Under pressure

Pressure ulcers are a main source of withheld payments and lawsuits, but physicians can be undereducated about them, according to one expert.

Pressure ulcers are a main source of withheld payments and lawsuits against hospitals, yet physicians are woefully undereducated about them, according to Joyce Black, PhD, RN, an expert witness in ulcer-related cases.

“When my son was in medical school, he called me one day and said ‘Mom, we had six minutes on pressure ulcers today,’” Dr. Black told an audience of hospitalists at the Mayo Clinic 2011 Update in Hospital Medicine last November in Tucson, Ariz. “That was it.”

Photo by Thinkstock
Photo by Thinkstock.

Education is the best weapon against pressure ulcers, according to Dr. Black. Hospitalists and nurses alike need to know the conditions that can cause the ulcers; how to prevent, diagnose and treat them; and what to do to make sure existing ulcers don't worsen.

Who's at risk?

General patient characteristics that should put hospitalists on alert for pressure ulcers include:

  • Inability to move voluntarily;
  • Thin skin, including from old age and/or corticosteroid use;
  • Lack of subcutaneous padding, with fat absent on bony prominences;
  • Lack of native blood supply to the skin, as with peripheral vascular disease or shock treated with medications that shunt blood from the skin;
  • Edematous skin, which prevents oxygen and nutrients from reaching cells;
  • Prior skin injury, from old scars or healed pressure ulcers; and
  • Inability to perceive pressure or pain.

Certain diseases, which involve some of the above risk factors, predispose patients to developing pressure ulcers. For example, people with diabetes-associated neuropathy are prone to getting pressure ulcers on their heels from prolonged contact with the bed (where they are often confined). These ulcers are sometimes misclassified as diabetic foot ulcers, but those typically occur on the plantar surface of the foot and not the posterior heel.

“The payment for diabetic foot ulcers is better, so some people misclassify it intentionally to get more money,” Dr. Black said. “Of course, that is fraud.”

Patients with peripheral vascular disease (PVD) are likely to ulcerate across the tips of the toes, down the dorsum of the foot, and sometimes along the ankle or up the shin, but this is part of the disease and usually not related to pressure. “Though these are the common points (of ulceration), the risk of heel ulceration is also higher in patients with PVD,” Dr. Black noted. “So the question is what are you doing about that? Are you getting the heels off the bed in an adequate amount of time, if you know the risk exists?”

Pressure ulcers can form on patients exposed to shear force—a tangential, ripping force created when a body slides along a surface (as when moving a patient from a gurney to a bed, or vice-versa). Head-of-bed elevation is a culprit for shear, since the angle creates slippage, and can lead to wounds on the sacrum. Critical care patients are at particular risk, as they are often automatically put to bed with their heads elevated.

“It seems the minute we put someone to bed in a hospital bed, we elevate the head. I don't know if it's so people can see the television, or if we think only dead people lay flat, but it increases the shear problem,” Dr. Black said. “Certainly some patients need the head up, but we need to be looking for people to sleep flat at night when possible.”

For those who do need the head of the bed elevated, composite or foam dressings on the sacrum can help prevent ulceration, she added.

Pressure ulcers on the trochanter can occur in non-supine patients with hip fracture who are lying mostly on one side of the body, with contractured patients especially at risk. Ulcers on the ischium occur in patients who sit in wheelchairs all day and in paraplegics, Dr. Black said.

Physicians and nurses often overlook the buttocks tissue lateral to the gluteal cleft, because it's not visible and isn't a bony prominence, yet ulcers here are common in patients who have spent much time lying flat and still in an operating room or intensive care unit. “Any time a patient is in one position for a prolonged period of time, you need to consider potential ulcers,” she said. Obese patients are at greater risk of pressure ulcers, so people who weigh more than 350 pounds need to be put in a bariatric bed as soon as they are admitted, Dr. Black said.

