Support of the metabolic response to burn injury

THE RISKS OF FIRST ONSET PRIMARY HYPERTENSION DIAGNOSIS IN THERMAL-INJURED PATIENTS

ABSTRACT

Introduction: Hypertension is a prevalent condition in the United States and leads to an increased risk of developing various comorbidities. However, the impact of new-onset hypertension after severe burns on patient outcomes is not known. We posit that hypertension onset after severe burn is associated with increased risk of developing comorbidities and mortality. Methods: Using the TriNetX database, burned patients diagnosed with essential hypertension after injury were compared with those who did not develop hypertension; neither had prior hypertension. Each cohort was grouped by sex, percent total body surface area (TBSA) burned, and age, then propensity matched for sex, race, ethnicity, and laboratory values. Outcomes assessed were acute kidney injury (AKI), hyperglycemia, heart failure, myocardial infarction (MI), and death. Results: Those diagnosed with hypertension after severe burn were 4.9 times more likely to develop AKI, 3.6 times for hyperglycemia, 5.3 times for heart failure, 4.7 times for acute MI, and 1.5 times for mortality. Sex analysis shows that men were at greater risk for AKI (1.5 times), heart failure (1.1 times), and death (1.4 times). Women were 1.3 times more likely to develop hyperglycemia. Percent TBSA burned grouping showed increased risk for all outcomes with increasing severity. Age grouping indicated an elevated risk of developing AKI, heart failure, acute MI, and death. Conclusion: New-onset hypertension diagnosis in severely burned patients is associated with acute kidney injury, heart failure, acute MI, and death. Overall, males, older patients, and those with a higher % TBSA burned are at a higher risk of developing these comorbidities.

Health-related quality of life after burn injury due to bioethanol-fueled fireplaces

OBJECTIVE

Commercially available bioethanol-fueled fireplaces are a potential source of burns and are commonly used for home use. The present study aimed to evaluate the quality of life following burn injuries that were caused by bioethanol-related accidents.

METHODS

Burned patients who were admitted to our burn unit with burn injury due to bio-ethanol fueled fire places between January 2010 and December 2021 were contacted to ask for their willingness to participate in this study. They were asked to answer questions regarding the circumstances of the accident and three questionnaires to capture burn specific and general health related quality of life (Burn Specific Health Scale-Brief (BSHS-B), Short-Form Health Survey 36 (SF-36)) and general information about the accident. Patients were matched and compared to a group of patients suffering comparable burns from other burn mechanisms, which were also admitted to our burn unit at the same time.

RESULTS

Of 35 patients that met the inclusion criteria, 19 answered the questionnaire and were compared to 38 patients with other burn mechanisms. There were no statistical differences regarding age (bioethanol: 37.4 ± 14.7 years vs. control: 36.2 ± 14.3 years, p = 0.777), TBSA (9.9 ± 6.8% vs. 8.9 ± 10.4, p = 0.715), and sex (42.1% females vs. 36.8% females, p = 0.882). Most patients in the bioethanol-group reported that they did not follow the manual instructions (68.4%) and that the accident happened during the refilling process (52.6%). There was no significant difference in any subscale of the BSHS-B or the SF-36.

DISCUSSION

Burns related to bioethanol-fueled fireplaces are rare compared to other typical burn mechanisms. However, as they are used for personal pleasure and interior design, psychological impairment following burn may be even more critical. Detailed education on the use of these fireplaces needs to take place in order to reduce the risk of accidents.

Correlation of thermal burn hepatic dysfunction with outcomes

INTRODUCTION

Organ dysfunction and failure increase the morbidity and mortality following major burn. Alteration of liver morphology and function is common following major burns; however, it has not received much attention. In this study we have assessed the impact of thermal burn on liver in relation with mortality.

MATERIAL AND METHODS

55 patients (33 female and 22 males) with TBSA 10-90% and age ranged from 18 to 75 years were included. A bed side serial ultrasonography to assess the volume of liver and liver function tests was done on the 2nd, 9th and 16th day following burn. Baseline demographic and clinical information such as age, gender, burn size and outcome of patient were also collected.

RESULTS -

8 patients died during 2nd week following burn and 47 survived. The mean TBSA for survivors was 37% and for non survivors 80%. Mean liver volume in survivors steadily decreased from 1693.70 cm3 to 1631.31 cm3 over 3 weeks. Mean liver volume in non- survivors steadily increased from 1855.88 cm3 to 2028.50 cm3 over 2 weeks. Liver function test in survivors steadily improved while in non survivors it deteriorated over 2 weeks.

CONCLUSION

There is a correlation between altered liver morphology and function with mortality among severely burnt patients however liver volume did not show statistical significance. A decreasing trend of liver dysfunction parameters and hepatomegaly following burn is associated with good prognosis.

Effects of hydrolyzed collagen alone or in combination with fish oil on the gut microbiome in patients with major burns

Burns are associated with gut dysbiosis. Collagen peptides and omega-3 fatty acids (FAs) are suggested to improve wound healing and the inflammatory response. These are also correlated with microbiome colonization. Therefore, the present study aimed to investigate the effect of hydrolyzed collagen alone or in combination with fish oil on specific species of the gut microbiome in patients with major burns. In this randomized double-blind clinical trial, 57 adults (aged 18-60 years) with 20-45% total body surface area burns were randomised into three groups to receive either 40 gr hydrolyzed collagen +10 ml sunflower oil, 40 g hydrolyzed collagen +10 ml fish oil or placebo, divided into two daily drinks, for two weeks. Gut bacteria were measured using the real-time quantitative polymerase chain reaction (qPCR) method. The mean concentration of Bifidobacterium was significantly reduced in the control (P = 0.002) and collagen (P = 0.005) groups compared with the baseline values, whereas no significant change was observed in the collagen omega-3 group. The Firmicutes to Bacteroidetes ratio decreased significantly in the collagen group (p = 0.002) after supplementation compared to baseline . No significant changes in concentration of Lactobacillus, Enterobacteriaceae, and F.prausnitzii were observed between or within the study groups. Two weeks of supplementation with collagen and omega-3 FAs in patients with major burns did not result in a significant difference in the concentration of bacteria measured between the study groups. However, the addition of omega-3 FAs prevented a significant reduction in gut Bifidobacterium. Future studies are suggested to investigate the potential efficacy of these nutrients in improving the gut microbiota and clinical outcomes in major burns. REGISTRATION NUMBER: IRCT20131125015536N9.

The Effect of Burns on Children's Growth Trajectory: A Nationwide Cohort Study

This study evaluates the short- and long-term effect of burns on children's height and weight, by comparing their pre and postburn growth trajectory. We invited children (≤17 years old), who sustained a burn requiring surgical treatment or admission at one of the Dutch burn centers in 2013 (n = 175). As well as children who sustained a severe burn, covering >10% of the total body surface area (TBSA), throughout 2009-2018 (n = 228). Data was collected from a survey on health-related topics, Youth Health Care records, and the Dutch Burn Repository R3. For all participants, height and weight were converted to Z-scores using Dutch reference values. Linear mixed modeling, nested on the individual level, was used to examine the associations between burns and children's height and weight Z-scores. Children's height and weight Z-scores remained within the normal range throughout the study period. During the first-year postburn, children's height and weight Z-scores decreased by -0.21 (95% CI -0.41, -0.01) and -0.23 (95% CI -0.46, -0.04), respectively. Beyond the first-year postburn, estimates were consistent with a positive linear association between burn size and the overall effect of burns on participants' height and weight Z-scores. This included a modest, but statistically significant, effect among participants with a burn covering ≤4.5% and >14.0% of the TBSA. Sensitivity analyses did not alter our findings. In conclusion, children were on track or even surpassed their growth potential. Our findings could therefore be considered reassuring to patients, parents, and clinicians.

Children's growth and motor development following a severe burn: a systematic review

Background

The epidemiological data on post-burn growth, body composition and motor development is ambiguous and scattered. The aim of this systematic review was therefore to summarize the current body of evidence on post-burn growth, body composition and motor development in children.

Methods

A literature search was conducted in PubMed, EMBASE and Web of Science up to March 2021. We considered observational studies that reported (1) metrics on weight, height, body composition, bone mineral content, bone mineral density or motor development, in (2) paediatric burn patients and (3) published in a peer-reviewed journal.

