Background

Uninterrupted pressure exerted on the skin, soft tissue, muscle, and bone can lead to the development of localized ischemia, tissue inflammation, shearing, anoxia, and necrosis. Pressure ulcers affect up to three million adults in the United States. Areas of the body prone to the development of pressure ulcers are depicted in Figure 1. Estimates of the incidence of pressure ulcers vary according to the setting, with ranges of 0.4 to 38.0 percent in acute-care hospitals, 2.2 to 23.9 percent in long-term nursing facilities, and 0 to 17 percent in home care.1,2 A review of international pressure ulcer prevalence surveys found an overall prevalence in acute and long-term care settings of 9.2 to 11.1 percent between 1989 and 1995 and a prevalence of 14.7 to 15.5 percent between 1999 and 2005.3

Figure 1 is an illustration of a human body in outline form, lying prone with common pressure ulcer sites indicated by red spots. Common sites indicated include the back of the head, shoulder, elbow, tailbone, hip, buttock, thigh, knee, ankle, toe and heel.

Figure 1

Common pressure ulcer sites.

Pressure ulcer healing rates – which are dependent on comorbidities, clinical interventions, and severity of the ulcer – vary considerably. Ulcer severity is assessed using a variety of different staging or grading systems; the United States National Pressure Ulcer Advisory Panel (NPUAP) staging system is the most commonly used (Figure 2). Comorbidities predisposing toward pressure ulcer development and affecting ulcer healing include those affecting patient mobility (e.g., spinal cord injury), wound environments (e.g., incontinence), and wound healing (e.g., diabetes, vascular disease). Delayed healing can add to the length of hospitalization and impede return to full functioning.2 Data on the costs of treatment for a pressure ulcer vary, but some estimates range between $37,800 and $70,000 per ulcer, with total annual costs for pressure ulcers in the United States as high as $11 billion.1,4 Pressure ulcers are used as an indicator of quality for long-term care facilities, and progression of pressure ulcers in hospitalized patients is often considered an avoidable complication representing failure of inpatient management.

Figure 2 depicts the NPUAP pressure ulcer stages I – IV with descriptions of the stages and an image of each type of ulcer: Stage I is described as intact skin with non-blanchable redness of a localized area usually over a bony prominence. Darkly pigmented skin may not have visible blanching; its color may differ from the surrounding area. Stage II is defined by a partial thickness loss of dermis presenting as a shallow open ulcer with a red pink wound bed, without slough. It may also present as an intact or open/ruptured serum-filled blister. Stage III is defined by full thickness tissue loss. Subcutaneous fat may be visible but bone, tendon or muscles are not exposed. Slough may be present but does not obscure the depth of tissue loss. This may include undermining and tunneling. Stage IV is defined by full thickness tissue loss with exposed bone, tendon or muscle. Slough or eschar may be present on some parts of the wound bed. Stage four ulcers often include undermining and tunneling. Two additional categories are listed with text descriptions: Suspected Deep Tissue Injury is defined by a purple or maroon localized area of discolored, intact skin or blood filled blisters due to damage of the underlying soft tissue from pressure and/or shear. Unstageable is defined by full thickness tissue loss in which the base of the ulcer is covered by slough in the wound bed.

Figure 2

National Pressure Ulcer Advisory Panel pressure ulcer stages. a Not pictured. NPUAP copyright, photos used with permission

Given the negative impact pressure ulcers have on health status and patient quality of life, as well as health care costs, treatments are needed that promote healing, shorten healing time, minimize the risk of complications, and increase the likelihood of complete healing. Pressure ulcer treatment involves a variety of different approaches, including interventions to treat the conditions that give rise to pressure ulcers (support surfaces and nutritional support), interventions to protect and promote healing of the ulcer itself (wound dressings, topical applications, and various adjunctive therapies including vacuum-assisted closure, ultrasound therapy, electrical stimulation, and hyperbaric oxygen therapy), and surgical repair of the ulcer.1,4 Most ulcers are treated using a combination of these approaches. Standards of care for pressure ulcer treatment are typically guided by clinical practice guidelines, such as those developed by the NPUAP, but also vary by patient-related factors such as comorbidities and nutritional status,5 local practice patterns, and the stage and features of the wound. Current guidelines primarily reflect expert opinions. An examination of the comparative effectiveness and harms of the wide variety of different therapies and approaches to treating pressure ulcers is important to guide clinical practice.

