Scald Injury Research Articles

594 Dermal Matrix versus Autologous Grafting for Full-Thickness Burns of Head and Neck: Trends, Outcomes, Cost

IntroductionBurns of the head and neck are particularly devastating, commonly occurring due to accidental flame or scald injury. Autologous grafting has traditionally been used for reconstruction in this area. Recently the use of dermal matrices as a reconstructive alternative has increased. This study compares annual trends, outcomes, and hospital costs between head and neck burn patients who underwent reconstruction with dermal matrix or autologous grafting.MethodsThe U.S Agency for Healthcare Research and Quality Healthcare Cost and Utilization Project Nationwide Inpatient Sample database was queried from 2012 to 2016. Patients with head and neck burns treated with dermal matrix or autologous graft were identified using International Classification of Disease Ninth and Tenth Revision diagnosis and procedure codes. Demographic, clinical characteristics, and outcome measures were reported. χ 2 and Student’s t-tests were used for univariate survey-adjusted comparisons between groups. Multivariate survey-adjusted linear regressions were used to identify associations between surgical intervention, length of stay and cost of hospitalization. Analyses were conducted with RStudio (1.4.1717).ResultsA total of 6,730 patients met inclusion criteria; 2,855 underwent reconstruction dermal matrix and 3,875 with autologous graft. There was an increasing number of patients undergoing dermal matrix reconstruction each year, peak in 2016 (1,450, 50.8%). The dermal matrix group was younger (33.7 vs 39.9, p< 0.001) had fewer females (27.3% vs 38.2%, p=0.003) and fewer inhalation injury (4.0% vs 11.0%, p< 0.001). The dermal matrix group had a shorter length of stay (11.2 vs 27.8, p< 0.001) and more home discharges (80.4% vs 53.4%, p< 0.001); they had lower Elixhauser Comorbidity Index score for readmission (6.57 vs 11.92, p< 0.001) and in hospital mortality (4.76 vs 9.69, p< 0.001). Median cost of care was lower for the dermal matrix group ($17,858 vs $59,860, p< 0.001). Multivariable regression demonstrated that reconstruction with dermal matrix was independently associated with decreased length of stay (11.01 [7.95 - 14.07], p< 0.001) and decreased cost ($38,297 [23,813], p< 0.001).ConclusionsOperative management of head and neck burns with dermal matrix is associated with a shorter hospital stay, greater likelihood of home discharge, and decreased hospital costs. Patients with autologous grafting had higher rates of inhalation injury, which may account for longer hospital stays and increased discharges to nursing facilities. A limit of this study is the inability to differentiate patients undergoing staged procedures. Further study is needed to evaluate factors contributing to faster discharges home in the head and neck burn population.

93 Foot Burns in Persons with Diabetes outcomes from the National Trauma Data Bank

IntroductionDiabetes Mellitus (DM) is an epidemic in the US that complicates the treatment of burn injuries. Lower extremity burns in diabetic patients, particularly the feet, are challenging problems with predictably unfavorable outcomes, as demonstrated by single-institution studies. National evaluations are absent, especially with regard to limb salvage. We aim to characterize lower extremity burns in persons with DM and evaluate the likelihood of amputation. We hypothesize that the incidence of DM associated foot burns is increasing in the US, and these patients are more likely to undergo lower extremity amputation than those without DM.MethodsThe National Trauma Data Bank (NTDB) was queried from 2007-2015 extracting encounters with primary burn injuries of the feet using International Classification of Diseases (ICD) 9th Edition codes. DM is a predefined comorbidity within the NTDB, allowing for cohort comparisons. Logistic regression modeled predictors of lower extremity amputation. Patient covariables included age, sex, race/ethnicity, and comorbidities. Burn covariables included % burn total body surface area (TBSA), mechanism, and region of burn center. Poisson regression evaluated for significance in temporal changes in DM foot burns.ResultsThere were 116,796 adult burn encounters of which 7,963 (7%) had foot burns. Of this group, 1,308 (16%) had DM. DM foot burn encounters were older, more likely to be male, and had more comorbidities than non-DM foot burn encounters (all p< 0.001). DM foot burn encounters were more likely to sustain a scald injury (compared to flame) and had smaller %TBSA (all p< 0.001). Additionally, 5.6% of encounters with DM foot burns underwent amputation compared to 1.5% of non-DM encounters (p< 0.001). Independent predictors of lower extremity amputation included DM (OR 3.70, 95% CI 2.98 – 4.59), alcohol use, smoking, chronic kidney disease, burn size >20%, African American/Black race, male sex, and age >40 years (all p< 0.01). The incidence of DM foot burns increased over the study period with an incidence rate ratio (IRR) of 1.09 (95% CI 1.07 – 1.12, p< 0.001).ConclusionsIn the largest cohort study to date, DM was associated with nearly a 4-fold increase in amputation after adjusting for available confounders. Furthermore, the incidence of DM foot burns is increasing. Strategies for optimizing care in persons with DM foot burns are need to improve limb salvage.

