Long-term propranolol use in severely burned pediatric patients: a randomized controlled study

β-2 agonist and antagonist adrenoceptors induce neuroprotection in a progressive model of parkinsonism

Parkinson's disease (PD) is a neurodegenerative disorder characterized by progressive dopaminergic dysfunction in the nigrostriatal pathway, as well as alterations in other monoamines systems. Research indicates that the use of β-adrenergic agonist and antagonists influences the risk of PD. This study evaluated the effects of salbutamol and propranolol on motor and neurochemical parameters in a progressive model of parkinsonism induced by reserpine (RES). Male Wistar rats were chronically treated with 12 subcutaneous injections of RES (0,1 mg/kg) given every other day for 24 days. From the 16th day onwards, the animals were daily treated with salbutamol (5 mg/kg) or propranolol (20 mg/kg) intraperitoneally for 8 days. Salbutamol reduced the motor deficit caused by RES in the catalepsy test, while propranolol reduced the damages caused by RES in the vacuous chewing movements evaluation. In immunohistochemical analysis both salbutamol and propranolol prevented dopaminergic damage in the substantia nigra pars compacta (SNpc), ventral tegmental area (VTA), striatum and noradrenergic damage in locus coeruleus (LC). In addition, salbutamol and propranolol prevented the increase in α-synuclein immunoreactivity caused by RES in the substantia nigra pars reticulata (SNr), striatum, prefrontal cortex (mPFC) and hippocampus. These data show that salbutamol and propranolol promote neuroprotective effects against reserpine-induced parkinsonism. However, further studies are needed to understand the mechanisms involved in β-adrenoceptors role in PD development.

The Effectiveness and Safety of Beta Antagonists in Patients With Burns: An Updated Meta-Analysis

AimsThe purpose of this systematic review was to assess the safety and effectiveness of beta antagonists for improving clinical care in burn patients, compared to placebo.MethodsArticles from randomized-controlled trials were identified by a literature search on PubMed and Cochrane. We included relevant trials involving patients with burn. Trials were eligible if they evaluated propranolol and compared to usual care or placebo. We conducted a meta-analysis using a random-effects model.ResultsA total of 2114 patients were included from 14 RCTs. Beta-blocker-treated patients had decreased heart rates (WMD = -14.73, 95% CIs = [-19.14, -10.32]), mean arterial pressure (WMD = -2.76, 95% CIs = [-3.81, -1.70]), rate pressure product (WMD = -1.13, 95% CIs = [-1.56, -0.71]), reduced time for wound healing (WMD = -5.08, 95% CIs [-8.97, -1.18]), and lower resting energy expenditure (WMD = -168.83, 95% CIs [-232.03, -105.63]). However, use of beta-blockers did not reduce mortality rate (WMD = 0.98, 95% CIs [0.68, 1.41]), incidence of sepsis (RR = 0.82, 95% CIs = [0.50, 1.35]), or length of stay in hospital (WMD = -1.50, 95% CIs [-4.76, 1.77]) compared with placebo.ConclusionOur findings indicate that the administration of propranolol to burned patients does not contribute to increased mortality rates, reduced length of hospital stays, or heightened sepsis occurrence. It demonstrates a protective effect on heart function by reducing heart rate, resting energy expenditure, rate pressure product, and wound healing. More randomized-controlled and multi-center studies are needed to effectively establish the use of beta antagonists in burn patients.

Metabolic response to burn injury: a comprehensive bibliometric study

Objective

Burns lead to systemic changes manifested by systemic disturbances in water-electrolyte balance and systemic metabolic and inflammatory responses. The hypermetabolic response after a burn injury relies on metabolic, hormonal, and inflammatory dysregulation mechanisms. This study aimed to provide a comprehensive bibliometric analysis of the burn metabolism research field, identifying key trends, influential contributors, and emerging research hotspots to inform future investigative efforts. Ultimately, we conducted an extensive review of the literature, synthesizing the findings to clarify the present understanding within our field of study.

Methods

We obtained 8,823 scientific publications on burn injury and metabolism from the core Web of Science (WOS) database collection. In this work, biblioshiny was used to visualize and analyze the data, and VOSviewer was used to verify the results.

Results

From a total of 8,823 publications, we found a general upward trend in annual publications and citation frequency. According to Bradford's Law, 21 high-production journals were classified as core sources based on the number of publications, and the most productive journal was Burns. The most published countries and authors in this field were the United States and Herndon DN. The most local cited document in this field was the article titled "Catecholamines: Mediator of the Hypermetabolic Response to Thermal Injury" authored by Wilmore DW. The thematic map showed that studies on injury, thermal injury, and sepsis were relatively mature. In contrast, research on metabolism, stress, and responses, and research on mortality, resistance, and management were less well-developed but were essential for the field.

Conclusion

Research on burns and metabolism is increasing. Based on the bibliometric analysis, our study summarized the complex interplay between burn-induced systemic metabolic alterations and inflammatory responses, emphasizing the significance of hypermetabolism and its management. The role of propranolol, insulin, oxandrolone, and nutritional interventions in modulating the hypermetabolic state was discussed. Additionally, our study underscored the challenges of managing sepsis and drug-resistant infections in burn patients as an important future area of research.

Inter-individual variability of aerobic capacity after rehabilitation exercise training in children with severe burn injury

INTRODUCTION

Severe burn trauma damages resting and exercise cardiac function that may affect long term cardiovascular health. The implementation of rehabilitation exercise training (RET) soon after hospital discharge improves cardiorespiratory fitness; however, it does not fully restore aerobic capacity and presents large inter-individual variability. We tested the hypothesis that the inter-individual variability of aerobic capacity for responders (R) compared to nonresponders (NR) would differ for exercise frequency and intensity.

METHODS

Thirty-three children (11 female, [mean±SD] 12 ± 3 years, 145 ± 18 cm, 40 ± 11 kg, 49 ± 31 BMI percentile) with severe burns (49 ± 15 % total body surface area burned, with 35 ± 22 % third-degree burns) completed a 6-week RET program. Cardiorespiratory fitness (peak VO2) was measured before and after RET. Frequency (session days/week), intensity (% peak heart rate), time (min/session), and volume (min/week) were compared between responders and non-responders. Significance was set at p < 0.05.

RESULTS

Sixty-four percent of the study population improved peak VO2 after RET whereas 36 % showed no improvements. Using a 2-way factorial ANOVA (group [G] × week [WK]), we found that exercise frequency and session time were similar and increased slightly over 6 weeks between R and NR (main effect for WK; P < 0.002). Exercise volume was significantly lower on week 2 for NR compared to R (G × WK interaction, P < 0.028). Exercise intensity over 6-weeks was significantly lower in the NR compared to the R group (G × WK interaction, P < 0.022).

CONCLUSIONS

Exercise intensity and volume may be important contributors for improving the interindividual response to exercise training for peak VO2. These data suggest that the appropriate dose-response requirement for exercise intensity may be > 80 % peak heart rate and exercise volume of > 150 min per week. Further understanding of the exercise prescription will provide insights important for cardiovascular rehabilitation in children with severe burns.

SUBJECT CODE

Inter-individual Variability, Exercise, Pediatrics, Exercise Training.

