Comparison of Two Silver Dressings for Wound Management in Pediatric Burns

Abstract: Purpose. Silver wound dressings are widely used in the treatment of burns. Dressings differ in material characteristics, various antimicrobial activities, and ease of use. The purpose of this study was to evaluate both dressing performance and amount of pain during the dressing changes of 2 silver dressings Urgotul SSD® (Laboratoires Urgo, Chenove, France), and Contreet Ag® (Coloplast, Minneapolis, MN) in children. Methods. A retrospective cohort study was performed with 2 groups of 20 burns treated with Urgotul SSD and Contreet Ag until the wounds were healed or grafted. Seventy dressing changes in the Contreet Ag group and 67 dressing changes in the Urgotul group were evaluated. Every dressing change was assessed regarding the dressing performance (exudate, adherence, bleeding, and dressing application/removal), and pain. Results. Pain was “absent or slight” in 61 (92%) dressing changes with Urgotul SSD, and in 60 (85%) of the dressing changes with Contreet Ag. Dressing application in the Urgotul group was more often “very easy” (n = 33; 49%) or “easy” (n = 32; 48%) than in the Contreet Ag group, “very easy” (n = 25; 35%), and “easy” (n = 42; 60%). Contreet Ag had a greater ability to absorb exudate (“very good” n = 60; 85%, and “good” n = 11; 15%) than Urgotul SSD (“very good” n = 34; 51%, and “good” n = 13; 19%). Conclusion. Urgotul SSD and Contreet Ag are comparable regarding pain during dressing change. The dressings differ in their ability to absorb exudate and ease of application. Both dressings provided nearly painless wound management, and therefore were highly accepted by the nurses and especially the children being treated.

Address correspondence to:
Ingo Jester, MD
Department of Paediatric Surgery
Birmingham Children’s Hospital
Steelhouse Lane
Birmingham B4 6NH
United Kingdom
Phone: 00 44 121 3338076
E-mail: Ingo.Jester@gmail.com


     For many years, silver sulfadiazine cream has been demonstrated as effective in the treatment of burn wounds and has been the standard of wound care in the authors’ hospital for a decade. More recently, many silver dressings have been developed for topical use in acute and chronic wound care.      While the development of antibiotic resistance is an alarming concern in clinical practice, the advantage of silver is that it has minimal bacterial resistance.¹ Therefore, many dressings with a broad range of components and material characteristics have been silver-coated and are available for therapeutic use. Acticoat™ (Smith & Nephew, Largo, FL) was one of the first silver-coated dressings on the market with a clinical indication for burn wounds. Most treatment experience for pediatric and even neonatal burns has been gained with Acticoat. ^2–6      Subsequently, the silver sulfadiazine impregnated hydrocolloid wound dressing, Urgotul® SSD (Laboratoires Urgo, Chenove, France), and the silver-coated foam, Contreet Ag® (Coloplast, Minneapolis, MN), became available on the market. Several in-vitro studies confirmed the effectiveness of these silver dressings against a broad range of Gram-negative and Gram-positive bacteria. ^7–11      Urgotul is a lipidocolloid dressing and is currently used for treating pediatric burns. ^12,13 The polyester mesh is impregnated with carboxymethylcellulose, Vaseline, and silver sulfadiazine (3.75%). The wound dressing is antibacterial for 48 hours. Contreet Ag is a silver-coated polyurethane foam. The silver maintains antimicrobial activity for up to 7 days. ^14,15      Today, fortunately, mortality due to wound infection is low in children. Therefore, differences between dressings might be found only in the potential to improve comfort for children by reducing the frequency of dressing changes and their ease of use. Contreet has not been evaluated in children regarding its handling characteristics and ease of use in comparison to established wound dressings. The purpose of the present study was, therefore, to compare the handling and comfort of dressing changes between Urgotul SSD and Contreet.

