​​Bac​​​kground

Pressure Inj​uries

Chronic wounds have a biologic or physiologic reason for not healing and have not completed the healing process in the expected period or have proceeded through the healing phase without reaching the expected functional result. These wounds usually do not close without intervention and are sometimes unresponsive to healing interventions. PIs are skin lesions caused by unrelieved pressure or shear resulting in damage of underlying tissue. Wounds often develop over bony prominences (sacrum, ischium, trochanter, and heel) in wheelchair- or bed-bound patients. Prolonged ischemia in the underlying tissue leads to necrosis and eventually an open wound. Preventing PIs is a primary goal in any at-risk patient. (See the UptoDate articles Overview of Treatment of Chronic Wounds and Clinical Staging and General Management of Pressure-Induced Skin and Soft Tissue Injury and the Medscape article Chronic Wounds.)

Standard of care or usual care for established PIs typically depends on the ulcer's stage and includes pressure relief using support surfaces and skin protection to prevent ulcer progression to advanced stages, nutritional assessment, infection control, debridement of necrotic tissue in advanced stages (stage 3 and 4 ulcers), wound cleansing/irrigation, and use of dressings that promote a moist wound environment and absorb exudate. Stages 1 and 2 pressure ulcers usually undergo conservative therapy, and stages 3 and 4 may require surgical intervention. PI healing is judged by wound closure typically after 12 weeks (percentage of wounds completely healed/epithelialized), wound area reduction in 12 weeks, amount of exudate still present, and wound infections during the treatment period. (See the UptoDate article Clinical Staging and General Management of Pressure-Induced Skin and Soft Tissue Injury.)

Wound Dre​ssings

Wound dressings assist wound healing by eliminating dead space, controlling exudate, preventing bacterial overgrowth, providing a moist wound environment, and being cost-effective and easy to use. (See the UptoDate article Basic Principles of Wound Management.) Dressings that retain moisture, such as hydrocolloids and alginates, will also provide for autolytic debridement. Antibiotic-containing dressings are intended only for infected wounds. No single dressing is best for all wounds, and clinicians must match the dressing to the individual's wound. Excessive moisture needs to be wicked away to prevent skin maceration, while dry wounds may need additional moisture. (For additional information on wound dressings, see the article by Weller et al. [2020]. WoundSource provides a list of wound dressings and their manufacturers.)

Fil​m

Film dressings are transparent, synthetic, self-adhesive sheets that allow gases, including oxygen and water vapor, to pass through the sheet but maintains a barrier to proteins and bacteria. These dressings have limited absorptive ability and are not appropriate for moderately to heavily exudative wounds and are often used to cover other dressings. Film dressings include Tegaderm Transparent Film Dressing (3M, Saint Paul, MN, USA), Opsite Film Dressings (Smith & Nephew, London, UK), and Kendall Transparent Film Dressing (Cardinal Health, Dublin, OH, USA).

F​oam

Foam dressings have two layers, a hydrophilic silicone or polyurethane-based foam inner layer and a hydrophobic, gas-permeable outer layer. The foam collects exudate and outer layer prevents leakage and bacterial contamination. Foam dressings may be used to pack wound cavities but may need to be changed daily. They are not intended for minimally exuding wounds. Foam dressings include 3M Tegaderm Silicone Foam Dressing, Aquacel Foam Dressing (Convatec, Bridgewater, NJ, USA), Allevyn (Smith & Nephew), Kendall Foam Dressing, and Mepilex Border Flex (Mölnlycke Health Care US, Peachtree Corners, GA, USA).

Calcium ​Alginate

Alginates are natural polysaccharide complexes formed from algae. In the wound bed, the polysaccharide exchanges calcium ions for sodium ions from the wound and forms a gel, making them excellent dressings for moderately to heavily exudative wounds. Alginates may be used for wound packing, can stay for several days, and washed out with normal saline, which reduces pain caused by dressing changes. They require a secondary dressing and are not used on minimally exudating wounds. Alginate dressings include Tegaderm High Integrity Alginate Dressing, Algicell Alginate Wound Dressing (Derma Sciences, Princeton, NJ, USA, originally from Integra LifeSciences Corp.), Kaltostat (Convatec), Algisite M Calcium Alginate Dressing (Smith & Nephew), and Kendall calcium alginate dressings.