β-Adrenergic blockade attenuates adverse adipose tissue responses after burn

Severe burn injuries are defined by a prolonged hypermetabolic response characterized by increases in resting energy expenditure, systemic catabolism, and multi-organ dysfunction. The sustained elevation of catecholamines following a burn injury is thought to significantly contribute to this hypermetabolic response, leading to changes in adipose tissue such as increased lipolysis and the browning of subcutaneous white adipose tissue (WAT). Failure to mitigate these adverse changes within the adipose tissue has been shown to exacerbate the post-burn hypermetabolic response and lead to negative outcomes. Propranolol, a non-selective β-blocker, has been clinically administered to improve outcomes of pediatric and adult burn patients, but there is inadequate knowledge of its effects on the distinct adipose tissue depots. In this study, we investigated the adipose depot-specific alterations that occur in response to burn injury. Moreover, we explored the therapeutic effects of β-adrenoceptor blockade via the drug propranolol in attenuating these burn-induced pathophysiological changes within the different fat depots. Using a murine model of thermal injury, we show that burn injury induces endoplasmic reticulum (ER) stress in the epididymal (eWAT) but not in the inguinal (iWAT) WAT depot. Conversely, burn injury induces the activation of key lipolytic pathways in both eWAT and iWAT depots. Treatment of burn mice with propranolol effectively mitigated adverse burn-induced alterations in the adipose by alleviating ER stress in the eWAT and reducing lipolysis in both depots. Furthermore, propranolol treatment in post-burn mice attenuated UCP1-mediated subcutaneous WAT browning following injury. Overall, our findings suggest that propranolol serves as an effective therapeutic intervention to mitigate the adverse changes induced by burn injury, including ER stress, lipotoxicity, and WAT browning, in both adipose tissue depots. KEY MESSAGES: Burn injury adversely affects adipose tissue metabolism via distinct changes in both visceral and subcutaneous adipose depots. Propranolol, a non-selective β-adrenergic blocker, attenuates many of the adverse adipose tissue changes mediated by burn injury.

Nutritional and metabolic modulation of inflammation in critically ill patients: a narrative review of rationale, evidence and grey areas

BACKGROUND

Inflammation is the hallmark of critical illness and triggers the neuro-endocrine stress response and an oxidative stress. Acute inflammation is initially essential for patient's survival. However, ongoing or exaggerated inflammation, due to persistent organ dysfunction, immune dysfunction or poor inflammation resolution, is associated to subsequent hypermetabolism and hypercatabolism that severely impact short and long-term functional status, autonomy, as well as health-related costs. Modulation of inflammation is thus tempting, with the goal to improve the short- and long-term outcomes of critically ill patients.

FINDINGS

Inflammation can be modulated by nutritional strategies (including the timing of enteral nutrition initiation, the provision of some specific macronutrients or micronutrients, the use of probiotics) and metabolic treatments. The most interesting strategies seem to be n-3 polyunsaturated fatty acids, vitamin D, antioxidant micronutrients and propranolol, given their safety, their accessibility for clinical use, and their benefits in clinical studies in the specific context of critical care. However, the optimal doses, timing and route of administration are still unknown for most of them. Furthermore, their use in the recovery phase is not well studied and defined.

CONCLUSION

The rationale to use strategies of inflammation modulation is obvious, based on critical illness pathophysiology and based on the increasingly described effects of some nutritional and pharmacological strategies. Regretfully, there isn't always substantial proof from clinical research regarding the positive impacts directly brought about by inflammation modulation. Some arguments come from studies performed in severe burn patients, but such results should be transposed to non-burn patients with caution. Further studies are needed to explore how the modulation of inflammation can improve the long-term outcomes after a critical illness.

The efficacy of therapeutic interventions on paediatric burn patients' height, weight, body composition, and muscle strength: A systematic review and meta-analysis

OBJECTIVE

To evaluate the efficacy of therapeutic interventions on pediatric burn patients' height, weight, body composition, and muscle strength.

METHODS

A systematic literature search was conducted in PubMed, Embase, and Web of Science up to March 2021. Eligible interventional studies reported metrics on the height, weight, body composition, or muscle strength of pediatric burn patients in a peer-reviewed journal. Meta-analyses were performed if ≥ 2 trials of clinical homogeneity reported on an outcome measure at the same time point post-burn.

RESULTS

Twenty-six interventional studies were identified, including twenty-two randomised controlled trials and four non-randomised trials. Most studies were conducted by a single institution. On average, the burn covered 45.3% ( ± 9.9) of the total body surface area. Three categories of interventions could be distinguished: rehabilitative exercise programs, pharmacologic agents, and nutrition support.

CONCLUSIONS

Each of the interventions had a positive effect on height, weight, body composition, or muscle strength. The decision to initiate an intervention should be made on a case-by-case basis following careful consideration of the benefits and risks. In future research, it is important to evaluate the heterogeneity of intervention effects and whether participation in an intervention allowed pediatric burn patients to reach the physical and functional status of healthy peers.

Update on Hypermetabolism in Pediatric Burn Patients

Despite advancements in pediatric burn care, the profound hypermetabolic response associated with severe burns remains a multifaceted challenge throughout the continuum of care. Understanding the various physiologic disturbances that constitute hypermetabolism is crucial for a thorough evaluation and for implementing appropriate surgical and nonsurgical interventions. In this article, we describe the pathophysiology and treatment of hypermetabolism in pediatric burn patients with a focus on reducing resting energy requirements, minimizing infection, and optimizing nutrition for patients undergoing frequent surgical intervention.

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.

Administration and effects of beta blockers and oxandrolone in severely burned adults: a post hoc analysis of the RE-ENERGIZE trial

Background

Prospective randomized trials in severely burned children have shown the positive effects of oxandrolone (OX), beta blockers (BB) and a combination of the two (BBOX) on hypermetabolism, catabolism and hyperinflammation short- and long-term post-burn. Although data on severely burned adults are lacking in comparison, BB, OX and BBOX appear to be commonly employed in this patient population. In this study, we perform a secondary analysis of an international prospective randomized trial dataset to provide descriptive evidence regarding the current utilization patterns and potential treatment effects of OX, BB and BBOX.

Methods

The RE-ENERGIZE (RandomizEd Trial of ENtERal Glutamine to minimIZE Thermal Injury, NCT00985205) trial included 1200 adult patients with severe burns. We stratified patients according to their receipt of OX, BB, BBOX or none of these drugs (None) during acute hospitalization. Descriptive statistics describe the details of drug therapy and unadjusted analyses identify predisposing factors for drug use per group. Association between OX, BB and BBOX and clinical outcomes such as time to discharge alive and 6-month mortality were modeled using adjusted multivariable Cox regressions.

Results

More than half of all patients in the trial received either OX (n = 138), BB (n = 293) or BBOX (n = 282), as opposed to None (n = 487, 40.6%). Per study site and geographical region, use of OX, BB and BBOX was highly variable. Predisposing factors for the use of OX, BB and BBOX included larger total body surface area (TBSA) burned, higher acute physiology and chronic health evaluation (APACHE) II scores on admission and younger patient age. After adjustment for multiple covariates, the use of OX was associated with a longer time to discharge alive [hazard ratio (HR) 0.62, confidence interval (CI) (0.47-0.82) per 100% increase, p = 0.001]. A higher proportion of days on BB was associated with lower in-hospital-mortality (HR: 0.5, CI 0.28-0.87, p = 0.015) and 6-month mortality (HR: 0.44, CI 0.24-0.82, p = 0.01).

Conclusions

The use of OX, BB and BBOX is common within the adult burn patient population, with its use varying considerably across sites worldwide. Our findings found mixed associations between outcomes and the use of BB and OX in adult burn patients, with lower acute and 6-month-mortality with BB and longer times to discharge with OX. Further research into these pharmacological modulators of the pathophysiological response to severe burn injury is indicated.