Results

A total of 16 studies were included. Each of the included studies used quantitative methods, but with differing methodology: prospective cohort studies (n = 8), retrospective chart reviews (n = 3), case-control studies (n = 2), cross sectional studies (n = 2) and a retrospective cohort study (n = 1). When combined, the included studies represented 2022 paediatric burn patients, with a mean age of 7.7 (±3.2) years. The average burn size was 52.8% (±12.7) of the total body surface area. Identified outcome measures included weight (n = 12), height (n = 7), muscular strength (n = 4), bone mineral content (n = 5), bone mineral density (n = 5), body mass index (n = 3), fat mass (n = 5), lean body mass (n = 7) and fine and gross motor development (n = 1).

Conclusions

Following an initial decline, patients' growth and motor development started to recover during the first or second year post-burn. Nonetheless, burns may have a profound and prolonged effect on the paediatric burn patients' muscular strength, bone mineral content and lean body mass. It should be noted that the vast majority of studies included only patients with burns covering ≥30% total body surface area. The evidence presented in this review may thus not be representative of the whole paediatric burn population.

Cardiometabolic disease risk markers are increased following burn injury in children

Introduction

Burn injury in children causes prolonged systemic effects on physiology and metabolism leading to increased morbidity and mortality, yet much remains undefined regarding the metabolic trajectory towards specific health outcomes.

Methods

A multi-platform strategy was implemented to evaluate the long-term immuno-metabolic consequences of burn injury combining metabolite, lipoprotein, and cytokine panels. Plasma samples from 36 children aged 4-8 years were collected 3 years after a burn injury together with 21 samples from non-injured age and sex matched controls. Three different ¹H Nuclear Magnetic Resonance spectroscopic experiments were applied to capture information on plasma low molecular weight metabolites, lipoproteins, and α-1-acid glycoprotein.

Results

Burn injury was characterized by underlying signatures of hyperglycaemia, hypermetabolism and inflammation, suggesting disruption of multiple pathways relating to glycolysis, tricarboxylic acid cycle, amino acid metabolism and the urea cycle. In addition, very low-density lipoprotein sub-components were significantly reduced in participants with burn injury whereas small-dense low density lipoprotein particles were significantly elevated in the burn injured patient plasma compared to uninjured controls, potentially indicative of modified cardiometabolic risk after a burn. Weighted-node Metabolite Correlation Network Analysis was restricted to the significantly differential features (q <0.05) between the children with and without burn injury and demonstrated a striking disparity in the number of statistical correlations between cytokines, lipoproteins, and small molecular metabolites in the injured groups, with increased correlations between these groups.

Discussion

These findings suggest a 'metabolic memory' of burn defined by a signature of interlinked and perturbed immune and metabolic function. Burn injury is associated with a series of adverse metabolic changes that persist chronically and are independent of burn severity and this study demonstrates increased risk of cardiovascular disease in the long-term. These findings highlight a crucial need for improved longer term monitoring of cardiometabolic health in a vulnerable population of children that have undergone burn injury.

Exploring the Past to Inform the Future to Optimize the Pharmacokinetics of Vancomycin in Children With Severe Burn Injuries

Sepsis remains one of the leading causes of death among pediatric patients with burn injuries. Despite limited vancomycin pharmacokinetic (PK) information within this population, it is widely used to treat severe burn injuries. Those with severe burns are at risk of nephrotoxicity, with an incidence of acute kidney injury (AKI) over 50%. Delivering an effective vancomycin dose and avoiding unnecessary toxicity is essential for improved patient outcomes. This was a retrospective analysis of 115 children aged 0.2 months to 18 years with severe burns, >10% total body surface area. Vancomycin was given via intravenous infusion; blood samples were drawn between 6- and 12-hour postinfusion. A population pharmacokinetic model was developed using nonlinear mixed-effect modeling (Monolix, version 2016R1). A one-compartment model described a steady-state volume of distribution (V), dependent on weight. Vancomycin clearance (CL) was influenced by age and estimated creatinine clearance (CrCL). The study population's (median age = 4 years, median weight = 20 kg, median total body surface area (%TBSA) = 40%) median V and CL were calculated to be 1.25 L/kg (95% CI, 1.04-1.46) and 0.15 L/h/kg (95% CI, 0.126-0.165), respectively. The PK model was explicitly developed to characterize the impact of physiological changes in children under 18 years of age and the percentage of the burn surface area using limited data. The analysis determined that weight, age, and estimated CrCL were important covariates in predicting vancomycin PK with high variability in CL and V.

Burns: Classification, Pathophysiology, and Treatment: A Review

Burns and their treatment are a significant medical problem. The loss of the physical barrier function of the skin opens the door to microbial invasion and can lead to infection. The repair process of the damage caused by the burn is impaired due to the enhanced loss of fluids and minerals through the burn wound, the onset of hypermetabolism with the concomitant disruption of nutrient supply, and derangements in the endocrine system. In addition, the initiated inflammatory and free radical processes drive the progression of oxidative stress, the inhibition of which largely depends on an adequate supply of antioxidants and minerals. Clinical experience and research provide more and more data to make the treatment of patients with thermal injury increasingly effective. The publication discusses disorders occurring in patients after thermal injury and the methods used at various stages of treatment.

Molecular mechanisms of post-burn muscle wasting and the therapeutic potential of physical exercise

After a severe burn injury, a systemic stress response activates metabolic and inflammatory derangements that, among other, leads to muscle mass loss (muscle wasting). These negative effects on skeletal muscle continue for several months or years and are aggravated by short-term and long-term disuse. The dynamic balance between muscle protein synthesis and muscle protein breakdown (proteolysis) is regulated by complex signalling pathways that leads to an overall negative protein balance in skeletal muscle after a burn injury. Research concerning these molecular mechanisms is still scarce and inconclusive, understanding of which, if any, molecular mechanisms contribute to muscle wasting is of fundamental importance in designing of therapeutic interventions for burn patients as well. This review not only summarizes our present knowledge of the molecular mechanisms that underpin muscle protein balance but also summarizes the effects of exercise on muscle wasting post-burn as promising strategy to counteract the detrimental effects on skeletal muscle. Future research focusing on the pathways causing post-burn muscle wasting and the different effects of exercise on them is needed to confirm this hypothesis and to lay the foundation of therapeutic strategies.

Reliability and feasibility of skeletal muscle ultrasound in the acute burn setting

OBJECTIVES

Despite the impact of muscle wasting after burn, tools to quantify muscle wasting are lacking. This multi-centre study examined the utility of ultrasound to measure muscle mass in acute burn patients comparing different methodologies.

METHODS

B-mode ultrasound was used by two raters to determine feasibility and inter-rater reliability in twenty burned adults following admission. Quadriceps muscle layer thickness (QMLT) and rectus femoris cross-sectional area (RF-CSA) were measured, comparing the use of i) a single versus average measurements, ii) a proximal versus distal location for QMLT, and iii) a maximum- versus no-compression technique for QMLT.

RESULTS

Analysis of twenty burned adults (50 years [95%CI 42-57], 32%TBSA [95%CI 23-40]) yielded ICCs of> 0.97 for QMLT (for either location and compression technique) and> 0.95 for RF-CSA, using average measurements. Relative minimal detectable changes were smaller using no-compression than maximum-compression (6.5% vs. 15%). Using no-compression to measure QMLT was deemed feasible for both proximal and distal locations (94% and 96% of attempted measurements). In 9.5% of cases maximum-compression was not feasible. 95% of RF-CSA measurements were successfully completed.

CONCLUSION

Ultrasound provides feasible and reliable values of quadriceps muscle architecture that can be adapted to clinical scenarios commonly encountered in acute burn settings.

The Complexity of the Post-Burn Immune Response: An Overview of the Associated Local and Systemic Complications

Burn injury induces a complex inflammatory response, both locally and systemically, and is not yet completely unravelled and understood. In order to enable the development of accurate treatment options, it is of paramount importance to fully understand post-burn immunology. Research in the last decades describes insights into the prolonged and excessive inflammatory response that could exist after both severe and milder burn trauma and that this response differs from that of none-burn acute trauma. Persistent activity of complement, acute phase proteins and pro- and anti-inflammatory mediators, changes in lymphocyte activity, activation of the stress response and infiltration of immune cells have all been related to post-burn local and systemic pathology. This "narrative" review explores the current state of knowledge, focusing on both the local and systemic immunology post-burn, and further questions how it is linked to the clinical outcome. Moreover, it illustrates the complexity of post-burn immunology and the existing gaps in knowledge on underlying mechanisms of burn pathology.

