Sex-Based Differences in Inpatient Burn Mortality

Sex Differences, Age, and Burn Size Contribute to Risk of PTSD and Depression After Burn Injury

The prevalence of psychological symptoms in burn survivors has been well documented; however, the role of biological sex requires further investigation. This study explored sex differences among burn survivors and examined the impact of sex, age, and total body surface area (TBSA) of the burn injury on the risk of developing posttraumatic stress disorder (PTSD) and depression and, subsequently, the influence of initial risk on symptom outcomes 30 days postinjury. Participants included 374 adult patients enrolled in the Burn Behavioral Health program at a regional Burn Center. T-tests and chi-square tests were conducted to determine differences between sexes on outcome measures. A path analysis was conducted to evaluate relationships between variables of interest. Findings revealed significant sex discrepancies in risk and symptom outcomes. Compared to men, women reported greater total risk scores of developing PTSD and depression (P = .005) early after their burn injury. A subscale analysis showed that women reported greater risk scores for depression (P < .001), but not on PTSD. Women did not report higher depression scores 30 days postinjury compared to men but did report higher PTSD scores than men (P = .020). When sex, age, and TBSA were included in a path analysis, female sex (P = .001), younger age (P < .001), and larger TBSA of the burn injury (P = .024) were associated with greater risk. In addition, risk scores significantly predicted PTSD (P < .001) and depression (P < .001) symptoms 30 days postinjury. Our research shows how sex, age, and TBSA affect the risk of PTSD and depression among burn survivors. It underscores the importance of accounting for sex and age differences in mental health risk, especially in women and younger patients. This emphasizes the urgency of early screening and intervention.

Reducing the excessive inflammation after burn injury in aged mice by maintaining a healthier intestinal microbiome

One in six people are projected to be 65 years or older by 2050. As the population ages, better treatments for injuries that disproportionately impact the aged population will be needed. Clinical studies show that people aged 65 and older experience higher rates of morbidity and mortality after burn injury, including a greater incidence of pulmonary complications when compared to younger burn injured adults, which we and others believe is mediated, in part, by inflammation originating in the intestines. Herein, we use our clinically relevant model of scald burn injury in young and aged mice to determine whether cohousing aged mice with young mice or giving aged mice oral gavage of fecal material from young mice is sufficient to alter the microbiome of the aged mice and protect them from inflammation in the ileum and the lungs. Aged burn injured mice have less DNA expression of Bacteroidetes in the feces and an unhealthy Firmicutes/Bacteroidetes ratio. Both Bacteroidetes and the ratio of these two phyla are restored in aged burn injured by prior cohousing for a month with younger mice but not fecal transfer from young mice. This shift in the microbiome coincides with heightened expression of danger-associated molecular patterns (DAMP), and pro-inflammatory cytokine interleukin-6 (il6) in the ileum and lung of aged, burn injured mice, and heightened antimicrobial peptide camp in the lung. Cohousing reverses DAMP expression in the ileum and lung, and cathelicidin-related antimicrobial peptide protein (camp) in the lung, while fecal transfer heightened DAMPs while reducing camp in the lung, and also increased IL-6 protein in the lungs. These results highlight the importance of the intestinal microbiome in mediating inflammation within the gut-lung axis, giving insights into potential future treatments in the clinic.

A Meta-Analysis of the Mortality and the Prevalence of Burn Complications in Western Populations

Management of burn injuries is complex, with highly variable outcomes occurring among different populations. This meta-analysis aims to assess the outcomes of burn therapy in North American and European adults, specifically mortality and complications, to guide further therapeutic advances. A systematic review of PubMed, Web of Science, and Cochrane was performed. Random-effect meta-analysis of proportions was conducted to assess the overall prevalence of the defined outcomes. In total, 54 studies were included, pooling 60 269 adult patients. A total of 53 896 patients were in North America (NA, 89.4%), and 6373 were in Europe (10.6%). Both populations experienced similar outcomes. The overall pooled prevalence of mortality was 13% (95% CI, 8%-19%) for moderate burns, 20% (95% CI, 12%-29%) for severe burns in the NA region, and 22% (95% CI, 16%-28%) for severe burns in Europe. Infectious complications were the most common across both regions. European studies showed an infection rate for patients with moderate and severe burns at 8% and 76%, respectively, while NA studies had rates of 35% and 54%. Acute kidney injury (39% vs 37%) and shock (29% vs 35%) were the next most common complications in European and NA studies, respectively. The length of stay was 27.52 days for patients with severe burns in Europe and 31.02 days for patients with severe burns in NA. Burn outcomes are similar between Western populations. While outcomes are reasonably good overall, infectious complications remain high. These findings encourage the development of further therapeutic strategies disclosing respective costs to enable cost/efficiency evaluations in burn management.