571 Ethnicity and Etiology in Burn Patients for the American Burn Association National Burn Repository (NBR)

IntroductionThe purpose of this study was to analyze data from the American Burn Association National Burn Repository (NBR)with particular focus on patient ethnicity and burn etiology. We hypothesize that burn etiology, severity and other characteristics will be significantly different between differing ethnic groups throughout the database. This information can be used to augment burn prevention strategies by targeting at risk ethnic groups.MethodsData on burn patients was derived from the American Burn Association National Burn Registry including all burn entries for a 10 year period (2009 to 2018) from 46 burn centers. The ethnic categories for this study were White, Black, Hispanic, Indigenous and Asian. The study also involved analysis of patient demographics, burn severity, context of injury, and hospital course.ResultsWhite patients were the largest group (64.0%), had the highest proportion of flame injury (53.1%) and shared the highest mortality rate with indigenous patients (3.1% compared with 2.6% for all other ethnicities). Black individuals (22.2%) had higher rates of scald burns (53.2%), the shortest average hospital stay (16.8 days) and along with indigenous patients the highest rates of assault/abuse (2.0% and 1.9% respectively). Hispanic patients (10.0%) had more scald burns (47%), the largest proportion of men (66.5%), the highest incident of work-related injuries (18.0%) and the largest average TBSA at 10.1%. Asian patients (2.7%) had the largest proportion of scald injury (63.1%) and the smallest proportion of male patients (54.5%). Indigenous patients (1.1%) had higher rates of flame burns, suffered full thickness burns at the highest rate (32.8%), had the longest average stays in hospital (21) and the ICU (15) and had the highest rates of blanks for data entry.ConclusionsThis study found multiple significant differences in burn populations when compared by ethnicity. We have found that the indigenous population suffered full thickness burns at the highest rate and have had the longest average hospital stay as well average ICU stay. We have also had the unexpected finding of higher rates of unknowns in the indigenous population which may reflect racial bias at an institutional level nationally.

Case Report: Medicolegal evaluation in a pediatric case of fatal scald injury from rural Nepal

Thermal injuries in young children involving the buttocks, perineum, and lower limbs raise suspicion of child abuse. Determining the manner of death and ruling out homicide in a fatal case of scalding remains a challenge for forensic practitioners. One such issue is reported in the present case report, where a medicolegal evaluation of a fatal scald in a two-year-old girl child is discussed. Young children sustaining serious injuries from scalds is a grave social concern. Such young lives need to be protected from scald injuries whether accidental or purposeful. Differences in injury patterns on the basis of their distribution and their characteristics are important to determine manner of death in such cases.

Scalds and the hazards of hair braiding – The first UK series from a paediatric tertiary burns centre

