Exudative glutamine losses contribute to high needs after burn injury

Decoding burn trauma: biomarkers for early diagnosis of burn-induced pathologies

Burn injuries represent a significant global challenge due to their multifaceted nature, characterized by a complex cascade of metabolic and immune dysfunction that can result in severe complications. If not identified and managed promptly, these complications can escalate, often leading to fatal outcomes. This underscores the critical importance of timely and precise diagnosis. Fortunately, biomarkers for burn-induced pathologies and outcomes have emerged as powerful diagnostic and prognostic tools. These biomarkers enable early diagnosis and intervention, facilitate risk assessment, support patient-specific treatment, monitoring of disease progression, and therapeutic efficacy, ultimately contributing to improved patient outcomes. However, while previous studies have provided valuable biomarkers for the detection of burn-induced pathologies, many of these were constrained by the techniques and sample sizes available at the time, which can limit the generalizability of the findings. This review highlights numerous biomarkers studied in the literature to date, underscoring the need to replicate these findings in more diverse and representative populations. It also emphasizes the importance of advancing research efforts to develop more efficient, accurate, and cost-effective approaches for integrating biomarkers into clinical practice.

Vitamin D administration increases serum alanine concentrations in thermally injured mice

Thermal or burn injury results in profound metabolic changes in the body. This can contribute to muscle atrophy, bone loss, as well as suppression of the immune system. While the mechanisms that underlie this hypermetabolic response remain unclear, patients with burn injury often have low circulating levels of vitamin D. Vitamin D has been shown to regulate bone formation as well as regulate muscle function. We sought to clarify the effects of vitamin D administration on skeletal muscle function following thermal injury using a mouse model. We found that thermal injury resulted in decreased vitamin D levels as well as decreased bone mineral density. Branched chain amino acid (BCAA)s levels were also significantly enhanced in the serum following burn injury. Vitamin D administration reversed the decrease in bone marrow-derived mesenchymal stem cell (BM-MSC)s observed post burn injury. Interestingly, vitamin D administration also resulted in increased tricarboxylic acid cycle (TCA) cycle metabolites in muscle which was decreased after burn conditions, enhanced the supply of alanine and glutamine in the blood which could contribute to gluconeogenesis and wound healing. Therefore, vitamin D supplementation after burn injury may have effects not only in bone metabolism, but may affect substrate metabolism in other organs/tissues.

Enteral glutamine supplements for patients with severe burns: A systematic review and meta-analysis

PURPOSE

Our previous study in 2009 concluded that glutamine may shorten the length of hospital stay (LOS) in patients with severe burns. Recent large-scale studies have suggested a decline in the effectiveness of glutamine in treating patients with severe burns over the last decade. Therefore, we conducted this systematic review and meta-analysis to update the status of glutamine uses in patients with severe burns.

METHODS

We retrieved related literature prior to December 2022 from the PubMed, Web of Science, Cochrane Library, Embase, SinoMed, Wanfang, and CNKI databases. Terms such as glutamine, enteral and burn were linked for searching. Adults patients with severe burns were included and non-randomized controlled trials were excluded. Data from studies that compared enteral glutamine for severe burns with a control group were extracted. The primary outcomes of mortality and infectious morbidities were pooled and analyzed. The modified Jadad scale and Cochrane collaboration's tool were used to assess the risk of bias in RCTs, and the Review Manager 5.4 was used to pool and analyze the data.

RESULTS

Six randomized controlled trials involving 1398 patients were included in the analysis. There were no significant differences in overall mortality (risk ratio (RR) = 0.37; 95% confidence interval (CI): 0.06 - 2.37; p = 0.300) or infectious morbidities (RR = 0.73; 95% CI: 0.41 - 1.31; p = 0.290). The incidence of multiple organ dysfunction syndrome was similar between the 2 groups (RR = 0.27; 95% CI: 0.03 - 2.24; p = 0.220). The LOS (mean difference (MD) = -8.97; 95% CI: -15.22 to -2.71; p = 0.005) and LOS/total burn surface area (MD = -0.27; 95% CI: -0.54 to 0.00; p = 0.050) decreased in the enteral glutamine group. The incidence of wound infection was significantly reduced (RR = 0.42; 95% CI: 0.16 - 1.06; p = 0.070).

CONCLUSION

Compared to the control group, enteral glutamine administration may not improve the mortality, although it may be associated with a shorter LOS, a lower LOS/total burn surface area ratio, and may reduce the risk of wound infection in patients with severe burns.

