Time to wound closure in trauma patients with disorders in wound healing is shortened by supplements containing antioxidant micronutrients and glutamine: a PRCT

LLL 44-4 : Micronutrients in acute disease and critical illness

Micronutrients (MN), i.e. trace elements and vitamins, are essential components of the diet in relatively small amounts in any form of nutrition, with special needs in critically ill patients. Critical illness is characterised by the presence of inflammation and oxidative stress. MNs are tightly involved in antioxidant and immune defences. In addition, some conditions, and treatments result in large losses of biological fluids containing MNs: therefore, acute renal injury requiring renal replacement therapy, acute intestinal failure, and major burns and trauma are at high risk of acute depletion of body stores, and of deficiency. MN requirements are increased above standard DRI. Blood level interpretation is complicated by inflammation: some biomarkers assist the status determination. Due to the acute challenges of critical illness, it of utmost importance to cover the needs to maintain the organism's endogenous immune and antioxidant defences, and capacity to repair tissues. Practical strategies are proposed.

Metabolic reprogramming in skin wound healing

Metabolic reprogramming refers to the ability of a cell to alter its metabolism in response to different stimuli and forms of pressure. It helps cells resist external stress and provides them with new functions. Skin wound healing involves the metabolic reprogramming of nutrients, such as glucose, lipids, and amino acids, which play vital roles in the proliferation, differentiation, and migration of multiple cell types. During the glucose metabolic process in wounds, glucose transporters and key enzymes cause elevated metabolite levels. Glucose-mediated oxidative stress drives the proinflammatory response and promotes wound healing. Reprogramming lipid metabolism increases the number of fibroblasts and decreases the number of macrophages. It enhances local neovascularization and improves fibrin stability to promote extracellular matrix remodelling, accelerates wound healing, and reduces scar formation. Reprogramming amino acid metabolism affects wound re-epithelialization, collagen deposition, and angiogenesis. However, comprehensive reviews on the role of metabolic reprogramming in skin wound healing are lacking. Therefore, we have systematically reviewed the metabolic reprogramming of glucose, lipids, and amino acids during skin wound healing. Notably, we identified their targets with potential therapeutic value and elucidated their mechanisms of action.

A Systematic Review on the Role of Vitamin C in Tissue Healing

Vitamin C is an essential nutrient for humans and animals which are unable to synthesise it themselves. Vitamin C is important for tissue regeneration due to the role it plays in collagen formation, and its antioxidant properties. We reviewed the literature to evaluate potential associations between vitamin C supplementation and healing of an acute or chronic condition. Embase, Medline, PubMed, and the Cochrane Library were searched for studies published prior to April 2022. Studies were eligible if they reported at least one association between vitamin C supplementation and healing outcomes. Eighteen studies met the inclusion criteria and were included in this review. Overall, vitamin C supplementation improved healing outcomes in certain pathologies, predominantly pressure ulcers. However, many of the studies had small sample sizes, combined nutritional treatments, and did not test baseline vitamin C. Future studies should be of larger scale, exclusively using vitamin C to determine its role in tissue healing in other wounds. We recommend consideration of vitamin C supplementation for people with pressure ulcers.

Cinnamaldehyde-Based Self-Nanoemulsion (CA-SNEDDS) Accelerates Wound Healing and Exerts Antimicrobial, Antioxidant, and Anti-Inflammatory Effects in Rats’ Skin Burn Model

Cinnamaldehyde, the main phytoconstituent of the cinnamon oil, has been reported for its potential wound healing activity, associated to its antimicrobial and anti-inflammatory effects. In this study, we are reporting on the cinnamaldehyde-based self-nanoemulsifying drug delivery system (CA-SNEDDS), which was prepared and evaluated for its antimicrobial, antioxidant, anti-inflammatory, and wound healing potential using the rat third-degree skin injury model. The parameters, i.e., skin healing, proinflammatory, and oxidative/antioxidant markers, were evaluated after 3 weeks of treatment regimens with CA-SNEDDS. Twenty rats were divided randomly into negative control (untreated), SNEDDS control, silver sulfadiazine cream positive control (SS), and CA-SNEDDS groups. An aluminum cylinder (120 °C, 10-s duration) was used to induce 3rd-degree skin burns (1-inch square diameter each) on the rat’s dorsum. At the end of the experiment, skin biopsies were collected for biochemical analysis. The significantly reduced wound size in CA-SNEDDS compared to the negative group was observed. CA-SNEDDS-treated and SS-treated groups demonstrated significantly increased antioxidant biomarkers, i.e., superoxide dismutase (SOD) and catalase (CAT), and a significant reduction in the inflammatory marker, i.e., NAP-3, compared to the negative group. Compared to SNEDDS, CA-SNEDDS exhibited a substantial antimicrobial activity against all the tested organisms at the given dosage of 20 µL/disc. Among all the tested microorganisms, MRSA and S. typhimurium were the most susceptible bacteria, with an inhibition zone diameter (IZD) of 17.0 ± 0.3 mm and 19.0 ± 0.9 mm, respectively. CA-SNEDDS also exhibited strong antifungal activity against C. albicans and A. niger, with IZD of 35.0 ± 0.5 mm and 34.0 ± 0.5 mm, respectively. MIC and MBC of CA-SNEDDS for the tested bacteria ranged from 3.125 to 6.25 µL/mL and 6.25 to 12.5 µL/mL, respectively, while the MIC and MBC for C. albicans and A. niger were 1.56 µL/mL and 3.125 µL/mL, respectively. The MBIC and MBEC of CA-SNEDDS were also very significant for the tested bacteria and ranged from 6.25 to 12.5 µL/mL and 12.5 to 25.0 µL/mL, respectively, while the MBIC and MBEC for C. albicans and A. niger were 3.125 µL/mL and 6.25 µL/mL, respectively. Thus, the results indicated that CA-SNEDDS exhibited significant wound healing properties, which appeared to be attributed to the formulation’s antimicrobial, antioxidant, and anti-inflammatory effects.