Scope and Key Questions

This topic was selected for review based on two separate nominations that also included questions related to risk assessment and prevention of pressure ulcers. This report addresses the comparative effectiveness of various pressure ulcer treatment approaches while the topic of prevention, including secondary prevention of recurrent pressure ulcers, is addressed in a companion report. Both reports are intended to serve as the foundation for the development of updated guidelines on pressure ulcer prevention and treatment.

The key questions were developed with input from Key Informants, including clinicians, wound care researchers, and patient advocates. The analytic framework and key questions used to guide this report are shown below (Figure 3). The analytic framework shows the target populations, interventions, outcomes, and harms that we evaluated.

Figure 3 is an analytic framework which lists experiences that individuals undergo while undergoing treatment for pressure ulcers. The framework includes four headers: population, treatment, harms, and outcomes. The patient population of interest is adults with pressure ulcers. The treatment is for pressure ulcers and includes interventions such as support surfaces, nutritional support, local wound care applications, surgical interventions, and adjunctive therapies. The outcomes are complete wound healing, wound surface area, healing time, pain, prevention of sepsis, prevention of osteomyelitis, and recurrence rate. For harms, treatment complications include pain, dermatologic complications, bleeding, and infection.

Figure 3

Analytic framework: Pressure ulcer treatment strategies.

The general categories of treatment included in this report are support surfaces, nutritional supplements, local wound applications (including wound dressings, topical therapies, and biological agents), surgical procedures, and various adjunctive therapies. Other facets of pressure ulcer care (e.g., repositioning, nonsurgical wound debridement, and wound cleansing) were not considered areas where comparative effectiveness evidence was likely to be found or to significantly influence clinical care. We evaluated the evidence on comparisons within the general categories (for example, comparisons between two types of dressings). We also sought direct evidence on comparisons across the general categories (for example, dressings vs. support surfaces). This review also included an assessment of adverse effects or harms associated with pressure ulcer treatment, such as dermatologic complications, bleeding, pain, or infection. Finally, we included an assessment of future research needs on this important clinical topic.

Key Question 1. In adults with pressure ulcers, what is the comparative effectiveness of treatment strategies for improved health outcomes including but not limited to: complete wound healing, healing time, reduced wound surface area, pain, and prevention of serious complications of infection?

Key Question 1a. Does the comparative effectiveness of treatment strategies differ according to features of the pressure ulcers, such as anatomic site or severity at baseline?

Key Question 1b. Does the comparative effectiveness of treatment strategies differ according to patient characteristics, including, but not limited to: age, race/ethnicity, body weight. specific medical comorbidities, and known risk factors for pressure ulcers, such as functional ability, nutritional status, or incontinence?

Key Question 1c. Does the comparative effectiveness of treatment strategies differ according to patient care settings such as home, nursing facility, or hospital, or according to features of patient care settings, including, but not limited to, nurse/patient staffing ratio, staff education and training in wound care, the use of wound care teams, and home caregiver support and training?

Key Question 2. What are the harms of treatments for pressure ulcers?

Key Question 2a. Do the harms of treatment strategies differ according to features of the pressure ulcers, such as anatomic site or severity at baseline?

Key Question 2b. Do the harms of treatment strategies differ according to patient characteristics, including: age, race/ethnicity, body weight, specific medical comorbidities, and known risk factors for pressure ulcers, such as functional ability, nutritional status, or incontinence?

Key Question 2c. Do the harms of treatment strategies differ according to patient care settings such as home, nursing facility, or hospital, or according to features of patient care settings, including, but not limited to, nurse/patient staffing ratio, staff education and training in wound care, the use of wound care teams, and home caregiver support and training?