IntroductionHair braiding is a popular method of hair styling thought to date as far back as 500BC. One of the techniques involves the use of hot water to ‘set the braids’ which carries the risk of significant scald injury. This study presents the first UK based case series of hair braiding associated scald burns referred to a paediatric tertiary burns centre. Our aim is to increase awareness of this novel mechanism of injury, highlight trends and develop targeted prevention strategies. MethodsRetrospective data collection of patients presenting to a regional paediatric burn centre with hair-braiding associated scald burns was collected over a 13 year period (2007–2020). Patient demographics, mechanism of injury, total body surface area (TBSA), location, depth and distribution were evaluated. The presence of additional family, quality, duration and delay of first aid were also collected. The need for admission and length of hospital stay and long-term outcomes were also appraised. ResultsFourteen patients with scald injuries secondary to hair braiding were identified. The mean age was 6.5 years (5–9) and all patients were female. The most prevalent ethnicity affected were patients with African heritage. The mean TBSA was 3% (1–7 %). First aid was performed in only 50% of cases, of which none was adequate. The distribution of burns was as follows: the back (43%), posterior nape of the neck (36%), posterior shoulder (14%), scalp and face (21.5%) chest (7%) and legs (7%).Nine patients required admission to hospital with the mean length of stay of 2.85 days (range 1–12). No patients required surgery. The mean time to healing was 14 days (range 9–26). Longterm complications included hypopigmentation and hypertrophic scarring requiring scar management strategies. DiscussionThis well recognized technique of hair styling carries significant risks of scald injury. Patients often require hospital admission, endure emotional distress and require time off school. Patients can develop significant hypopigmented and hypertrophic scarring at a young age leading to considerable psychosocial morbidity. We recommend spreading awareness of the dangers of hair braiding through education, safety device development, prevention campaigns and targeted outreach work to minimise the hazards of this hair styling technique.

Effects of Thymosin β4 on Myocardial Apoptosis in Burned Rats.

The aim of this study was to investigate the effects of thymosin β4 on myocardial apoptosis following burns. Fifty healthy Sprague Dawley (SD) rats were randomly divided into the normal control group, resuscitation group the low-dose Tβ4 (thymosin β4) group (2g), the medium-dose Tβ4 group (6g), and the high-dose Tβ4 group (18g). The rats were immersed in 95°C hot water for 18 seconds, and then the model of 30% body surface area (TBSA) III° scald was established. The resuscated rats were injected with lactate Ringer's solution for antishock rehydration, while the Tβ4 treatment group was injected with lactate Ringer's solution for antishock rehydration, and the animals were sacrificed 6 h after scald. The degree of histopathological damage was observed by HE (hematoxylin and eosin) staining. Western blot was used to detect STAT1 and STAT3 protein expression levels. Real-time PCR was used to detect mRNA expressions of STAT1 and STAT3. The results showed that the apoptosis rate of the resuscitation group was significantly higher than that of the control group (P < 0.01). Compared with the resuscitation group, the apoptosis rate of thymosin β4 in the treatment group was significantly reduced (P < 0.01). Compared with the normal control group, the expression of STAT1 protein was increased and the expression of STAT3 protein was decreased in model group rats after ischemia and reperfusion. Compared with the model group, the expression of STAT1 protein decreased and the expression of STAT3 protein increased after ischemia-reperfusion in the thymosin β4 treatment group. Thymosin β4 may protect the myocardium by downregulating STAT1 and upregulating STAT3 expression and inhibiting myocardial apoptosis induced by ischemia and reperfusion after severe scald injury.

Effect of Thymosin β4 on Deep Second-Degree Scald Wound Healing in Rats via Wnt/β-Catenin Pathway

&lt;sec&gt; &lt;title&gt;Objective:&lt;/title&gt; The purpose of this research is to explore the influences of thymosin β4 (Tβ4) in deepsecond-degree scald wound healing of rat skin and its relationship with Wnt/β-catenin pathway. &lt;/sec&gt; &lt;sec&gt; &lt;title&gt;Methods:&lt;/title&gt; Deep second-degree scalded model rats were prepared and divided into normal saline (NS) treatment group, Tβ4 treatment group and FH535 inhibitor group. Then, the concentrations of inflammatory factors in the rats were monitored via adopting the correlated TNF-α and IL-1β ELISA kits. In the meantime, the wound healing rate was analyzed via photography. Subsequently, the qRTPCR procedure was wielded to determine Wnt1 and β-catenin expression in wound tissues, and the degree of wound tissue injury was examined via hematoxylin and eosin (HE) staining. Finally, Western blotting (WB) was adopted to assess Wnt/β-catenin pathway-associated protein levels. &lt;/sec&gt; &lt;sec&gt; &lt;title&gt;Results:&lt;/title&gt; Releasing amount of TNF-α and IL-1β were conspicuously up-regulated after scalding (p &lt;0.01), and Wnt1 and β-catenin expression at molecular transcription level was also significantly raised (p &lt; 0.01). Besides, treatment with 18 μg of Tβ4 significantly increased the wound healing rate of scalded rats (p &lt; 0.01). In addition, Tβ4 treatment significantly promoted wound healing (p &lt; 0.01) and increased the Wnt1 and β-catenin expression levels (p &lt; 0.01). Moreover, FH535 significantly restrained the Wnt/β-catenin pathway-correlated protein levels (p &lt; 0.01) and wound healing. &lt;/sec&gt; &lt;sec&gt; &lt;title&gt;Conclusion:&lt;/title&gt; Tβ4 can promote scald wound healing in rats and may play a role via evoking Wnt/β-catenin pathway activation. &lt;/sec&gt;