Precursors to oliguria during major burn resuscitation: An analysis of a prospective observational trial at 5 major US burn centers

Currently, urine output is the leading variable used to tailor fluid resuscitation in patients with large TBSA burns. However, this metric often lags with respect to resuscitation. Our group sought to identify derangements in variables that precede development of oliguria (<30 cc/hr) that we hypothesize will aid in more efficient resuscitation. We performed a retrospective analysis of 146 adult patients admitted within 4 h of a large TBSA (>20%) burn. We then divided them into two cohorts: those who developed oliguria within 6 h of admission and those who did not. Patients who experienced early oliguria had a higher incidence of invasive SBP < 90 (p = 0.02) or DBP < 40 (p = 0.009), lower minimum bicarbonate level (p = 0.04), more full thickness burns (p = 0.004), and higher TBSA (p = 0.01). More female patients were found in the oliguric group (p = 0.003). Multivariate analysis was used to develop a model to predict development of oliguria. When evaluated together, minimum DBP, sex, TBSA (or percent full thickness burn), and maximum base deficit constituted the most parsimonious model that significantly predicted oliguria (AUC = 0.92). Interestingly, the model lost significance when DBP was omitted, highlighting the importance of diastolic pressure in the development of oliguria.

Epidemiology of Burn Injuries Among Adult Females in Southern Iran; A Retrospective Study from 2007 to 2022

Burn-by flame, flush, scald, electrical, and chemical types-accounts for 5%-12% of trauma injuries worldwide. In Iranian studies, females were the main victims of domestic burns with higher mortality and frequencies. This retrospective study evaluates the epidemiology and etiology of burn injuries in females aged 25-64 years between October 2007 and May 2022 in southern Iran. Demographics and burn etiology information were collected by questionnaires at admission. Univariate and multivariate regression analysis was used to determine the relationship between variables and burn mortality. Pearson's Chi-Square and One-way ANOVA tests were utilized to compare different burn etiologies. Of 3212 females with burn injuries, 1499 (46.6%) were included with a mean age of 38.5 ± 10.8 years. Flame (59.7%) and flush (28.9%) were significantly the most common injuries mechanism. Burn was most common in rural areas (53.9%) and indoor settings (62.1%) (P-value < .001). 77.9% of the population were under-diploma (P-value < .001), and 3.5% were divorced with higher burn-suicide attempts. The mean Total Body Surface Area (TBSA%) was 41.1 ± 28.3%, and the mean Length of Stay (LOS) was 14.5 ± 13.2 days with a 39.1% mortality rate. With univariate and multivariate analysis, TBSA%, indoor places, flame, flush, and urban living were risk factors for burn mortality. Briefly, flame in indoor settings is the most common type of burn injury affecting adult females with lower educational levels living in rural areas. Such epidemiological studies of burns in adult females may be helpful for health policymakers to develop burn prevention programs.

Sex-Related Mortality After Burns: A Scoping Review in the Sadc-Region

Findings on mortality by sex after burns in low- and middle-income countries (LMICs) are contradictory and, where differences have been described, the reasons are often based on speculation and not on the analysis of factors that could have affected the outcome, such as patient or injury characteristics or provided care. Since the paucity of studies on burns from single LMICs is notorious, merging data from neighboring countries with similar socio-economic backgrounds might provide a larger dataset, contributing to identifying recurrent causes. This scoping review aimed therefore to analyze differences in mortality after burns between the sexes, as well as to identify aspects that could explain possible differences, in countries belonging to the South African Development Community (SADC) region. Studies in English published between 2010 and 2020 were identified according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines by searching PubMed and/or Medline, Clinical Trials and Cochrane Library, and using the screening tool "Covidence". The 13 included studies could not consistently show association between sex and mortality after burns, but contradictory findings. In the case of differences in outcome between the sexes, explanations were mainly based on speculation (e.g., hormonal differences, self-harm intention), while rarely burn specific factors were reported and included in the analysis of the mortality risk. This study indicates the need for prospective burn specific data collection in LMICs that would contribute to identifying factors associated with death.