Hydrocollo​id

Hydrocolloid d​ressings c​ontain gel-forming agents attached to a polyurethane film. The colloid portion absorbs exudate to form a gel and create a moist wound environment. Bacteria and debris are trapped and removed during dressing changes. Hydrocolloid dressings may need to be changed daily, and some individuals may develop contact dermatitis. Hydrocolloid dressings include: Tegaderm Hydrocolloid Dressing, DuoDerm CGF Border Dressing (Convatec), Comfeel Plus (Coloplast Corp., Minneapolis, MN, USA), and Cardinal Health Hydrocolloids.

Hydr​​ogel

Hydrogels are synthetic polymers with more than 95% water content that are formed into sheets, gels, or foams between two sheets of removable film. These dressing can absorb or release water, depending on the wound's hydration. They are mostly used with dry wounds. Hydrogel dressings include DuoDERM Hydroactive Sterile Gel, Intrasite Gel (Smith a& Nephew), and Kendall hydrogel wound dressings.

Hydrof​iber

Hydrofiber dressings are made from sodium carboxymethylcellulose spun into fibers. These dressings form a gel in contact with wound fluid and are more absorbent than alginates. They aid in autolytic debridement, are nonadherent, and require a secondary dressing cover. Hydrofiber dressings include Aquacel Extra Hydrofiber dressing (Convatec), DuraFiber gelling fiber dressing (Smith & Nephew), and Exufiber (Mölnlycke Health Care US).

Coll​agen

Collagen is an animal protein that makes up a large portion of connective tissue. Type 1 collagen is most often used in collagen dressings and is obtained from bovine, ovine, or porcine sources. (For additional information, see the article by Wu et al. 2017.) Collagen dressings include Fibracol Plus Collagen Wound Dressing with Alginate (3M) and Puracol Plus Microscaffold collagen (Medline Industries, Inc., Mundelein, IL, USA).

Gau​ze

Cotton gauze dressings are moistened with saline and laid over or packed in the wound. They must be changed several times a day to prevent drying out and adhering to the wound bed. Gauze may also be impregnated with petroleum, paraffin wax, or other ointment, but they do not provide exudate control or maintain a moist wound environment. These products include Adaptic Touch Non-Adhering Silicone Dressing (3M), Dermacea nonadherent dressings (Cardinal Health), and Jelonet (Smith & Nephew).

​Clinical ​​Literature

Search dates: all available literature published from January 1, 2017, through November 30, 2022. We reviewed full text of 7 SRs reporting on 4,287 patients.

We searched PubMed, Embase, and selected web-based resources for documents relevant to this topic. Our search strategies included the following keywords: "wound dressing" AND "pressure ulcer." Please see the Selected Resources and References section for detailed search strategies.

Study selection criteria: We sought SRs that compared advanced wound dressings with other types of advanced or basic dressings and reported on patient-oriented outcomes (e.g., wound healing, exudate control, infection) in patients having a PI and treated with a wound dressing. Because of the large retrieval, we selected the best available evidence and included SRs only.

We identified and reviewed full text of seven published SRs.

Included studies:

• 1 SR (Kamińska et al. 2020, 8 studies, n = 679) assessed hydrocolloid dressings for PI and reported healing.(1)
• 1 SR (Furuya-Kanamori et al. 2019, 40 RCTs, n = 1,757) assessed various topical treatments for PI and reported healing.(2)
• 1 SR (Walker et al. 2018, 9 RCTs, n = 483) assessed foam dressings for PI and reported healing.(3)
• 1 SR (Dissemond et al. 2017, 39 studies; 3 PI studies, n = 180) assessed silver dressing use in various wounds and reported healing.(4)
• 1 SR (Dumville et al. 2015, 6 RCTs, n = 336) assessed alginate dressings for PI and reported wound healing.(5)
• 1 SR (Dumville et al. 2015, 11 RCTs, n = 523) assessed hydrogel dressings for PI and reported healing.(6)
• 1 SR (Zheng et al. 2015, 7 RCTs, n = 329) compared hydrocolloid dressing with saline gauze for PI and reported healing.(7)

See Table 1 for SR summaries. We review full text of the included studies available through open access or our library subscriptions.

We also identified but excluded from review five SRs that meet the inclusion criteria but were superseded by a later and more comprehensive SR.(8-12)

​Findin​​​gs

We assessed seven SRs that addressed advanced wound dressing use for PIs.

