ADVERTISEMENT
A Study to Compare a New Self-Adherent Soft Silicone Dressing with a Self-Adherent Polymer Dressing in Stage II Pressure Ulcers
Pressure ulcers are a common and painful problem among the elderly. Despite progress in prevention, many patients still develop pressure ulcers, and managing these wounds remains a challenge to healthcare professionals.
Most wound management products are designed to achieve a number of goals. Many provide a moist environment in order to promote healing.1,2 An effective dressing should absorb large amounts of exudate and stay in place a reasonable length of time. Another important aspect of dressing performance is minimizing pain and trauma to the wound and surrounding skin on removal. Dressing removal is a major challenge for the clinician when the patient's skin is fragile and easily broken, especially around sacral pressure ulcers in elderly patients where body fluids (often due to incontinence) and/or microbial proliferation can damage the surrounding skin. In addition, removing a dressing with a strong adhesive can damage the surrounding skin, be painful, and cause new wounds. A variety of techniques has been used to protect and treat periwound skin, including skin barriers, powders, pastes, and skin sealant. Analgesia is sometimes given to reduce the procedural pain of dressing changes.
One traditional approach to producing adhesive dressings involves use of an adhesive plaster that makes contact only with the peaks of the skin. However, when dressings coated with these adhesives are removed from the skin, the adhesion threshold is reached and a layer of epidermal cells is peeled off. The hydropolymer dressing, like many adhesive dressings, consists of an adhesive that may remove epithelial cells when the dressing is changed.3
A new dressing, with an adhesive technology consisting of a soft silicone layer that adheres to the surrounding skin but does not stick to the moist wound (silicone is hydrophobic), has been developed. The soft silicone layer is more flexible than other wound dressing adhesives and moves into the uneven skin surface to create a larger effective contact area with the skin. As a result, less adhesion force per square millimeter is needed with a level of adhesion that is comparable to traditional adhesive dressings. When the same peeling force is applied, the soft silicone will distribute the forces over a larger area of skin under the dressing. This means that dressings with what has been termed atraumatic soft silicone technology cause significantly less epidermal stripping on removal than dressings with other adhesive technologies.3 To compare the new self-adherent soft silicone dressing to a commonly used hydropolymer dressing in the treatment of Stage II pressure ulcers, an open, randomized, controlled clinical study was conducted.
Methods
Participants. Study participants were recruited among inpatients at three nursing homes linked to hospital departments - one in Paris, France, one in Antwerp, Belgium, and one in Pisa, Italy. Eligible patients were adults aged 65 years or older with a Stage II pressure ulcer stage determined according to the European Pressure Ulcer Advisory Panel (EPUAP),4 a Modified Norton scale5 score of 11 or above, and a red/yellow wound according to the Red-Yellow-Black System.6 The EPUAP defines a Stage II pressure ulcer as a partial-thickness skin loss involving the epidermis, dermis, or both. The ulcer is superficial and presents clinically as an abrasion, blister, or shallow crater. The Modified Norton Scale contains the following variables: mental condition, activity, mobility, food intake, fluid intake, incontinence, and general physical condition. Each of these seven variables receives a rating of between one (lowest level of functioning) and four (highest level of functioning). The Red-Yellow-Black system describes the wound bed based on the continuum of the wound healing process. Wounds can be in the inflammatory (reaction) phase, proliferation (regeneration), or maturation (remodeling) phase of wound healing. Yellow wounds are infected or contain fibrinous slough and are not ready to heal. Black wounds contain necrotic tissue (eschar) and also are not ready to heal.
Patients were excluded from this study if they suffered from an underlying disease that, according to the investigator, might possibly interfere with the treatment of the pressure ulcer. Patients also were not eligible to participate if they had a food and/or fluid intake score of 2 or below on the Modified Norton Scale5; allergic/hypersensitivity problem with any material in the two dressings; a wound larger than 11 cm x 11 cm; or a wound with black necrotic tissue or clinical signs of local infection at baseline. Only pressure ulcers that did not improve during the preceding 4 weeks were included in the study.
Study design. The study was performed in accordance with the ethical principles set forth in the Declaration of Helsinki and was approved by local ethics committees. Written or witnessed informed consent was obtained from all patients.
Participants were randomly assigned to one of the two treatment options by a predetermined computer-generated randomization list stratified by study center, and the block size was unknown to the investigators. Each center received numbered, sealed envelopes to be opened in consecutive order. The study was not blinded because dressing differences make blinding difficult to achieve.
