Current problems in burn hypermetabolism

Recovery of functional independence following major burn: A systematic review

BACKGROUND

Major burn injury, despite advancements in care and prevention, can have a profound impact on long-term morbidity, affecting quality of life and socioeconomic standing. We aim to explore factors predicting recovery of independence, the expected rate and time in majorly burned patients, and the measures of progress used.

METHOD

A systematic search of four databases (MEDLINE, EMBASE, COCHRANE, CINAHL) was conducted for studies reporting outcomes pertaining to physical ability indicative of independent function in adult (>15 y) cohorts who had suffered a major burn (>20% TBSA) up to 30 years after treatment in a developed specialised burn service. Data extracted included factors affecting rate of and time to achievement of function in five independence domains, as well as the outcome measures used.

RESULTS

21 eligible studies were included comprising 1298 major burns survivors with a combined mean age of 39.6 y and a mean TBSA of 25.8%. The most significant recurring factors impacting recovery of independent function were older age, female gender, burn severity, prolonged ICU and hospital admission, preceding mental health conditions, and post-acute psychological issues. Exercise-based rehabilitation conferred benefits on major burn patients even over 2 years following injury. Discharge to independent living from hospital occurred in 27% to 97% of patients, while reported return to work rates varied from 52% to 80%. Burns Specific Health Scale-Brief, Functional Independence Measure, and Physical Composite Score (SF-36) were the most widely used outcome scoring systems.

CONCLUSION

Major burn survivors have protracted recovery with potential for persistent chronic impairments, remaining consistently below baseline levels of function. Non-modifiable factors such as age and gender, and disease characteristics such as burn size with associated physical, physiological and psychosocial sequelae are contributory. Further research is required to explore achievement of specific milestones of major burn and polytrauma critical care patients, while early targeted rehabilitation addressing physical, psychological, and vocational needs has promising potential benefit.

Main mechanisms and clinical implications of alterations in energy expenditure state among patients with pheochromocytoma and paraganglioma: A review

Pheochromocytoma and paraganglioma (PPGL) are rare neuroendocrine tumors with diverse clinical presentations. Alterations in energy expenditure state are commonly observed in patients with PPGL. However, the reported prevalence of hypermetabolism varies significantly and the underlying mechanisms and implications of this presentation have not been well elucidated. This review discusses and analyzes the factors that contribute to energy consumption. Elevated catecholamine levels in patients can significantly affect substance and energy metabolism. Additionally, changes in the activation of brown adipose tissue (BAT), inflammation, and the inherent energy demands of the tumor can contribute to increased resting energy expenditure (REE) and other energy metabolism indicators. The PPGL biomarker, chromogranin A (CgA), and its fragments also influence energy metabolism. Chronic hypermetabolic states may be detrimental to these patients, with surgical tumor removal remaining the primary therapeutic intervention. The high energy expenditure of PPGL has not received the attention it deserves, and an accurate assessment of energy metabolism is the cornerstone for an adequate understanding and treatment of the disease.

Large area fractional laser treatment of mouse skin increases energy expenditure

Fractional laser (FL) treatment is a common dermatologic procedure that generates arrays of microscopic treatment zones separated by intact tissue, promoting fast wound healing. Using a mouse model, we introduced a large area fractional laser treatment (LAFLT) method to study metabolic effects. Using two laser modalities, ablative FL (AFL) and non-ablative FL (NAFL), and exposing different percentages of mice's total body surface area (TBSA), we followed changes in metabolic parameters in real time using metabolic cages. Additionally, body composition, markers of inflammation, neurohormonal signaling, and browning of adipocytes were investigated. LAFLT, especially in high TBSA groups, had specific metabolic effects such as significantly increased average daily energy expenditure, increased fat mass loss, systemic browning of adipocytes, and inflammatory states, without compromising other organs. The ability of LAFLT to stimulate metabolism in a controlled way could develop into a promising therapeutic treatment to induce positive metabolic changes that replace or augment systemic drugs.