• Combined dressing: An SR and network meta-analysis (Furuya-Kanamori et al. 2019) compared advanced dressings with basic dressings (saline gauze or similar inert dressings) and reported that all advanced dressings ranked better than basic dressings.(2) Relative risk for comparing foam with basic dressings was 1.52 (95% confidence interval [CI] 1.01 to 2.28); for hydroactive (hydrocolloid, hydrogel, moisture-retentive dressings), the RR was 1.32 (95% CI 0.78 to 2.25).
• Alginate: An SR (Dumville et al. 2015) reported that alginate dressings were comparable with other advanced wound dressings for complete wound healing and adverse events.(5) Alginate dressings were an effective treatment with similar wound healing responses as other dressings or treatment. One study comparing alginate with hydrocolloid showed no differences in wound healing. Wound reduction at eight weeks was 42.5% for hydrocolloid and 69.1% for alginate. All the evidence was of low or very low quality.
• Foam: An SR (Walker et al. 2018) reported that foam dressings were equal to other advanced dressings for healing (relative risk [RR] 1.00, 95% CI: 0.78 to 1.28) and for time to complete healing, adverse events, and reduction in wound size.(3) The certainty of the evidence was very low.
• Hydrocolloid:
• An SR (Kamińska et al. 2020) reported that hydrocolloid dressings were similar to advanced therapies for healing and adverse events.(1) Hydrocolloid dressings had similar healing rates to other advanced dressings in six studies and superior healing in two studies comparing hydrocolloid with simple gauze dressings.
• An SR (Zheng et al. 2015) of RCTs comparing hydrocolloid dressings with saline gauze reported significantly better healing with hydrocolloid dressings (RR 2.20, 95% CI: 1.21 to 4.02)(7)

• ​​​​Hydrogel: An SR (Dumville et al. 2015) reported hydrogel dressings had similar healing to other dressings (hydrocolloid, foam, and basic wound contact dressing).(6) All included studies were small, had short follow-up times, and were at unclear risk of bias.
  

• ​Silver dressi​​ng: An SR (Dissemond et al. 2017) reported better healing with silver dressings in three studies but did not report study details or the comparison dressings.(4)

Evidence limitations: The potential for heterogeneity across studies due to differences in other PI treatment protocols is a primary limitation with wound dressings SRs. These interventions tend to vary considerably across studies even when they are controlled within studies. Generalization of outcomes becomes problematic if the heterogeneity is too large.

The SRs reported the following limitations: small sample size, differences in study duration, variation in patient inclusion and exclusion criteria, uncontrolled patient variables (age, health, comorbidities, nutritional status, medication use, concurrent treatments, and pressure ulcer history, ulcer cause, size, and location), and variations in healthcare setting and quality.

Additional well-designed and -conducted RCTs will be needed to determine whether any one advanced wound dressing is superior for PI healing.

Table 1. Systematic Reviews on T​reatment

Gui​​delines, Position and Consensus Statements

Searched PubMed, Embase, and ECRI Guidelines Trust® (EGT®) for relevant documents published January 1, 2016, through November 28, 2022. We reviewed eight documents.

We searched ECRI Guidelines Trust® and prominent specialty societies for clinical practice guidelines, consensus statements, and position statements published from January 1, 2016, through November 28, 2022. We sought guidelines that are clearly supported by published SRs or that meet certain U.S. National Academy of Medicine criteria.

