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Skin Health: Preventing Pressure Ulcers

AFter My Injury, I was unable to move and therefore at high risk for developing pressure ulcers. As a doctor, I knew how serious they were. And that knowledge worked—to this day, I’ve never developed a pressure ulcer. If you’re partially or completely paralyzed in any limb, or lack sensation, you are at risk for developing a pressure ulcer. If you lack sensation, you can’t tell when your skin begins to hurt. In fact, any time you spend extended periods of time in one position without moving, putting pressure on a vulnerable part of your body for a prolonged amount of time, you are susceptible to a pressure ulcer. For example, if you cross your legs in bed at night and have one ankle or knee resting on another ankle or knee for eight hours, you may develop a pressure ulcer. In this chapter, you’ll learn how to maintain healthy skin and avoid pressure ulcers, because prevention is the best medicine.

What Is a Pressure Ulcer?

Pressure ulcers—also called bedsores, decubitus ulcers, and pressure sores—are areas where the skin breaks down (actually, it dies) due to a lack of oxygen. This happens when there are high levels of prolonged pressure, which can occur when you are sitting or lying for several hours without moving. Sustained pressure on places such as your tailbone and pelvis can decrease blood flow to deeper skin layers, leading to death of skin cells, infection, and ulcers.

How to Recognize Pressure Ulcers

The earliest appearance of a pressure ulcer is usually a red spot that does not blanch (return to a normal flesh color) after being pressed. Press on the red or dark area with your finger. The area should turn white if you have a lighter skin tone or become lighter than your normal skin color if you have darker skin. If, when you remove the pressure, the area returns to a red or dark color within a few seconds (indicating good blood flow), the discoloration is not a pressure ulcer. If the area stays lightened, the blood flow has been impaired and damage has begun. It’s important to perform this test for any discoloration, even if it’s as small as a quarter-inch in diameter, because an ulcer is like an iceberg. Beneath the red area may be a large sack of fluid that is much bigger than what you can see.

Stages and Treatment: Pressure ulcers are classified in four stages based on the ulcer surface area, depth, edges, tunneling, undermining, exudate type, and amount of dead tissue (Figure 25).

Figure 25. Stages of pressure ulcers

• Stage I: Intact skin that is red but does not blanch in a localized area, usually over a bony prominence. (Note: Stage I pressure ulcers may be difficult to detect in people who have darkly pigmented skin; ask your doctor or nurse to help you identify what a stage I pressure would look like on you.) Treatment: See your doctor and take all pressure off the site. Healing time is about three days.

• Stage II: An obvious loss of skin that has become a shallow, open ulcer with a red or pink wound bed or that has a fluid-filled blister. See your doctor immediately. Healing time is three days to three weeks.

• Stage III: Full-thickness skin loss; fat is visible but bone, tendon, or muscle are not exposed. There may be pieces of dead skin present. There may also be undermining and tunneling of the pressure ulcer. See your doctor immediately; you may be referred to a wound care specialist. Healing time ranges from one to three months.

• Stage IV: Full-thickness skin and tissue loss with exposed bone, tendon, or muscle. Dead skin or brown to black colored material (eschar) may be present in the wound. Stage IV ulcers can extend into muscle, tendon, or joint capsule, making bone infection (osteomyelitis) likely. Surgery is frequently required. Healing time ranges from three months to two years.

Causes and Risk Factors

There are four mechanisms that contribute to pressure ulcer development. Learning which situations in your daily life include them enables you to take precautions and to develop other approaches for tasks that are high-risk.

External pressure: The most common cause of pressure ulcers is something pushing against your skin with sufficient force and time to prevent blood flow to the tissue. Because bony prominences are hard and located near the skin surface, they are the most common sites where pressure causes ischemia (deficiency of blood flow) and hypoxia (deficiency of oxygen). The cells in the skin may start to die within ten minutes to two hours, depending on your nutritional state, blood flow to the affected skin (which is decreased in people with diabetes and peripheral vascular disease), and fluid in the skin (edema).

Friction: Friction damages the superficial blood vessels directly under the skin when you rub your skin against a surface repetitively. This can occur when you are being moved in bed or transferred onto a stretcher. When I’m pedaling on a stationary recumbent bike, I have to be careful that my shoulder blades don’t rub against the seat back. If I rock too much from side to side, a blister can form on my back.