Prognostication of the development of septic complications in children with burn injuries

OBJECTIVE

Aim: To determine the prognostic criteria for the development of septic complications in children with thermal injury.

PATIENTS AND METHODS

Materials and Methods: A single-center retrospective-prospective cohort study included a retrospective analysis of 98 medical histories of children of different ages with severe burns who were treated from 2007 to 2017. A prospective study was conducted among children (n=63) from 1 to 5 years old, who received various degrees severity burn injury, according to an open comparative method in the period from 2018 to 2021.

RESULTS

Results: Indicators of a high risk of developing sepsis were burns by flames of any etiology, damage severity index ≥75 units, total burn surface ≥25 %, deep burn area ≥ 5%. The threshold value of procalcitonin (PCT) ≥ 0.86 ng/ml on the 1st-3rd day and PCT > 0.51 ng/ml on the 7th day of burn disease, had a prognostic value for assessing the probability of sepsis. On the 1st day of hospitalization, the development of sepsis was predicted if the C-reactive protein (CRP) value was higher than 6.98 ng/ml, on the 3rd - the CRP level was above 7.43 ng/ml, on the 7th day - above 7.28 ng/ml.

CONCLUSION

Conclusions: Based on the obtained data, we selected the criteria with the best prognostic characteristics, which allows us to predict and prevent the development of sepsis in the early stages of burn disease in children.

Changes in body composition of burn patients during the phases of response to trauma

OBJECTIVE

To assess the changes in body composition of burn patients through electrical bioimpedance in the phases of response to trauma.

METHODS

a longitudinal observational study, carried out from October 2019 to March 2020. Sociodemographic, clinical, epidemiological, anthropometric and body composition data were collected. Statistical analysis was performed with SPSS, considering a significance of 5%. The comparison between variables was performed using the paired Student's t test.

RESULTS

the sample consisted of 58 adult burn patients, with a mean age of 38.2±12.5 years. The mean body surface area (BSA) with burns was 10.8±7.3%. Nutritional assessment demonstrated a depletion of body weight, Body Mass Index, fat-free mass and muscle mass in the phases of response to trauma (p<0.005).

CONCLUSION

metabolic alterations in the different phases of the metabolic response to trauma led to a depletion of the nutritional status of burn patients of both sexes during hospitalization.

Inpatient Rehabilitation Following Burn Injury

Inpatient rehabilitation confers excellent benefit to burn survivors and should be considered as a potential destination during discharge planning. Consulting physiatrists identify and manage complications within the inpatient rehabilitation setting. Interventions can be taken to address medical sequelae of injury, including pain, itch, neuropathy, psychological coping and mood, and nutritional needs. Physiatrists also oversee and direct a rehabilitation program focusing on scar management, contracture prevention, dysphagia treatment, and evaluation and treatment of cognitive impairments. Aerobic and resistive exercise are key components of an inpatient rehabilitation program to reduce the systemic impact of a burn injury and improve quality of life.

Skeletal muscle wasting after burn is regulated by a decrease in anabolic signaling in the early flow phase

Following burns a sustained catabolic stress response is activated, resulting in skeletal muscle wasting. A better understanding of the underlying mechanisms of postburn skeletal muscle wasting is essential for the development of preventive and/or therapeutic strategies. Six weeks old female rats underwent a sham, 10% or 40% total body surface area scald burn. Ten days post-injury, severely burned animals gained significantly less weight compared to sham treated and minor burned animals, reflected in a significantly lower ratio of muscle to total body weight for Soleus (SOL) and Extensor Digitorum Longus (EDL) in the severely burned group. Postburn, total fiber number was significantly lower in EDL, while in SOL the amount of type1 fibers significantly increased and type2 fibers significantly decreased. No signs of mitochondrial dysfunction (COX/SDH) or apoptosis (caspase-3) were found. In SOL and EDL, eEF2 and pAKT expression was significantly lower after severe burn. MURF1,2,3 and Atrogin-1 was significantly higher in SOL, whilst in EDL MURF1,2,3 was significantly lower postburn. In both muscles, FOXO3A was significantly lower postburn. This study identified postburn changes in muscle anthropomorphology and proteins involved in pathways regulating protein synthesis and breakdown, with more pronounced catabolic effects in SOL.