An Overview of Recent Developments in the Management of Burn Injuries

According to the World Health Organization (WHO), around 11 million people suffer from burns every year, and 180,000 die from them. A burn is a condition in which heat, chemical substances, an electrical current or other factors cause tissue damage. Burns mainly affect the skin, but can also affect deeper tissues such as bones or muscles. When burned, the skin loses its main functions, such as protection from the external environment, pathogens, evaporation and heat loss. Depending on the stage of the burn, the patient's condition and the cause of the burn, we need to choose the most appropriate treatment. Personalization and multidisciplinary collaboration are key to the successful management of burn patients. In this comprehensive review, we have collected and discussed the available treatment options, focusing on recent advances in topical treatments, wound cleansing, dressings, skin grafting, nutrition, pain and scar tissue management.

Key Exercise Concepts in the Rehabilitation from Severe Burns

This article presents information on the benefits of exercise in counteracting the detrimental effects of bed rest, and/or severe burns. Exercise is key for maintaining physical function, lean body mass, metabolic recovery, and psychosocial health after major burn injuries. The details of an exercise training program conducted in severely burned persons are presented, as well as information on the importance of proper regulation of body temperature during exercise or physical activity. The sections on exercise and thermoregulation are followed by a section on the role of exercise in scarring and contractures. Finally, gaps in the current knowledge of exercise, thermoregulation, and contractures are presented.

Propranolol Normalizes Metabolomic Signatures Thereby Improving Outcomes After Burn

OBJECTIVE AND BACKGROUND

Propranolol, a nonselective beta-receptor blocker, improves outcomes of severely burned patients. While the clinical and physiological benefits of beta-blockade are well characterized, the underlying metabolic mechanisms are less well defined. We hypothesized that propranolol improves outcomes after burn injury by profoundly modulating metabolic pathways.

METHODS

In this phase II randomized controlled trial, patients with burns ≥20% of total body surface area were randomly assigned to control or propranolol (dose given to decrease heart rate <100 bpm). Outcomes included clinical markers, inflammatory and lipidomic profiles, untargeted metabolomics, and molecular pathways.

RESULTS

Fifty-two severely burned patients were enrolled in this trial (propranolol, n=23 and controls, n=29). There were no significant differences in demographics or injury severity between groups. Metabolomic pathway analyses of the adipose tissue showed that propranolol substantially alters several essential metabolic pathways involved in energy and nucleotide metabolism, as well as catecholamine degradation ( P <0.05). Lipidomic analysis revealed that propranolol-treated patients had lower levels of proinflammatory palmitic acid ( P <0.05) and saturated fatty acids ( P <0.05) with an increased ratio of polyunsaturated fatty acids ( P <0.05), thus shifting the lipidomic profile towards an anti-inflammatory phenotype after burn ( P <0.05). These metabolic effects were mediated by decreased activation of hormone-sensitive lipase at serine 660 ( P <0.05) and significantly reduced endoplasmic reticulum stress by decreasing phospho-JNK ( P <0.05).

CONCLUSION

Propranolol's ability to mitigate pathophysiological changes to essential metabolic pathways results in significantly improved stress responses.

Modified Nutrition Risk in Critically ill is an effective nutrition risk screening tool in severely burned patients, compared with Nutrition Risk Screening 2002

Objective

The present study aimed to evaluate the value of Modified Nutrition Risk in Critically ill (mNUTRIC) and Nutrition Risk Screening 2002 (NRS2002) in the prognosis of severely burned patients.

Methods

The retrospective cohort study used medical data of severely burned patients admitted to the burn center of Shanghai Ruijin Hospital between January 2015 and September 2021. Demographics, clinical characteristics, laboratory nutritional indicators, mNUTRIC score and NRS2002 score were collected and analyzed in evaluation the value of two nutrition risk screening tools. Spearman correlation analysis was carried out to show the correlation between variables. The area under receiver operating characteristic (ROC) curve was used to assess the ability of mNUTRIC and NRS2002 to predict mortality. Kaplan-Meier survival curves and log-rank tests were conducted to compare the overall survival (OS). Multivariate Cox proportional hazard regression model was used to identify risk factors for 28-day mortality of severely burned patients.

Results

A total of 429 adult patients with burn area larger than 30% total body surface area (TBSA) were included in this study. Incidence of nutrition risk was detected in 52.21% by mNUTRIC and 20.51% by NRS2002. However, mNUTRIC was superior to NRS2002 in predicting 28-day mortality (area under ROC curve: 0.795 vs. 0.726). Multivariate Cox regression analysis showed that high mNUTRIC [hazard ratio (HR) = 4.265, 95% CI = 1.469-12.380, P = 0.008] and TBSA (HR = 1.056, 95% CI = 1.033-1.079, P < 0.001) were independent predictors for 28-day mortality. After adjusting for covariates, high NRS2002 was not associated with 28-day mortality (P = 0.367).

Conclusion

The present study illustrated the effectiveness of mNUTRIC as nutrition risk screening tool among severely burned patients. Early identification of nutrition risk may help to maximize benefits of nutritional therapy by providing more aggressive nutritional therapy for patients at nutrition risk.

Pediatric Perioperative Clinical Pharmacy Practice: Clinical Considerations and Management: An Opinion of the Pediatrics and Perioperative Care Practice and Research Networks of the American College of Clinical Pharmacy

Pediatric perioperative clinical pharmacists are uniquely positioned to provide therapeutic and medication management expertise at a particularly vulnerable transition of care from the preoperative space, through surgery, and postoperative setting. There are many direct-patient care activities that are included in the role of the pediatric perioperative pharmacist, as well as many opportunities to develop effective, optimized, and safe medication use processes. This article outlines many of the areas in which a pediatric perioperative clinical pharmacist may intervene.

The use of propranolol in adult burn patients: Safety and outcome influence

OBJECTIVES

This study investigated safety and effect of propranolol on adult patients with severe burn.

METHODS

A prospective study was conducted on 124 severely adult burn patients who were randomly divided into propranolol and non-propranolol group. Propranolol was given by nasogastric tube to achieve the target of lowering 15-20% of initial heart rate.

RESULTS

Average dose of propranolol was 1.9 ± 0.5 mg/kg/day ranging from 0.9 to 3.3 mg/kg/day and was not affected by burn extent and inhalation injury. Mean heart rate reduced by 21.2% during the 28 day period. Recorded adverse events included hypotension (11.9%), bradycardia (1.6%), hypoglycemia (17.7%) and total number of held events was 8 occurring in 7 (11.3%) patients. Serum levels of glucose, total protein, albumin, cholesterol and triglyceride at different times were not significantly different between the two groups. Significantly lower resting energy expenditure on the 7^th and 14^th day were seen in propranolol group (p < 0.05). After 3 weeks, liver size in the propranolol group did not change significantly from admission, while in the non-propranolol group, liver size increased significantly (p < 0.05). The complete healing time of partial-thickness burns and donor sites were significantly shorter in propranolol group (p < 0.01). Duration of ventilation, length of stay in intensive care unit and in hospital, number of operations, rate of multiple organ failure, and death were not different between the two groups (p > 0.05).

CONCLUSION

For severely burned adults, propranolol was safe and effective on reducing energy expenditure, limited hepatomegaly, and accelerated partial burn wound and donor site closure, but does not affect length of stay in ICU, hospitalization, complication ormortality rate.

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.