A Systematic Review of Oral Nutritional Supplement and Wound Healing

OBJECTIVE

To explore the current literature for effects of oral nutritional supplement on wound healing rates in humans.

METHODS

A systematic review of the literature was performed using the Medline and PubMed database following PRISMA guidelines. The PubMed database was searched using terms relating to oral nutritional supplement and wound healing from 1837 to March 2020. Study inclusion criteria were: (i) design: randomized controlled trials, clinical studies, observational studies, clinical trials; (ii) population: adults; and (iii) intervention: oral nutritional supplement.

RESULTS

The search yielded 2433 studies, 313 of which were clinical trials or clinical studies. After abstract review, 28 studies qualified to be included in the review evaluating the following supplementation categories on wound healing: protein and amino acids (10), mineral, vitamin and antioxidants (9), probiotics (1), and mixed nutrients (8). Arginine and omega-3 supplement were shown to improve wound healing in head and neck cancer patients with surgical wounds by decreasing incidence of postoperative complications and reducing length of hospital stay. Mineral, vitamins, and antioxidants enriched supplements were more beneficial in increasing wound healing than non-enriched protein supplement for diabetic foot and pressure ulcers.

CONCLUSIONS

Supplementation of a variety of nutrients had variable effects on improving wound healing in different types of wounds. However, further research on the impact of nutritional supplements on surgical wound healing is necessary. The impact of multiple nutrient formulations may also need to be further evaluated for efficacy.

Molecular mechanisms underlying the promotion of wound repair by coenzyme Q10: PI3K/Akt signal activation via alterations to cell membrane domains

Coenzyme Q10 (CoQ10) promotes wound healing in vitro and in vivo. However, the molecular mechanisms underlying the promoting effects of CoQ10 on wound repair remain unknown. In the present study, we investigated the molecular mechanisms through which CoQ10 induces wound repair using a cellular wound-healing model. CoQ10 promoted wound closure in a dose-dependent manner and wound-mediated cell polarization after wounding in HaCaT cells. A comparison with other CoQ homologs, benzoquinone derivatives, and polyisoprenyl compounds suggested that the whole structure of CoQ10 is required for potent wound repair. The phosphorylation of Akt after wounding and the plasma membrane translocation of Akt were elevated in CoQ10-treated cells. The promoting effect of CoQ10 on wound repair was abrogated by co-treatment with a phosphatidylinositol 3-kinase (PI3K) inhibitor. Immuno­histochemical and biochemical analyses showed that CoQ10 increased the localization of caveolin-1 (Cav-1) to the apical membrane domains of the cells and the Cav-1 content in the membrane-rich fractions. Depletion of Cav-1 suppressed CoQ10-mediated wound repair and PI3K/Akt signaling activation in HaCaT cells. These results indicated that CoQ10 increases the translocation of Cav-1 to the plasma membranes, activating the downstream PI3K/Akt signaling pathway, and resulting in wound closure in HaCaT cells.