(Mal)nutrition in critical illness and beyond: a narrative review

Close liaison with ICU-trained dietitians and early initiation of nutrition is a fundamental principle of care of critically ill patients- this should be done while monitoring closely for refeeding syndrome. Enteral nutrition delivered by volumetric pumps should be used where possible, though parenteral nutrition should be started early in patients with high nutritional risk factors. Malnutrition and loss of muscle mass are common in patients who are admitted to ICUs and are prognostic for patient-centred outcomes including complications and mortality. Obesity is part of that story, and isocaloric and high-protein provision of nutrition is important in this group of patients who comprise a growing proportion of people treated. Assessing protein stores and appropriate dosing is, however, challenging in all groups of patients. It would be beneficial to develop strategies to reduce muscle wasting as well; various strategies including amino acid supplementation, ketogenic nutrition and exercise have been trialled, but the quality of data has been inadequate to address this phenomenon. Nutritional targets are rarely achieved in practice, and all ICUs should incorporate clear guidelines to help address this. These should include local nutritional and fasting guidelines and for the management of feed intolerance, early access to post-pyloric feeding and a multidisciplinary framework to support the importance of nutritional education.

Surgical Repair of the Acute Burn Wound: Who, When, What Techniques? What Is the Future?

Modern burns surgery is multidisciplinary, multimodal and includes a dermal preservation approach. The management of the surgical wound starts in the pre-hospital environment with stabilization and assessment of the burn injured patient according to protocols of trauma resuscitation with special emphasis in the assessment of the burn depth and surface area. A large burn requires fluid resuscitation and physiological support, including counterbalancing hyper metabolism, fighting infection and starting a long burns intensive care journey. A deep burn may impose the need for surgical debridement and cover through a staged approach of excision of devitalized tissue depending on its extension and patient circumstances. These methodologies warrant patients survivability and require professionals integrated in a multidisciplinary team sharing decisions and directing management. Burns Multimodality involves multiple techniques used according to patient's needs, wound environment, operators experience and available resources. Traditional practices used together with new techniques may reduce morbidity and operative time but also challenge stablished practice. The concept of using the best teams with the best techniques combines with the need for selective and judicious surgery that preserves tissue architecture and spares as much as possible dermal component, therefore reducing the possibility of functional impairment and cosmetic embarrassment caused by pathological scars. Who is best placed to perform these tasks, the appropriate or best timing of surgery and the different practices used to achieve best results will be discussed, together with a reflection on what the future holds for these fundamental steps in the management of the burn injured patient turning into a functional burn survivor.

Modulation of Burn Hypermetabolism in Preclinical Models

Severe burns elicit a state of physiological stress and increased metabolism to help the body compensate for the changes associated with the traumatic injury. However, this hypermetabolic state is associated with increased insulin resistance, cardiovascular dysfunction, skeletal muscle catabolism, impaired wound healing, and delayed recovery. Several interventions were attempted to modulate burn hypermetabolism, including nutritional support, early excision and grafting, and growth hormone application. However, burn hypermetabolism still imposes significant morbidity and mortality in burn patients. Due to the limitations of in vitro models, animal models are indispensable in burn research. Animal models provide researchers with invaluable tools to test the safety and efficacy of novel treatments or advance our knowledge of previously utilized agents. Several animal studies evaluated novel therapies to modulate burn hypermetabolism in the last few years, including recombinant human growth hormone, erythropoietin, acipimox, apelin, anti-interleukin-6 monoclonal antibody, and ghrelin therapies. Results from these studies are promising and may be effectively translated into human studies. In addition, other studies revisited drugs previously used in clinical practice, such as insulin and metformin, to further investigate their underlying mechanisms as modulators of burn hypermetabolism. This review aims to update burn experts with the novel therapies under investigation in burn hypermetabolism with a focus on applicability and translation. Furthermore, we aim to guide researchers in selecting the correct animal model for their experiments by providing a summary of the methodology and the rationale of the latest studies.

Two-Dimensional Mg2 Si Nanosheet-Enabled Sustained Hydrogen Generation for Improved Repair and Regeneration of Deeply Burned Skin

Molecular hydrogen holds a high potential for wound healing owing to its anti-inflammatory effect and high biosafety, but commonly used hydrogen administration routes hardly achieve the sustained supply of high-dosage hydrogen, limiting hydrogen therapy efficacy. Here, two-dimensional Mg₂ Si nanosheet (MSN) is exploited as a super-persistent hydrogen-releasing nanomaterial with high biocompatibility, and the incorporation of MSN into the chitosan/hyaluronic acid hydrogel (MSN@CS/HA) is developed as a dressing to repair deeply burned skin. The MSN@CS/HA hydrogel dressing can continuously generate hydrogen molecules for about 1 week in the physiological conditions in support of local, long-term, and plentiful hydrogen supply and remarkably promotes the healing and regeneration of deep second-degree and third-degree burn wounds without visible scar and toxic side effect. Mechanistically, a sustained supply of hydrogen molecules induces anti-inflammatory M2 macrophage polarization in time by enhancing CCL2 (chemokine C-C motif ligand 2) expression to promote angiogenesis and reduce fibrosis and also enhances the proliferation and migration capability of skin cells directly and indirectly by locally scavenging overexpressed reactive oxygen species, synergistically favoring wound repair. The proposed synthesis method, therapeutic strategy, and mechanisms will open a window for synthesizing a variety of MSene nanomaterials and developing their various proangiogenesis applications besides wound healing.

Ameliorative effect of bone marrow-derived mesenchymal stem cells on burn-induced hepatic and metabolic derangements in rats

AIMS

The current study aims to investigate the therapeutic potential of bone marrow-derived mesenchymal stem cells (MSCs) as a solo therapy in ameliorating both skin lesions and liver injury induced by cutaneous severe burn injury (SBI) in rats.

MAIN METHODS

In anesthetized male adult Wistar albino rats, 30 % total burn surface area and established hepatic injury was achieved via direct contact of each experimental animal's dorsum with heated metal rod (100 °C) for 10 s. On the next day following burn, human MSCs or mouse MSCs was administered locally around the burn site and intraperitonially (0.5 × 10⁶ cells/rat for each route) and outcomes were investigated at 4 and 14 days following burn induction.

KEY FINDINGS

Both types of MSCs significantly improved skin and liver histology, decreased liver enzymes, and ameliorated oxidative stress in hepatocytes of SBI-rats. Further, SBI-induced rises in hepatic apoptotic marker (caspase-3, Bax) and serum inflammatory markers (TNF-α, IL-1β, and IL-6) were reduced following either human or mouse MSC administration. In addition, MSCs augmented insulin receptor substrate-1, phosphorylated protein kinase-B (phospho-Akt), while alleviating serum glucose levels in SBI-rats. These previous effects persisted even at the 14-day time point.

SIGNIFICANCE

Following single administration, bone marrow-derived MSCs is capable of counteracting SBI-induced skin lesions as well as related hepatic complications, specifically via mitigating postburn hyperglycemia and hyperinflammation.

Early detection of soluble CD27, BTLA, and TIM-3 predicts the development of nosocomial infection in pediatric burn patients

Thermal injury induces concurrent inflammatory and immune dysfunction, which is associated with adverse clinical outcomes. However, these effects in the pediatric population are less studied and there is no standard method to identify those at risk for developing infections. Our goal was to better understand immune dysfunction and identify soluble protein markers following pediatric thermal injury. Further we wanted to determine which early inflammatory, soluble, or immune function markers are most predictive of the development of nosocomial infections (NI) after burn injury. We performed a prospective observational study at a single American Burn Association-verified Pediatric Burn Center. A total of 94 pediatric burn subjects were enrolled and twenty-three of those subjects developed a NI with a median time to diagnosis of 8 days. Whole blood samples, collected within the first 72 hours after injury, were used to compare various markers of inflammation, immune function, and soluble proteins between those who recovered without developing an infection and those who developed a NI after burn injury. Within the first three days of burn injury, innate and adaptive immune function markers (ex vivo lipopolysaccharide-induced tumor necrosis factor alpha production capacity, and ex vivo phytohemagglutinin-induced interleukin-10 production capacity, respectively) were decreased for those subjects who developed a subsequent NI. Further analysis of soluble protein targets associated with these pathways displayed significant increases in soluble CD27, BTLA, and TIM-3 for those who developed a NI. Our findings indicate that suppression of both the innate and adaptive immune function occurs concurrently within the first 72 hours following pediatric thermal injury. At the same time, subjects who developed NI have increased soluble protein biomarkers. Soluble CD27, BTLA, and TIM-3 were highly predictive of the development of subsequent infectious complications. This study identifies early soluble protein makers that are predictive of infection in pediatric burn subjects. These findings should inform future immunomodulatory therapeutic studies.