Current understanding of thermo(dys)regulation in severe burn injury and the pathophysiological influence of hypermetabolism, adrenergic stress and hypothalamic regulation—a systematic review

Background

In this systematic review, we summarize the aetiology as well as the current knowledge regarding thermo(dys)regulation and hypothermia after severe burn trauma and aim to present key concepts of pathophysiology and treatment options. Severe burn injuries with >20% total body surface area (TBSA) affected commonly leave the patient requiring several surgical procedures, prolonged hospital stays and cause substantial changes to body composition and metabolism in the acute and long-term phase. Particularly in severely burned patients, the loss of intact skin and the dysregulation of peripheral and central thermoregulatory processes may lead to substantial complications.

Methods

A systematic and protocol-based search for suitable publications was conducted following the PRISMA guidelines. Articles were screened and included if deemed eligible. This encompasses animal-based in vivo studies as well as clinical studies examining the control-loops of thermoregulation and metabolic stability within burn patients

Results

Both experimental animal studies and clinical studies examining thermoregulation and metabolic functions within burn patients have produced a general understanding of core concepts which are, nonetheless, lacking in detail. We describe the wide range of pathophysiological alterations observed after severe burn trauma and highlight the association between thermoregulation and hypermetabolism as well as the interactions between nearly all organ systems. Lastly, the current clinical standards of mitigating the negative effects of thermodysregulation and hypothermia are summarized, as a comprehensive understanding and implementation of the key concepts is critical for patient survival and long-term well-being.

Conclusions

The available in vivo animal models have provided many insights into the interwoven pathophysiology of severe burn injury, especially concerning thermoregulation. We offer an outlook on concepts of altered central thermoregulation from non-burn research as potential areas of future research interest and aim to provide an overview of the clinical implications of temperature management in burn patients.

Application of beta-blockers in burn management

Severe burn injuries cause chronic inflammation, which produces a subsequent hypermetabolic response that starts immediately and persists for at least 3 years. The hypermetabolic state, which is thought to be due to postburn elevations of endogenous catecholamines and cortisol, is associated with a number of harmful physiologic derangements including immunosuppression, impaired wound healing, muscle catabolism, and hepatic dysfunction. Beta-blockers have become first line agents for reducing these adverse effects of hypermetabolism in severe burns. This review discusses the underlying pharmacological mechanisms demonstrated by clinical studies evaluating the safety and efficacy of beta-blockers in the management of burn injuries. A literature search was performed using the PubMed database to identify articles on beta-blockers and burn management. The review yielded 33 relevant results consisting of randomized controlled trials, original research articles, and meta-analyses in pediatric and adult burn patients. Propranolol administration reduced insulin resistance, lipolysis, proteolysis, cardiac work, and bone loss resulting from burn-associated hypermetabolism. Propranolol also effectively reduced myocardial stress, resting energy expenditure, and central deposition of fat. Recent studies have begun to evaluate incorporation of anabolic agents and rehabilitative exercise therapy. However, at this time propranolol continues to be the most effective therapy for reducing the hypermetabolic response and other morbidities resulting from burn injuries.

Beta-Adrenergic Blockade in Critical Illness

Catecholamine upregulation is a core pathophysiological feature in critical illness. Sustained catecholamine β-adrenergic induction produces adverse effects relevant to critical illness management. β-blockers (βB) have proposed roles in various critically ill disease states, including sepsis, trauma, burns, and cardiac arrest. Mounting evidence suggests βB improve hemodynamic and metabolic parameters culminating in decreased burn healing time, reduced mortality in traumatic brain injury, and improved neurologic outcomes following cardiac arrest. In sepsis, βB appear hemodynamically benign after acute resuscitation and may augment cardiac function. The emergence of ultra-rapid βB provides new territory for βB, and early data suggest significant improvements in mitigating atrial fibrillation in persistently tachycardic septic patients. This review summarizes the evidence regarding the pharmacotherapeutic role of βB on relevant pathophysiology and clinical outcomes in various types of critical illness.

Thermal Stress Induces Long-Term Remodeling of Adipose Tissue and Is Associated with Systemic Dysfunction

ABSTRACT

Severe burns are characterized by the magnitude and duration of the hypermetabolic response thereafter, and demarcated by the loss of lean body mass and catabolism of fat stores. The aim of the present study was to delineate the temporal and location-specific physiological changes to adipose depots and downstream consequences post-burn in a murine model of thermal injury. C57BL/6 mice were subjected to a 30% total body surface area burn and body mass, food intake, and tissue mass were monitored for various time points up until 60 days postinjury. Mitochondrial respirometry was performed using a Seahorse XF96 analyzer. Lipolytic markers and browning markers were analyzed via Western blotting and histology. A severe burn results in a futile cycle of lipolysis and white adipose tissue (WAT) browning, the sequelae of which include fat catabolism, hepatomegaly, and loss of body mass despite increased food intake. A dynamic remodeling of epididymal WAT was observed with acute and chronic increases in lipolysis. Moreover, we demonstrate that pathological browning of inguinal WAT persists up to 60 days post-burn, highlighting the magnitude of the β-adrenergic response to thermal injury. Our data suggests that adipose depots have a heterogeneous response to burns and that therapeutic interventions targeting these physiological changes can improve outcomes. These data may also have implications for treating catabolic conditions such as cancer cachexia as well as developing treatments for obesity and type II diabetes.

Long-term sequelae of critical illness in sepsis, trauma and burns: A systematic review and meta-analysis

BACKGROUND

Sepsis, major trauma, and severe burn injury are life-threatening critical illnesses that remain significant contributors to worldwide morbidity and mortality. The three underlying etiologies share pathophysiological similarities: hyperinflammation, hypermetabolism, and acute immunomodulation. The aims of this study were to assess the current state of long-term outcome research and to identify key outcome parameters between the three forms of critical illness.

METHODS

This systematic review and meta-analysis (MA) were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. PubMed was searched from January 1, 1975, to December 31, 2019. Studies were assessed for eligibility by independent reviewers. Inclusion criteria were studies reporting at least a 6-month follow-up of health-related quality of life and organ-specific sequelae within the three etiologies: severe burn injury, sepsis, and major trauma.

RESULTS

In total, 125 articles could be included in the systematic review and 74 in the MA. The mean follow-up time was significantly longer in burn studies, compared with sepsis and trauma studies. The majority of patients were from the sepsis group, followed by burns, and major trauma studies. In the overall health-related quality of life, as assessed by Short Form 36 and European Quality-of-Life Index, the three different etiologies were comparable with one another.

CONCLUSION

The effects of critical illness on survivors persist for years after hospitalization. Well-reported and reliable data on the long-term outcomes are imperative, as they can be used to determine the treatment choice of physicians and to guide the expectations of patients, improving the overall quality of care of three significant patient cohorts.

LEVEL OF EVIDENCE

Systematic review and MA, level III.

Drugs Interfering with Insulin Resistance and Their Influence on the Associated Hypermetabolic State in Severe Burns: A Narrative Review

It has become widely accepted that insulin resistance and glucose hypermetabolism can be linked to acute pathologies, such as burn injury, severe trauma, or sepsis. Severe burns can determine a significant increase in catabolism, having an important effect on glucose metabolism and on muscle protein metabolism. It is imperative to acknowledge that these alterations can lead to increased mortality through organ failure, even when the patients survive the initial trauma caused by the burn. By limiting the peripheral use of glucose with consequent hyperglycemia, insulin resistance determines compensatory increased levels of insulin in plasma. However, the significant alterations in cellular metabolism lead to a lack of response to insulin's anabolic functions, as well as to a decrease in its cytoprotective role. In the end, via pathological insulin signaling associated with increased liver gluconeogenesis, elevated levels of glucose are detected in the blood. Several cellular mechanisms have been incriminated in the development of insulin resistance in burns. In this context, the main aim of this review article is to summarize some of the drugs that might interfere with insulin resistance in burns, taking into consideration that such an approach can significantly improve the prognosis of the burned patient.