Rational selection of bioactive principles for wound healing applications: Growth factors and antioxidants

Wound healing is a complex process of communication between growth factors, reactive species of oxygen, cells, signalling pathways, and cytokines in the extracellular matrix, in which growth factors are the key regulators. In humans, the main regulators of the cellular responses in wound healing are five growth factors, namely EGF, bFGF, VEGF, and TGF-β1. On the other hand, antioxidants such as astaxanthin, beta-carotene, epigallocatechin gallate, delphinidin, and curcumin have been demonstrated to stimulate cell proliferation, migration and angiogenesis, and control inflammation, to suggest a practical approach to design new strategies to treat non-healing cutaneous conditions. Based on the individual effects of growth factors and antioxidants, it may be envisioned that the use of both types of bioactives in wound healing formulations may have an additive or synergistic effect on the healing potential. This review addresses the effect of growth factors and antioxidants on wound healing-related processes. Furthermore, a prospective on their potential additive or synergistic effect on wound healing formulations, based on their individual effects, is presented. This may serve as a guide for the development of a new generation of wound healing formulations.

Phytochemical-Based Nano-Pharmacotherapeutics for Management of Burn Wound Healing

Medicinal plants have been used since ancient times for their various therapeutic activities and are safer compared to modern medicines, especially when properly identifying and preparing them and choosing an adequate dose administration. The phytochemical compounds present in plants are progressively yielding evidence in modern drug delivery systems by treating various diseases like cancers, coronary heart disease, diabetes, high blood pressure, inflammation, microbial, viral and parasitic infections, psychotic diseases, spasmodic conditions, ulcers, etc. The phytochemical requires a rational approach to deliver the compounds to enhance the efficacy and to improve patients’ compatibility. Nanotechnology is emerging as one of the most promising strategies in disease control. Nano-formulations could target certain parts of the body and control drug release. Different studies report that phytochemical-loaded nano-formulations have been tested successfully both in vitro and in vivo for healing of skin wounds. The use of nano systems as drug carriers may reduce the toxicity and enhance the bioavailability of the incorporated drug. In this review, we focus on various nano-phytomedicines that have been used in treating skin burn wounds, and how both nanotechnology and phytochemicals are effective for treating skin burns.

[Glutamine as a component of nutritional and metabolic therapy for surgical patients in ICU]

Glutamine is the most abundant amino acid in the human body that is involved in various metabolic processes. The development of hypermetabolic and hypercatabolic syndrome that accompanies critical conditions of ICU patients is associated with a decrease in the concentration of glutamine, especially in the blood plasma and muscles. This process may last for quite a long time and lead to a number of complications up to a fatal outcome. This review was aimed to analyze clinical studies conducted over the past 20 years that demonstrate the effect of intravenous infusion of glutamine dipeptide as part of balanced parenteral nutrition on the perioperative period: the severity of inflammatory response; the state of the intestinal mucosa; the incidence and severity of complications; mortality; the duration of stay in the ICU and hospital in general, etc. The analysis was performed using systematic reviews and meta-analyses based on randomized double-blind, placebo-controlled trials in different countries selected in the main databases (PubMed, EMBASE, Web of Science, The Cochrane Library, etc.). Most of the reports state that the inclusion of glutamine dipeptide in nutritional and metabolic therapy (NMT) in surgical patients reduces the frequency and severity of infectious complications and mortality, reduces the length of stay in ICU and in hospital in general, improves the biochemical parameters that reflect the condition of patients, and reduces the treatment costs. Thus, the conducted systematic reviews and meta-analyses confirm that the use of the parenteral form of glutamine dipeptide (Dipeptiven 20%) as part of balanced standard parenteral nutrition (PN) is a clinically and pharmacoeconomically justified strategy of NMT in surgical ICU patients.

Nutritional Support for Bariatric Surgery Patients: The Skin beyond the Fat

Body contouring surgery after the massive weight loss due to bariatric surgery deals with different kinds of complications. The aim of this review is to analyze the role that some nutrients may play in tissue healing after surgery, thus helping plastic surgeons to improve the aesthetic and health outcomes in massive weight loss patients under a multidisciplinary approach. As a matter of fact, preoperative nutritional deficiencies have been shown for vitamins and minerals in a large percentage of post-bariatric patients. Preoperative deficiencies mainly concern iron, zinc, selenium, and vitamins (both fat-soluble and water-soluble), but also total protein. During the postoperative period, these problems may increase because of the patients' very low intake of vitamins and minerals after bariatric surgery (below 50% of the recommended dietary allowance) and the patients' low compliance with the suggested multivitamin supplementation (approximately 60%). In the postoperative period, more attention should be given to nutritional aspects in regard to the length of absorptive area and the percentage of weight loss.