Description of Aspartate Aminotransferase and Alanine Aminotransferase in Burn Patients at the Burn Unit of Dr. Hasan Sadikin General Hospital (Rshs) Bandung

Burn injury is trauma with several metabolic reactions including hepatocytes that can cause apoptosis and necrosis. Proliferation occurs to compensate for this reaction but complicates with the loss of protein of the injury. The aim of this study is to describe the level of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in burn injury. This study was a descriptive retrospective design using secondary data from medical records of patients at the Burns Unit of Dr. Hasan Sadikin Hospital Bandung (RSHS) in the period August 2017 to July 2019. Total samples in this study were 116 people. Normal level of AST and ALT was found in 23 people (19.8%), elevation of AST in 31 people (26.7%), elevation of ALT in 5 people (4.3%) and elevation of both AST and ALT in 57 people (41.3%). Increased levels of AST and ALT mostly occurred in men (51%), aged 45 years (56%), with injury due to electricity (26%), 20-29% burn area (32%), and occurred in the first week of wound onset. Most cases of burn injury showed increasing levels of AST and ALT. This might be due to the metabolism of hepatocytes in burn cases. Elevation of AST and ALT was mainly found in burn injury cases at RSHS notably in the first week of onset. Further research is needed to verify the relation of this condition. Elevated levels of AST and ALT should be the consideration of clinicians in giving therapy.

Investigation of glucose, serum insulin levels, and insulin resistance in patients with major burn: a retrospective cross-sectional study

BACKGROUND

Many studies have reported that insulin resistance (IR) is present and persistent in patients with major burns; however, the evidence remains insufficient. This study was planned to investigate insulin levels and IR in the early post-traumatic period in patients with major burns and to determine the prevalence of IR after burn injury.

METHODS

This study included 68 patients. These patients were followed up once a week for 4 weeks after hospitalization. In the follow-up examinations, demographic and burn injury characteristics; HbA1c, procalcitonin serum glucose, and insulin levels; and IR were evaluated.

RESULTS

IR was seen in some weeks only in 25 of the 68 patients included in the study. Among all patients, IR was determined in only 11 (16.17%) patients from the 1st day of hospitalization until discharge. Patients with and without IR were evaluated as 2 groups, and their biochemical parameters were compared, and no significant difference was found between glucose and procalcitonin levels (P>0.05). Glucose levels were >100 mg/dL in the first few weeks in all patients who were followed up; however, they returned to the normal range in the following weeks.

CONCLUSION

In patients with IR, there was insufficient evidence to conclude that the condition persists. We believe that the HOMA-IR value is not directly related to burn injuries and that other additional pathologies may cause it during treatment.

Transcriptomics, metabolomics, and in-silico drug predictions for liver damage in young and aged burn victims

Burn induces a systemic response affecting multiple organs, including the liver. Since the liver plays a critical role in metabolic, inflammatory, and immune events, a patient with impaired liver often exhibits poor outcomes. The mortality rate after burns in the elderly population is higher than in any other age group, and studies show that the liver of aged animals is more susceptible to injury after burns. Understanding the aged-specific liver response to burns is fundamental to improving health care. Furthermore, no liver-specific therapy exists to treat burn-induced liver damage highlighting a critical gap in burn injury therapeutics. In this study, we analyzed transcriptomics and metabolomics data from the liver of young and aged mice to identify mechanistic pathways and in-silico predict therapeutic targets to prevent or reverse burn-induced liver damage. Our study highlights pathway interactions and master regulators that underlie the differential liver response to burn injury in young and aged animals.