Finally, comatose patients represent special cases since they are completely immobile. Clinicians should closely monitor all pressure points, including the occipital region of the head. In addition to usual body pressure off-loading, these patients should have their heads regularly and gently turned side to side and have appropriate padding in place.

Equipped to ulcerate

Medical equipment and devices play a big role in causing or exacerbating pressure ulcers, Dr. Black said. The most obvious example is standard hospital beds, whose mattress covers don't breathe and thus trap patients' sweat on their bodies.

The heat and humidity created by the trapped sweat increase the metabolic demand of the tissue, which can't be met because the patient is lying on that tissue. This leads to superficial ulcers, which are very difficult to heal; some take months or even a year to heal fully, Dr. Black said.

A full-thickness pressure ulcer that developed after use of a CPAP mask Photo courtesy of Joyce Black
A full-thickness pressure ulcer that developed after use of a CPAP mask. Photo courtesy of Joyce Black.

A few companies on the market have beds with “microclimate management systems” that show promise in easing the problem, she said. Hospitalists can expect to get sales pitches from companies about these soon, if they haven't already. In the meantime, it's important to reposition patients regularly to improve air flow around the skin.

Other devices that can put pressure on the skin and lead to ulcers included tracheotomy ties, endotracheal tubes, arterial lines, oxygen tubing, oximetry probes, stockings, splints, braces, boots, and wheelchair arms, she added. Hospitalists need to regularly check the skin areas that have contact with these devices. Edematous patients, in particular, are susceptible to ulcers from devices that were placed before fluid resuscitation, Dr. Black noted.

Some devices should really be modified by manufacturers to decrease the risk of irritation, she added, offering the example of oxygen tubing that is stiffer than it needs to be and can cause ulcers down the nasal cannula route. “I think, as care providers, we need to be aghast at the number of ulcers from medical devices. We need to own up to the ones we caused by not looking under devices, but we also need to send devices back when we've provided reasonable care and patients are still ulcerating.”

Making the differential

Not all wounds are pressure ulcers, so a good history is essential. Also, it is ideal to obtain medical photographs of wounds, Dr. Black noted. Of course, knowing whether a wound is a pressure ulcer involves having a firm understanding of other kinds of ulcers and skin wounds, she added. Differential diagnoses include arterial ulcers, venous ulcers, diabetic foot wounds, and incontinence and intertriginous dermatitis.

By definition, intertriginous dermatitis occurs in the skin folds, which is why it's important to do a skin fold assessment on admission—including the area under a woman's breasts, she said. During one assessment she performed, a remote control and a ham sandwich fell out from between the folds of an obese man's abdomen, Dr. Black recalled as an aside.

One would assume that skin folds grow Candida, and the literature suggests folds can contain Pseudomonas and Staphylococcus as well, she said. But when Dr. Black's research group conducted a small study in which they cultured skin-fold wounds, they grew a lot of bowel organisms, including in the axilla, she said.

“We weren't surprised to find these organisms in the groin or abdominal area, but it was surprising to find it everywhere else,” Dr. Black said. “We took our results to the surgeons and said perhaps they shouldn't be cutting through this tissue, because the preop cleaning products probably aren't killing the contamination in one pass. So we have been working with using InterDry (dressings) on skin folds (before surgery).”

Incontinence-related dermatitis occurs when urine or stool seeps into the skin folds, but there is no pressure involved. These wounds will look like burns, and will have considerable pain and weeping but will never fully ulcerate, she said.

Arterial ulcers, another differential diagnosis, can be confused with pressure ulcers because they are usually on the foot. However, they don't usually show up on the heels, but on the tips of the toes or the top of the foot down the shin. The wounds are punctate and painful, especially when elevated, Dr. Black said.

Arterial wounds can be diagnosed from an ankle brachial index score lower than 0.65, low tissue oxygen, and obstruction or poor flow on an arteriogram. Clinicians should also look for a history of peripheral vascular disease or atherosclerosis that has been managed medically (for example, with vasodilators or low-dose aspirin) or surgically (for example, with coronary bypass, carotid bypass or leg bypass for claudication).