Nanotechnology Development for Formulating Essential Oils in Wound Dressing Materials to Promote the Wound-Healing Process: A Review

Wound healing refers to the replacement of damaged tissue through strongly coordinated cellular events. The patient’s condition and different types of wounds complicate the already intricate healing process. Conventional wound dressing materials seem to be insufficient to facilitate and support this mechanism. Nanotechnology could provide the physicochemical properties and specific biological responses needed to promote the healing process. For nanoparticulate dressing design, growing interest has focused on natural biopolymers due to their biocompatibility and good adaptability to technological needs. Polysaccharides are the most common natural biopolymers used for wound-healing materials. In particular, alginate and chitosan polymers exhibit intrinsic antibacterial and anti-inflammatory effects, useful for guaranteeing efficient treatment. Recent studies highlight that several natural plant-derived molecules can influence healing stages. In particular, essential oils show excellent antibacterial, antifungal, antioxidant, and anti-inflammatory properties that can be amplified by combining them with nanotechnological strategies. This review summarizes recent studies concerning essential oils as active secondary compounds in polysaccharide-based wound dressings.

Enhanced full-thickness wound healing via Sophora gibbosa extract delivery based on a chitosan/gelatin dressing incorporating microemulsion

There are many synthetic drugs in literature have been utilized in healing of the wounds although the natural product specially antioxidants can offer similar if not better biological activity in that regard. Genus Sophora is well known to contain flavonoids and phenolic compounds which have antioxidant and inflammatory effects. So, the aim of the current study was to develop and evaluate chitosan/gelatin based Sophora gibbosa extract-loaded microemulsion as wound dressing. Sophora gibbosa extract (SGE) contained 16 major compounds which have reasonable antioxidant activity. The developed microemulsion showed that Tween 80 produced significant (p < 0.05) lower particle size than Pluronic F127 at the same SGE concentration whereas high concentration of extract results in large particle size. Thermodynamic stability studies showed that using higher concentration of the extract produced less stable formulations. The selected formulation was impregnated in the dressing base (chitosan/gelatin; 2:1 w/w ratio) which exhibited more water absorption. In vivo evaluation revealed that the dressing displayed superior wound repair compared to the control in terms histological examination and determination of alpha smooth muscle actin (α-SMA) and proliferating cell nuclear antigen (PCNA). Thus, SGE-loaded microemulsion-impregnated gelatin/chitosan could be a potential candidate for the wound healing.

Hyaluronan/Poly-L-lysine/Berberine Nanogels for Impaired Wound Healing

Physiological wound healing process can be delayed in the presence of certain pathologies, such as diabetes or cancer. In this perspective, the aim of this study was to design a new nanogel platform of hyaluronan, poly-L-lysine and berberine suitable for wound treatment. Two different nanogel formulations were selected after a first formulation screening. They were prepared by adding dropwise 2 mg/mL hyaluronan aqueous solution (200 or 700 kDa) to 1.25 mg/mL poly-L-lysine aqueous solution. Blank nanogels formulated with 200 kDa HA resulted stable after freeze-drying with dimensions, polydispersity index and zeta potential of 263.6 ± 13.1 nm, 0.323 ± 0.029 and 32.7 ± 3.5 mV, respectively. Both blank and berberine-loaded nanogels showed rounded-shape structures. Loaded nanogels released nearly 50% of loaded berberine within 45 min, whereas the remaining 50% was released up to 24 h in vitro. Both, blank and berberine-loaded nanogels were able to completely close the fibroblasts gap in 42 h.

Development of Hypericum perforatum oil incorporated antimicrobial and antioxidant chitosan cryogel as a wound dressing material

In this study, a herbal infused oil (Hypericum perforatum, HP) incorporated chitosan (CS) cryogel as a wound dressing material was produced in order to be used in wound healing process. The main strategy is to combine the traditional perspective of using medicinal oils with polymeric scaffolds manufactured by an engineering approach to fabricate a potential tissue engineering product that provides both new tissue formation and wound healing. The scaffolds manufactured by cryogelation were soft, spongy, highly porous, physically stable, elastic and could be easily cut in any desired shape. Physicochemical, mechanical and morphological analyzes were used to characterize the produced cryogels. Young modulus of the plain chitosan cryogel was about 21 kPa whereas it increased with increasing HP oil content and became 61 kPa for 20% HP oil ratio. Further, the antimicrobial studies, antioxidant and DNA cleavage effects were investigated. Samples including the highest ratio of oil (CS4) showed the highest DPPH scavenging activity as 69.9%. In addition, 20% HP oil loaded chitosan cryogel demonstrated single strain DNA cleavage activitiy at 500 μg/mL concentration. Antimicrobial studies were applied against seven strains. The lowest activities were obtained against E. hirae and B. cereus, the highest against E. coli and L. pneumophila. This study concluded that the newly developed HP oil loaded chitosan cryogel scaffolds with unique antimicrobial and antioxidant properties are promising candidates to be used in tissue engineering applications as wound dressing for exudative and long-term healing wounds.

Ferulic Acid-NLC with Lavandula Essential Oil: A Possible Strategy for Wound-Healing?