Methods

     Patient collection. From July 2003 to May 2004 all children with partial- and/or full-thickness thermal burns caused by fire, scalds, or contact were treated by default in the authors’ burn center with Urgotul SSD. The comparison group was composed of patients treated by default with Contreet between June 2004 and January 2006.      During a 4-week initial test period in July 2003, the nursing staff learned how to handle the new Urgotul wound dressing. After this period, Urgotul was used for standard wound coverage. After a second 4-week period in June 2004 to learn how to handle the Contreet dressing, documentation of the dressing changes continued.      Treatment. In all children, blisters were removed and wounds disinfected under S-ketamine and midazolam anesthesia. After this initial treatment, the wound dressings were applied with sterile technique.      In the Urgotul group, each wound was covered with 2 layers of Urgotul SSD. The hydrocolloid was covered with sterile gauzes and fastened with a self-adhesive bandage (Gazofix®, BSN Medical, Hamburg, Germany).      For all patients treated with Contreet, the polyurethane-foam was applied to the wound. When using the adhesive foam dressing, Contreet was fastened as a precaution, with an additional self-adhesive bandage. As far as the nonadhesive foam dressing was used, the polyurethane-foam was covered with Comfeel® Plus (Coloplast) and fastened with Gazofix.      The dressings in both groups were changed every 72 hours.      Data collection. Data collection included ease of application and removal of the wound dressing, bleeding, adherence to the wound bed, discoloration of wound bed, signs of infection, duration of dressing change, and pain as assessed by an experienced nurse and investigator (burn surgeon). Four experienced nurses in burn care and two investigators participated in the study.      Analgesics were administered only before the dressing changes according to the physician’s practice. Pain was assessed using a visual analog scale if the child experienced breakthrough pain during dressing change.      Wound healing progress was photographed and documented. Complete wound closure was achieved when more than 95% of the wound was epithelialized.      The primary endpoint of the study was pain during dressing change and the dressing performance (exudate absorption, dressing application and removal).

Statistical Analysis

     Descriptive statistical analysis is summarized by medians ± standard deviation (SD). All comparisons between patients in the Urgotul SSD and in the Contreet group were performed with an independent sample t-test. Significance was defined as P < 0.05. Data were analyzed using StatView 5.

Results

     Forty patients with complete documentation were enrolled in the trial retrospectively. Treatments (N = 137) were documented in both groups, 70 dressing applications in the Contreet group and 67 dressing changes in the Urgotul group. The median age in the Contreet group was 1.50 ± 2.19 years, and 1.50 ± 4.52 years in the Urgotul group. The weight of the patients was 13 kg ± 6.14 kg in the Contreet group and 13.5 kg ± 12.64 kg in the Urgotul group. The median total body surface area (% TBSA) was 6% ± 2.66% in the Contreet group and 5% ± 7.49% in the Urgotul group. No adverse events occurred.      Pain evaluation. Pain during dressing changes was considered to be “absent” or “slight” in 92% of the cases in the Urgotul group, “moderate” in 5% and “severe” in 3% of the dressing changes. In the Contreet group, the pain was “absent” or “slight” in 85% of the wound dressings. In 10% of the dressing changes pain was “moderate” and in 5% pain was noted as “severe.” The difference in pain during dressing changes between the wound dressings was not significant (Figure 1).      Dressing performance. The application of the wound dressing in the Contreet group was “very easy” (n = 25, 35%) and “easy” (n = 42, 60%) in all dressing changes. In the Urgotul group, the application was “very easy” (n = 34, 49%) and “easy” (n = 33, 48%).      In the Urgotul group, the dressing removal was more often “very easy” (n = 49, 73%) than in the Contreet group (n = 39, 56%). In 2 (3%) of the dressing changes, the removal of Urgotul was “difficult” or “very difficult”; none of the dressing changes were graded as such in the Contreet group. Adherence of the wound dressings was “absent” in 52 (75%) and “slight” in 18 (25%) of changes in the Contreet group. In the Urgotul group, adherence was “absent” in 48 (72%) and “slight” in 13 (19%) of the dressing changes. In 5 (7%) of the dressing changes with Urgotul adherence was “moderate,” and in 1 case (1%) “severe.” Bleeding during dressing changes did not occur in 46 (65%) of the cases in the Contreet group, and in 43 (63%) of the cases in the Urgotul group. “Slight” bleeding was noticed in 25 (36%) cases in the Contreet group and in 24 (35%) cases in the Urgotul group. Bleeding was “moderate” in 1 (1%) of the dressing changes with Urgotul.      Exudate was mostly absorbed into the dressing in the Contreet group (60 [85%] “very good” and 10 [15%] “good”). In the Urgotul group, exudate absorption was rated as “very good” in 35 (51%), “good” in 27 (39%), and “moderate” in 7 (10%) of the dressing changes.      The time to complete the dressing change was comparable in both groups. Dressing changes were completed within 20 minutes for 40 (60%) patients in the Urgotul group, and 49 (70%) in the Contreet group. Fourteen (20%) of the dressing changes took 20–30 minutes in the Contreet group and 20 (30%) in the Urgotul group. Seven (10%) dressing changes in the Contreet group and 7 (10%) in the Urgotul group took longer than 30 minutes.      None of the wounds showed signs of infection during the study period. Wound discoloration was not observed in either group.      Time to heal. In both groups, 17 out of 20 burn wounds (85%) healed within the study period. The median time to healing was 10 ± 4.97 days in the Contreet group, and 10.5 ± 6.89 days in the Urgotul group. The burn wounds of 3 patients in each group had to be grafted because of deep-thickness burns. These patients were excluded from the healing time assessment.      No statistically significant differences were found (Table 1).