Hypercatabolism and Anti-catabolic Therapies in the Persistent Inflammation, Immunosuppression, and Catabolism Syndrome

Owing to the development of intensive care units, many patients survive their initial insults but progress to chronic critical illness (CCI). Patients with CCI are characterized by prolonged hospitalization, poor outcomes, and significant long-term mortality. Some of these patients get into a state of persistent low-grade inflammation, suppressed immunity, and ongoing catabolism, which was defined as persistent inflammation, immunosuppression, and catabolism syndrome (PICS) in 2012. Over the past few years, some progress has been made in the treatment of PICS. However, most of the existing studies are about the role of persistent inflammation and suppressed immunity in PICS. As one of the hallmarks of PICS, hypercatabolism has received little research attention. In this review, we explore the potential pathophysiological changes and molecular mechanisms of hypercatabolism and its role in PICS. In addition, we summarize current therapies for improving the hypercatabolic status and recommendations for patients with PICS.

Tranexamic acid reduced blood transfusions in acute burn surgery: A retrospective case-controlled trial

OBJECTIVE

Early excision and grafting of burn wounds are key for reducing prevalence of infection and sepsis. However, it is associated with massive blood loss and patients frequently require large numbers of blood transfusions. This study aimed to evaluate the effect of tranexamic acid (TXA) on blood transfusion requirements in acute burn surgery.

METHODS

Patients admitted to the burn intensive care unit between January 2018 and May 2021 and received TXA before first surgery for wound excision and grafting were matched in a 1:2 ratio to patients that did not receive TXA (confounders age,sex,total body surface area (TBSA) burned). Primary endpoint of the analysis was the total number of transfused units of red blood cells (RBC) intra- and postoperatively up to 48 h. Fresh frozen plasma (FFP) and platelets were evaluated. Endpoints were compared between groups using van Elteren tests adjusting for strata variable age, gender, TBSA.

RESULTS

Twenty-six TXA patients were matched with 52 control patients resulting in similar distributions of gender (77.9%(TXA)vs. 82.7%(control) males, p=0.542), age (51.7±21.3vs.48.3 ±17.4years,p = 0.459) and %TBSA burned (33.5%(IQR34)vs. 38.5% (IQR 30.5),p = 1.000). TXA group received significantly less RBC units intraoperatively (2.5(IQR 2.0)vs.4.0 units (IQR4.0), p = 0.038) and in total (4.0(IQR3.0)vs.6.0(IQR4.0),p = 0.017). TXA patients also received less blood products in general (RBC, FFP, platelets) in each period and in total. We found no significant difference in length of stay (24.0(IQR26.0)vs.33.0 days (IQR 0.5),p = 0.367) or mortality (15.4%vs.21.2%, p = 0.542).

DISCUSSION

This study shows that necessity for blood transfusions in acute burn surgery may be reduced significantly by administration of TXA perioperatively. Randomized-controlled trials are needed to prove these findings.

Urine Hydrogen Peroxide Levels and Their Relation to Outcome in Patients with Sepsis, Septic Shock, and Major Burn Injury

Hydrogen peroxide (H2O2) and oxidative stress have been suggested as possible instigators of both the systemic inflammatory response and the increased vascular permeability associated with sepsis and septic shock. We measured H2O2 concentrations in the urine of 82 patients with severe infections, such as sepsis, septic shock, and infections not fulfilling sepsis-3 criteria, in patients with major burn injury with associated systemic inflammation, and healthy subjects. The mean concentrations of H2O2 were found to be lower in patients with severe infections compared to burn injury patients and healthy subjects. Patients with acute kidney injury (AKI), vs. those without AKI, in all diagnostic groups displayed higher concentrations of urine H2O2 (p < 0.001). Likewise, urine concentrations of H2O2 were higher in non-survivors as compared to survivors (p < 0.001) at day 28 in all diagnostic groups, as well as in patients with severe infections and burn injury (p < 0.001 for both). In this cohort, increased H2O2 in urine is thus associated with mortality in patients with sepsis and septic shock as well as in patients with burn injury.

Epidemiology and etiology of blood stream infections in a Belgian burn wound center

BACKGROUND

Infections are a major cause of morbidity in burn patients. We aimed to investigate the epidemiology and antibiotic susceptibility of blood stream infections in order to gain a better understanding of their role and burden in our Burn Wound Center.

METHODS

This retrospective epidemiological investigation analyzed data derived from medical files of patients admitted to our Burn Wound Center having had at least one positive blood culture between 1 January and 31 December 2018. We focused on the prevalence of causative agents in blood stream infections in function of the time after injury and on their drug sensitivity.

RESULTS

Among the 363 patients admitted to our Burn Wound Center during the study period, 29 had at least one episode of blood stream infection. Gram-negative organisms accounted for 56,36% of the pathogens in blood stream infections, Gram-positives for 38,17%, and yeasts for 5,45%. Pseudomonas aeruginosa was the most common bacterium (20%), followed by Staphylococcus epidermidis (16.36%), Escherichia coli and Klebsiella pneumoniae (9,09% each). A third of the Gram-negative isolates were multidrug resistant. Gram-positive cocci were isolated from blood cultures at a median of 9 days after the injury, earlier than Gram-negative rods (median 15 days). The main sources of blood stream infections were the burn wounds, followed by infected catheters.

CONCLUSIONS

Multidrug resistant bacteria must be considered when selecting empirical antibiotic therapy in septic burn patients. In our center, we need to update our antibiotic guidelines, to review the hospital infection control measures and to introduce routine typing technology.

Metabolic Responses to Severe Burn Injury

ABSTRACT

Management of the metabolic responses to severe burn injury is recognized as a fundamental part of burn care. Definition of burn hypermetabolism is being refined to subcellular and genomic levels, and treatment concepts are need to be refined into increasingly sophisticated strategies.

Bio-Psychological Predictors of Acute and Protracted Fatigue After Burns: A Longitudinal Study

Objective

Fatigue after burns is often attributed to the hyperinflammatory and hypermetabolic response, while it may be best understood from a bio-psychological perspective, also involving the neuro-endocrine system. This longitudinal multi-center study examined the course of fatigue up to 18 months postburn. The contribution of bio-psychological factors, including burn severity, pain, and acute PTSD symptoms, to the course and persistence of fatigue was studied in a multifactorial model.

Methods

Participants were 247 adult burn survivors. Fatigue symptoms were assessed with the Multidimensional Fatigue Inventory during the acute phase and subsequently at 3, 6, 12, and 18 months postburn, and were compared to population norms. Age, gender, burn severity, acute PTSD symptoms and pain were assessed as potential predictors of fatigue over time in a latent growth model.

Results

At 18 months postburn, 46% of the burn survivors reported fatigue, including 18% with severe fatigue. In the acute phase, higher levels of fatigue were related to multiple surgeries, presence of pain, and higher levels of acute PTSD symptoms. Fatigue gradually decreased over time with minor individual differences in rate of decrease. At 18 months, pain and acute PTSD symptoms remained significant predictors of fatigue levels.

Conclusions

Protracted fatigue after burns was found in almost one out of five burn survivors and was associated with both pain and acute PTSD symptoms. Early detection of PTSD symptoms and early psychological interventions aimed at reducing PTSD symptoms and pain may be warranted to reduce later fatigue symptoms.

Glutamine relieves the hypermetabolic response and reduces organ damage in severe burn patients: A multicenter, randomized controlled clinical trial

BACKGROUND

Severe burns can cause a hypermetabolic response and organ damage. Glutamine is a conditionally essential amino acid with various pharmacological effects. In this study, whether glutamine could alleviate the hypermetabolic response and maintain organ function after burn injury was analyzed.