Global Disparities in Burn Outcomes: Does Gender Predict Mortality in the Global Burn Registry?

INTRODUCTION

Global burn injury burden disproportionately impacts low- and middle-income countries. Surgery is a mainstay of burn treatment, yet access to surgical care appears to be inequitably distributed for women. This study sought to identify gender disparities in mortality and access to surgery for burn patients in the World Health Organization Global Burn Registry (GBR).

METHODS

We queried the World Health Organization GBR for a retrospective cohort (2016-2021). Patients were stratified by sex. Outcomes of interest were in-hospital mortality and surgical treatment. Patient demographics, injury characteristics, outcomes, and health facility resources were compared between sexes with Wilcoxon rank sum test for nonparametric medians, and chi-squared or Fisher's exact test for nonparametric proportions. Multivariable logistic regressions were performed to assess the relationships between sex and mortality, and sex and surgery.

RESULTS

Of 8445 patients in the GBR from 20 countries (10 low resource), 40% of patients were female, with 51% of all patients receiving surgical treatment during their hospitalization. Female patients had a higher incidence of mortality (24% versus 15%, P < 0.001) and a higher median total body surface area (20% versus 15%, P < 0.001), yet a lower incidence of surgery (47% versus 53%, P < 0.001) following burn injury when compared to males. In multivariable analysis, female sex was independently associated with mortality after controlling for age, time to presentation, smoke injury, percent total body surface area, surgery, and country income status. Female sex was independently associated with surgical care (odds ratio 0.86, P = 0.001).

CONCLUSIONS

Female burn patients suffer higher mortality compared to males and are less likely to receive surgery. Further study into this gender disparity in burns is warranted.

Cutaneous burn injury induces neuroinflammation and reactive astrocyte activation in the hippocampus of aged mice

BACKGROUND

By 2050, one in six people globally will be 65 or older. Confusion and delirium are significant complications after burn injury, especially in the elderly population. The etiology is still unknown, however complications may be driven by pro-inflammatory activation of astrocytes within the hippocampus (HPC) after burn injury. Reduced levels of phosphorylated cyclic-AMP response binding element (pCREB), caused by elevated systemic pro-inflammatory cytokines, could lead to cognitive decline and memory impairment.

METHODS

To examine the effects of remote injury on neuroinflammation in advanced age, young and aged mice were subjected to a 15 % total body surface area scald burn or sham injury, and euthanized after 24 h. Expression of ccl2 and tnfa were measured by qPCR in the whole brain and HPC. Astrocyte activation was measured by immunofluorescence within the HPC. pCREB was measured by immunohistochemistry in the dentate gyrus.

RESULTS

We saw an 80-fold increase in ccl2 and a 30-fold elevation in tnfa after injury in the whole brain of aged mice compared to young groups and aged sham mice (p < 0.05 and p < 0.05, respectively). Additionally, there was a 30-fold increase in ccl2 within isolated HPC of aged injured mice when compared to sham injured animals (p < 0.05). When investigating specific HPC regions, immunofluorescence staining showed a >20 % rise in glial fibrillary acidic protein (GFAP) positive astrocytes within the cornu ammonis 3 (CA3) of aged injured mice when compared to all other groups (p < 0.05). Lastly, we observed a >20 % decrease in pCREB staining by immunohistochemistry in the dentate gyrus of aged mice compared to young regardless of injury (p < 0.05).

CONCLUSIONS

These novel data suggest that remote injury in aged, but not young, mice is associated with neuroinflammation and astrocyte activation within the HPC. These factors, paired with an age related reduction in pCREB, could help explain the increased cognitive decline seen in burn patients of advanced age. To our knowledge, we are the first group to examine the impact of advanced age combined with burn injury on inflammation and astrocyte activation within the brain.

Age and Injury Size Influence the Magnitude of Fecal Dysbiosis in Adult Burn Patients