Discussion

     The principal aim of wound management in burn care in particular is to prevent nosocomial bacterial wound infection. Additionally, the wound healing should be promoted and the pain minimized during the change of dressing, especially in children.      In 1997, Sheridan et al¹⁶ highlighted the possibility of reducing the frequency of dressing changes with the silver sulfadiazine cream to once daily as a great advantage. Since this time, several silver-content wound dressings were developed and proved to fulfill the demands of a wound dressing in different ways.^{3,4,9,11,13,15,17,18}      After using silver sulfadiazine cream for many years, we were dissatisfied with the daily dressing changes. Looking for a new standard in burn wound management, the default therapy of using Urgotul SSD in 2003 and using Contreet on all children from June 2004 to 2006 was implemented. To evaluate the wound management procedures the differences between Urgotul SSD and Contreet regarding handling, dressing use characteristics, and pain during dressing changes, were examined retrospectively.      Most importantly, both wound dressings caused minimal pain in the majority of dressing changes. However, in both groups, the children still experienced some pain during dressing changes.      In the Urgotul group, pain was caused by adherence of the wound dressing to the wound. In the Contreet group, children complained mostly about pain caused by the adhesive foam. Contreet is available in an adhesive and nonadhesive version. During the test period in June 2004, it was noticed that the nonadhesive Contreet foam sticks more to the wound and causes more adhesions than the adhesive foam version. Therefore, the nursing staff decided to use the Contreet foam with the adhesive border for the majority of the time. Unfortunately, in some children the adhesive border was too sticky and caused moderate pain in 10% of the dressing changes in the Contreet group. A new adhesive border dissolver from Coloplast, which was not tested in this study, might solve this problem.      The nurses refined the dressing techniques in the initial trial period in July 2003 to prevent adherence with Urgotul SSD. Using Urgotul as a monolayer, following the manufacturer’s instructions, exudate dried within the first 3 post-trauma days and the sterile gauzes adhered to the lipocolloid dressing and the wound. It turned out to be useful to apply the lipidocolloid dressing in 2 layers during primary wound treatment to prevent adherence of the wound dressing caused by increased exudation of the burn. This additional expense is not necessary in Contreet, which had a “very good” absorption capability in 85% of all dressing changes right from the start of burn treatment, while Urgotul provided “very good” absorption of the exudate in 51% of the cases. These clinical findings are supported by Parsons et al.⁹ They found in a standardized comparison of foam dressings and woven wound dressings that foam dressings had greater fluid absorption.      Other silver dressings (Acticoat™, Smith and Nephew; Aquacel® Ag, ConvaTec; and PolyMem Silver®, Ferris Mfg) also have been tested in in-vitro studies. All silver dressings are comparably effective against a broad range of bacteria. ⁷ Many studies claim advantages in each tested silver dressing in acute wounds. ^5,9,11,19 Considering the results of the present study, it seems that these silver dressings might be comparably useful in the treatment of an acute wound and/or effective in the protection against superinfection of the wound.      