METHODS

A multicenter, randomized, single-blind, parallel controlled trial was conducted to evaluate the efficacy of glutamine in decreasing hypermetabolism after burn injury. Physiological and biochemical indexes, such as vital signs, metabolic hormones, metabolic rate, and organ damage, were recorded on the 7th and 14th days after treatment.

RESULTS

In total, 55 adult burn patients with a total burn surface area (TBSA) of 30-70% were included in this study and randomly divided into the burn control (B, 28 patients) and burn+glutamine (B+G, 27 patients) groups. Except for the glutamine administration, the groups did not differ in the other treatments and nutrition supplements. The levels of diamine oxidase (DAO), lactulose/mannitol (L/M), β₂-microglobulin, lactate dehydrogenase (LDH), hydroxybutyrate dehydrogenase (HBD) and cardiac troponin l (cTnl) in the B+G group were significantly lower than those in the B group (p < 0.05 or 0.01). The levels of resting energy expenditure (REE), serum catecholamines, glucagon, lactate and Homeostasis model assessment (HOMA) in the B+G group were significantly lower than those in the B group (p < 0.05 or 0.01). No significant difference was found in the length of hospitalization or the mortality rate between the two groups (p > 0.05).

CONCLUSIONS

Glutamine moderately alleviates the hypermetabolic response and reduces organ damage after severe burns. Therefore, the early application of glutamine, which is effective and safe, should be used as an active intervention as early as possible.

Hepatic functional pathophysiology and morphological damage following severe burns: a systematic review and meta-analysis

INTRODUCTION

Severe burns are devastating injuries affecting multiple organ systems. Little is known about the influence on the hepatic system and its physiology. This systematic review aimed to assess the current state of research on morphologic liver damage following severe burns.

METHODS

A search was conducted in Pubmed, Web of Science and Cochrane databases using PRISMA guidelines. Outcomes included serum levels of transaminases, fatty infiltration and necrosis. Weighted individual study estimates were used to calculate pooled transaminase levels and necrosis/fatty infiltration rates using a random-effects approach. Risk ratios (RRs) or Odds ratios (ORs) and 95% confidence intervals (CIs) were used to describe pooled estimates for risk factors.

RESULTS

The literature search retrieved 2548 hits, of which 59 studies were included into qualitative synthesis, and finally ten studies were included into meta-analysis. Studies were divided into those reporting autopsies and those reporting changes of serum transaminase levels. The majority of liver autopsies showed fatty infiltration 82% (95% CI39%-97%) or necrosis of the liver 18% (95% CI13%-24%).

DISCUSSION

Heterogeneity in studies on hepatic functional damage following severe burns was high. Only few were well-designed and published in recent years. Many studies could not be included because of insufficient numerical data. There is a high number of patients deceasing from burns that present with fatty infiltration or necrosis of hepatic tissue. Transaminases were elevated during the first days after burn. Further research on how severe burns affect the hepatic function and outcome, especially long-term, is necessary.

Early Transcriptomic Response to Burn Injury: Severe Burns Are Associated With Immune Pathway Shutdown

Burn injury induces a systemic hyperinflammatory response with detrimental side effects. Studies have described the biochemical changes induced by severe burns, but the transcriptome response is not well characterized. The goal of this work is to characterize the blood transcriptome after burn injury. Burn patients presenting to a regional center between 2012 and 2017 were prospectively enrolled. Blood was collected on admission and at predetermined time points (hours 2, 4, 8, 12, and 24). RNA was isolated and transcript levels were measured with a gene expression microarray. To identify differentially regulated genes (false-discovery rate ≤0.1) by burn injury severity, patients were grouped by TBSA above or below 20% and statistically enriched pathways were identified. Sixty-eight patients were analyzed, most patients were male with a median age of 41 (interquartile range, 30.5-58.5) years, and TBSA of 20% (11%-34%). Thirty-five patients had % TBSA injury ≥20%, and this group experienced greater mortality (26% vs 3%, P = .008). Comparative analysis of genes from patients with </≥20% TBSA revealed 1505, 613, 380, 63, 1357, and 954 differentially expressed genes at hours 0, 2, 4, 8, 12, and 24, respectively. Pathway analysis revealed an initial up-regulation in several immune/inflammatory pathways within the ≥20% TBSA groups followed by shutdown. Severe burn injury is associated with an early proinflammatory immune response followed by shutdown of these pathways. Examination of the immunoinflammatory response to burn injury through differential gene regulation and associated immune pathways by injury severity may identify mechanistic targets for future intervention.

Standards in Biologic Lesions: Cutaneous Thermal Injury and Inhalation Injury Working Group 2018 Meeting Proceedings

On August 27 and 28, 2018, the American Burn Association, in conjunction with Underwriters Laboratories, convened a group of experts on burn and inhalation injury in Washington, DC. The goal of the meeting was to identify and discuss the existing knowledge, data, and modeling gaps related to understanding cutaneous thermal injury and inhalation injury due to exposure from a fire environment, and in addition, address two more areas proposed by the American Burn Association Research Committee that are critical to burn care but may have current translational research gaps (inflammatory response and hypermetabolic response). Representatives from the Underwriters Laboratories Firefighter Safety Research Institute and the Bureau of Alcohol, Tobacco, Firearms and Explosives Fire Research Laboratory presented the state of the science in their fields, highlighting areas that required further investigation and guidance from the burn community. Four areas were discussed by the full 24 participant group and in smaller groups: Basic and Translational Understanding of Inhalation Injury, Thermal Contact and Resulting Injury, Systemic Inflammatory Response and Resuscitation, and Hypermetabolic Response and Healing. A primary finding was the need for validating historic models to develop a set of reliable data on contact time and temperature and resulting injury. The working groups identified common areas of focus across each subtopic, including gaining an understanding of individual response to injury that would allow for precision medicine approaches. Predisposed phenotype in response to insult, the effects of age and sex, and the role of microbiomes could all be studied by employing multi-omic (systems biology) approaches.

Effect of Collagen Hydrolysate and Fish Oil on High-Sensitivity C-Reactive Protein and Glucose Homeostasis in Patients with severe Burn; a Randomized Clinical Trial

Introduction:

Collagen and omega-3 fatty acids (FAs) are suggested to have anti-inflammatory, anti-oxidant, and insulin-sensitizing properties. The aim of this study was to investigate the effect of collagen hydrolysate and omega-3 FAs on inflammation and insulin resistance in patients with major burns.

Methods:

In this double-blind randomized clinical trial, 66 patients with 20-45% burns were assigned to either of the three groups of collagen (40 gr/d), collagen (40 gr/d) plus fish oil (10 ml/d), or control. High-sensitivity C-reactive protein (hs-CRP), fasting blood glucose (FBG) and insulin concentrations, and homeostatic model assessment for insulin resistance (HOMA-IR) were assessed at baseline, as well as end of weeks two and three.

Results:

Based on post-hoc analyses, hs-CRP levels were significantly lower in the collagen (p=0.026) and collagen+omega-3 (p=0.044) groups compared to the control group, at week three. However, pre- to post- (week three) changes of hs-CRP were significantly higher only in the collagen+omega-3 group compared to the control group (173.2 vs. 103.7 mg/l, p=0.024). After three weeks of the intervention, insulin (11.3 and 11.9 vs. 22.8 µIU/ml) and HOMA-IR (2.9 and 2.8 vs. 7.9) values seemed to be clinically, but not statistically, lower in both intervention groups compared to the control group. Pre- to post- (week three) values of FBG decreased significantly in the collagen (p=0.002) and collagen+omega-3 (p=0.036) groups. Insulin (p=0.008) and HOMA-IR (p=0.001) decreased significantly only in the collagen+omega-3 group at week three compared to the baseline.

Conclusions:

Supplementation with collagen hydrolysate and omega-3 FAs can improve hs-CRP concentration and probably insulin resistance in patients with severe burns. Omega-3 FAs had additional effects on modulating inflammation. Larger clinical trials are needed to confirm the current findings especially in terms of glucose homeostasis.