Rehabilitative Exercise Training for Burn Injury

Due to improvements in acute burn care over the last few decades, most patients with severe burns (up to 90% of the total body surface) survive. However, the metabolic and cardiovascular complications that accompany a severe burn can persist for up to 3 years post injury. Accordingly, there is now a greater appreciation of the need for strategies that can hasten recovery and reduce long-term morbidity post burn. Rehabilitation exercise training (RET) is a proven effective treatment to restore lean body mass, glucose and protein metabolism, cardiorespiratory fitness, and muscle strength in burn survivors. Despite this, very few hospitals incorporate RET in programs to aid the rehabilitation of patients with severe burns. Given that RET is a safe and efficacious treatment that restores function and reduces post-burn morbidity, we propose that a long-term exercise prescription plan should be considered for all patients with severe burns. In this literature review, we discuss the current understanding of burn trauma on major organ systems, and the positive benefits of incorporating RET as a part of the long-term rehabilitation of severely burned individuals. We also provide burn-specific exercise prescription guidelines for clinical exercise physiologists.

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.

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.

"Living Well" After Burn Injury: Using Case Reports to Illustrate Significant Contributions From the Burn Model System Research Program

The Burn Model System (BMS) program of research has been funded since 1993 by the National Institute on Disability, Independent Living, and Rehabilitation Research (NIDILRR). The overarching aim of this program is to improve outcomes and quality of life for people with burns in the areas of health and function, employment, and community living and participation. This review reports on BMS contributions that have affected the lives of individuals with a significant burn injury using case reports to associate BMS contributions with recovery. In January 2020, current BMS grantee researchers assessed peer-reviewed BMS publications from 1994 to 2020. Using case report methodology, contributions were linked to three individuals treated at one of the four Burn Model System institutions. With over 25 years of NIDILRR funding, unique BMS contributions to patient recovery were identified and categorized into one of several domains: treatment, assessment measures, sequelae, peer support, employment, and long-term functional outcomes. A second review for significant results of BMS research that add to the understanding of burn injury, pathophysiology, and recovery research was identified and categorized as injury recovery research. The case study participants featured in this review identified select NIDILRR research contributions as having direct, personal benefit to their recovery. The knowledge generation and clinical innovation that this research program has contributed to our collective understanding of recovery after burn injury is considerable. Using case study methodology with three adult burn survivors, we highlight the impact and individual significance of program findings and reinforce the recognition that the value of any clinical research must have relevance to the lives of the study population.

Beta-blocker-associated hypoglycaemia: New insights from a real-world pharmacovigilance study

AIMS

To investigate the statistical association between hypoglycaemia and β-blocker use and to define what patient and drug characteristics could potentially increase the risk for its occurrence.

METHODS

We investigated the relationship between pharmacological parameters of β-blockers and the occurrence of hypoglycaemia by conducting a case/non case analysis using the Food and Drug Administration Adverse Event Reporting System database. Pharmacological properties that could represent a predictive factor for hypoglycaemia were analysed through a multilinear binary logistic regression (null hypothesis rejected for values of P < .05). We also performed a systematic review of clinical studies on this association.

RESULTS

Of 83 954 selected reports, 1465 cases (1.75%) of hypoglycaemia were identified. The association was found statistically significant for nadolol (reporting odds ratio [95% confidence interval]: 6.98 [5.40-9.03]), celiprolol (2.35 [1.35-4.10]), propranolol (2.14 [1.87-2.46]) and bisoprolol (1.42 [1.25-1.61]). Paediatric cases (n = 310) showed a positive association with hypoglycaemia for long half-life drugs (odds ratio [95% confidence interval]: 2.232 [1.398-3.563]) and a negative association for β1-selectivity (0.644 [0.414-0.999]). Seven papers were included in the systematic review. Because of great heterogeneity in study design and demographics, hypoglycaemia incidence rates varied greatly among studies, occurring in 1.73% of the cases for propranolol treatment (n total participants = 575), 6.6% for atenolol (n = 30) and 10% for carvedilol (n = 20).

CONCLUSION

Nadolol appears to be the β-blocker significantly most associated with hypoglycaemia and children represent the most susceptible sample. Furthermore, long half-life and nonselective β-blockers seem to increase the risk for its occurrence.

Retrospective cohort study of health service use for cardiovascular disease among adults with and without a record of injury hospital admission

OBJECTIVE

To quantify postinjury cardiovascular-related health service use experienced by mid to older aged adults hospitalised for injury, compared with uninjured adults. Additionally, to explore the effect of beta-blocker medications on postinjury cardiovascular hospitalisations among injury patients, given the potential cardioprotective effects of beta blockers.

DESIGN

A retrospective cohort study using linked administrative and survey data.

PARTICIPANTS

Records of 35 026 injured and 60 823 uninjured matched adults aged over 45 from New South Wales, Australia, who completed the 45 and up survey.

PRIMARY AND SECONDARY OUTCOME MEASURES

Admission rates and cumulative lengths of stay for cardiovascular hospitalisations, and prescription rates for cardiovascular medications. Negative binomial and Cox proportional hazards regression modelling were used to generate incident rate ratios (IRRs) and HR.

RESULTS

Compared with the uninjured, those with injury had a 19% higher adjusted rate of postinjury cardiovascular admissions (IRR 1.19, 95% CI 1.14 to 1.25), spent 40% longer in hospital for ardiovascular disease (IRR 1.40, 95% CI 1.26 to 1.57) and had slightly higher cardiovascular prescription rates (IRR 1.04, 95% CI 1.02 to 1.06), during study follow-up. Those in the injury cohort that used beta blockers both prior to and after injury (continuous) appeared to have reduced need for post-injury cardiovascular hospitalisation (IRR 1.09, 95% CI 1.17 to 1.42) compared with those commencing on beta blockers after injury (after 30 days: IRR 1.69, 95% CI 1.37 to 2.08).

CONCLUSIONS

Apparent increased postinjury hospitalisation rates and prolonged length of stay related to cardiovascular disease suggest that injury patients may require clinical support for an extended period after injury. Additionally, injury patients who were on continuous beta blocker treatment appeared to have lower need for post-injury cardiovascular hospitalisations. However, the data do not allow us to draw clear conclusions and further clinical research is required.

The effectiveness and safety of beta antagonist in burned patients: A systematic review and meta-analysis

Beta antagonist is one of the most effective and the least toxic pharmacological treatments to attenuate the raised catecholamine effects for burned patients. To evaluate the effectiveness and safety of beta blocker compared with placebo or usual care in burned patients, a meta-analysis of randomised controlled trials (RCTs) was conducted. We searched the database of PubMed, Embase, the Cochrane Library, and Web of Science to 10 April 2020. Two investigators independently assessed articles for inclusion and exclusion criteria and selected studies for the final analysis. We performed the meta-analysis using a random-effect model. A total of 12 RCTs were included in the study, including 1887 patients. Propranolol-treated patients have a decrease in length of hospital stay in adults (weighted mean difference [WMD] = -9.06, 95% CIs = [-12.88, -5.24]) and prepare time of graft (WMD = -7.88, 95% CIs = [-12.27, -3.50]). Similarly, the use of propranolol could significantly decrease heart rate (WMD = -15.16, 95% CIs = [-20.37, -9.94]), rate pressure product (WMD = -1.32, 95% CIs = [-1.67, -0.97]), and mean arterial pressure (WMD = -2.75, 95% CIs = [-4.23, -1.26]). Moreover, there is no significant difference between propranolol and placebo with respect to mortality (risk difference [RD] = 0.00, 95% CIs [-0.03, 0.04]), sepsis (RD = -0.03, 95% CIs [-0.09, 0.03]), and events of post-traumatic stress disorder (PTSD) and acute stress disorder (RD = -0.01, 95% CIs [-0.07, 0.05]), and also, there is no significant difference in subgroup analysis based on age. The use of beta antagonist in burned patients does reduce length of hospital stay in adults, shorten the preparation time for graft, and reduce heart burden, without increasing mortality, sepsis, or PTSD compared with those who had usual care or placebo. So beta antagonist can be considered as an appropriate treatment strategy in burned patients. More prospective, randomised-controlled, multi-centre studies were needed to define their place in therapeutic algorithms.