Amphibian-derived peptide homodimer OA-GL17d promotes skin wound regeneration through the miR-663a/TGF-β1/Smad axis.

BackgroundAmphibian-derived peptides exhibit considerable potential in the discovery and development of new therapeutic interventions for clinically challenging chronic skin wounds. MicroRNAs (miRNAs) are also considered promising targets for the development of effective therapies against skin wounds. However, further research in this field is anticipated. This study aims to identify and provide a new peptide drug candidate, as well as to explore the underlying miRNA mechanisms and possible miRNA drug target for skin wound healing.MethodsA combination of Edman degradation, mass spectrometry and cDNA cloning were adopted to determine the amino acid sequence of a peptide that was fractionated from the secretion of Odorrana andersonii frog skin using gel-filtration and reversed-phase high-performance liquid chromatography. The toxicity of the peptide was evaluated by Calcein-AM/propidium iodide (PI) double staining against human keratinocytes (HaCaT cells), hemolytic activity against mice blood cells and acute toxicity against mice. The stability of the peptide in plasma was also evaluated. The prohealing potency of the peptide was determined by MTS, scratch healing and a Transwell experiment against HaCaT cells, full-thickness injury wounds and scald wounds in the dorsal skin of mice. miRNA transcriptome sequencing analysis, enzyme-linked immunosorbent assay, real-time polymerase chain reaction and western blotting were performed to explore the molecular mechanisms.ResultsA novel peptide homodimer (named OA-GL17d) that contains a disulfide bond between the 16th cysteine residue of the peptide monomer and the sequence ‘GLFKWHPRCGEEQSMWT’ was identified. Analysis showed that OA-GL17d exhibited no hemolytic activity or acute toxicity, but effectively promoted keratinocyte proliferation and migration and strongly stimulated the repair of full-thickness injury wounds and scald wounds in the dorsal skin of mice. Mechanistically, OA-GL17d decreased the level of miR-663a to increase the level of transforming growth factor-β1 (TGF-β1) and activate the subsequent TGF-β1/Smad signaling pathway, thereby resulting in accelerated skin wound re-epithelialization and granular tissue formation.ConclusionsOur results suggest that OA-GL17d is a new peptide drug candidate for skin wound repair. This study emphasizes the importance of exogenous peptides as molecular probes for exploring competing endogenous RNA mechanisms and indicates that miR-663a may be an effective target for promoting skin repair.

Liver Dysfunction in Sternness Burn Injury in Association to Age Estimate: A Conceivable Role of Antioxidant Biomarker and Tumor Necrosis Factor Alpha