Nowadays, an increasing interest in combinatorial drug delivery systems is emerging, highlighting the possibility of exploiting essential oils (EO) for topical applications. This work aimed at developing nanostructured lipid carriers (NLC) for the combined delivery of ferulic acid and Lavandula EO, whose beneficial effects in wound-healing processes have been widely reported. Homogeneous (polydispersity index, PDI < 0.2) nanoparticles with a small size (<150 nm) and a high encapsulation efficiency (>85%) were obtained. The co-presence of ferulic acid and Lavandula EO, as compared to synthetic isopropyl myristate-based NLC, increased nanoparticles’ stability, due to higher ordering chains, as confirmed by morphological and physicochemical studies. An enhanced cytocompatibility was observed when combining ferulic acid and Lavandula EO, as confirmed by in vitro studies on fibroblasts. Furthermore, the combined delivery of ferulic acid and Lavandula EO significantly promoted cell migration with higher effectiveness in respect to the free drug solution and the carrier without the EO. Taken all together, our results suggest a potential combined effect of the antioxidant ferulic acid and Lavandula EO co-delivered in lipid nanoparticles in promoting cell proliferation and migration, representing a promising strategy in the treatment of wounds.

Multinutrient Supplementation Increases Collagen Synthesis during Early Wound Repair in a Randomized Controlled Trial in Patients with Inguinal Hernia

BACKGROUND

Inguinal hernia disease is associated with an imbalanced collagen metabolism. Surgical stress has a negative impact on nutrients important for collagen synthesis.

OBJECTIVE

We hypothesized that supplementation with a combination of nutrients would enhance collagen biosynthesis in inguinal hernia disease patients when undergoing hernia repair.

METHODS

In this exploratory randomized controlled trial, 21 men (age: 55.2 ± 2.8 y; BMI: 25.0 ± 0.7 kg/m2) scheduled for Lichtenstein inguinal hernia repair were assigned to multinutrient supplementation (n = 10; multinutrient group) or no multinutrient supplementation (n = 11; control group). The multinutrient group received 14 g l-arginine, 14 g l-glutamine, 1250 mg vitamin C, and 55 mg zinc daily starting 14 d before surgery and ending 14 d after surgery. The multinutrient and control groups received high-quality protein to ensure a daily intake of 1.5 g protein/kg. Collagen biosynthesis was measured by the biomarkers type I procollagen propeptide (CICP), type III procollagen propeptide (PRO-C3), and type V procollagen propeptide (PRO-C5) in the sera on days -14, 0, and 1, and in the wound fluids on postoperative days 1 and 2. Compliance was recorded after the 28-d intervention period.

RESULTS

Serum PRO-C5 concentrations decreased (P < 0.05) postoperatively in the control but not the multinutrient group. Neither CICP nor PRO-C3 serum concentrations differed significantly between the 2 groups. In wound fluid, the CICP concentrations increased (P < 0.05) from days 1 to 2 in the multinutrient group and were 49% higher (P = 0.10) than those in the control group on day 2. Wound fluid concentrations PRO-C3 and PRO-C5 showed no significant time or group differences. The 28-d compliance was similar (P = 0.27) in the 2 groups.

CONCLUSION

Oral supplementation with arginine, glutamine, vitamin C, and zinc augment collagen synthesis during the first 2 d after inguinal hernia repair. This trial was registered at clinicaltrials.gov as NCT03221686.

Wound healing and antimicrobial effect of active secondary metabolites in chitosan-based wound dressings: A review

Wound healing can lead to complex clinical problems, hence finding an efficient approach to enhance the healing process is necessary. An ideal wound dressing should treat wounds at reasonable costs, with minimal inconveniences for the patient. Chitosan is one of the most investigated biopolymers for wound healing applications due to its biocompatibility, biodegradability, non-toxicity, and antimicrobial activity. Moreover, chitosan and its derivative have attracted numerous attentions because of the accelerating wound healing, and easy processability into different forms (gels, foams, membranes, and beads). All these properties make chitosan-based materials particularly versatile and promising for wound dressings. Besides, secondary natural metabolites could potentially act like the antimicrobial and anti-inflammatory agents and accelerate the healing process. This review collected almost all studies regarding natural compounds applications in wound healing by focusing on the chitosan-based bioactive wound dressing systems. An accurate analysis of different chitosan formulations and the influence of bioactive compounds on their wound healing properties are reported.