The Effect of β-Blockers for Burn Patients on Clinical Outcomes: Systematic Review and Meta-Analysis

OBJECTIVES

To assess the effects and safety of β-blockers in hospitalized patients with burns.

METHODS

A systematic review and meta-analysis of the literature. A broad search was conducted to identify all randomized controlled trials (RCTs) comparing β-blockers to control in hospitalized patients with burns. The primary outcome was 3-month all-cause mortality. Secondary outcomes were clinical patient-relevant end points. We subgrouped results by children/adults and burn severity. Risk of bias was assessed using the individual domain approach.

RESULTS

Four RCTs reported in 11 publications were included. Primary outcome of mortality was assessed in children (2 trials, n = 424) and adults (2 trials, n = 148) with severe burns. No significant difference was found between propranolol and control for mortality (risk ratio [RR] = 0.82, 95% CI = 0.48-1.39, 4 trials with broad confidence intervals in adults and children), sepsis (RR = 0.81, 95% CI = 0.46-1.43, 2 trials), and survivors' length of stay (absolute mean difference = 2.53, 95% CI = -2.58-7.63, 3 trials). There was no significant difference in bradycardia (RR = 1.33, 95% CI = 0.77-2.3, 2 trials), hypotension (RR = 1.26, 95% CI = 0.73-2.17, 3 trials), or cardiac arrhythmia (RR: 2.97, 95% CI: 0.12-71.87, 1 trial). The evidence was graded as very low certainty, due to trial's internal risk of bias, imprecision, and possible selective reporting.

CONCLUSIONS

No sufficient evidence was found to support or refute an advantage for β-blocker use in children or adults after burns. Additional studies are needed to create a consensus and formulate practice guidelines on the optimal β-blocker to use, indications for initiation, and duration of treatment.

The Safety and Efficacy of Propranolol in Reducing the Hypermetabolic Response in the Pediatric Burn Population

Pediatric burn patients often have hypertension and tachycardia for several years post-injury. Propranolol has shown to be effective in treating the hypermetabolic state secondary to a major burn injury. This study was conducted to document a safe and effective dosing regimen for three different age groups. One hundred four burn-injured children with a 30% to 92% total body surface area burn were treated for 1 to 2 years with propranolol in the outpatient setting. Guardians of the patients were instructed on how to take and monitor the systolic blood pressure and heart rate, and document their vital signs several times a day. The documentation was reviewed with the guardian and patient, and based on age-specific vital sign parameters, propranolol dosing adjustment was done to measure at least 15% to 20% reduction in admission heart rate. Mean doses for the age groups were as follows: 0 to 3 years 5.2 ± 2.8 mg/kg/day, 4 to 10 years 4.2 ± 1.8 mg/kg/day, and 11 to 18 years 2.9 ± 1.4 mg/kg/day. The propranolol dose decreased as time post-burn increased. On selected patients, propranolol was stopped due to changes in the heart rate, but at all times, it was safe and effective. No adverse effects were noted. The dosing regimen was not affected by burn size or gender. Propranolol can be safely stopped abruptly with no rebound hypertension. Individuals older than 10 years required a lower dose per kilogram following the burn injury than prepubertal burn survivors. Propranolol proved to be both safe and effective in the management of cardiovascular changes occurring in the hypermetabolic state.

The Long-Term Impact of Severe Burn Trauma on Musculoskeletal Health

Severe burn injury causes a profound stress response that leads to muscle and bone cachexia. Evidence suggests that these deficits persist for several months or even years after injury and are associated with growth delay, increased incidence of fractures, and increased hospital admissions for musculoskeletal disorders. Thus, there is an overwhelming need to determine the optimal acute and rehabilitative strategies to mitigate these deficits and improve quality of life for burn survivors. To date, there is limited research on the long-term impact of cachexia on functional performance and overall health, as well as on the lasting impact of pharmacological, nutritional, and exercise interventions. The aim of this review is to emphasize the long-term consequences of musculoskeletal cachexia and determine the best evidence-based strategies to attenuate it. We also underline important knowledge gaps that need to be addressed in order to improve care of burn survivors.

Quantification of an Exercise Rehabilitation Program for Severely Burned Children: The Standard of Care at Shriners Hospitals for Children®-Galveston

Currently, there are no clear guidelines for the implementation of rehabilitative exercise training (RET) in burned individuals. Therefore, we quantified the training logs for exercise intensity, frequency, and duration of 6 weeks of this program to develop a basic framework for outpatient RET in patients recovering from severe burns. Thirty-three children (11 female, [mean ± SD] 12 ± 3 years, 145 ± 18 cm, 40 ± 11 kg, 49 ± 31 BMI percentile) with severe burns (49 ± 15% total body surface area burned, with 35 ± 22% third-degree burns) completed our 6-week resistance and aerobic exercise training program. Cardiorespiratory fitness (peak VO2), strength, power, and lean body mass (LBM) were measured before and after RET. Outcome measures were analyzed as a relative percentage of values in age- and sex-matched nonburned children (11 female, 12 ± 3 years, 154 ± 20 cm, 49 ± 22 kg, 56 ± 25 BMI percentile). At discharge, burned children had lower LBM (77% of age-sex-matched nonburn values), peak torque (53%), power (62%), and cardiorespiratory fitness (56%). After 6 weeks of training, LBM increased by 5% (82% of nonburn values), peak torque by 18% (71%), power by 20% (81%), and cardiorespiratory fitness by 18% (74%; P < .0001 for all). Quantification of data in exercise training logs suggested that physical capacity can be improved by aerobic exercise training performed at five metabolic equivalents (>70% of peak VO2) at least 3 days/week and 150 minutes/week and by resistance training performed at volume loads (reps × sets × weight) of 131 kg for the upper body and 275 kg for the lower body for 2 days/week. We present for the first time the quantification of our RET and provide clear exercise prescription guidelines specific to children with severe burn injury.

Burns: modified metabolism and the nuances of nutrition therapy

OBJECTIVE

To review the effects of burn injury on nutritional requirements and how this can best be supported in a healthcare setting.

METHOD

A literature search for articles discussing nutrition and/or metabolism following burn injury was carried out. PubMed, Embase and Web of Science databases were searched using the key search terms 'nutrition' OR 'metabolism' AND 'burn injury' OR 'burns'. There was no limitation on the year of publication.

RESULTS

A total of nine articles met the inclusion criteria, the contents of which are discussed in this manuscript.

CONCLUSION

Thermal injury elicits the greatest metabolic response, among all traumatic events, in critically ill patients. In order to ensure burn patients can meet the demands of their increased metabolic rate and energy expenditure, adequate nutritional support is essential. Burn injury results in a unique pathophysiology, involving alterations in endocrine, inflammatory, metabolic and immune pathways and nutritional support needed during the inpatient stay varies depending on burn severity and idiosyncratic patient physiologic parameters.