Background: Burn injuries represent one of the greatest public health problems that induce significant patient morbidity and mortality. Scalds are the most common cause of burn injuries which is known to have long term grave consequences on general health. Aim: The current study was performed to identify the age of scald burn from histopathological changes and TNF-α immunoexpression. As well, study the probable relation between the scald age and the hepatic function impairment. Materials and Methods: A total number of 40 adult male albino rats were used in the study. Eight kept as control group I. Thirty-two rats were exposed to scald injury involving 20% of total body surface area (TBSA). Histopathological examination for the scald area, liver, and skin TNF-α immunohistochemistry was performed. Liver function tests and liver tissue malondialdehyde (MDA) were also determined. The study was carried out after 2, 7 days, 1 and 3 months of scald incidence. Results: Progressive histopathological changes and elevated liver enzymes were observed in the early scald ages while manifestations of healing and improvement in liver parameters, started to occur after 1 and 3 months of scald infliction in comparison with the other periods. There was a highly significant (P < 0.001) increase in malondialdehyde level and TNF-α expression in scald injured groups after 2 and 7 days compared with control group I. Conclusion: Overall, the results showed the ability to identify the age of scald injury using routine histopathological examination. Also, scald injury involving 20% of TBSA may cause long term impairment of hepatic function. Moreover, the proinflammatory results revealed that TNF-α may consider as mediators in the post-burn pathophysiological process. Furthermore, our results declare a significant correlation between MDA levels and the degree of burn complications, including shock and remote organ damage.

Epidemiology of severe scald in 0–5–year-old children at the Department of Plastic and Reconstructive Surgery, Gauhati Medical College and Hospital – A 5-year retrospective study

Background: The 0–5-year-old age group has the highest incidence of scalds. In assessing a child with scalds, it will be beneficial to look at the interactions between the host, substance, mechanism, and environment. These factors have an effect on the degree, percentage, distribution, and pattern of injury sustained by the child. Subjects and Methods: This retrospective study comprised children aged 0–5 years who were admitted to the Burn Unit of the GMCH, Guwahati, with scald wounds between January 1, 2017, and December 31, 2021, for a period of 5 years. After receiving ethical committee approval, the records of the patients were gathered from the medical records department of GMCH, Guwahati, during this time period. Results: Majority of the incidences were found in male children aged 9–12 months. Scalds commonly occur in rural areas and indoor at home. The upper lower class had the most scald injuries and parents had a poor educational status. The most common substance was hot water in a vessel. The most common mechanism was for a child to pull a hot water down over themselves. In descending order, children suffered a significantly higher proportion of scalds to the hand, chest, and face. Conclusions: Children should be closely supervised by elders or parents, particularly in the kitchen while at home. Parents and caregivers should receive preventive education and training. All kitchen practices, such as floor cooking, low-level shelves, and keeping hot liquids in easily accessible places, should be avoided to prevent childhood scalds.

Skin Graft Versus Local Flaps in Management of Post-burn Elbow Contracture.

IntroductionContracture is a pathological scar tissue resulting from local skin tissue damage, secondary to different local factors. It can restrict joint mobility, resulting in deformity and disability. This study aimed to investigate the outcomes of skin grafts compared to local flaps to reconstruct post-burn elbow contractures. These parameters included regaining function, range of movement, recurrence, and local wound complications.MethodologyA retrospective study reviewed 21 patients for elbow reconstruction over 12 months. Only patients with post-burn elbow contracture were included. Other causes, including previous corrective surgery, associated elbow stiffness, and patients who opted out of post-operative physiotherapy, were excluded. Patients were categorized according to the method of coverage into three groups: graft alone (G1), local flap (G2), or combined approach (G3). ResultsFemales were three times at higher risk to suffer a burn injury, while almost half of the cases were children. Scald injury represented 81% of burn causes. G1,2,3 were used in 47.6%, 42.9% and 9.5% of cases retrospectively. The overall rate of infection was 28.6%. Hundred percent graft taken was recorded in 83.3 % of cases; however, flap take was 91.1%. After 12 months of follow-up, re-contracture was 60% and 22.8% in G1 and G2; however, the satisfaction rate was 70% and 100% in both groups retrospectively. The overall satisfaction was 85.7% in all groups.ConclusionGrafts and local flaps are reasonable options for post contracture release; however, flaps are superior. Coverage selection depends on the lost tissue area and exposure of underlying deep structures. Physiotherapy and patient satisfaction are crucial in the outcomes.