Micelle-nanogel platform for ferulic acid ocular delivery

Corneal wound healing after a trauma or a chemical injury has been shown to correlate with antioxidant levels at the ocular surface. However, ocular bioavailability of efficient antioxidants (e.g. ferulic acid) after topical administration is limited by their poor solubility, low stability and short residence time. The aim of this work was to formulate ferulic acid in a nanocomposite platform composed of nanogels and micelles for efficient delivery to cornea. Solubility enhancement factor of ferulic acid was found to be equal to 1.9 ± 0.3 and 3.4 ± 0.3 for 50 and 100 mg/ml Pluronic® F68 micellar solutions. Hyaluronan was added to blank and ferulic acid loaded micelles, and then cross-linked with ε-polylysine. Hyaluronan nanogels showed dimensions of ~300 nm with positive zeta potential values. The formulations were characterized in terms of rheological behavior, biocompatibility, wound healing properties, ferulic acid release pattern and penetration into excised bovine corneas. In comparison to Pluronic® micelles that released ferulic acid rapidly, micelle-nanogel composites sustained the release up to 2 days. Furthermore, the micelle-nanogel formulation favored in vitro wound closure promoting fibroblasts growth and ex vivo accumulation of ferulic acid into both healthy and damaged corneas (>100 µg/cm²).

Nutrition in wound healing: investigation of the molecular mechanisms, a narrative review

Nutrition can be outlined in terms of epigenetic signals influencing each of the wound healing steps (haemostasis, inflammatory, proliferative and remodelling phase). Specific nutrients, such as amino acids, minerals, vitamins, natural compounds and herbal extracts, target DNA-regulating transcription factors, cytokines, extracellular matrix proteins and glycosaminoglycan, and are specifically involved in the wound healing process. This review focuses on experimental in vivo and clinical evidence of dietary supplements administration in pressure ulcers. A good nutritional status is, for example, fundamental to the haemostasis phase of skin wounds. In the inflammatory phase, vitamin A enhances cytokine release, bromelain and amino acids prevent prolonged inflammatory events, while vitamin C enhances neutrophil migration and lymphocyte activation. In the proliferative phase, vitamin C and Centella asiatica are required for collagen synthesis. Glucosamine enhances hyaluronic acid production, vitamin A promotes epithelial cell differentiation, zinc is required for DNA and protein synthesis and cell division, and Aloe vera supports granulation tissue generation. Finally, in the remodelling phase, amino acids and proteins play a key role in wound scar stabilisation.

Antioxidant and Trace Element Supplementation Reduce the Inflammatory Response in Critically Ill Burn Patients

Oxidative stress after burn injury induces inflammatory and hypermetabolic responses associated with adverse outcomes. We propose that antioxidant and trace element supplementation may reduce oxidative stress and subsequently alleviate inflammation and hypermetabolism, thus improving clinical outcomes. We conducted a cohort study of adult patients with an acute burn injury admitted to our provincial burn center. Patients in the antioxidant group received an intravenous infusion of multivitamins and trace elements for the first 14 days after admission. The inflammatory profile was assessed at early time points, < 14 days postburn, and later time points, ≥ 15 days postburn, and included interleukin (IL)-1β, interferon-γ, IL-1 receptor antagonist, IL-6, granulocyte-macrophage colony-stimulating factor, and FMS-like tyrosine kinase 3 ligand. Hypermetabolism was assessed by resting energy expenditure. Clinical outcomes included mortality, morbidities, hospital length of stay, and infections including days to the last positive culture after injury. We studied 172 patients, mean age 49 ± 17 years and 33 ± 13% TBSA burned, with 91 controls and 81 patients in the antioxidant group. Patients in the antioxidant group had significantly lower levels of inflammatory markers at both early and late time points, P < .05. Antioxidant treatment was associated with decreased measure of hypermetabolism, P < .05. Morbidity and mortality were not significantly different between groups. Length of hospital stay was significantly shorter in the antioxidant group when adjusted for patient demographics and injury characteristics (risk ratio (RR), 0.78; 95% confidence interval (CI), 0.66-0.92). In the antioxidant group, while infections were not different, the last positive culture post-injury was documented at median 19 days (Interquartile range (IQR), 11-43 days) compared with controls at 35 days (IQR, 15-59 days), P = .012. Patients receiving antioxidant and trace element supplementation had reduced markers of burn stress-induced inflammation; they were also associated with a decreased hypermetabolic response, shorter length of stay, and improved bacterial clearance.