Sustainable Approach of Functional Biomaterials-Tissue Engineering for Skin Burn Treatment: A Comprehensive Review

Burns are a widespread global public health traumatic injury affecting many people worldwide. Non-fatal burn injuries are a leading cause of morbidity, resulting in prolonged hospitalization, disfigurement, and disability, often with resulting stigma and rejection. The treatment of burns is aimed at controlling pain, removing dead tissue, preventing infection, reducing scarring risk, and tissue regeneration. Traditional burn wound treatment methods include the use of synthetic materials such as petroleum-based ointments and plastic films. However, these materials can be associated with negative environmental impacts and may not be biocompatible with the human body. Tissue engineering has emerged as a promising approach to treating burns, and sustainable biomaterials have been developed as an alternative treatment option. Green biomaterials such as collagen, cellulose, chitosan, and others are biocompatible, biodegradable, environment-friendly, and cost-effective, which reduces the environmental impact of their production and disposal. They are effective in promoting wound healing and reducing the risk of infection and have other benefits such as reducing inflammation and promoting angiogenesis. This comprehensive review focuses on the use of multifunctional green biomaterials that have the potential to revolutionize the way we treat skin burns, promoting faster and more efficient healing while minimizing scarring and tissue damage.

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.

Relationship of zinc level with pathogenetically significant homeostasis disorders in severely burned patients

The aim of the study was to assess the zinc content and identify the relationship between the concentration of this element and changes in the biochemical status of patients and markers of inflammation during burn shock. We examined 23 patients aged 45.3±16.1 years with burns of I-II-III degree, area of 31-80%. The serum concentrations of zinc, albumin, interleukin-6, C-reactive protein (CRP), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined. The majority of patients (21/23) had severe hypocincemia, correlated with burn area (r=-0.53; p=0.008). A decrease in zinc levels during burn shock was associated with the development of hypoalbuminemia (r=0.52, p=0.01). The association of deviations in ALT and AST activity with changes in zinc concentration was revealed (-0.59<γ<-0.61, 0.008<p<0.009), which may indicate the role of hepatic dysfunction in the development of hypocinkemia. The development of a systemic inflammatory response was revealed. The correlation analysis revealed an association between the zinc and interleukin-6 levels (r=-0.63, p=0.03), as well as zinc and CRP (r=-0.41, p=0.04). From the first days after the injury, zinc deficiency is observed in severely burned patients, which is affected by an inflammatory reaction and hypoalbuminemia. Due to the fact that zinc is one of the key factors in maintaining homeostasis in the body, it is necessary to further study the molecular mechanisms of regulating the level of this trace element in burned patients and to develop ways to correct hypocinkemia that contribute to the effective treatment of burn disease.

The involvement of the adrenergic nervous system in activating human brown adipose tissue and browning

Obesity is a chronic condition of multifactorial etiology characterized by excessive body fat due to a calorie intake higher than energy expenditure. Given the intrinsic limitations of surgical interventions and the difficulties associated with lifestyle changes, pharmacological manipulation is currently one of the main therapies for metabolic diseases. Approaches aiming to promote energy expenditure through induction of thermogenesis have been explored and, in this context, brown adipose tissue (BAT) activation and browning have been shown to be promising strategies. Although such processes are physiologically stimulated by the sympathetic nervous system, not all situations that are known to increase adrenergic signaling promote a concomitant increase in BAT activation or browning in humans. Thus, a better understanding of factors involved in the thermogenesis attributed to these tissues is needed to enable the development of future therapies against obesity. Herein we carry out a critical review of original articles in humans under conditions previously known to trigger adrenergic responses-namely, cold, catecholamine-secreting tumor (pheochromocytoma and paraganglioma), burn injury, and adrenergic agonists-and discuss which of them are associated with increased BAT activation and browning. BAT is clearly stimulated in individuals exposed to cold or treated with high doses of the β3-adrenergic agonist mirabegron, whereas browning is certainly induced in patients after burn injury or with pheochromocytoma, as well as in individuals treated with β3-adrenergic agonist mirabegron for at least 10 weeks. Given the potential effect of increasing energy expenditure, adrenergic stimuli are promising strategies in the treatment of metabolic diseases.