TREATMENT OF HUMAN SKIN BURNS THROUGH USING TILAPIA SKIN

Burns are medical conditions that are the fifth major reason behind non-fatal and adult injuries due to compulsiveness and a lack of risk calculation ability. 1.2 In Pakistan, 2500 children suffer serious burns that necessitate medical attention each year, with 15,000 requiring hospitalizations. The WHO (World Health Organization) has revealed in the reports that child burn mortality is greater (seven times) in countries with low and middle-income backgrounds compared to those with high incomes. Polypeptides of varied molecular weights were discovered in MCPs. These MCPs come from Nile tilapia’s skin with the help of enzyme-aided hydrolysis, with polypeptides with a molecular weight smaller than 5kDa accounting for 99.1 percent of the total. The key molecular conformations within MCPs were casual coil, according to FTIR. The MCPs application was done in the quantity of 50g/ml. The treatment significantly affected scratch closure in an in vitro scratch assay. MCPs improve wound healing in child burn skin with a deep partial-thickness scald wound. As a result, it was concluded that the MCPs derived from Nile tilapia‘s skin have promising wound care effects and results.

Integrated analysis of dysregulated microRNA and mRNA expression in intestinal epithelial cells following ethanol intoxication and burn injury

Gut barrier dysfunction is often implicated in pathology following alcohol intoxication and burn injury. MicroRNAs (miRNAs) are negative regulators of gene expression that play a central role in gut homeostasis, although their role after alcohol and burn injury is poorly understood. We performed an integrated analysis of miRNA and RNA sequencing data to identify a network of interactions within small intestinal epithelial cells (IECs) which could promote gut barrier disruption. Mice were gavaged with ~ 2.9 g/kg ethanol and four hours later given a ~ 12.5% TBSA full thickness scald injury. One day later, IECs were harvested and total RNA extracted for RNA-seq and miRNA-seq. RNA sequencing showed 712 differentially expressed genes (DEGs) (padj < 0.05) in IECs following alcohol and burn injury. Furthermore, miRNA sequencing revealed 17 differentially expressed miRNAs (DEMs) (padj < 0.1). Utilizing the miRNet, miRDB and TargetScan databases, we identified both validated and predicted miRNA gene targets. Integration of small RNA sequencing data with mRNA sequencing results identified correlated changes in miRNA and target expression. Upregulated miRNAs were associated with decreased proliferation (miR-98-3p and miR-381-3p) and cellular adhesion (miR-29a-3p, miR-429-3p and miR3535), while downregulated miRNAs were connected to upregulation of apoptosis (Let-7d-5p and miR-130b-5p) and metabolism (miR-674-3p and miR-185-5p). Overall, these findings suggest that alcohol and burn injury significantly alters the mRNA and miRNA expression profile of IECs and reveals numerous miRNA–mRNA interactions that regulate critical pathways for gut barrier function after alcohol and burn injury.

Scald Injury in Children

Scald Injury in Children

Combination of an engineered Lactococcuslactis expressing CXCL12 with light-emitting diode yellow light as a treatment for scalded skin in mice.

SummaryImpaired wound closure is an increasingly crucial clinical challenge. Recently, wound healing has shifted towards innovative treatments that exploit nanotechnology, biomaterials, biologics and phototherapy. Here, we constructed an engineered MG1363‐pMG36e‐mCXCL12 strain with pMG36e plasmid encoding stromal cell‐derived factor 1α (named CXCL12) and evaluated the synergistic effects of light‐emitting diode (LED) yellow light and MG1363‐pMG36e‐mCXCL12 on scald wounds in mice. The results indicated that the combined treatment with LED yellow light with mCXCL12 delivering strain accelerated wound closure, tissue remodelling, re‐epithelialization and hair follicle regeneration and inhibited over‐inflammation oppositely in the central and surrounding wounds by macroscopic, histopathologic and immunohistochemistry parameters. Furthermore, combination therapy increased the epidermal growth factor and Ki67‐positive cells and upregulated beta‐catenin (β‐catenin), cellular‐myelocytomatosis (c‐Myc), wingless‐type MMTV integration site family member 1 (Wnt1), Jagged 1, neurogenic locus notch homolog protein 1 (Notch 1) and hairy and enhancer of split 1 (Hes 1) protein levels of the Wnt and Notch signalling pathways. It also facilitated collagen fibrogenesis and deposition and improved the activities of hydroxyproline, superoxide dismutase and glutathione peroxidase in scalded granulation tissue, in addition to reducing the inflammatory factors interleukin 1 beta (IL‐1β) and tumour necrosis factor alpha (TNF‐α). The combined treatment effectively reduced skin pathogens Ralstonia and Acinetobacter to further reduce the risk of infection. Overall, combination of LED yellow light and MG1363‐pMG36e‐mCXCL12 represents a potential strategy for the treatment of cutaneous wounds.

