August, 2005

Dear Readers,

In this month’s Evidence Corner, Dr. Laura Bolton reviews and includes commentary on 2 very interesting studies on the effects of sharp debridement. In her introduction to the article, she defines a distinction between the 2 terms, sharp debridement and surgical debridement. Bolton’s summaries of the published articles entitled “Effect of sharp debridement using curette on recalcitrant nonhealing venous leg ulcers: a concurrently controlled, prospective cohort study” (Williams et al.) and “Effect of extensive debridement and treatment on the healing of diabetic foot ulcers” (Steed et al.) provide the reader with important findings on the merits of sharp debridement of chronic wounds. Debridement using a curette was found to be an effective approach to expedite area reduction of intractable chronic venous leg ulcers. Aggressive sharp debridement of diabetic foot ulcers as described in the second article was shown to be an important factor in the care of these wounds. While the importance of removing necrotic tissue and slough from chronic wounds is generally accepted (and shown by the 2 reviewed articles), there remain many open questions as to the best methods of removal (sharp, autolytic, enzymatic, biosurgical, etc.) and frequency of debridement. Future studies will certainly lead to approaches optimizing healing outcomes.

Gardner et al. (Diabetes and inflammation in infected chronic wounds) investigated the expression of the clinical signs of chronic wound infection in a series of 7 patients with diabetes and 10 patients without diabetes. All the infected wounds contained greater than 10⁵ organisms per gram of tissue or ß-hemolytic Streptococcus. The wound types included venous ulcers, pressure ulcers, traumatic wounds, and incisions. Diabetic foot ulcers were excluded from the study. The authors found that pain, edema, heat, and purulent exudation were comparable in the infected wounds of the patients with diabetes and those without diabetes; however, the expression of erythema was markedly reduced in the wounds of the patients with diabetes. The significance of these findings is discussed.

Two articles report on the use of negative pressure wound therapy (NPWT) in case studies. Datiashvili and Knox (Negative pressure dressings: an alternative to free tissue transfers?) share their experiences in the management of complex open wounds of the extremities. They concluded that NPWT served as an effective approach when free tissue transfer was not an option. Pattison et al. (Case report: using dual therapies—negative pressure wound therapy and modified silicone gel liner—to treat a limb postamputation and dehiscence) present a case study showing the use of NPWT and a silicone gel liner together resulted in closing a nonhealing postamputation wound (below-the-knee amputation) while actively reshaping the limb for a prosthesis. In this case, the authors conclude that the technique shortened the rehabilitation process, physical therapy requirements were reduced, fewer prosthesis refittings were needed, and the risk of thromboembolism was reduced.

In-vitro studies on the effects of a wound antiseptic are reported by Reinhardt et al. (A topical wound disinfectant [ethacridine lactate] differentially affects the production of immunoregulatory cytokines in human whole-blood cultures). Ethacridine lactate is an old topical disinfectant used since 1923. The authors found that this material exhibited an immunomodulatory activity regarding the release of several cytokines from human leukocytes. These included effects on the release of interleukins (IL-5, IL-6, IL-10, and IL-12). Some cytokines were stimulated, while others were inhibited, rather than simply inhibiting or stimulating leukocytes in general. They discuss the significance of their findings and suggest that ethacridine lactate may actually act through aiding the immune system to better control infection.

Parsons et al. (Silver antimicrobial dressings in wound management: a comparison of antibacterial, physical, and chemical characteristics) conducted laboratory tests to evaluate and compare 7 commercially available silver-containing dressings. The parameters investigated included antibacterial activity against Pseudomonas aeruginosa or Staphylococcus aureus in a simulated wound fluid, fluid handling properties, and dressing pH. Interestingly, there appeared to be no correlation between silver content, silver release, and antibacterial activity. In selecting among the available products, the authors conclude that it is most important to consider the wound type and condition and that the treatment choice should be based upon the most clinically relevant performance characteristics of the silver-containing dressing.