Interventions. Participants were randomized to treatment either with the new dressing containing silicone, polyurethane foam, and polyacrylate fibers (Mepilex® Border, Mölnlycke Health Care AB, Sweden) (size 10 cm x 10 cm or 15 cm x 15 cm) or a hydropolymer dressing containing polyurethane foam, a nonwoven layer, and polyurethane backing (Tielle™, Johnson + Johnson Medical, England) (size 11 cm x 11 cm, 15 cm x 15 cm, or 18 cm x 18 cm). If necessary, extra fixation (Mefix®/Mefilm®, Mölnlycke Health Care AB, Sweden) could be used, as could a hydrating gel (Normlgel®, Mölnlycke Health Care AB, Sweden). The study protocol followed manufacturer instructions for removal of the hydropolymer dressing with water. Dressings were changed at least once a week or more frequently as needed. If the pressure ulcer was highly exudating in the initial period, the dressing was changed more frequently to avoid leakage.
Endpoints. The patients were evaluated at baseline and weekly for 8 weeks or until completely healed. Several efficacy endpoints were assessed: wound size, granulation, epithelialization, exudate, signs of inflammation, damage to tissue (bed, edge, surrounding skin), maceration, odor, leakage, number and ease of dressing changes, and the use of offloading devices. Damage to tissue was defined as any damage to the wound bed, edge, or surrounding skin caused by the adhesive; maceration was defined as the softening and breaking down of skin resulting from prolonged exposure to moisture.7
Wounds were traced to determine size. Other wound variables were assessed as present or absent. If present, some variables were sub-classified - eg, amount of exudate was assessed as low, moderate, or high, and granulation tissue was classified as covering 0% to 25%, 26% to 50%, 51% to 75%, or 76% to 100% of the wound bed. Surrounding skin damage was described as redness, blisters, or other. Dressing removal was rated as very easy, easy, minor difficulties, or difficult. The dressings were removed and the wound assessments were made by the same healthcare professional (a physician or a nurse) throughout the study. Wound assessments were conducted during the approximately 10-minute interval between removal of the old dressing, wound cleansing, and application of the new dressing.
The safety and tolerance analysis was based on the number of participants reporting one or more adverse events during the course of the study, including the number of participants reporting a serious adverse event, the incidence of events considered to be related to the intervention, and any events that lead to withdrawal from the study.
Statistical methods. Descriptive statistics were used to describe the study population and results. A post-hoc significance test using the Fischer exact test was performed for the damage to tissue variable.
Results
Patients. Thirty-eight (38) patients with Stage II pressure ulcers were enrolled in the study. Of these, 18 were randomized to the soft silicone and 20 to the hydropolymer dressing group. The dressing groups were similar in distribution of patient age and gender (see Table 1). All patients included in the study were Caucasians. Heels and the sacral area were the most frequently observed ulcer locations in both groups.
Nearly all patients used some type of pressure ulcer prevention product or method before and during the study. Most patients reported use of pressure-relieving mattresses; a few patients were managed by position changes and/or the use of heel boots. The distribution of static and dynamic mattresses was similar for both groups. All patients except one had pressure relief for more than 2 hours per day.
Efficacy. Changes in wound characteristics from baseline to the last visit are presented in Table 2.
Wound healing. During the study, eight of the 18 patients treated in the soft silicone dressing group and 10 of the 20 patients in the hydropolymer dressing group healed. Of 10 wounds in the soft silicone dressing group that did not heal, seven improved, two deteriorated, and one patient died after baseline assessments were made. In the hydropolymer dressing group, nine wounds improved and one deteriorated.
The two groups showed no difference in terms of granulation tissue, epithelialization (island and/or the border of the pressure ulcer), or exudate. Signs of inflammation (redness only reported) were reported in a few cases - four in the soft silicone dressing group and three in the hydropolymer dressing group.
Dressing performance. The number of dressing changes during the study was similar in the two groups (7.9 and 8.8, respectively), with dressing changes occurring approximately once every 6 days. Removal of the dressing was reported as very easy or easy for the soft silicone dressing. Only one patient reported minor removal difficulties during the study. Removal also was reported as very easy or easy in the majority of cases with the hydropolymer dressing, with nine patients reporting minor difficulties on 23 occasions.
Figure 1 shows the assessments of tissue damage in general, including edge, bed, and/or surrounding skin of the wound. Two early reports of tissue damage in general were reported in the soft silicone dressing group in weeks 1 and 2. In the hydropolymer dressing group, 32 reports of tissue damage occurred. Two patients had signs of tissue damage at the final visit after 8 weeks.
In most patients, the sign/symptom reported as damage to the surrounding skin was redness. Two patients in the hydropolymer group developed blisters on the surrounding skin and two developed new ulcers. This type of damage was not observed in the soft silicone group (see Figures 2a, 2b, and 2c).
Maceration occurred six times in the soft silicone dressing group, compared to 20 times in the hydropolymer dressing group. Extra dressings and dressing fixation was frequently used in both groups during application and between dressing changes.
Leakage was reported on 13 occasions in the soft silicone dressing group and on 18 occasions in hydropolymer dressing group.