Clinical studies have demonstrated that age 50 years or older is an independent risk factor associated with poor prognosis after burn injury, the second leading cause of traumatic injuries in the aged population. While mechanisms driving age-dependent postburn mortality are perplexing, changes in the intestinal microbiome, may contribute to the heightened, dysregulated systemic response seen in aging burn patients. The fecal microbiome from 22 patients admitted to a verified burn center from July 2018 to February 2019 was stratified based on the age of 50 years and total burn surface area (TBSA) size of ≥10%. Significant differences (P = .014) in overall microbiota community composition (ie, beta diversity) were measured across the four patient groups: young <10% TBSA, young ≥10% TBSA, older <10% TBSA, and older ≥10% TBSA. Differences in beta diversity were driven by %TBSA (P = .013) and trended with age (P = .087). Alpha diversity components, richness, evenness, and Shannon diversity were measured. We observed significant differences in bacterial species evenness (P = .0023) and Shannon diversity (P = .0033) between the groups. There were significant correlations between individual bacterial species and levels of short-chain fatty acids. Specifically, levels of fecal butyrate correlated with the presence of Enterobacteriaceae, an opportunistic gut pathogen, when elevated in burn patients lead to worsen outcomes. Overall, our findings reveal that age-specific changes in the fecal microbiome following burn injuries may contribute to immune system dysregulation in patients with varying TBSA burns and potentially lead to worsened clinical outcomes with heightened morbidity and mortality.

Prevalence and predictors of scar contracture-associated re-hospitalisation among burn inpatients in China

Scar contracture, a common destructive complication causing increased re-hospitalisation rate of burn survivors and aggravated burden on the medical system, may be more seriously in Chinese population because of their higher susceptibility to scar formation. This study aims to evaluate the prevalence and predictors of scar contracture-associated re-hospitalisation among Chinese burn inpatients. This cross-sectional study screened burn inpatients hospitalised during 2013 to 2018 through the Hospital Quality Monitoring System database, among whom re-hospitalised for scar contracture were identified. Variables including sex, age, occupations, burn area, burn site and surgical treatment were analysed. Potential predictors of scar contracture-associated re-hospitalisation among burn inpatients were determined by univariate regression analyses. Of the 220,642 burn inpatients, 2146 (0.97%) were re-hospitalised for scar contracture. The re-hospitalised inpatients were predominantly men and blue-collar workers, showing younger median age at the time of burns, larger burn sizes, and higher percentage of surgical treatment compared other burn inpatients. Significant univariate predictors of scar contracture-associated re-hospitalisation included male sex, age < 50 years, blue-collar work, ≥ 40% total body superficial area burned, inhalation injured, and surgical treatment. Scar contracture is an intractable complication and a significant factor to increase re-hospitalisation rate among Chinese burn inpatients.

Epidemiology And Outcomes Of Radiator Burns At A High Throughput Burns Centre

Indoor radiator burns can cause significant morbidity and mortality, especially in vulnerable patients. However, the epidemiology and clinical outcomes are poorly characterized. A retrospective study of all radiator burns referred to a tertiary regional burns centre between 2013-2019 was conducted. Four hundred and forty-seven patients (median age 25.6 years, male:female ratio 1.4:1) were referred; 109 (24%) admitted, 201 (45%) managed in outpatients and 137 (31%) managed locally. The incidence of burns leading to referral was 0.65/100,000/year, but increased annually. Contact burns consisted of 99.6%. Age distribution was bimodal: <5 years (43%), >65 years (27%), although all ages were affected. Median TBSA was 0.75% (0.1-11.5%), but 79% had injuries <2%. Childhood burns were predominantly superficial dermal grab injuries, usually manageable as outpatients. Elderly patients had larger burns usually secondary to falls or impaired sensorium, and were more likely to die (p<0.05). Burns due to impaired sensorium were deeper and more likely to require surgery (p<0.05). Sixty-three (14%) patients required surgery. Thirty-day mortality was 1.1%. Age was the only significant predictor of mortality. This study quantifies the epidemiology and outcomes of a growing problem. It identifies at risk populations (extremes of age), and important features of the clinical assessment.

Factors contributing to the restoration of normothermia after hypothermia in people with a major burn injury in the first 24 h of hospital admission

BACKGROUND

People with burn injury experiencing hypothermia are at risk of serious complications such as shock, multisystem organ failure, and death. There is limited information available for health professionals with regard to factors that contribute to restoration of normothermia after hypothermia in people with a major burn injury.

OBJECTIVE

The aim of the study was to identify factors that contribute to normothermia restoration after hypothermia in people with 10% or more total body surface area (TBSA) burn in the first 24 h of admission to a burn care hospital.

METHODS

The study was guided by the Gearing Framework for retrospective chart audit. The sample comprised medical charts of all adult people (n = 113) with a burn injury more than 10% of their TBSA admitted to a single-site burn care hospital intensive care unit in Victoria, Australia, between May 31, 2013, and June 1, 2015. Descriptive statistics were used to describe the sample, and logistic regression was conducted to predict variables contributing to return to normothermia in people with burn injury. Charts with incomplete data were excluded.