Venous ulcers are not as often confused with pressure ulcers because they tend to be on different parts of the body. These darker wounds usually occur on the lower third of a leg that is swollen and heavy with venous disease. The ulcer itself is broad, fairly shallow, fairly slough-covered, and inflamed, with a lot of dry, flaky skin around it, Dr. Black said.

Diabetic foot wounds tend to occur on the walking pressure points, such as the metatarsal heads and the tops of the toes. They usually affect patients who have had known diabetes for a decade or more. To diagnose, clinicians should do protective testing; the Semmes Weinstein 5.07 gram monofilament test is best, “rather than a true, sharp needle. I want to make sure they can feel a stone in their shoe or bathwater that is too hot,” not just extreme pain, Dr. Black said.

When diagnosing diabetic foot wounds, clinicians should remind patients—and their families—to look at their feet regularly, because they will often have neuropathy that prevents them from feeling hot water, sharp objects or ill-fitting shoes, she added. It's also a good time to encourage patients to buy shoes that fit correctly, she said.

Deep tissue injury: A sticky wicket

Many hospitals across the U.S. are being sued because they have labeled deep tissue injuries (DTIs) as stage I or II pressure ulcers, Dr. Black said. (For more on staging, see Table.) While the latter should heal in a couple of days once pressure is removed, DTIs will not, and patients end up with amputated legs and diverting colostomies that attorneys claim resulted from poor care, Dr. Black said.

The problem with DTIs is that by the time they are detected—through the appearance of purple or maroon localized areas of discolored intact skin, or blood-filled blisters—the areas of the body can't always be rescued, Dr. Black said. DTIs come from fracture damage to muscle cells; the injury is to the muscle-bone interface, not just the skin, she said.

“What you are seeing on the skin is reflected, poorly perfused skin lying over the top of very damaged purple tissue,” she said.

Often, a DTI was precipitated by an event outside the hospital. Dr. Black has noticed that a pressure event usually precedes development of a DTI's purple tissue by about 48 hours.

“For the other 47 hours, the tissue looked normal, then the purple tissue appeared. So, 48 hours ago, Martha was on the kitchen floor, then she came into our facility looking fine, then the day after admission she has these purple pressure ulcers that look hospital-acquired, but they are not,” Dr. Black said.

Such cases illustrate the importance of taking a careful patient history—in this case, the causative factor is that the patient was on the kitchen floor 48 hours ago.

Clinicians should also note the position a patient was in when she was found. Patients who were face down don't tend to develop DTIs, while those on their back do, particularly on the buttocks and heel, Dr. Black said.

A deep tissue ulcer that developed in the operating room The location of the ulcers lateral to the gluteal cleft only occurs in patients who are flat on a surface said Joyce Black PhD RN Photo co
A deep tissue ulcer that developed in the operating room. The location of the ulcers lateral to the gluteal cleft only occurs in patients who are flat on a surface, said Joyce Black, PhD, RN. Photo courtesy of Dr. Black.

Hospitalists may, in some cases, be able to catch a DTI before it worsens. DTIs are sometimes preceded by skin that is painful, mushy, boggy, and/or warmer or cooler than the adjacent tissue. DTIs often evolve from looking like a bruise to resembling a thin blister over a dark wound bed covered by thin or thick eschar to exposing additional layers of tissue, she said.

Differentials for DTIs include the purple skin and epidermal slough that can appear directly over a hematoma (history is important in making this distinction); the purple skin that develops from venous engorgement, but changes colors when the patient is moved; the bruising that occurs from blunt trauma; and the ulcers that can form on peripheral tissue from prolonged hypotension and use of norepinephrine bitartrate (Levophed). They could also be Kennedy terminal ulcers: necrotic, superficial ulcers of unknown etiology that develop rapidly about 48 hours before death, Dr. Black said.