Hypoxia-Inducible Factor-1α Knockdown Plus Glutamine Supplementation Attenuates the Predominance of Necrosis over Apoptosis by Relieving Cellular Energy Stress in Acute Pancreatitis

The present study was conducted to investigate the effect and potential mechanism of hypoxia-inducible factor-1α (HIF-1α) genetic inhibition plus glutamine (Gln) supplementation on necrosis-apoptosis imbalance during acute pancreatitis (AP), with a specific focus on the regulations of intracellular energy metabolism status. Wistar rats and AR42J cells were used to establish AP models. When indicated, a HIF-1α knockdown with or without a Gln supplementation was administered. In vivo, local and systemic inflammatory injuries were assessed by serum cytokine measurement, H&E staining, and transmission electron microscope (TEM) observation of pancreatic tissue. In vitro, intracellular energy metabolism status was evaluated by measuring the intracellular adenosine triphosphate (ATP), lactic acid, and Ca²⁺ concentrations and the mitochondrial potential. In addition, changes in the apoptotic activity were analyzed using TUNEL staining in vivo and an apoptosis assay in vitro. HIF-1α knockdown alleviated AP-related inflammatory injury as indicated by the measurements of serum cytokines and examinations of TEM and H&E staining of pancreatic tissues. HIF-1α knockdown played an antioxidative role against AP-related injuries by preventing the increase in the intracellular Ca²⁺ concentration and the decrease in the mitochondrial membrane potential and subsequently by suppressing the glycolysis pathway and increasing energy anabolism in AR42J cells after AP induction. Apoptosis was significantly upregulated when HIF-1α was knocked down before AP induction due to an attenuation of the translocation of nuclear factor-kappa B to the nuclei. Furthermore, these merits of HIF-1α knockdown in the relief of the metabolic stress and upregulation of apoptosis were more significant when Gln was administered concomitantly. In conclusion, Gln-supplemented HIF-1α knockdown might be promising for the future management of AP by relieving the intracellular energy stress, thereby attenuating the predominance of necrosis over apoptosis.

Soy isoflavone-loaded alginate microspheres in thermosensitive gel base: attempts to improve wound-healing efficacy

OBJECTIVES

This study aims to develop thermosensitive gel containing soy isoflavone (antioxidant and anti-inflammatory natural agent) alginate microspheres for enhancement of wound-healing performance.

METHODS

Soy isoflavone microspheres were prepared by ionic cross-linking method and optimized using the Box-Behnken optimization design. Formulations were characterized in terms of particle size, encapsulation efficiency and equilibrium swelling degree. The optimized formula was incorporated in Pluronic F127 gel base and examined for in vivo wound-healing efficacy.

KEY FINDINGS

Results showed mean particle size between 18 and 25 μm, encapsulation efficiency of over 75% and equilibrium swelling degree over 1.9. Thermal analysis indicated interaction between alginate and CaCl2 and embedding of soy isoflavone in microspheres. In vivo wound-healing efficacy showed significant advance in re-epithelization, mature collagen synthesis and proangiogenesis. Immunohistochemical investigation exhibited promising alpha-smooth muscle actin immunopositive cells expression, fibroblast activation and expression of proliferating cell nuclear antigen (proliferation marker) in the epidermis and in the dermis.

CONCLUSIONS

The developed formulation would appear to be a promising topical preparation for accelerating healing process.

Nutrition and Wound Healing: An Overview Focusing on the Beneficial Effects of Curcumin

Wound healing implicates several biological and molecular events, such as coagulation, inflammation, migration-proliferation, and remodeling. Here, we provide an overview of the effects of malnutrition and specific nutrients on this process, focusing on the beneficial effects of curcumin. We have summarized that protein loss may negatively affect the whole immune process, while adequate intake of carbohydrates is necessary for fibroblast migration during the proliferative phase. Beyond micronutrients, arginine and glutamine, vitamin A, B, C, and D, zinc, and iron are essential for inflammatory process and synthesis of collagen. Notably, anti-inflammatory and antioxidant properties of curcumin might reduce the expression of tumor necrosis factor alpha (TNF-α) and interleukin-1 (IL-1) and restore the imbalance between reactive oxygen species (ROS) production and antioxidant activity. Since curcumin induces apoptosis of inflammatory cells during the early phase of wound healing, it could also accelerate the healing process by shortening the inflammatory phase. Moreover, curcumin might facilitate collagen synthesis, fibroblasts migration, and differentiation. Although curcumin could be considered as a wound healing agent, especially if topically administered, further research in wound patients is recommended to achieve appropriate nutritional approaches for wound management.

MicroRNA Expression is Associated with Sepsis Disorders in Critically Ill Polytrauma Patients

A critically ill polytrauma patient is one of the most complex cases to be admitted to the intensive care unit, due to both the primary traumatic complications and the secondary post-traumatic interactions. From a molecular, genetic, and epigenetic point of view, numerous biochemical interactions are responsible for the deterioration of the clinical status of a patient, and increased mortality rates. From a molecular viewpoint, microRNAs are one of the most complex macromolecular systems due to the numerous modular reactions and interactions that they are involved in. Regarding the expression and activity of microRNAs in sepsis, their usefulness has reached new levels of significance. MicroRNAs can be used both as an early biomarker for sepsis, and as a therapeutic target because of their ability to block the complex reactions involved in the initiation, maintenance, and augmentation of the clinical status.