The Effect of Burn Trauma on Lipid and Glucose Metabolism: Implications for Insulin Sensitivity

Severe burns represent a unique form of trauma in terms of the magnitude and persistence of the stress response they incur. Given advances in acute burn care in the last quarter of a century and the resultant reduction in mortality rates, even for those with massive burns, greater emphasis is now placed on understanding the metabolic stress response to severe burn trauma in order to devise strategies that promote recovery and reduce morbidity. Derangements in metabolism including protein and lipid redistribution and altered glucose handling are hallmarks of the pathophysiological response to burn trauma. In this review article, we aim to distill and discuss the c urrent literature concerning the effect of burn trauma on lipid and glucose metabolism. Furthermore, we will discuss the implications of altered lipid metabolism with regards to insulin sensitivity and glucose control, while discussing the utility of agents and strategies aimed at restoring normal lipid and glucose metabolism in burned patients.

Ghrelin abates bacterial translocation following burn injury by improving gastric emptying

BACKGROUND

In severe burns, increased intestinal permeability facilitates bacterial translocation, resulting in systemic endotoxemia and multi^- organ failure. We investigated the role of burn-induced gastrointestinal dysmotility (BIGD) in promoting bacterial translocation following burn injury, and the protective effect of ghrelin in this process.

METHODS

We assessed gastric emptying (GE%) and intestinal transit (IT by geometric center "GC") in a 60% total body surface area scald burn rat model and measured bacterial counts in mesenteric lymph nodes (MLN) and distal small intestine by colony-forming unit per gram of tissue (CFU/g). A group of animals was treated with ghrelin or saline after burn.

KEY RESULTS

Scald burn was associated with a significant delay in GE (62% ± 4% vs 74% ± 4%; P = .02) and a trend of delay in intestinal transit (GC: 5.5 ± 0.1 vs 5.8 ± 0.2; P = .09). Concurrently, there was a marginal increase in small intestinal bacterial overgrowth (6 × 10⁵ vs 2 × 10⁵  CFU/g; P = .05) and significant translocation to MLN (2 × 10² vs 4 × 10¹ ; P = .03). We observed a negative correlation between GE and intestinal bacterial overgrowth (r_s  = -0.61; P = .002) and between IT and translocation (r_s  = -0.63; P = .004). Ghrelin administration significantly accelerated GE following burn injury (91% ± 3% vs 62% ± 4; P = .03), reduced small intestinal bacterial overgrowth, and completely inhibited translocation to MLN (0.0 vs 5 × 10² ; P = .01).

CONCLUSIONS & INFERENCES

Burn-induced gastrointestinal dysmotility is correlated with the systemic translocation of gram-negative gut bacteria that are implicated in multiple organ failure in burn patients. Therapeutic interventions to restore BIGD are warranted (Neurogastroenterol Motil, 2012, 24, 78).

Resting β-Adrenergic Blockade Does Not Alter Exercise Thermoregulation in Children With Burn Injury: A Randomized Control Trial

The objective of this study was to test the hypothesis that propranolol, a commonly prescribed β-blocker to burned children, in combination with exercise-heat stress, increases the risk of heat illness and exercise intolerance. In a randomized double-blind study, propranolol was given to 10 burned children, and placebo was given to 10 additional burned children (matched for TBSA burned; mean ± SD, 62 ± 13%), while nonburned children served as healthy controls. All groups were matched for age and body morphology (11.2 ± 3.0 years; 146 ± 19 cm; 45 ± 18 kg; 1.3 ± 0.4 m2). All children exercised in hot conditions (34.3 ± 1.0°C; 26 ± 2% relative humidity) at 75% of their peak aerobic capacity. At the end of exercise, none of the groups differed for final or change from baseline intestinal temperature (38.0 ± 0.5°C; 0.02 ± 0.01Δ°C·min-1), unburned (37.0 ± 0.6°C) and burned skin temperatures (36.9 ± 0.7°C; nonburn group excluded), heat loss (21 ± 18 W m-2), whole-body thermal conductance (118 ± 113 W m-2), or physiological strain index (5.6 ± 1). However, burn children exercised less than nonburn group (21.2 ± 8.6 vs 30 ± 0.0 min; P < .001) and had a lower calculated exercise tolerance index (1.0 ± 0.0 vs 6.7 ± 4.3; P < .01). Burned children had lower peak heart rates than nonburned children (173 ± 13 vs 189 ± 7 bpm; P < .01), with greater relative cardiac work rates at the end of exercise (97 ± 10 vs 85 ± 11% peak heart rate; P < .01). Resting β-adrenergic blockade does not affect internal body temperature of burned children exercising at similar relative intensities as nonburn children in the heat. Independent of propranolol, a suppressed cardiac function may be associated to exercise intolerance in children with severe burn injury.

Anabolic and anticatabolic agents used in burn care: What is known and what is yet to be learned

Major thermal injury induces profound metabolic derangements secondary to an inflammatory "stress-induced" hormonal environment. Several pharmacological interventions have been tested in an effort to halt the hypermetabolic response to severe burns. Insulin, insulin growth factor 1, insulin growth factor binding protein 3, metformin, human growth hormone, thyroid hormones, testosterone, oxandrolone, and propranolol, among others, have been proposed to have anabolic or anticatabolic effects. The aim of this broad analysis of pharmacological interventions was to raise awareness of treatment options and to help establishing directions for future clinical research efforts. A PubMed search was conducted on the anabolic and anticatabolic agents used in burn care. One hundred and thirty-five human studies published between 1999 and 2017 were included in this review. The pharmacological properties, rationale for the treatments, efficacy considerations and side effect profiles are summarized in the article. Many of the drugs tested for investigational purposes in the severely thermally injured are not yet gold-standard therapies in spite of their potential benefit. Propranolol and oxandrolone have shown great promise but further evidence is still needed to clarify their potential use for anabolic and anticatabolic purposes.

The Role of Mitochondrial Stress in Muscle Wasting Following Severe Burn Trauma

Increased resting metabolic rate and skeletal muscle wasting are hallmarks of the pathophysiological stress response to severe burn trauma. However, whether these two responses occur independently in burn patients or are in fact related remains unclear. In light of recent evidence demonstrating that increased proteolysis in skeletal muscle of burned patients is accompanied by mitochondrial hypermetabolism, oxidative stress, and protein damage; in this article, we discuss the evidence for a role for the mitochondrion in skeletal muscle wasting following severe burn trauma. In particular, we focus on the role of mitochondrial superoxide production in oxidative stress and subsequent proteolysis, and discuss the role of the mitochondrion as a signaling organelle resulting in protein catabolism in other cellular compartments following severe burn trauma.