Shearing: Shearing occurs when your skin is moved more rapidly than the underlying tissue, causing it to separate. For example, when you’re sitting up in bed, your skin may stick to the sheet, and when you slide down toward the foot of the bed, the movement can cause shearing. Shearing can also occur if you don’t transfer properly and skid from your chair to the neighboring surface. Shearing disrupts the blood vessels between the skin, fat, and muscle.

Moisture: Sweat, urine, feces, and wound drainage increase skin friction and accelerate the damage done by pressure and shear. Prolonged exposure to moisture breaks down the skin’s natural protective barrier, making it more likely to become infected. To avoid this problem, it’s important to change dressings and clothes as soon as they get wet.

Risk Factors: There are more than one hundred risk factors for pressure ulcers, but the major ones include immobility, type 2 diabetes, peripheral vascular disease, poor nutrition, and low blood pressure. Additional factors are being over the age of seventy, smoking, dry skin, urinary and fecal incontinence, and a history of pressure ulcers.

How to Prevent Pressure Ulcers

Good news: 95 percent of all pressure ulcers are preventable!

Inspection: Pressure ulcers usually occur in areas of skin that lack sensation. Because you may not feel the problem, you and your caregiver should check your skin twice a day (in the morning and before you go to bed at night). Carefully inspect areas that are at the highest risk, which are places where the skin covers a bone, particularly the sacrum (lower back), coccyx (tailbone), ischium (the base of the buttocks, aka “sit bones”), trochanters (hip), knees, ankles, heels, toes, and bony areas of the feet. Inspect any areas of skin that are in contact with casts or braces, and bruises, especially if they’re below your waist.

Pressure relief and redistribution: Pressure relief is simply moving or lifting yourself to take the pressure off the skin that has been under pressure, usually from sitting or lying in one position, so that blood can circulate. You’ll need to shift throughout the day and night routinely so that it becomes a habit. Before you leave the hospital, your therapist will teach you how to do pressure relief.

The methods and timing of pressure relief depend on your injury and skin tolerance. On a manual wheelchair cushion, this usually means shifting your weight off bony prominences every fifteen to thirty minutes for a duration of at least thirty to ninety seconds; a single “pushup” from a standard wheelchair is not adequate to prevent pressure ulcers; you’ll need to do several. On an electric chair, there should be a tilt function that enables you to offload weight from your sacrum, coccyx, and ischium every two hours. On a mattress, you’ll need to roll over every two to four hours; set a timer with an alarm to remind yourself.

Use pillows and foam pads (not folded towels or blankets) to protect bony areas. No two skin surfaces with bone underneath (especially knees and ankles) should ever rest against each other as you sleep. If you’re at high risk, your doctor may prescribe a special bed or cushion that distributes the pressure against your skin so that there are no high-pressure spots. There are also pressure-mapping mats that can be used to measure the pressure your body exerts against your bed or your chair cushion. Using that information, equipment specialists can adjust the mattress and cushion to eliminate the high-pressure spots.

Skin hygiene: It’s essential to keep your skin clean and dry. Bathe daily with mild, non-abrasive soap and rinse and dry your skin thoroughly. If you’ve leaked stool or urine, immediately wash and dry your skin. Avoid skin sanitizers that have alcohol, as well as antibacterial soaps. Don’t use any powders. Dry skin can be a significant problem, particularly on the lower legs, if you have edema. Be sure to keep your skin moist with the daily application of a body lotion approved by your doctor.

Support surfaces: There are three common support surfaces for wheelchair seat cushions and mattresses: foam, gel, and air-filled. There are pros and cons for each type of support. Foam is the least expensive but also the least durable, and it can’t be adjusted. Gel conforms to your body and maintains an even pressure over bony prominences, but it doesn’t breathe and is hotter and more likely to allow moisture to develop. It’s also heavier than air or foam supports. Air cushions consist of soft, flexible air-filled containers called cells that are connected by small channels, which are adjusted by inflating them with varying amounts of air. A more expensive air cushion for both bed and wheelchair is one in which the pressure changes regularly using multiple air chambers that are alternately pumped up and down. While these pressure-redistributing support surfaces may seem like the best choice, there are no large studies confirming a significant improvement. There are also mattresses in which an air pump blows a continuous flow of air under the entire support surface. These are excellent at distributing pressure, but the air flow may make you feel cold. (More on this in chapter 15.)