Carry That Weight! The Challenge of Managing Weight Changes During Inpatient Admission for Patients With Burn Injuries ≥20% TBSA

The hypermetabolic state of patients with ≥20% total body surface area (TBSA) causes loss of muscle mass and compromised immune function with delayed wound healing. Weight loss is most severe in patients with ≥20% TBSA with initial weight gain due to fluid resuscitation. The American Burn Association (ABA) proposed quality measures for burn injury admissions, including weight loss from admission to discharge. We assessed how our outcomes adhere to these measures and if they correlate with previously described results. We retrospectively reviewed adult admissions with ≥20% TBSA burn injuries from 2016 to 2021. Four groups were established based on %TBSA: 20% to 29% (Group 1), 30% to 39% (Group 2), 40% to 59% (Group 3), and ≥60% (Group 4). We assessed weight changes from admission to discharge and performed multivariate analyses to account for age, sex, total surgeries, and length of stay. Data from 123 patients revealed 40 with 20% to 29% TBSA, 29 with 30% to 39% TBSA, 33 with 40% to 59% TBSA, 21 with ≥60% TBSA. A significant difference in weight loss was observed when comparing Groups 1 and 2 and Groups 3 and 4 (Group 1: −3.63%, Group 2: −2%, Group 3: −9.28%, Group 4: −13.85%; P-value ≤ .05). Groups 3 and 4 had significantly longer lengths of stay compared to Groups 1 and 2 (Group 1: 32.16, Group 2: 37.5, Group 3: 71.13, Group 4: 87.18; P-value ≤ .01). Most patients that experienced weight loss during their admission had &lt;15% weight loss. We found no significant difference in outcomes for patients receiving oxandrolone vs not. The mean weight change was −11% for patients with an overall weight loss and +5% for patients with an overall weight gain. The significant difference between the two groups was admission body mass index (BMI; loss: 30.4 kg/m2, gain: 26.0 kg/m2; P-value ≤ .05). Patients with ≥20% TBSA suffer weight changes, likely due to metabolic disturbances. Increased length of stay and higher %TBSA may be associated with greater weight loss. Patients experiencing weight gain had lower admission BMI suggesting that patients with higher BMI are more prone to weight loss. Our findings support that patients with %TBSA ≥40 are unique, requiring specialized nutritional protocols and metabolic analysis.

Burn-induced hypermetabolism and skeletal muscle dysfunction

Critical illnesses, including sepsis, cancer cachexia, and burn injury, invoke a milieu of systemic metabolic and inflammatory derangements that ultimately results in increased energy expenditure leading to fat and lean mass catabolism. Burn injuries present a unique clinical challenge given the magnitude and duration of the hypermetabolic response compared with other forms of critical illness, which drastically increase the risk of morbidity and mortality. Skeletal muscle metabolism is particularly altered as a consequence of burn-induced hypermetabolism, as it primarily provides a main source of fuel in support of wound healing. Interestingly, muscle catabolism is sustained long after the wound has healed, indicating that additional mechanisms beyond wound healing are involved. In this review, we discuss the distinctive pathophysiological response to burn injury with a focus on skeletal muscle function and metabolism. We first examine the diverse consequences on skeletal muscle dysfunction between thermal, electrical, and chemical burns. We then provide a comprehensive overview of the known mechanisms underlying skeletal muscle dysfunction that may be attributed to hypermetabolism. Finally, we review the most promising current treatment options to mitigate muscle catabolism, and by extension improve morbidity and mortality, and end with future directions that have the potential to significantly improve patient care.

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.