Oxidative damage to protein and alterations to antioxidant levels in human cutaneous thermal injury

Conflicting recommendations and clinical applications have been given concerning best practices for the management of burn blisters associated with partial-thickness burns. Arguments for the preservation of intact blisters center on the idea of naturally occurring biologic protection whereas the debridment of blisters has been advocated because of the perceived decreases in wound infection and complications. Recurring themes in burn wound management that are considered in this debate include infection, healing, functional and aesthetic outcome, patient comfort, ease of dressing care, and cost efficiency. The management of burn blisters should be supported by evidence across these six categories, should match the expertise of the provider, and should use the available resources in the practice setting. The purpose of this review is combine the findings of a comprehensive review of the published literature with respect to the management of blisters in the partial-thickness burn into a clinical guideline for best practice based on available evidence.

Management of blisters in the partial-thickness burn: an integrative research review.

Each year there are over 500,000 burns that present to the emergency department (ED). Most burns are minor, and their care focuses on local wound management. The current article will present a typical case and then review the epidemiology, pathophysiology, diagnosis, and management of minor burns in the ED.

Management of local burn wounds in the ED.

. Objective: Early postburn debridement of burn blisters is controversial. This study was conducted to compare rates of infection and reepithelialization in debrided vs nondebrided second-degree burns in swine. Methods: This was a prospective, blinded, controlled, experimental trial using isoflurane-anesthetized swine. Standardized partial-thickness burns were inflicted by applying an aluminum bar preheated to 80°C to the backs and flanks of two young pigs for 20 seconds. In half of the burns the necrotic epidermis was manually debrided. All burns were randomly treated with octylcyanoacrylate spray (OCA) or dry gauze (C). Full-thickness biopsies were taken at 7, 10, and 14 days for blinded histopathologic evaluation. The primary outcomes were the proportions of infected burns at days 7 and 10 and the proportion of completely reepithelialized burns at day 14. Burns were considered infected in the presence of intradermal neutrophils containing bacteria (intraobserver agreement, κ= 1.00). A secondary outcome was the proportion of burns with the presence of scar tissue (abnormal collagen under polarized light; intraobserver correlation, κ= 0.93). Chi-square tests were used for group comparisons. This study had 90% power to detect a 40-percentage-point difference in infection rates (α= 0.05). Results: A total of 126 biopsies from 42 burns were available for review. Infection rates were higher in the debrided burns both at day 7 (55% vs 4.5%, p < 0.001) and at day 10 (65% vs 9%, p < 0.001) after injury. The proportion of nondebrided burns that were completely reepithelialized was higher at days 10 (68% vs 0%, p < 0.001) and 14 (100% vs 65%, p = 0.003). The presence of scar tissue was more common in debrided burns (75% vs 4.5%, p < 0.001). Burns treated with OCA had fewer infections than controls (4% vs 55%, p < 0.001). Fewer OCA-treated debrided burns were reepithelialized at 14 days than those that were not debrided (30% vs 100%, p = 0.001). Conclusions: Under the current study conditions, early postburn epidermal debridement of second-degree burns resulted in more infections and slower reepithelialization rates in swine. The effects of early postburn epidermal debridement in humans should be explored.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1553-2712.2000.tb00511.x

The Effects of Epidermal Debridement of Partial‐thickness Burns on Infection and Reepithelialization in Swine

The burn wound healing process, which is reviewed in this paper, has features that differ from the healing of incised cutaneous wounds. This study used immunohistochemical staining and cell counting to examine the inflammatory cell response in biopsy samples of burn wounds from live human subjects obtained at six hours until 23 days after injury in order to determine how the age of a burn could be estimated. Acute inflammatory cells predominated in samples taken six hours to two days after injury. However, neutrophils were often minimal in early samples or could be present late. Elevated numbers of macrophages tended to be encountered from days 2 to 20, but it was not uncommon to observe a minimal or absent macrophage response. Unexpectedly, there was no trend in the number of lymphocytes. A small study was also made of burn wound samples that had been obtained at post-mortem examination of subjects that died in a fire or up to 77 days after injury from fire. This revealed a similar trend of neutrophil an...

Using the inflammatory cell infiltrate to estimate the age of human burn wounds: A review and immunohistochemical study.

It is unclear whether burn blister fluid is beneficial or deleterious to the healing of the underlying wound. We investigated the calcium binding protein calmodulin in human burn blister fluid and its role in the mitogenicity of this fluid in the culture of human keratinocytes, fibroblasts, and mouse 3T3 fibroblasts. Calmodulin levels in blister fluid were three times greater than in serum (p < 0.005), whereas epidermal growth factor and platelet-derived growth factor concentrations were significantly lower (p < 0.001). Calmodulin in blister fluid was biochemically identified after affinity chromatography, Western blotting, and immunostaining with a monoclonal antibody. Inhibiting calmodulin with either an antagonist or antibody to calmodulin reduced the mitogenic activity of blister fluid in three cell types by 26% to 80%. These in vitro studies suggest that burn blister fluid may promote wound healing, and locally released calmodulin contributes to this effect. In appropriate cases it may be beneficial to leave burn blisters intact.

S Mac Neil

Papers

Investigation of the presence and role of calmodulin and other mitogens in human burn blister fluid.