Nutritional interventions in patients with burn injury: an umbrella review of systematic reviews and meta-analyses of randomised clinical trials

Multiple reviews have examined the impact of nutritional interventions in patients with burn injuries; however, discrepancies among results cast doubt about their validity. We implemented this review to assess the impact of various nutritional interventions in adult patients with burn injuries. We conducted a thorough search of PubMed, Scopus and Web of Science databases until 1 August 2024, to identify relevant meta-analyses of intervention trials, examining the impact of nutritional interventions on burn patients. We adopted the random-effect models to determine the pooled effect sizes while employing the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) to examine evidence certainty. Thirty-three original intervention trials from eleven meta-analyses were entered in our review. Early enteral nutrition could substantially reduce overall mortality (relative risk (RR): 0·36, 95 % CI: 0·19, 0·68, GRADE = moderate certainty), hospital stay (mean difference (MD): -15·3, 95 % CI: -20·4, -10·2, GRADE = moderate certainty) and sepsis risk (RR: 0·23, 95 % CI: 0·11, 0·45, GRADE = moderate certainty). Glutamine showed a notable decrease in the length of hospital stay (MD: -6·23, 95 % CI: -9·53, -2·94, GRADE = low certainty). However, other nutritional interventions, including combined immunonutrition, branched-chain amino acids, fish oil, ornithine α-ketoglutarate and trace elements, did not significantly affect the assessed clinical outcomes. Early enteral nutrition might impose a beneficial effect on mortality, hospital stay length and incidence of sepsis with moderate evidence. Lower length of hospital stay was also seen in burn patients supplemented with glutamine, although the evidence was weak.

Evaluation of a Cosmetic Formulation Containing Arginine Glutamate in Patients with Burn Scars: A Pilot Study

Background: Patients with burn scars require effective treatments able to alleviate dry skin and persistent itching. Ion pairing has been employed in cosmetic formulations to enhance solubility in solvents and improve skin permeability. To evaluate the efficacy and safety of the cosmetic formula "RE:pair (arginine-glutamate ion pair)", we analyzed scar size, itching and pain, skin barrier function, scar scale evaluation, and satisfaction in our study participants. Methods: A total of 10 patients were recruited, and the formula was used twice a day for up to 4 weeks. Results: Itching was significantly alleviated after 4 weeks of treatment (95% CI = -0.11-1.71) compared to before application (95% CI = 2.11-4.68). Transepidermal water loss (TEWL) showed an 11% improvement after 4 weeks (95% CI = 3.43-8.83) compared to before application (95% CI = 3.93-9.88), and skin coreneum hydration (SCH) showed a significant 41% improvement after 4 weeks (95% CI = 43.01-62.38) compared to before application (95% CI = 20.94-40.65). Conclusions: Based on the confirmation that RE:pair improves skin barrier function and relieves itching, it is likely to be used as a topical treatment for burn scars pending evaluation in follow-up studies (IRB no. HG2023-016).

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.

Glutamine Supplementation on Burn Patients: A Systematic Review and Meta-analysis

To evaluate the effect of glutamine supplement on patients with burns, we conducted a systematic review and meta-analysis via synthesizing up-to-date studies. Databases including PubMed, Cochrane Central Register, EMBASE, Google scholar, Wanfang data, and ClinicalTrials.gov were searched up to October 2023 to find randomized trials evaluating glutamine supplement on patients with burns. The main outcomes included hospital stay, in-hospital mortality, infection, and wound healing. Twenty-two trials that randomized a total of 2170 patients were included in this meta-analysis. Pooled the length of hospital stay was shortened by glutamine supplement (weighted mean differences [WMD] = -7.95, 95% confidence interval [CI] -10.53 to -5.36, I2 = 67.9%, 16 trials). Both pooled wound healing rates (WMD = 9.15, 95% CI 6.30 to 12.01, I2 = 82.7%, 6 studies) and wound healing times (WMD = -5.84, 95% CI -7.42 to -4.27, I2 = 45.7%, 7 studies) were improved by glutamine supplement. Moreover, glutamine supplement reduced wound infection (risk ratios [RR] = 0.38, 95% CI 0.21 to 0.69, I2 = 0%, 3 trials), but not nonwound infection (RR = 0.88, 95% CI 0.73 to 1.05, I2 = 39.6%, 9 trials). Neither in-hospital mortality (RR = 0.95, 95% CI 0.74 to 1.22, I2 = 36.0%, 8 trials) nor the length of intensive care unit stay (WMD = 1.85, 95% CI -7.24 to 10.93, I2 = 78.2%, 5 studies) was improved by glutamine supplement. Subgroup analysis showed positive effects were either influenced by or based on small-scale, single-center studies. Based on the current available data, we do not recommend the routine use of glutamine supplement for burn patients in hospital. Future large-scale randomized trials are still needed to give a conclusion about the effect of glutamine supplement on burn patients.

Nutrition after severe burn injury

PURPOSE OF REVIEW

Severe burn injury causes significant metabolic changes and demands that make nutritional support particularly important. Feeding the severe burn patient is a real challenge in regard to the specific needs and the clinical constraints. This review aims to challenge the existing recommendations in the light of the few recently published data on nutritional support in burn patients.