Population and Conditions of Interest

The population studied was adults ages 18 and older with a pressure ulcer. Patients with pressure ulcers usually also have limited or impaired mobility and suffer from other chronic illnesses. Pressure ulcers are most common in the elderly or people with spinal cord injuries or other conditions that restrict mobility. Patients with nonpressure-related ulcers, including, but not limited to, venous ulcers and diabetic foot ulcers, were excluded because treatment considerations for these patients may differ significantly from those for pressure ulcers. A systematic review of treatment for chronic venous ulcers, sponsored by the Agency for Healthcare Research and Quality (AHRQ), is in progress. We excluded children because this topic was originally nominated and scoped for adults.a Key Informants agreed with the broadly defined proposed population of interest as “adults with pressure ulcers.” They endorsed the proposed list of included patient characteristics that should be considered, but they also noted that “adults with pressure ulcers” are a heterogeneous group and that variability in the comparative effectiveness of pressure ulcer treatments may be related to a large number of patient characteristics. In addition to age, sex, race/ethnicity, socioeconomic status, and diverse specific medical comorbidities (e.g., diabetes, end-stage renal disease, and dementia), many informants suggested that we include specific known risk factors for pressure ulcers (e.g., nutritional status, incontinence, peripheral vascular disease, mobility limitations, and functional ability). See Appendix B for detailed inclusion and exclusion criteria.

Interventions and Comparators

Various treatment strategies for pressure ulcers were addressed, including, but not limited to, therapies that address the underlying contributing factors (e.g., support surfaces and nutritional supplements), therapies that address local wound care (e.g., wound dressings, topical therapies, and biological agents), surgical repair, and adjunctive therapies (e.g., electrical stimulation). The comparative effectiveness and harms of other interventions (e.g., repositioning, wound debridement, and wound cleansing) were considered but not reviewed, based on input from the Technical Expert Panel (TEP) that these modalities were either considered standard care or lacked comparative studies.

Combined treatment modalities (cointerventions), such as comparison of two treatments in combination compared with a single treatment, were also evaluated.

Comparators included placebo or active control, usual care, or other interventions. In some cases, particularly in older studies, newer interventions were compared to older ones that might no longer be considered standard care in the field. However, in many care settings these applications (e.g., gauze dressings, standard hospital beds) are still used, and we therefore included studies using those types of comparators because of their continued relevance in some treatment settings.

Outcomes

The most commonly examined outcomes were various measures of wound improvement. Some studies examined complete wound healing as the primary outcome, though many studies evaluated wound size reduction. Based on input from the TEP, we considered complete wound healing to be the principal health outcome of interest. However, we also considered other indicators of “wound improvement” in synthesizing evidence. Notably, many studies reported findings in terms of wound size reduction rather than complete wound healing. We considered wound size reduction to be an important outcome for two reasons. First, it represents a necessary intermediate step towards the principal outcome of complete wound healing (i.e., complete wound healing can be considered 100 percent wound size reduction). Second, the likelihood of complete wound healing is lower for larger or higher-stage ulcers and therapies deployed for more advanced ulcers may not be expected to achieve complete wound healing over the course of several weeks, which was the duration of most of the studies in our review. Thus, in summarizing the evidence about a given treatment, we considered wound size reduction to be part of the continuum of the outcome of “wound healing,” but we gave more weight to evidence of complete wound healing. Some studies used composite outcome measures commonly used to monitor pressure ulcer status. The Pressure Ulcer Scale for Healing (PUSH) tool combines wound surface area, amount of wound exudate, and tissue appearance.6 The Pressure Sore Status Tool (PSST) considers multiple ulcer characteristics including dimensions, exudate, and tissue appearance.7 Other studies reported outcomes in terms of wound healing rate. We included these outcomes, when reported in studies, as indicators of “wound improvement” but prioritized findings for complete wound healing, as noted above, based on feedback from the TEP. Other outcomes included wound healing rate and time, pain, and avoidance of serious complications of infection. For harms of treatment, we evaluated pain, dermatologic complications, bleeding, infection, and other adverse outcomes as reported in identified studies.

Timing

We did not apply minimum followup duration for studies.

Setting

Settings included patient care settings, such as home, nursing facility, or hospital.

Footnotes

a

Although treatment approaches for children with pressure ulcers may be similar to those for adults, other factors may influence the effectiveness differently in this population, including setting, caregiver attention, healing potential, and comorbidities.