Odor was not a major problem in this study. However, one patient in the hydropolymer dressing group reported a bad odor throughout the study and three reported odor at the final follow-up.
Safety and tolerance. Three patients in the soft silicone dressing group reported four adverse events - one, development of hypergranulation tissue, could be classified as an Adverse Device Effect. Six adverse events in four patients were reported in the hydropolymer group - three could be classified as Adverse Device Effects: hypergranulation tissue formation, new wounds (due to surrounding skin trauma), and redness and irritation.
Three serious adverse events were reported in the soft silicone dressing group; all three were considered to be unrelated to the study dressings. One patient who was in poor general health at baseline died during the study, one suffered a hip fracture, and a third had a pressure ulcer that deteriorated to Stage IV. In the hydropolymer group, two serious, non-dressing related adverse events occurred. One patient died of broncho-pneumonia and another developed symptoms of a heart disorder.
Discussion
Damage to the surrounding skin is an important concern for patients with pressure ulcers. The skin around pressure ulcers in elderly patients is very fragile. With aging, the skin (epidermis) becomes thinner and dryer.8 Dermal collagen is also decreased, resulting in wrinkling and translucency.9 These changes are thought to make the skin more susceptible to injury.10
Research has traditionally focused on healing as the principal outcome of wound management at the expense of other important patient-centered outcomes such as pain and other quality-of-life issues.11 It has been suggested that more attention should be paid to wound product evaluations and surveys involving characteristics such as pain, maceration, trauma, and comfort.12,13 A survey of 3,918 practitioners from 11 countries14 showed that the majority considered trauma prevention the most important factor to consider when changing dressings, and pain prevention was the second most important consideration. Adherent products were considered the most important contributory factor to trauma at dressing changes.
Two previous investigations with another atraumatic dressing featuring the same adhesive technology noted a significant decrease in pain and trauma at dressing changes compared with paraffin gauze.15,16 The results of this study, evaluating tissue damage in general, support the impression that the new soft silicone technology is superior to traditional adhesive dressings in these respects.
Other study variables were not found to differ between groups, but the small sample size provides limited power to detect any significant differences. Another limitation of this study is the open design, which may increase the risk of bias in the assessments of wound characteristics.
Conclusion
The results of this exploratory study indicate that the soft silicone dressing is superior to dressings using traditional adhesives technologies with regard to tissue damage and ease of dressing changes and similar to other dressings in other respects. These findings need to be confirmed in other controlled studies.
1. Winter GD. Effect of air-drying and dressings on the surface of wounds. Nature. 1963;197:91-93.
2. Dyson M, Young S, Pendle CL, et al. Comparison of the effects of moist and dry conditions on dermal repair. J Invest Dermatol. 1988;91:434-439.
3. Dykes P. Effect of adhesive dressings on the stratum corneum of the skin. Journal of Wound Care. 2001;10:2:7-10.
4. European Pressure Ulcer Advisory Panel (EPUAP). Classification of pressure ulcers (leaflet from the panel). Available at www.epuap.org. Accessed August 1, 2003.
5. Ek AC, Bjurulf P. Inter-rater variability in a modified Norton scale. Scandinavian Journal of Caring Sciences. 1987;1:3-4:99-102.
6. Krasner D. Wound care: how to use the red-yellow-black system. Am J Nurs. 1995;May:44-47.
7. Cutting KF, White RJ. Maceration of the skin and wound bed 1: its nature and causes. Journal of Wound Care. 2002;11:275-278.
8. Carter DM, Balin AK. Dermatological aspect of aging. Med Clin North Am. 1983;67:531-543.
9. Kligman AM. Perspectives and problems in cutaneous gerontology. J Invest Dermatol. 1979;73:39-46.
10. Gilchrest BA. Age associated changes in the skin. J Am Geriatr Soc. 1982;30:139-143.
11. Royal College of Nursing. Clinical practice guidelines. The management of patients with venous leg ulcers. Royal College of Nursing;1998. Available at: http:/www.rcn.org.uk. Accessed August 1, 2003.
12. Nielsen A. Management of wound exudate. Journal of Community Nursing. 1999;13:27-34.
13. Martini L, Reali UM, Borgognoni L, et al. Comparison of two dressings in the management of partial thickness donor sites. Journal of Wound Care. 1999;8:457-460.
14. Moffat CJ, Franks P, Hollinworth H. Understanding wound pain and trauma: an international perspective. In: EWMA Position Document: Pain at Wound Changes. London, UK: Medical Education Partnership; 2002:2-7.
15. Platt Phillips AJ, Judkins K. A comparative study of silicone net dressing and paraffin gauze dressing in skin-grafted sites. Burns. 1996; 22:7:543-545.
16. Dahlstrom, KK. New silicone rubber dressing used as a temporary dressing before delayed split skin grafting. Scand J Plast Reconstr Hand Surg. 1995;29:325-327.