Guidelines Supported by Systematic Review

• Health Improvement Scotland. Standards for Prevention and Management of Pressure Ulcers. 2020. The guideline presents information on standards required for prevention and management of PIs but does not provide specific standards for dressing use.
• Japanese Society of Pressure Ulcers. Wound, Pressure Ulcer and Burn Guidelines – 1: Guidelines for Wounds in General, Second Edition. 2020. The guideline provides information on specific dressing types including silver-containing dressings and their use in heavy, moderate to low, and low exudate wounds. The guideline states:
• Treatment of shallow chronic skin wounds - A number of reports have confirmed that occlusive dressing promotes wound healing, and various materials are now in clinical use. As long as the appropriate dressing material can be selected for wound bed preparation and moist wound healing, it will promote wound healing. However, a systematic review reported that no clear wound healing promoting effect was confirmed for dressing materials other than hydrocolloids.
• In the present guidelines, dressing materials refer to modern wound dressing materials that promote a moist wound environment. They exclude conventional sterilized gauze.
• The occlusion of the wound with a dressing material and the creation of a moist environment contribute to wound healing by retaining the cell growth factors and cytokines contained in exudates, by promoting the migration of epidermal cells, and by preventing the spread of, or promoting the autolysis of, necrotic tissue.
• ​​Eur​opean Pressure Ulcer Advisory Panel, National Pressure Injury Advisory Panel, and Pan Pacific Pressure Injury Alliance. Prevention and Treatment of Pressure Ulcers/Injures: Quick Reference Guide. 2019. The guideline has numerous recommendations related to preventing and treating PIs. The full Clinical Practice Guideline includes the SR. ​The guideline made the following primary statements regarding dressings for managing and treating PIs:
• For all [PIs], select the most appropriate wound dressing based on goals and self-care abilities of the individual and/or their informal caregiver and based on clinical assessment, including: diameter, shape and depth of the [PI], need to address bacterial bioburden, ability to keep the wound bed moist, nature and volume of wound exudate, condition of the tissue in the wound bed, condition of the peri-wound skin, presence of tunneling and/or undermining, and pain. (Hydrocolloid, hydrogel, foam, and polymeric dressings were recommended for non-infected stage II [PIs]; hydrogel, calcium alginate, and foam dressings were recommended for non-infected stage III and IV pressure injuries depending on the level of exudate; super-absorbent wound dressings were recommended for heavily exuding pressure injuries.)
• Consider applying collagen dressings to nonhealing pressure injuries to improve rate of healing and decrease signs and symptoms of wound inflammation.
  ​
• Japanese Society of Pressure Ulcers. Wound​​, Pressure Ulcer and Burn Guidelines - 2: Guidelines for the Diagnosis and Treatment of Pressure Ulcers, Second Edition. 2018. The guideline's goals are “systematically presenting evidence-based recommendations to support clinical decisions in the prevention, care and treatment of pressure ulcers, serving as a tool for improving the quality of diagnosis and treatment of pressure ulcer patients, and improving the care for pressure ulcers in Japan as a whole." The guideline designated recommendations as 1 (strong) and 2 (weak) and strength of evidence as A (strong evidence), B (moderate evidence), C (weak), and D (very weak). The guideline made the following recommendations:
• If dressing materials are to be used in the acute phase, those that allow observation of the wound surface such as polyurethane film (1D) and hydrocolloids (1D) are recommended.
• Careful observation of the systemic condition and course of the lesion with local decompression, polyurethane film, and translucent hydrocolloid dressings (1D).
• Protection of the wound while maintaining an appropriate moist environment is necessary for the cure of shallow pressure ulcers within the dermal level (erosion, shallow ulcers). Therefore, dressing materials often play a primary role in treatment. Hydrocolloids (1A), hydrogels (1B), polyurethane foam (1B) and chitin (1C) are recommended.
• For dried necrotic tissue, the use of silver sulfadiazine (1D) is recommended. Among dressing materials, the use of hydrogels (1B) is recommended.
• For dressing material when wound infection is localized, we recommend the use of silver-containing Hydrofiber (1A), silver-containing polyurethane foam (1A) and silver-containing alginate (1A).
• When there are excessive exudates, highly absorbent alginate (1A), polyurethane foam (including silver-containing preparations) (1A), chitin, Hydrofiber (including silver-containing preparations) (1C), hydropolymer (1C) and polyurethane foam/soft silicone (1D) are recommended.
• The use of hydrogels (1B) is recommended when dried necrotic tissue has adhered to the wound and exudate levels are low.
• The use of hydrocolloids (1A), hydrogels (1B), hydropolymer (1B), polyurethane foam (1B) and polyurethane foam/soft silicone (1B) is recommended for wound surfaces with appropriate to deficient exudates. The use of alginate (1C) or chitin (1C) is recommended for wound surfaces with excessive exudates or marked edema.
• The use of drugs such as anti-inflammatory analgesics and psychotropic drugs (2C), body pressure-dispersion beds (2C) and dressing materials (2C) is proposed as options for alleviating pain in pressure ulcers. Dressings that are less prone to causing pain include those made from soft silicone, hydrogels, hydrofiber, and alginate.
• ​​Eur​opean Union Seventh Framework Program. Non-pharmacological Interventions to Prevent or Treat Pressure Ulcers in Older Patients: Clinical Practice Recommendations. 2016. This document contains recommendations for non-pharmacological interventions for older subjects at risk of developing [PIs], as well as for older subjects with [PIs].

