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Background Burn injury progression in the secondary zone of ischemia is common leading to delayed healing and increased scarring. We hypothesized that a topical surfactant, would reduce burn injury progression in a validated rat comb burn model compared with topical antibiotic ointment. Methods We created 40 comb burns on 20 rats which were randomized to daily topical application of the surfactant or a triple antibiotic ointment. The comb burns consisted of 4 full thickness burns with 3 unburned interspaces between the 4 burns. These unburned interspaces represented the zone of ischemia, and when left untreated, generally progress to full thickness necrosis within several days. Comb burns were assessed daily for the presence of gross necrosis of the interspaces. At 7 days the comb burns were excised and blindly evaluated for the presence of histological evidence of necrosis. The study had 80% power to detect a 25% difference in the percentages of necrotic interspaces on day 7. Results There were no differences in the percentages of histologically necrotic interspaces at 7 days in burns treated with the surfactant or antibiotic ointment (85% [95%CI, 74 to 92] vs. 75% [95%CI, 63 to 84]; mean difference 10% [95%CI −4 to 24]). There were also no between group differences in the percentages of grossly necrotic interspaces on any of the seven days of the experiment. The surfactant remained intact and adherent while the antibiotic had been absorbed at each daily dressing change. Conclusions A topical surfactant did not reduce injury progression in the rat comb burn model when compared with antibiotic ointment. The surfactant was more durable than the antibiotic ointment.

Whether the depth and healing of scalds and contact burns are similar is controversial. Due to water's greater heat capacity, we hypothesized that when exposed to similar temperatures and durations of exposure, burns caused by hot water would be deeper than those caused by contact with hot metal. Forty standardized burns were created in two anesthetized female domestic pigs using a brass bar or circulating heated water. In one pig, the temperature was kept constant (95°C) while the duration of exposure varied (5, 10, 15 seconds) In the second pig, the exposure time was kept constant (10 seconds) while the temperature of exposure varied (70°C, 80°C, 98°C). Periodic punch biopsies were taken to determine burn depth immediately after injury, percentage burns reepithelialized within 21 days, and depth of scar at 28 days. The analysis was performed using analysis of variance. When the temperature was held constant, duration of exposure (5, 10, and 15 seconds) was associated with scar depth (2.1 vs 3.8 vs 5.0 mm, respectively, P = 0.001) but not with burn depth (2.0 vs 2.2 vs 2.3 mm, respectively, P = 0.10). When exposure duration was held constant, temperature (70°C, 80°C, 98°C) was associated with scar depth (0.6 vs 1.7 vs 3.6, P < 0.001) but not with burn depth (1.2 vs 1.5 vs 1.7 mm, respectively, P = 0.21). Burn depths were greater for scald than contact burns although not significantly greater. After controlling for temperature, the difference in scar depth between scalds and contact burns was statistically significant (marginal means 3.0 for contact burns, 4.3 for scalds, P = 0.008). We conclude that burns created in swine with circulating hot water result in deeper scars than those created by contact with a brass bar when controlling for temperature and duration of exposure.

Introduction Prior studies comparing scalds and contact burns rarely address the affect of burn etiology on burn depth. However, it is commonly believed that scalds tend to heal faster than similarly sized contact and flame burns. As a result, expectant therapy is often preferred after scald injuries. We compared the percentages of full-thickness burns based on burn etiology controlling for burn size, location and patient age. We hypothesized that the percentage of full thickness burns would be lower after scalds compared with contact and flame burns. Methods We performed a retrospective chart review of a prospectively collected burn registry of all patients admitted to a regional burn center between 2000–2010. Data collection included patient and burn characteristics including age, gender, body location, and burn etiology. We compared the percentages of full thickness burns among scald, contact and flame burns using Chi-square tests. Stepwise logistic regression was used to adjust for age, location, and burn size. Results There were 1038 patients in the study with either scald (n=537, 52%), fire/flame (n=434, 42%) or contact (n=67, 6%) burn. Mean (SD) age was 29 (25); 75% were male. Mean (SD) total body surface area (TBSA) was 11 (13)%. Mean (SD) length of stay was 10 (18) days. The percentages of full thickness burns by etiology were scalds 13.1%, fire/flame 34%, and contact burns 45% (P< 0.001). Patients with scalds were younger (22+/-24) than patients with contacts (32+/-28) and fire/flame (38+/-22) burns. Multivariate analysis for predicting full thickness burns found that compared with contact burns, scalds were less likely full thickness (OR 0.23, 95%CI 0.11–0.48) while fire/flame burns were as likely to be full thickness (OR 0.54, 95%CI 0.26–1.15). TBSA and age were also associated with full thickness burns (OR 1.06, 95%CI 1.04–1.09 and OR 1.015, 95%CI 1.007–1.024, respectively). Burns on the head and neck were less likely to be full thickness (OR 0.30, 95%CI, 0.11–0.82). Conclusions Scald burns are significantly less likely to be full thickness than contact or fire/flame burns. Applicability of Research to Practice Based on these results, expectant therapy may be more appropriate for scalds than contact or fire/flame burns.

Introduction Whether the depth and healing of scalds and contact burns are similar is controversial. Prior studies have not compared scalds and contact burns using identical temperatures and durations of exposure limiting direct comparison. We hypothesized that when exposed to similar temepratures and durations of exposure, burns caused by hot water and contact with hot metal would be similar. Methods Multiple 2.5 or 5 cm diameter standardized cutaneous burns were created in two anesthetized female domestic pigs (~45kg) using a brass bar or circulating heated water in replicates. The temperatures were controlled and kept constant using thermosensors. In one pig, the temperature was kept constant (95 degrees C) while the duration of exposure varied (5, 10, 15 sec.) In the second pig, the exposure time was kept constant (10 sec.) while the temperature of exposure varied (70, 80, 98 degrees C). Burns were covered with a topical antibiotic ointment and frequent dressing changes were performed for 4 weeks. Periodic punch biospies were taken to determine burn depth immediately after injury, percentage burns reepithelialized within 21 days, and depth of scar at 28 days. Analysis was performed using analysis of variance. Results When temperature was held constant, duration of exposure (5, 10, and 15 sec.) was associated with scar depth (2.1 vs 3.8 vs 5.0 mm respectively, P=0.001) and there was a trend for an association with burn depth (2.0 vs 2.2 vs 2.3 mm respectively, P=0.10). When exposure duration was held constant, temperature (70, 80, 98 degrees C) was associated with scar depth (0.6 vs 1.7 vs 3.6, P< 0.001) but not significantly associated with burn depth (1.2 vs 1.5 vs 1.7 mm respectively, P=0.21). For each pig a comparison of burn and scar depth by device generally showed that depths were greater for scald than contact burns although not significantly greater. Only scar depth in the first pig showed a difference with a significance of less than 0.10 (2.9 for contact vs 4.1 mm for scalds, P=0.08). After controlling for temperature the difference between scalds and contact burns was statistically significant (marginal means 3.0 for contact burns, 4.3 for scalds, P=0.008). When combining data from both pigs and controlling for temperatures and duration, scar depths for scalds (2.7 mm) vs contacts (1.9 mm) showed a significant difference (P=0.02) while burn depth was not quite significant (1.7 vs 1.5 mm, P=0.07). Almost all burns were reepithelialized by day 21. Conclusions Burns created in swine with circulating hot water tend to be deeper and result in deeper scars than those created by contact with a brass bar when controlling for temperature and duration of exposure. Applicability of Research to Practice Scalds of similar temperature and exposure times result in deeper scars than contact burns.