The effects of epidermal debridement of partial-thickness burns on infection and reepithelialization in swine

Objective: Early postburn debridement of burn blisters is controversial. Th is study was conducted to compare rates of infection and reepithelializatio n in debrided vs nondebrided second-degree burns in swine. Methods: This wa s a prospective, blinded, controlled, experimental trial. using isoflurane- anesthetized swine. Standardized partial-thick ness burns were inflicted by applying an aluminum bar preheated to 80 degrees C to the backs and flanks of two young pigs for 20 seconds. In half of the burns the necrotic epider mis was manually debrided. All burns were randomly treated with octylcyanoa crylate spray (OCA) or dry gauze (C). Full-thickness biopsies were taken at 7, 10, and 14 days for blinded histopathologic evaluation. The primary out comes were the proportions of infected burns at days 7 and 10 and the propo rtion of completely reepithelialized burns at day 14. Burns were considered infected in the presence of intradermal neutrophils containing bacteria (i ntraobserver agreement, kappa = 1.00). A secondary outcome was the proporti on of burns with the presence of scar tissue (abnormal collagen under polar ized light; intraobserver correlation, kappa = 0.93). Chi-square tests were used for group comparisons. This study had 90% power to detect a 40-percen tage-point difference in infection rates (alpha = 0.05). Results: A total o f 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 w ith OCA had fewer infections than controls (4% vs 55%, p < 0.001). Fewer OC A-treated debrided burns were reepithelialized at 14 days than those that w ere not debrided (30% vs 100%, p = 0.001). Conclusions: Under the current s tudy conditions, early postburn epidermal debridement of second-degree burn s resulted in more infections and slower reepithelialization rates in swine . The effects of early postburn epidermal debridement in humans should be e xplored.