• ​R​egistered Nurses' Association of Ontario. Assessment and Management of Pressure Injuries for the Interprofessional Team, Third Edition. 2016. The guideline “provides evidence-based practice recommendations for interprofesssional teams across all care settings who are assessing and providing care to people with existing [PI]. A [PI] is defined as “localized damage to the skin and/or underlying soft tissue usually over a bony prominence or related to a medical or other device." The guideline made the following recommendations and statements regarding dressings:

• Wound dressings: silicone, hydrogels, alginates, polymeric membrane foams, and foam dressings require less frequent changes, and cause less pain and trauma on removal.
• Wound dressings: hydrocolloid dressings with aggressive adhesive film dressings and wet-to dry dressings are considered to be painful.
• According to the expert panel and several pressure ulcer/injury guideline groups, the interprofessional team, in collaboration with the person and his/her circle of care, should select a dressing that meets the following criteria: matches the volume of wound exudate, so that the wound bed is kept moist and the peri-wound is kept dry and intact; decreases the frequency of dressing changes, provides thermal insulation and wound temperature stability, protects from contamination by outside micro-organisms, may address bacterial bioburden, and minimizes pain and trauma to the wound bed particularly on application and removal.
• For healable wounds, it is recommended that moisture-retentive dressings be used on stage 2, 3, and 4 pressure injuries.
• A range of moisture-retentive dressings have been studied in the literature, and the following benefits identified.
• Alginate dressings absorb excess wound exudate and keep the wound bed moist. They are available in sheet and rope forms and can be left on pressure injuries for a maximum of several days, depending on the degree of exudate saturation or according to health-care facility/agency policy or the manufacturer's recommendation.
• Collagen dressings bind to wound-bed fluid and metalloproteinases to control wound exudates.
• Foam dressings wick exudate away from the wound bed and move it to the surface of the wound dressing in a fluid balance mechanism that can cause peri-wound maceration. However, superabsorbent dressings can absorb and retain fluid with a “fluid lock."
• Hydrocolloid dressings, which typically consist of materials such as polyisiobutylene, sodium carboxymethylcellulose, gelatin, and pectin, absorb wound fluid and aid in debridement.
• Hydrogel dressings help retain wound-bed moisture and rehydrate tissue.
• Overall, the current literature does not provide confirmatory evidence of the superiority of one moisture-retentive “advanced" wound dressing over another. However, the evidence in general does seem to support the use of advanced rather than simple dressings to support [PI] healing. Thus, because pressure injuries require a moist environment to heal, the expert panel does not recommend dry gauze dressings/modalities.
• Current literature identifies silver as an antimicrobial agent that may provide benefits in the healing of pressure injuries. Silver dressings and creams help control bacterial infection and inflammation, and there is emerging randomized controlled evidence on the effectiveness of silver on [PI] healing rates and improved PUSH scores [Pressure Ulcer Scale for Healing]. There are also reviews that conclude that silver preparations promote faster healing; however, additional research is required to confirm these results.
• Choose dressings that reduce the need for dressing changes (e.g., foam, alginates, hydrocolloids, and hydrogels) or that may be embedded with analgesia or anti-inflammatory medication, including topical opioids, topical anesthetics, or ibuprofen.
  

• ​​​Wound​ Healing Society. Wound Healing Society 2015 Update on Guidelines for Pressure Ulcers. 2016. The guideline stated the following regarding dressings:

• Local moisture balance is necessary to facilitate granulation and reepithelization of the ulcer. A moist wound environment accelerates wound healing with more rapid epithelization.
• Use clinical judgment to select a moist wound dressing. Results from existing studies have not demonstrated any specific moisture retentive topical therapy to be superior in terms of healing rate. Wet-to-dry dressings are not continuously moist and are an inappropriate wound dressing selection. Some dressings can provide both a moist wound environment and decrease bacterial bioburden in the wound.

• ​​​​Wound, Ostomy and Continence Nurses Society (WOCN). WOCN Guideline for Prevention and Management of Pressure Ulcers. 2016. T​he guideline provides specific recommendations for assessment, prevention, and treatment of PIs. The guideline made the following recommendations regarding dressings:

• Consider prophylactic dressings to prevent sacral and heel ulcers in at-risk patients. Level of Evidence = A (Benefit/Effectiveness/Harm = Class I).
  

• Modify the type of dressing as appropriate due to changes in the wound during healing or if the pressure ulcer deteriorates. Monitor and assess the wound on a regular basis and at every dressing change to determine whether the type of dressing is appropriate or should be modified. Level of Evidence = C (Benefit/Effectiveness/Harm = Class I)