Dressing technique refinement, as modified in the present study by changing the Urgotul application into 2 layers, can improve dressing performance. The handling of a wound dressing might, therefore, be responsible for different study results. The application and the removal of Urgotul SSD in the 2-layer option were evaluated in 97% of the dressing changes more often as “easy” or “very easy” compared to 95% of the dressing changes in the Contreet group.      The dressings have 2 essential characteristic differences. Urgotul SSD is characterized by a soft material structure that facilitates adaptation on irregular body surfaces such as the face or fingers. Contreet is applied more easily to larger wound areas. Therefore, the authors confirm the conclusion of Parsons et al⁹ that wound dressing choice might be mainly dependent on the wound type, wound localization, and wound exudate.      While systemic effects of silver with possible toxicity have been reported in the literature, ^8,20,21 many different statements concerning importance of high silver levels and the content of silver in a dressing regarding the antibacterial effect and development of bacterial resistance exist. ¹ Even more confusing is the fact that in-vitro studies demonstrate cytotoxic effects of silver in cultured skin substitutes, while other authors report no disturbance of silver in wound healing in vivo. ^22–26 White et al, ¹¹ as well as Leaper¹⁷ and Silver et al, ¹ clearly demonstrated that all data from silver release levels in in-vitro studies have not been confirmed by in-vivo studies, and therefore might not be extrapolated.      Clinical evidence does not exist in the literature to support that the efficacy of silver dressings is dependent on the silver content and dosage. While the development of bacterial resistance to silver is possible and the widespread use of silver, especially with exposure to low silver levels, might induce bacterial resistance; ^3,17 no clinical studies provide the evidence that a minimum silver level is necessary to prevent resistance. ^1,11,27      In the present study, no clinical symptoms of silver toxicity were observed in any child, and fortunately, no adverse effects to the wound dressings were reported. The wound healing time was comparable in both dressings. Neither wound healing nor take-rate of skin grafts in any of the patients seemed to be affected in this study.      Skin staining is a known effect of silver and has been reported in studies on Acticoat. ^8,28 Therefore, evaluation of burn depth and grafting can be more difficult. Obvious discoloration of the skin was not observed in the present study.      Contreet is reported to have in-vitro antimicrobial activity of up to 7 days. ¹⁴ Therefore, it might be a promising alternative to other silver wound dressings, because the frequency of wound dressings can be further reduced, and the comfort of the patient and time to healing might improve. As a result of this study, the authors have begun changing the Contreet wound dressing in children with superficial scald burns only every 5 days, and have yet to observe any complications.

Conclusion

     The development of silver containing wound dressings could remarkably improve the comfort level for patients with burns. Urgotul SSD and Contreet are 2 different wound dressings with comparably high dressing performance. Both dressings have different characteristics regarding performance, but cause comparably modest pain during dressing changes and can therefore be recommended, especially for the treatment of pediatric burns. From the Department of Paediatric Surgery, Birmingham Children’s Hospital, United Kingdom; Department of Pediatrics, Evangelische Diakonissenanstalt, Speyer, Germany; Department of Pediatric Surgery, University Hospital Mannheim, Germany