Arginine Supplementation Promotes Extracellular Matrix and Metabolic Changes in Keratoconus

Keratoconus (KC) is a common corneal ectatic disease that affects 1:500–1:2000 people worldwide and is associated with a progressive thinning of the corneal stroma that may lead to severe astigmatism and visual deficits. Riboflavin-mediated collagen crosslinking currently remains the only approved treatment to halt progressive corneal thinning associated with KC by improving the biomechanical properties of the stroma. Treatments designed to increase collagen deposition by resident corneal stromal keratocytes remain elusive. In this study, we evaluated the effects of arginine supplementation on steady-state levels of arginine and arginine-related metabolites (e.g., ornithine, proline, hydroxyproline, spermidine, and putrescine) and collagen protein expression by primary human corneal fibroblasts isolated from KC and non-KC (healthy) corneas and cultured in an established 3D in vitro model. We identified lower cytoplasmic arginine and spermidine levels in KC-derived constructs compared to healthy controls, which corresponded with overall higher gene expression of arginase. Arginine supplementation led to a robust increase in cytoplasmic arginine, ornithine, and spermidine levels in controls only and a significant increase in collagen type I secretion in KC-derived constructs. Further studies evaluating safety and efficacy of arginine supplementation are required to elucidate the potential therapeutic applications of modulating collagen deposition in the context of KC.

Muscle deteriorations become prominent within 24 hours after admission in severely burned adults

BACKGROUND

Severe burn injury results in profound catabolic deterioration. Although burn-related catabolism has been well stated, it is unclear when the catabolic response begins. This study characterized acute changes of muscle protein breakdown at the admission and the day after in severely burned adults.

METHODS

Twelve patients (43 ± 19 years old) with 40% ± 21% total body surface area burns were prospectively enrolled into an observational study approved by institutional review board. Urinary samples were collected on admission day and the day after (day 1). Patient demographic and clinical data of vital signs, blood gas and chemistry, and coagulation status were collected. Catabolic changes of muscle breakdown were quantified by urinary excretion of 3-methylhisitidine, determined by gas chromatography and mass spectrometry analysis.

RESULTS

Compared with admission day, burned patients had elevated mean ± SD arterial pressure (from 90 ± 5 mm Hg to 108 ± 7 mm Hg) and heart rate (from 102 ± 7 beats per minute to 119 ± 4 beats per minute both p < 0.05) after 24 hours. Their 24-hour urinary output was 1,586 ± 813 mL at admission day to 1,911 ± 1,048 mL on day 1. The 24-hour urea excretion was elevated from 172 ± 101 mg/kg per day at admission day to 302 ± 183 mg/kg per day on day 1 (both p < 0.05), with no change in creatinine excretion. Urinary 3-methylhisitidine excretion increased from 0.75 ± 0.74 mg/kg per day at admission to 1.14 ± 0.86 mg/kg per day on day 1 (p < 0.05). The estimated skeletal muscle protein breakdown was increased from 1.1 ± 1.0 g/kg per day at admission day to 1.6 ± 1.2 g/kg per day on day 1 (p < 0.05). There were no changes in prothrombin time, activated partial thromboplastin time, or platelets.

CONCLUSION

In severely burned patients, catabolic muscle protein breakdown is elevated within 24 hours after admission and before changes in coagulation. These findings suggest that early interventions may be needed to effectively attenuate the catabolic responses in burn patients.

LEVEL OF EVIDENCE

Prospective and observational study, level II.

Oral Aminoacids Supplementation Improves Corneal Reinnervation After Photorefractive Keratectomy: A Confocal-Based Investigation

Aim of this retrospective study was to estimate the effect of oral supplementation with amino acids (AA) on corneal nerves regrowth after excimer laser refractive surgery with photorefractive keratectomy (PRK). Based on the pre and post-surgical treatment received, 40 patients with 12 months of follow-up were distributed in two groups: 20 patients had received oral AA supplementation 7 days before and 30 days after PRK, and 20 patients without AA supplementation, as untreated reference control. All patients followed the same standard post-operative topical therapy consisting of an association of antibiotic and steroid plus sodium hyaluronate during the first week, then steroid alone progressively decreasing during 30 days and sodium hyaluronate for the following 3 months. In vivo corneal confocal microscopy was used to evaluate the presence of sub-basal corneal nerve fibers during 12 months after PRK. Results have shown that sub-basal nerves regenerated significantly faster (p <0.05), and nerve fibers density was significantly higher (p <0.05) with a more regular pattern in the eyes of AA treated patients with respect to the untreated control group. Therefore, our data indicate that oral supplementation with AA improved significantly corneal nerve restoration after PRK and could thus be considered as an additional treatment during corneal surgical procedures.

Tertiary peritonitis: considerations for complex team-based care

Peritonitis, as a major consequence of hollow visceral perforation, anastomotic disruption, ischemic necrosis, or other injuries of the gastrointestinal tract, often drives acute care in the emergency department, operating room, and the ICU. Chronic critical illness (CCI) represents a devastating challenge in modern surgical critical care where successful interventions have fostered a growing cohort of patients with prolonged dependence on mechanical ventilation and other organ supportive therapies who would previously have succumbed much earlier in the acute phase of critical illness. An important subset of CCI patients are those who have survived an emergency abdominal operation, but who subsequently require prolonged open abdomen management complicated by persistent peritoneal space infection or colonization, fistula formation, and gastrointestinal (GI) tract dysfunction; these patients are described as having tertiary peritonitis (TP).The organ dysfunction cascade in TP terminates in death in between 30 and 64% of patients. This narrative review describes key—but not all—elements in a framework for the coordinate multiprofessional team-based management of a patient with tertiary peritonitis to mitigate this risk of death and promote recovery. Given the prolonged critical illness course of this unique patient population, early and recurrent Palliative Care Medicine consultation helps establish goals of care, support adjustment to changes in life circumstance, and enable patient and family centered care.

Population Pharmacokinetic Modeling and Simulations of Imipenem in Burn Patients With and Without Continuous Venovenous Hemofiltration in the Military Health System

Continuous venovenous hemofiltration (CVVH) is a life‐sustaining procedure in patients with severe burns and acute kidney injury. Physiologic changes from burn injury and use of CVVH may alter imipenem pharmacokinetics (PK). We aimed to compare imipenem clearance (CL) in burn patients with and without CVVH, determine the effect of burn on imipenem volume of distribution (CVVH, n = 12; no CVVH, n = 11), in combination with previously published models. Model qualification was performed with standard diagnostics and comparing predicted PK parameters/time‐concentration profiles with those in the existing literature. Monte Carlo simulations were conducted to evaluate the probability of target attainment. A 2‐compartment model best described the data. Utilizing albumin as a covariate on volume parameters and leveraging the clearance model from prior literature, our model predicted imipenem central volume and CL within a 10% margin of error across healthy, renally impaired, and burn populations. We provide direct comparison of imipenem CL in burn patients with and without CVVH. Notably, there was no significant difference. Large imipenem V_d in patients with severe burns is likely explained by increased capillary permeability, for which serum albumin may be a reasonable surrogate. Dosing 500 mg every 6 hours is adequate for burn patients on renally dosed CVVH; however, suspicion of augmented renal clearance or patients placed on CVVH without renal impairment may necessitate dosing of 1000 mg every 6 hours.

Cardiac Dysfunction in Severely Burned Patients: Current Understanding of Etiology, Pathophysiology, and Treatment

Patients who experience severe burn injuries face a massive inflammatory response resulting in hemodynamic and cardiovascular complications. Even after immediate and appropriate resuscitation, removal of burn eschar and covering of open areas, burn patients remain at high risk for serious morbidity and mortality. As a result of the massive fluid shifts following the initial injury, along with large volume fluid resuscitation, the cardiovascular system is critically affected. Further, increased inflammation, catecholamine surge, and hypermetabolic syndrome impact cardiac dysfunction, which worsens outcomes of burn patients. This review aimed to summarize the current knowledge about the effect of burns on the cardiovascular system.A comprehensive search of the PubMed and Embase databases and manual review of articles involving effects of burns on the cardiovascular system was conducted.Many burn units use multimodal monitors (e.g., transpulmonary thermodilution) to assess hemodynamics and optimize cardiovascular function. Echocardiography is often used for additional evaluations of hemodynamically unstable patients to assess systolic and diastolic function. Due to its noninvasive character, echocardiography can be repeated easily, which allows us to follow patients longitudinally.The use of anabolic and anticatabolic agents has been shown to be beneficial for short- and long-term outcomes of burn survivors. Administration of propranolol (non-selective β-receptor antagonist) or oxandrolone (synthetic testosterone) for up to 12 months post-burn counteracts hypermetabolism during hospital stay and improves cardiac function.A comprehensive understanding of how burns lead to cardiac dysfunction and new therapeutic options could contribute to better outcomes in this patient population.