What's New in Shock, July 2021?

What's New in Shock, July 2021?

Serum-derived exosomes accelerate scald wound healing in mice by optimizing cellular functions and promoting Akt phosphorylation.

Wound exudate holds great clinical and research potential in wound repair via paracrine signaling. In essence, exudate is modified serum that contains a high concentration of exosomes. The aim of this study was to investigate the role of serum-derived exosomes in scald wound healing of NIH mice skin and to explore the underlying mechanisms. Hence, we constructed a deep second-degree scald model in NIH mice, testing the benefits of exosomes in the scald wound healing. The scratch wound assay, apoptosis assay and MTT assay were conducted to assess the effects of serum-derived exosomes on migration, apoptosis and proliferation of HaCaT cells and fibroblasts. Our results showed that serum-derived exosomes injected subcutaneously entered cells and effectively accelerated wound healing processes in mice. Additionally, serum-derived exosomes optimized functions of cells related to skin injury repair by stimulating fibroblast proliferation, promoting HaCaT cell migration, and suppressing apoptosis of HaCaT cells induced by heat stress. Further study revealed that serum-derived exosomes enhanced phosphorylation of the serine-threonine kinase Akt in scalded skin tissue. These results suggest a potential clinical use of serum-derived exosomes for treating skin scald.

The cGAS-STING pathway connects mitochondrial damage to inflammation in burn-induced acute lung injury in rat

ObjectiveDamage associated molecular patterns (DAMPs) are pathological mediators linking local tissue damage to systemic inflammation in various diseases. Some DAMPs, such as mitochondrial DNA (mtDNA), can be recognized by the cytoplasmic cGAS protein to trigger the activation of the stimulator of interferon genes (STING)-dependent innate immune pathway responsible for infection or sterile inflammation. The objective of our study was to evaluate the association between circulating mtDNA and cGAS-STING pathway activation in mediating inflammation following burn injury. Methods48 adult Sprague-Dawley male rats were divided into eight groups (Sham, 2, 4, 8, 12, 24, 48, 72 h after burn injury). The animals underwent 40% total body surface area scald injury to produce a full-thickness burn. Plasma samples were collected via cardiac puncture under deep anesthesia. Tissues were harvested and placed in formalin, followed by paraffin embedment. Total plasma DNA was isolated followed by measurement of mtDNA using quantitative polymerase chain reaction. Haemotoxylin-Eosin stain and Western blot was used for lung histology and protein assays, respectively. Statistical analyses were performed using ANOVA and student’s t-test and represented as mean ± s.d. ResultsPlasma mtDNA trended upward at early time-points following burn injury with peak levels at 8 h after burn when compared to the control group (345 ± 83.4 copies/μl vs. 239 ± 43.1 copies/μl, p = 0.07) and followed a bell-shaped distribution. Lung slices from burned rats showed acute injury marked by increased inflammatory infiltrate, with the maximum changes seen at 24 h, accompanied with significant upregulation of neutrophil elastase (p = 0.04). Compared with sham animals, cGAS and STING protein levels in lung tissue were up-regulated at 4 and 8 h after burn (p = 0.03 and p < 0.001, respectively). ConclusionActivation of the cGAS-STING pathway by increased plasma mtDNA is an important pathway driving neutrophil infiltration in burn-induced acute lung injury in rats. A further understanding of the STING-mediated immunopathology in lung and other susceptible organs may be important for the development of novel therapies for burn injury.