RECENT FINDINGS

Some key macro- and micro-nutrients have been recently studied in severe burn patients. Repletion, complementation or supplementation of omega-3 fatty acids, vitamin C, vitamin D, antioxidant micronutrients may be promising from a physiologic perspective, but evidence of benefits on hard outcomes is still weak due to the studies' design. On the contrary, the anticipated positive effects of glutamine on the time to discharge, mortality and bacteremias have been disproved in the largest randomized controlled trial investigating glutamine supplementation in burns. An individualized approach in term of nutrients quantity and quality may proof highly valuable and needs to be validated in adequate trials. The combination of nutrition and physical exercises is another studied strategy that could improve muscle outcomes.

SUMMARY

Due to the low number of clinical trials focused on severe burn injury, most often including limited number of patients, developing new evidence-based guidelines is challenging. More high-quality trials are needed to improve the existing recommendations in the very next future.

Local Drug Delivery Strategies towards Wound Healing

A particular biological process known as wound healing is connected to the overall phenomena of growth and tissue regeneration. Several cellular and matrix elements work together to restore the integrity of injured tissue. The goal of the present review paper focused on the physiology of wound healing, medications used to treat wound healing, and local drug delivery systems for possible skin wound therapy. The capacity of the skin to heal a wound is the result of a highly intricate process that involves several different processes, such as vascular response, blood coagulation, fibrin network creation, re-epithelialisation, collagen maturation, and connective tissue remodelling. Wound healing may be controlled with topical antiseptics, topical antibiotics, herbal remedies, and cellular initiators. In order to effectively eradicate infections and shorten the healing process, contemporary antimicrobial treatments that include antibiotics or antiseptics must be investigated. A variety of delivery systems were described, including innovative delivery systems, hydrogels, microspheres, gold and silver nanoparticles, vesicles, emulsifying systems, nanofibres, artificial dressings, three-dimensional printed skin replacements, dendrimers and carbon nanotubes. It may be inferred that enhanced local delivery methods might be used to provide wound healing agents for faster healing of skin wounds.

Effects of Different Ratios of Carbohydrate-Fat in Enteral Nutrition on Metabolic Pattern and Organ Damage in Burned Rats

(1) Background: Nutritional support is one of the most important cornerstones in the management of patients with severe burns, but the carbohydrate-to-fat ratios in burn nutrition therapy remain highly controversial. In this study, we aimed to discuss the effects of different ratios of carbohydrate–fat through enteral nutrition on the metabolic changes and organ damage in burned rats. (2) Methods: Twenty-four burned rats were randomly divided into 5%, 10%, 20% and 30% fat nutritional groups. REE and body weight were measured individually for each rat daily. Then, 75% of REE was given in the first week after burns, and the full dose was given in the second week. Glucose tolerance of the rats was measured on days 1, 3, 7, 10 and 14. Blood biochemistry analysis and organ damage analysis were performed after 7 and 14 days of nutritional therapy, and nuclear magnetic resonance (NMR) and insulin content analysis were performed after 14 days. (3) Results: NMR spectra showed significant differences of glucose, lipid and amino acid metabolic pathways. The energy expenditure increased, and body weight decreased significantly after burn injury, with larger change in the 20%, 5% and 30% fat groups, and minimal change in the 10% fat group. The obvious changes in the level of plasma protein, glucose, lipids and insulin, as well as the organ damage, were in the 30%, 20% and 5% fat groups. In relative terms, the 10% fat group showed the least variation and was closest to normal group. (4) Conclusion: Lower fat intake is beneficial to maintaining metabolic stability and lessening organ damage after burns, but percentage of fat supply should not be less than 10% in burned rats.

Single-Cell Transcriptome Profiling Reveals Neutrophil Heterogeneity and Functional Multiplicity in the Early Stage of Severe Burn Patients

The pathophysiological mechanisms, especially the roles of immune cells, underlying early stages of severe burn injury have not yet been fully clarified. Here, we analyzed circulating neutrophils (PMNs) in healthy donors and early burned patients by single-cell RNA sequencing to provide a comprehensive transcriptional landscape of PMNs in heterogeneity and functional multiplicity. Circulating PMNs in the healthy donors and burned groups were divided into five subgroups (G3, G4, G5a, G5b, G5c) with different functions. The dominant subsets of PMNs in homeostasis and burn injury significantly differed between groups. In addition, cells in the same subpopulation had the same core identity markers but performed different functions in healthy and burned states. Under burned conditions, PMN activation was very evident and accompanied by clear degranulation and metabolic abnormalities. Interestingly, was found that PMN activation, degranulation, chemotaxis, phagocytosis and reactive oxygen species (ROS) production in burned patients significantly differed between day 1 and days 2 or 3, thus providing a theoretical basis for PMN interventions in early burn stages. Significantly, previously undescribed transcription factors were also identified, including ZNF-787, ZNF-467, ZNF-189, ZNF-770, ZNF-262. In conclusion, this study conducted for the first time a detailed analysis of the heterogeneity and functional multiplicity of PMNs in early stages of severe burn injuries. Our findings attempted to clarify the influence of PMN heterogeneity on the pathophysiology and related mechanisms of burn injuries, which can provide new ideas for further research in burn intervention.