Validation of the modified NUTrition Risk Score (mNUTRIC) in mechanically ventilated, severe burn patients: A prospective multinational cohort study

BACKGROUND

Whether nutrition therapy benefits all burn victims equally is unknown. To identify patients who will benefit the most from optimal nutrition, the modified Nutrition Risk in Critically Ill (mNUTRIC) Score has been validated in the Intensive Care Unit. However, the utility of mNUTRIC in severe burn victims is unknown. We hypothesized that a higher mNUTRIC (≥5) will be associated with worse clinical outcomes, but that greater nutritional adequacy will be associated with better clinical outcomes in patients with higher mNUTRIC score.

METHODS

This prospective study included data from mechanically ventilated, severe burn patients (n = 359) from 51 Burn Units worldwide included in a randomized trial. Our primary and secondary outcomes were hospital mortality and the time to discharge alive (TTDA) from hospital. We described the association between nutrition performance and clinical outcomes.

RESULTS

Compared to low mNUTRIC (n = 313), the high mNUTRIC group (n = 46) had higher mortality (61% vs. 19%, p = 0.001), and longer TTDA (>90 [87->90] vs. 64 [38-90] days, p = <0.0001). Only in the high mNUTRIC group, increased calorie intake (per 20% increase) was associated with lower mortality and a faster TTDA.

CONCLUSIONS

The mNUTRIC score identifies those with poor clinical outcomes and may identifies those mechanically ventilated, severe burn patients in whom optimal nutrition therapy may be more advantageous.

Glucose Metabolism in Burns-What Happens?

Severe burns represent an important challenge for patients and medical teams. They lead to profound metabolic alterations, trigger a systemic inflammatory response, crush the immune defense, impair the function of the heart, lungs, kidneys, liver, etc. The metabolism is shifted towards a hypermetabolic state, and this situation might persist for years after the burn, having deleterious consequences for the patient's health. Severely burned patients lack energy substrates and react in order to produce and maintain augmented levels of glucose, which is the fuel "ready to use" by cells. In this paper, we discuss biological substances that induce a hyperglycemic response, concur to insulin resistance, and determine cell disturbance after a severe burn. We also focus on the most effective agents that provide pharmacological modulations of the changes in glucose metabolism.

Contemporary Aspects of Burn Care

The past one hundred years have seen tremendous improvements in burn care, allowing for decreased morbidity and mortality of this pathology. The more prominent advancements occurred in the period spanning 1930-1980; notably burn resuscitation, early tangential excision, and use of topical antibiotic dressings; and are well documented in burn literature. This article explores the advancements of the past 40 years and the areas of burn management that are presently topics of active discussion and research.

Cardiovascular and Renal Disease in Chronic Critical Illness

With advances in critical care, patients who would have succumbed in previous eras now survive through hospital discharge. Many survivors suffer from chronic organ dysfunction and induced frailty, representing an emerging chronic critical illness (CCI) phenotype. Persistent and worsening cardiovascular and renal disease are primary drivers of the CCI phenotype and have pathophysiologic synergy, potentiating one another and generating a downward spiral of worsening disease and clinical outcomes manifest as cardio-renal syndromes. In addition to pharmacologic therapies (e.g., diuretics, beta adrenergic receptor blockers, angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, and blood pressure control), special consideration should be given to behavioral modifications that avoid the pitfalls of polypharmacy and suboptimal renal and hepatic dosing, to which CCI patients may be particularly vulnerable. Smoking cessation, dietary modifications (e.g., early high-protein nutrition and late low-sodium diets), and increased physical activity are advised. Select patients benefit from cardiac re-synchronization therapy or renal replacement therapy. Coordinated, patient-centered care bundles may improve compliance with standards of care and patient outcomes. Given the complex, heterogeneous nature of cardiovascular and renal disease in CCI and the dismal long-term outcomes, further research is needed to clarify pathophysiologic mechanisms of cardio-renal syndromes in CCI and develop targeted therapies.

Immunological Endotyping of Chronic Critical Illness After Severe Sepsis

Improved management of severe sepsis has been one of the major health care accomplishments of the last two decades. Due to enhanced recognition and improved management of severe sepsis, in-hospital mortality has been reduced by up to 40%. With that good news, a new syndrome has unfortunately replaced in-hospital multi-organ failure and death. This syndrome of chronic critical illness (CCI) includes sepsis patients who survive the early "cytokine or genomic storm," but fail to fully recover, and progress into a persistent state of manageable organ injury requiring prolonged intensive care. These patients are commonly discharged to long-term care facilities where sepsis recidivism is high. As many as 33% of sepsis survivors develop CCI. CCI is the result, at least in part, of a maladaptive host response to chronic pattern-recognition receptor (PRR)-mediated processes. This maladaptive response results in dysregulated myelopoiesis, chronic inflammation, T-cell atrophy, T-cell exhaustion, and the expansion of suppressor cell functions. We have defined this panoply of host responses as a persistent inflammatory, immune suppressive and protein catabolic syndrome (PICS). Why is this important? We propose that PICS in survivors of critical illness is its own common, unique immunological endotype driven by the constant release of organ injury-associated, endogenous alarmins, and microbial products from secondary infections. While this syndrome can develop as a result of a diverse set of pathologies, it represents a shared outcome with a unique underlying pathobiological mechanism. Despite being a common outcome, there are no therapeutic interventions other than supportive therapies for this common disorder. Only through an improved understanding of the immunological endotype of PICS can rational therapeutic interventions be designed.

Interorgan Metabolism of Amino Acids in Human Health and Disease

Amino acids are integral for human health, influencing an array of physiological processes from gene expression to vasodilation to the immune response. In accordance with this expansive range of unique functions, the tissues of the body engage in a complex interplay of amino acid exchange and metabolism to respond to the organism's dynamic needs for a range of nitrogenous products. Interorgan amino acid metabolism is required for numerous metabolic pathways, including the synthesis of functional amino acids like arginine, glutamate, glutamine, and glycine. This physiological process requires the cooperative handling of amino acids by organs (e.g., the small intestine, skeletal muscle, kidneys, and liver), as well as the complete catabolism of nutritionally essential amino acids such as the BCAAs, with their α-ketoacids shuttled from muscle to liver. These exchanges are made possible by several mechanisms, including organ location, as well as the functional zonation of enzymes and the cell-specific expression of amino acid transporters. The cooperative handling of amino acids between the various organs does not appear to be under the control of any centralized regulation, but is instead influenced by factors such as fluctuations in nutrient availability, hormones, changes associated with development, and altered environmental factors. While the normal function of these pathways is associated with health and homeostasis, affected by physical activity, diet and body composition, dysregulation is observed in numerous disease states, including cardiovascular disease and cancer cachexia, presenting potential avenues for the manipulation of amino acid consumption as part of the therapeutic approach to these conditions in individuals.

Age-dependent influence of premorbid underweight status on mortality in severe burn patients: An administrative database study

PURPOSE

To examine the associations between premorbid nutritional status and in-hospital mortality in severe burn patients according to age in Japan.

METHODS

We retrospectively extracted the data of 14,345 patients aged 18-84 years admitted for burns from April 1, 2014, to March 31, 2018, using the Japanese Diagnosis Procedure Combination database. The exclusion criteria were out-of-hospital cardiac arrest, death in the emergency room, readmission, and planned admission. We collected data on age, sex, height, weight, comorbidities, burn index, and mechanical ventilation use and performed age-stratified multilevel logistic regression analyses to estimate associations between premorbid body mass index (BMI) and in-hospital mortality.

RESULTS

We analyzed 2968 patients with a burn index ≥10, including 831 elderly aged 75-84 years. In patients aged 18-74 years, being underweight (BMI < 18.5) significantly decreased mortality (0.34 [0.15-0.77]; P = 0.010). In contrast, in patients aged 75-84 years, being underweight significantly increased mortality (2.11 [1.05-4.25]; P = 0.036). Being overweight (BMI >25) increased mortality in both age groups, but not significantly.