FINDINGS

The sample (n = 50) recorded a median initial temperature on admission to the emergency department (ED) of 35.4°C (range = 31.9-37.2°C) and took on an average of 6.2 (standard deviation [SD] = 4.96) hours to return to normothermia (36.5°C). Women took around 6 h longer than men to return to normothermia (mean = 11.14 h, SD = 5.58; mean = 5.38 h, SD = 4.41). Positive correlations were noted between TBSA%, the length of time between admission to the ED and the intensive care unit, and the hours taken to reach normothermia. Regression analysis suggests the initial recorded temperature on admission to the ED was the main predictor of the time body temperature takes to return to normothermia (β = .513, p < .001).

CONCLUSION

This study provides information for practice changes by highlighting the need for guidelines and education programs for health professionals to ensure the delivery of optimum care to people with burn injury.

Burns Impair Blood-Brain Barrier and Mesenchymal Stem Cells Can Reverse the Process in Mice

Neurological syndromes are observed in numerous patients who suffer burns, which add to the economic burden of societies and families. Recent studies have implied that blood-brain barrier (BBB) dysfunction is the key factor that induces these central nervous system (CNS) syndromes in peripheral traumatic disease, e.g., surgery and burns. However, the effect of burns on BBB and the underlying mechanism remains, largely, to be determined. The present study aimed to investigate the effect of burns on BBB and the potential of umbilical cord-derived mesenchymal stem cells (UC-MSCs), which have strong anti-inflammatory and repairing ability, to protect the integrity of BBB. BBB permeability was evaluated using dextran tracer (immunohistochemistry imaging and spectrophotometric quantification) and western blot, interleukin (IL)-6, and IL-1β levels in blood and brain were measured by enzyme-linked immunosorbent assay. Furthermore, transmission electron microscopy (TEM) was used to detect transcellular vesicular transport (transcytosis) in BBB. We found that burns increased mouse BBB permeability to both 10-kDa and 70-kDa dextran. IL-6 and IL-1β levels increased in peripheral blood and CNS after burns. In addition, burns decreased the level of tight junction proteins (TJs), including claudin-5, occludin, and ZO-1, which indicated increased BBB permeability due to paracellular pathway. Moreover, increased vesicular density after burns suggested increased transcytosis in brain microvascular endothelial cells. Finally, administering UC-MSCs at 1 h after burns effectively reversed these adverse effects and protected the integrity of BBB. These results suggest that burns increase BBB permeability through both paracellular pathway and transcytosis, the potential mechanism of which might be through increasing IL-6 and IL-1β levels and decreasing Mfsd2a level, and appropriate treatment with UC-MSCs can reverse these effects and protect the integrity of BBB after burns.

Insulin Modulates Myogenesis and Muscle Atrophy Resulting From Skin Scald Burn in Young Male Rats

BACKGROUND

Burn injuries (BIs) due to scalding are one of the most common accidents among children. BIs greater than 40% of total body surface area are considered extensive and result in local and systemic response. We sought to assess morphological and myogenic mechanisms through both short- and long-term intensive insulin therapies that affect the skeletal muscle after extensive skin BI in young rats.

MATERIALS AND METHODS

Wistar rats aged 21 d were distributed into four groups: control (C), control with insulin (C + I), scald burn injury (SI), and SI with insulin (SI + I). The SI groups were submitted to a 45% total body surface area burn, and the C + I and SI + I groups received insulin (5 UI/Kg/d) for 4 or 14 d. Glucose tolerance and the homeostatic model assessment of insulin resistance index were determined. Gastrocnemius muscles were analyzed for histopathological, morphometric, and immunohistochemical myogenic parameters (Pax7, MyoD, and MyoG); in addition, the expression of genes related to muscle atrophy (MuRF1 and MAFbx) and its regulation (IGF-1) were also assessed.

RESULTS

Short-term treatment with insulin favored muscle regeneration by primary myogenesis and decreased muscle atrophy in animals with BIs, whereas the long-term treatment modulated myogenesis by increasing the MyoD protein. Both treatments improved histopathological parameters and secondary myogenesis by increasing the MyoG protein.

CONCLUSIONS

Treatment with insulin benefits myogenic parameters during regeneration and modulates MuRF1, an important mediator of muscle atrophy.