep decubitus ulcers can cause sepsis (a life-threatening bloodstream infection), osteomyelitis (infection of the bone under the sore), cellulitis and septic arthritis. Long-standing wounds also cause malnutrition and, rarely, a type of skin cancer. Early pressure relief and treatment prevent most of these complications.

What is the difference between a decubitus ulcer and a pressure ulcer?

There is no difference. Decubitus ulcer, pressure ulcer, pressure injury, pressure sore and bedsore all describe the same thing: damage caused by sustained pressure over bony areas. "Pressure injury" is now the preferred clinical term in the US.

How fast can a bedsore develop?

Tissue damage can begin after about 2 hours of unrelieved pressure, and faster in frail, very ill or poorly nourished people. A deep tissue injury can look like a bruise at first and then open into a deep wound over a few days.

Can a stage 4 pressure ulcer heal?

Yes, but slowly. Stage 4 ulcers often take many months and sometimes need surgery with a muscle flap. Healing depends on removing pressure completely, treating infection and good nutrition. In people near the end of life, the goal may shift to comfort rather than closure.

Are bedsores a sign of neglect?

Not always. Some pressure ulcers develop despite good care in very ill or dying patients. However, many are preventable, and a new or worsening ulcer should prompt a review of turning schedules, mattresses, nutrition and continence care.