CONCLUSIONS

The results suggest that pre-morbidly underweight elderly patients aged 75-84 years with severe burns have high mortality risks. Further research is needed to identify optimal care strategies for this population.

A case series of concomitant burn and COVID-19

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Heightened inflammation and acute lung injury in major burn and COVID-19.

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Baseline comorbidities and possible worsening consequence.

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Medical management in concomitant burn and SARS-CoV-2 infection.

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Multidisciplinary approaches to manage coexisting diseases.

Background

The recently emerged severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) disease (COVID-19) has become a human pandemic. Heightened inflammation, vascular hyperpermeability, acute lung injury, coagulopathy, and cardiovascular abnormalities are among the SARS-CoV-2 infection-related complications. Major burn is also associated with metabolic derangements, vascular leak, and hemodynamic instability. Burn patients are at high risk for infections and developing sepsis. COVID-19 in burn victims might worsen the clinical outcome and make their medical management challenging.

Result

Here, we present four cases of concomitant burn and COVID-19 with different degrees of complications. They had no (three out of four) or multiple (one out of four) baseline comorbidities and all were admitted to hospital for further management. Three out of four cases demonstrated acute respiratory failure and were intubated (no longer than 7 days). It seems that one of them had COVID-19 on arrival, the other apparently contracted at outside hospital, and the last two infected during the index hospitalization.

Conclusion

Concomitant severe burn and COVID-19 might complicate the clinical presentation and hospital course. Such combination was associated with poor outcome in a case with baseline comorbidities, beyond what was expected from the severity of burn injury. However, a more comprehensive study with larger sample size is required to make a valid conclusion. With an ongoing COVID-19 global pandemic, SARS-CoV-2 infection might be a concurrent disease with other illnesses or traumas such as burn. This dictate multidisciplinary approaches to risk stratify, screen, assess, and manage coexisting diseases. Additionally, appropriate preparations and careful precautions need to be executed in burn units to prevent COVID-19 exposure and transmission to limit potential adverse outcomes.

The Genetic Evidence of Burn-Induced Cardiac Mitochondrial Metabolism Dysfunction

Burn-induced cardiac dysfunction is thought to involve mitochondrial dysfunction, although the mechanisms responsible are unclear. In this study, we used our established model of in vivo burn injury to understand the genetic evidence of burn-induced mitochondrial confusion dysfunction by describing cardiac mitochondrial metabolism-related gene expression after burn. Cardiac tissue was collected at 24 hours after burn injury. An O2K respirometer system was utilized to measure the cardiac mitochondrial function. Oxidative phosphorylation complex activities were determined using enzyme activity assays. RT Profiler PCR array was used to identify the differential regulation of genes involved in mitochondrial biogenesis and metabolism. The quantitative qPCR and Western blotting were applied to validate the differentially expressed genes. Burn-induced cardiac mitochondrial dysfunction was supported by the finding of decreased state 3 respiration, decreased mitochondrial electron transport chain activity in complex I, III, IV, and V, and decreased mitochondrial DNA-encoded gene expression as well as decreased levels of the corresponding proteins after burn injury. Eighty-four mitochondrial metabolism-related gene profiles were measured. The mitochondrial gene profile showed that 29 genes related to mitochondrial energy and metabolism was differentially expressed. Of these 29 genes, 16 were more than 2-fold upregulated and 13 were more than 2-fold downregulated. All genes were validated using qPCR and partial genes were correlated with their protein levels. This study provides preliminary evidence that a large percentage of mitochondrial metabolism-related genes in cardiomyocytes were significantly affected by burn injury.

The Effects of Two Different Burn Dressings on Serum Oxidative Stress Indicators in Children with Partial Burn

In this study, we evaluated and compared the effect of treatment with a hydrofiber dressing with silver (HFAg) and a polylactic membrane (PLM) on systemic oxidative stress in systemic inflammatory reaction in thermal burn injuries in children. A prospective randomized and matched pairing study of 20 to 50% of TBSA was performed from children equal to both sexes affected by thermal injuries. The control group was included in normal children of both sexes. Serum malondialdehyde (MDA), total antioxidant capacity (TAC), total oxidant capacity (TOC), and glutathione (GSH) levels were analyzed and the results were analyzed statistically. In this study, it was found that PLM treatment increased TAC and GSH levels in burn patients significantly more than the other group. With the use of PLM, TOC decreased to normal level from day 3. In the HFAg group, TAC and GSH levels began to increase on the seventh day. On the first day of the burn, the TOC level started to increase. This increase continued on days 7 and 14. The TOC level began to fall on the 21st day. The increase in TAC was higher in the PLM group. In the PLM group, TOC fell faster. As a result, we think that different burn dressings can have different systemic effects. We can speculate that PLM has an antioxidant effect in the burn tissue due to high lactate content. Therefore, PLM may have decreased serum oxidative stress indicators more effectively than HFAg.

25-Hydroxycholecalciferol Concentration Is Associated with Protein Loss and Serum Albumin Level during the Acute Phase of Burn Injury

Background: Burned patients have an increased need for vitamin D supply related to the maintenance of calcium–phosphate homeostasis and the regulation of cell proliferation/differentiation. This study aimed to analyze the concentration of 25-hydroxycholecalciferol and its relationship with severe condition after burn injury. Methods: 126 patients were enrolled in the study. Patients were qualified due to thermal burns—over 10% of total body surface area. On the day of admission, the following parameters were assessed: 25-hydroxycholecalciferol concentration, total protein concentration, albumin concentration, aspartate transaminase activity, alanine transaminase activity, albumin concentration, creatinine concentration, c-reactive protein concentration, procalcitonin concentration, and interleukin-6 concentration. Results: Almost all patients (92%) in the study group had an improper level of vitamin D (<30 ng/mL), with the average of 11.6 ± 10.7 ng/mL; 17.5% of patients had levels of vitamin D below the limit of determination—under 3 ng/mL. The study showed that there are several factors which correlated with vitamin D concentration during the acute phase of burn injury, including: total protein (r = 0.42, p < 0.01), albumin, (r = 0.62, p < 0.01), percentage of body burns (r = 0.36, p < 0.05), aspartate aminotransferase (r = 0.21, p < 0.05), and c-reactive protein (r = 0.22, p < 0.05). We did not find any significant correlation between vitamin D concentration and body mass index. Conclusions: The burn injury has an enormous impact on the metabolism and the risk factors of the deficiency for the general population (BMI) have an effect on burned patients. Our study showed that concentration of 25-hydroxycholecalciferol is strongly correlated with serum albumin level, even more than total burn surface area and burn degrees as expected. We suspect that increased supplementation of vitamin D should be based on albumin level and last until albumin levels are balanced.

Extensive burn injury causes bone collagen network alteration and growth delay related to RANK-L immunoexpression change

PURPOSE

Extensive burn injury mainly affects children, and hypermetabolic state can lead to growth delay. This study aimed to investigate bone histopathological and morphometric aspects, collagen fibers network and the immunoexpression of biological markers related to bone development in a young experimental model for extensive burn.

MATERIALS AND METHODS

A total of 28 male Wistar rats were distributed into Control (C) and subjected to scald burn injury (SBI) groups. Sham or injured animals were euthanized 4 or 14 days post-lesion and proximal epiphyses of the femur were submitted to histological, morphometric (thickness epiphyseal plate), and RUNX-2 and receptor activator of nuclear factor kappa- β ligand (RANK-L) immunoexpression methods.

RESULTS

Histopathological femoral findings showed delayed appearance of the secondary ossification center in SBI, 14 days post-injury. Collagen fibers 4 days after injury were observed in articular cartilage as a pantographic network with a transversally oriented lozenge-shaped mesh, but this network was thinner in SBI. Fourteen days after the injury, the pantographic network of collagen presented square-shaped mesh in C, but this aspect was changed to a wider mesh in SBI. Morphometric analysis of epiphyseal plate revealed that the SBI group had less thickness than the respective controls (p<0.05). RUNX-2 showed no difference between groups, but RANK-L score was higher in all SBI groups.

CONCLUSIONS

Extensive burn injury causes delayed bone growth and morphological changes. Alterations in collagen network and enhancement in immunoreactivity of RANK-L result in increased osteoclastogenesis.