“What we know about DTIs is this: The location is always on the tissue on the side where there has been pressure. We know there is an approximately 48-hour delay in timing from the pressure to the appearance of the injury. We know they are not red but maroon or purple, and we know they rapidly deteriorate,” she said. “That makes them a unique pressure ulcer.”

Treat it right

For DTIs, the first step in treatment is to completely relieve pressure from all areas of purple skin through the use of side-to-side turning, support surfaces (like a low air-loss bed surface), and putting heels in boots. MIST Therapy®—a noncontact ultrasound delivered through saline mist—has been shown to work, as well. There is no evidence supporting early debridement of purple tissue, hyperbaric oxygen therapy, or any type of topical treatment, she said, although adherent eschar or wet necrosis of overlying tissue are indications for surgical debridement.

Stage II ulcers, which are open wounds without slough, can be dressed, although topical skin ointments work well on their own, she said.

“We aren't dressing a lot of stage IIs where I'm from,” Dr. Black said. “The dressings don't stay on, they tend to peel, and if the patient is incontinent it gets under the dressings.”

Stage III ulcers are open ulcers with slough confined mostly to the wound bed; they heal by granulation tissue, “so if you see granulation tissue, it's a stage III,” Dr. Black said. To keep the tissue robust and healthy, use a dressing to absorb the drainage, like foams and alginates, she said. “What we are seeing today is almost all pressure ulcers that are full-thickness (stage III) have biofilms,” Dr. Black said. “The recommended treatment for biofilms are the silvers, the honeys and the cadoxemer iodine, with the latter being the most potent.”

Deep tissue injury of the heel after lying on a concrete floor for an unknown amount of time Photo courtesy of Joyce Black
Deep tissue injury of the heel after lying on a concrete floor for an unknown amount of time. Photo courtesy of Joyce Black.

Stage IV ulcers are wounds in which bone, tendon and muscle are visible. These require more aggressive debridement, though stable eschar in an ischemic limb shouldn't be debrided or softened, she warned. “The body can't really keep the eschar intact, so don't create an open wound that the patient doesn't have the blood flow to heal,” Dr. Black said.

The dressings for stage IV ulcers are the same as for stage III, she said. Clinicians should consider changing the bed a patient is lying on, or the chair cushion he or she is sitting on; these may be creating pressure that aggravates the wound, she said. It's also important to rule out osteomyelitis, she said.

For all the staged ulcers, clinicians should move the patient so he isn't sitting on the ulcer—get a chair cushion if the ulcer is on the buttocks, or turn the patient from side to side if he is on bed rest. Nutritional intake should be examined to make sure it's adequate. “For pressure ulcers I look at three things: what is being done for the wound, the bed the patient's on, and what she is being fed,” because diet is important for healing, Dr. Black noted.

Consider incontinence issues, too. While many patients are on Foley catheters for urinary incontinence, it's actually fecal incontinence that's the bigger problem. “We've got the tubes in the wrong places. Urinary incontinence is a nuisance, but it's not the culprit in terms of contaminating ulcers,” Dr. Black said.

For unstageable ulcers, the general rule is that they can be debrided if there is eschar or slough—as long as they're not on an ischemic limb. For dry hard eschar with stable tissue, a sharp debride is ideal, while cross hatching is of questionable value, she said. As an alternative, collagenase (Santyl) works but takes two weeks before debridement, “so you need to think about whether this is a wound a patient can live with for two weeks,” Dr. Black said.

In those with soft eschar on a stable wound, it's best to debride with honey and silver dressings and the enzymatics. Wet to dry or wet to moist dressings are not ideal here, she added: “You pack a wet to dry in and pull it out, and you pull out everything—granulation tissue, slough…you pull out the good with the bad.”

In unstageable ulcers where there is soft, slimy eschar with erythematous tissue, “call a surgeon,” she said.