84 Pediatric Scald Burns: Using Geographic Information Systems to Identify High Risk Communities

Abstract Introduction Identifying modifiable risk factors for pediatric scald burn injury prevention efforts is an important function for burn registries. Geographic information systems (GIS) analysis can provide additional census tract data about patient home and injury location. We hypothesize that (GIS) analysis of burn registry data using census tract data could identify geographic areas and additional risk factors for pediatric scald burn injury prevention efforts. Methods The burn registry of a U.S. regional burn center was used retrospectively to identify burn admissions, ages 0–17, within the county from 1/1/2018 to 7/31/2020. Data collected included demographics, vitals, burn type and body surface area burned (BSA%), hospital charges, length of stay, complications, and mortality. GIS geocoding of patient home addresses with census tract data including poverty level, languages spoken at home and highest educational level was performed. Burn incident hot spot analysis to identify statistically significant burn incident clusters was done using the Getis Ord Gi* statistic. Results There were 1057 burn initial admissions during the study period, 152 (14.3%) patients were children 17 and younger with scald injury who were county residents. The average age was 4.0 ± 4.0 years, and 59.9% were male. Mean scald injury BSA was 4.9% ± 5.7, 14/152 admissions (9.2%) had a burn ≥10% BSA. There were no in-hospital deaths. 120/728 county census tracts were identified as high risk with higher rates of child scald injury admissions than the countywide mean of 1.27 cases/1000 children. Regression analysis of high-risk census tracts were more likely to have increased poverty levels (O.R. 3.30, 95% C.I.: 1.1–9.7, p&amp;lt; 0.031) and lower educational attainment (O.R. 1.10, 95% C.I.: 1.0–1.18, p&amp;lt; 0.047). Non-white race, unemployment level, living with grandparents and speaking Spanish at home were non-significant risk factors. GIS analysis identified geographic hot spots for child scald injury admissions (p&amp;lt; 0.001). Conclusions GIS analysis of county burn registry data identified census tracts with increased poverty and lower educational attainment levels to have an increased risk of pediatric scald injury admission. Burn prevention efforts should be focused on these high-risk areas.

122 In Patients with Lower Extremity Burns and Osteomyelitis, Diabetes Mellitus Increases Amputation Rate

Abstract Introduction Diabetes mellitus (DM) is a critical comorbidity with burn injury due to the disrupted healing process. Previous reports have confirmed the increased rate of osteomyelitis (OM) and subsequent amputation in this cohort, however this has yet to be studied in comparison to non-diabetic patients. In this retrospective analysis, we investigate OM and amputation in both the diabetic and non-diabetic lower extremity burn populations to determine the impact of DM on these outcomes. Methods The burn registry was used to identify all patients admitted to our tertiary burn center from January 1, 2014 to December 31, 2018. Only patients with lower extremity burns (foot and/or ankle) were included. Patients with burns to additional body areas were excluded. Amputations were categorized by time from injury. Statistical analysis was performed using Student’s t test, chi-squared test, and Fischer’s exact test. Results Of the 315 patients identified, 103 had a known diagnosis of DM and 212 did not. Scald injury was the most common mechanism and average TBSA was similar. Differences were observed in average length of stay (LOS) and admission cost, with diabetics demonstrating both a higher LOS (13.7 days vs 9.2 days, p-value= 0.0016) and cost ($72,883 vs $50,500, p-value= 0.0058) (Table 1). In total, 17 patients were found to have radiologically confirmed OM within three months of the burn injury. Fifteen of these patients had a history of DM and two had no history of DM (p-value= &amp;lt; 0.001) (Table 2). The DM OM patients were found to have a higher blood glucose level on admission (219 mg/dL vs 110 mg/dL, p-value= 0.0452). No significant difference was seen in Hgb A1c in diabetics with or without OM (9.26% vs 8.81%, p= 0.2743). Notably, when non-diabetics were diagnosed with OM, significant differences were observed in both LOS and cost in comparison to their counterparts without OM (36 days vs 9 days; p= 0.0003; $226,289 vs $48,818, p=0.0001). Of the 11 patients who required an amputation, 10 (90.9%) of these patients had comorbid DM. Conclusions DM patients with lower extremity burns are more likely to develop OM than their non-diabetic counterparts. When radiologically confirmed OM is present, DM patients have an increased rate of amputation. OM incurs significant healthcare utilization and cost in both the diabetic and non-diabetic populations.