Carbon Monoxide and Cyanide Poisoning in the Burned Pregnant Patient: An Indication for Hyperbaric Oxygen Therapy

Carbon monoxide (CO) is a small molecule poison released as a product of incomplete combustion. Carbon monoxide binds hemoglobin, reducing oxygen delivery. This effect is exacerbated in the burned pregnant patient by fetal hemoglobin that binds CO 2.5- to 3-fold stronger than maternal hemoglobin. With no signature clinical symptom, diagnosis depends on patient injury history, elevated carboxyhemoglobin levels, and alterations in mental status. The standard of care for treatment of CO intoxication is 100% normobaric oxygen, which decreases the half-life of CO in the bloodstream from 5 hours to 1 hour. Hyperbaric oxygen (HBO2) is a useful adjunct to rapidly reduce the half-life of CO to 20 minutes and the incidence of delayed neurologic sequelae. Because of the slow disassociation of CO from hemoglobin in the fetus, there is a far stronger indication for HBO2 in the burned pregnant patient than in other burn patient populations.Cyanide intoxication is often a comorbid disease with CO in inhalation injury from an enclosed fire, but may be the predominant toxin. It acts synergistically with CO to effectively lower the lethal doses of both cyanide and CO. Diagnosis is best made in the presence of high lactate levels, carboxyhemoglobin concentrations greater than 10%, injury history of smoke inhalation from an enclosed fire, and alterations in consciousness. While treatment with hydroxocobalamin is the standard of care and has the effect of reducing concomitant CO toxicity, data indicate cyanide may also be displaced by HBO2.Carbon monoxide and cyanide poisoning presents potential complications impacting care. This review addresses the mechanism of action, presentation, diagnosis, and treatment of CO and cyanide poisonings in the burned pregnant patient and the use of HBO2 therapy.

The role of the musculoskeletal system in post-burn hypermetabolism

Burn injury results in a triad of inter-related adaptive responses: a systemic inflammatory response, a stress response, and a consequent hypermetabolic state which supports the former two. Details of what precisely triggers these responses as well as the sequence of events leading up to these responses are not clear. We review the musculoskeletal effects of burn injury to determine the precise contributions of this system in the generation and sustenance of this post-burn triad as well as the possible effects of pharmacologic intervention in the musculoskeletal response to burns on the resulting hypermetabolism. Inflammation-associated bone resorption liberates calcium, which may either prolong or intensify the systemic inflammatory response. Phosphate and magnesium liberated from bone could contribute to sustaining the increased ATP turnover in skeletal muscle that accompanies burn hypermetabolism. Reduced bone formation resulting from both pro-inflammatory cytokines and elevated endogenous glucocorticoid production results in reduced bone mass and therefore reduced osteocalcin production, which may contribute to reduced glucose uptake by skeletal muscle. Moreover, bone resorption liberates muscle catabolic factors such as transforming growth factor β, which contribute to the muscle wasting of burn hypermetabolism. Pharmacologic intervention with anti-resorptive agents early in the process preserve bone and muscle mass post-burn and future research should address the consequences for the hypermetabolic triad duration and intensity accompanying burn injury.

Myocardial Adipose Triglyceride Lipase Overexpression Protects against Burn-Induced Cardiac Lipid Accumulation and Injury

Maladaptive cardiac metabolism is a common trigger of cardiac lipid accumulation and cardiac injury under serious burn challenge. Adipose triglyceride lipase (ATGL) is the key enzyme that catalyzes triglyceride hydrolysis; however, its alteration and impact on cardiac function following serious burn injury are still unknown. Here, we found that the cardiac fatty acid (FA) metabolism increased, accompanied by augmented FA accumulation and ATGL expression, after serious burn injury. We generated heterozygous ATGL knockout and heterozygous cardiac-specific ATGL overexpression thermal burn mice. The results demonstrated that partial loss of ATGL could not relieve burn-induced cardiac lipid accumulation and cardiac injury, possibly due to the suppression of cardiac FA metabolism plus insufficient compensatory glucose utilization. In contrast, cardiac-specific overexpression of ATGL alleviated cardiac lipid accumulation and cardiac injury following burn challenge by switching the substrate preference from FA towards increased glucose utilization. The underlying mechanism was possibly related to increased glucose transporter-1 expression and reduced cardiac lipid accumulation induced by ATGL overexpression. Our data first demonstrated that elevated cardiac ATGL expression after serious burn injury is an adaptive, albeit insufficient, response to compensate for the increase in energy consumption and that further overexpression of ATGL is beneficial for ameliorating cardiac injury, indicating its therapeutic potential.

Systematic review of clinical outcome reporting in randomised controlled trials of burn care

INTRODUCTION

Systematic reviews collate trial data to provide evidence to support clinical decision-making. For effective synthesis, there must be consistency in outcome reporting. There is no agreed set of outcomes for reporting the effect of burn care interventions. Issues with outcome reporting have been identified, although not systematically investigated. This study gathers empirical evidence on any variation in outcome reporting and assesses the need for a core outcome set for burn care research.

METHODS

Electronic searches of four search engines were undertaken from January 2012 to December 2016 for randomised controlled trials (RCTs), using medical subject headings and free text terms including 'burn', 'scald' 'thermal injury' and 'RCT'. Two authors independently screened papers, extracted outcomes verbatim and recorded the timing of outcome measurement. Duplicate outcomes (exact wording ± different spelling), similar outcomes (albumin in blood, serum albumin) and identical outcomes measured at different times were removed. Variation in outcome reporting was determined by assessing the number of unique outcomes reported across all included trials. Outcomes were classified into domains. Bias was reduced using five researchers and a patient working independently and together.

RESULTS

147 trials were included, of which 127 (86.4%) were RCTs, 13 (8.8%) pilot studies and 7 (4.8%) RCT protocols. 1494 verbatim clinical outcomes were reported; 955 were unique. 76.8% of outcomes were measured within 6 months of injury. Commonly reported outcomes were defined differently. Numbers of unique outcomes per trial varied from one to 37 (median 9; IQR 5,13). No single outcome was reported across all studies demonstrating inconsistency of reporting. Outcomes were classified into 54 domains. Numbers of outcomes per domain ranged from 1 to 166 (median 11; IQR 3,24).

CONCLUSIONS

This review has demonstrated heterogeneity in outcome reporting in burn care research which will hinder amalgamation of study data. We recommend the development of a Core Outcome Set.

PROSPERO REGISTRATION NUMBER

CRD42017060908.

Propranolol and Oxandrolone Therapy Accelerated Muscle Recovery in Burned Children

INTRODUCTION

Severe burns result in prolonged hypermetabolism and skeletal muscle catabolism. Rehabilitative exercise training (RET) programs improved muscle mass and strength in severely burned children. The combination of RET with β-blockade or testosterone analogs showed improved exercise-induced benefits on body composition and muscle function. However, the effect of RET combined with multiple drug therapy on muscle mass, strength, cardiorespiratory fitness, and protein turnover are unknown. In this placebo-controlled randomized trial, we hypothesize that RET combined with oxandrolone and propranolol (Oxprop) will improve muscle mass and function and protein turnover in severely burned children compared with burned children undergoing the same RET with a placebo.

METHODS

We studied 42 severely burned children (7-17 yr) with severe burns over 30% of the total body surface area. Patients were randomized to placebo (22 control) or to Oxprop (20) and began drug administration within 96 h of admission. All patients began RET at hospital discharge as part of their standardized care. Muscle strength (N·m), power (W), V˙O2peak, body composition, and protein fractional synthetic rate and fractional breakdown rate were measured pre-RET (PRE) and post-RET (POST).

RESULTS

Muscle strength and power, lean body mass, and V˙O2peak increased with RET in both groups (P < 0.01). The increase in strength and power was significantly greater in Oxprop versus control (P < 0.01), and strength and power was greater in Oxprop over control POST (P < 0.05). Fractional synthetic rate was significantly higher in Oxprop than control POST (P < 0.01), resulting in improved protein net balance POST (P < 0.05).

CONCLUSIONS

Rehabilitative exercise training improves body composition, muscle function, and cardiorespiratory fitness in children recovering from severe burns. Oxprop therapy augments RET-mediated improvements in muscle strength, power, and protein turnover.