Nutrition: Adequate intake of protein and calories is important to prevent pressure ulcers, because people who have less muscle and fat to protect the areas covering the bone are at higher risk. Skin health depends on making keratin, the major protein that comprises skin, which is highly dependent on diet. If you develop a pressure ulcer, consider seeing a nutritionist to make sure that your diet is sufficient for ulcer prevention. The standard recommendation is a protein intake of 1.2 to 1.5 gm/kg body weight daily.¹ If the ulcer is stage III or IV, the fluid that drains from it will have high levels of protein and sugars, so your intake of high-quality protein and nutrient-rich calories should be increased as well. Don’t waste your money on supplements; there are none that have shown a benefit for healing pressure ulcers.

Treating Pressure Ulcers

When you and your doctor make a decision regarding medical or surgical treatment for an ulcer, it will be helpful to consider the overall size and composition of the pressure ulcer.

Principles of treatment: Most pressure ulcers should be treated medically, with surgery being a last resort. The key to effective treatment is recognizing any underlying medical conditions (like type 2 diabetes) and treating those conditions intensively, as well as improving nutrition, relieving pressure and shear force, keeping the wound moist and covered, and helping the body get rid of dead skin and tissue with debridement.

Medical Therapy

Debridement (removal of tissue): In most cases, dead tissue should be removed, because it provides an ideal place for bacteria to grow. As your wound care specialist will explain, there are several ways to remove dead tissue, starting with your body’s own system, which is called autolytic debridement. Debriding the ulcer requires multiple approaches which may include dressings that selectively remove dead tissue, cleaning with mildly abrasive bactericidal soap, use of a whirlpool to warm the ulcer and improve blood flow while agitating dead tissue away, and negative pressure to suck the dead tissue away and increase blood flow.

Dressings: Despite many studies, it’s unclear which topical agent or dressing is best for treating pressure ulcers. Protease-containing dressings, antimicrobial drug dressings (containing antibiotics or metals like zinc and silver), foam dressings, hydrogel dressings, and collagenase ointment may be better for healing than plain gauze, because they more rapidly and selectively remove dead tissue. Some of them also kill bacteria (antibiotics) or prevent proliferation (zinc and silver).

Antibiotics: The jury is still out on whether antibiotics improve healing of pressure ulcers. This is likely due to the fact that poor blood vessel supply limits penetration of the antibiotics into the dead tissue where the bacteria are growing. But there’s an undisputed role for antibiotics when the bacteria invade the bone, muscle, or—even worse—the bloodstream.

Surgical Therapy

Surgical debridement is the fastest method of removing dead tissue. A drawback to this approach (compared to autolytic debridement, your body’s ability to rid itself of the dead tissue), is that it causes more damage to underlying healthy tissue, which increases the size of the ulcer. Stage III and IV pressure ulcers often require surgical intervention because of their high rate of recurrence and the length of time necessary for medical therapy to work (three months to two years). During this time, you are confined to your bed every day!

Surgery is the best option when the ulcer has tunneled into underlying tissue, especially bone and muscle, since medical therapy cannot reach deeper infections. Increasingly, closure after surgery uses skin grafts. In particular, skin “flaps” that contain their own blood supply are used, because they bring oxygen and white blood cells to fight the infection as well as protecting the underlying wound from contamination. The need for pressure relief and bedrest is even more critical after surgery, to allow the graft to join with the debrided skin and tissue and revitalize the ulcerated tissue.

 

Everything You Need to Know

Pressure ulcers are a serious threat to your health and recovery. You’re at risk if you spend most of your day in a wheelchair or in bed. You can avoid pressure ulcers by following these proven prevention steps:

• Check your skin twice daily (and have someone else check the parts of your body you can’t see) for signs of pressure ulcers.

• Notify your doctor as soon as you find what you believe may be a pressure ulcer.

• Avoid staying in the same seated or prone position for long periods of time.

• Invest in quality pressure-relieving support cushions, mattresses, and devices.

• Eat a nutritious diet.

• Keep your skin clean, dry, and properly moisturized.