ESPEN guideline on clinical nutrition in the intensive care unit

Following the new ESPEN Standard Operating Procedures, the previous guidelines to provide best medical nutritional therapy to critically ill patients have been updated. These guidelines define who are the patients at risk, how to assess nutritional status of an ICU patient, how to define the amount of energy to provide, the route to choose and how to adapt according to various clinical conditions. When to start and how to progress in the administration of adequate provision of nutrients is also described. The best determination of amount and nature of carbohydrates, fat and protein are suggested. Special attention is given to glutamine and omega-3 fatty acids. Particular conditions frequently observed in intensive care such as patients with dysphagia, frail patients, multiple trauma patients, abdominal surgery, sepsis, and obesity are discussed to guide the practitioner toward the best evidence based therapy. Monitoring of this nutritional therapy is discussed in a separate document.

Changes of serum trace elements in early stage trauma and its correlation with injury severity score

BACKGROUND

Severe trauma can cause secondary multiple organ dysfunction syndrome and death. The absolute and relative concentrations of trace elements in both critical care and conventional treatment, which can lead to acute trace element deficiency, constitute an important mechanism of multiple organ dysfunction syndrome (MODS)/multiple organ failure (MOF).

METHODS

We investigated the changes in serum Cu, Zn, and Fe in early stage trauma of patients with the high injury severity score (ISS) and correlated the change in trace elements with ISS. Blood samples were collected within an hour of admittance and the patients were scored according to ISS. We collected clinical data records and ISS score values, and determined serum Fe, Zn, and Cu by inductively coupled plasma mass spectrometry.

RESULTS

Compared with the control group, the serum Zn and Fe values of trauma patients were decreased. There was no significant difference in serum Cu between the patients and the control group. In the trauma group, the serum Zn and Fe were lower than that of the minor injury group, and the difference of Cu concentration was not statistically significant.

CONCLUSIONS

Serum Zn and Fe levels in patients with multiple trauma fractures were significantly different than those in the normal group, suggesting that Zn and Fe need to be monitored in the early stage of trauma.

The Physiological Mechanisms of Effect of Vitamins and Amino Acids on Tendon and Muscle Healing: A Systematic Review

Aims/Objectives: To evaluate the current literature via systematic review to ascertain whether amino acids/vitamins provide any influence on musculotendinous healing and if so, by which physiological mechanisms. Methods: EBSCO, PubMed, ScienceDirect, Embase Classic/Embase, and MEDLINE were searched using terms including “vitamins,” “amino acids,” “healing,” “muscle,” and “tendon.” The primary search had 479 citations, of which 466 were excluded predominantly due to nonrandomized design. Randomized human and animal studies investigating all supplement types/forms of administration were included. Critical appraisal of internal validity was assessed using the Cochrane risk of Bias Tool or the Systematic Review Centre for Laboratory Animal Experimentation Risk of Bias Tool for human and animal studies, respectively. Two reviewers performed duel data extraction. Results: Twelve studies met criteria for inclusion: eight examined tendon healing and four examined muscle healing. All studies used animal models, except two human trials using a combined integrator. Narrative synthesis was performed via content analysis of demonstrated statistically significant effects and thematic analysis of proposed physiological mechanisms of intervention. Vitamin C/taurine demonstrated indirect effects on tendon healing through antioxidant activity. Vitamin A/glycine showed direct effects on extracellular matrix tissue synthesis. Vitamin E shows an antiproliferative influence on collagen deposition. Leucine directly influences signaling pathways to promote muscle protein synthesis. Discussion: Preliminary evidence exists, demonstrating that vitamins and amino acids may facilitate multilevel changes in musculotendinous healing; however, recommendations on clinical utility should be made with caution. All animal studies and one human study showed high risk of bias with moderate interobserver agreement (k = 0.46). Currently, there is limited evidence to support the use of vitamins and amino acids for musculotendinous injury. Both high-quality animal experimentation of the proposed mechanisms confirming the physiological influence of supplementation and human studies evaluating effects on tissue morphology and biochemistry are required before practical application.

α-Tocopherol promotes HaCaT keratinocyte wound repair through the regulation of polarity proteins leading to the polarized cell migration

In many developed countries including Japan, how to care the bedridden elderly people with chronic wounds such as decubitus becomes one of the most concerned issues. Although antioxidant micronutrients including vitamin E, especially α-tocopherol (α-Toc), are reported to shorten a period of wound closure, the promoting effect of α-Toc on wound healing independent of its antioxidant activity remains to be fully elucidated. The aim of this study was to examine whether α-Toc affects wound-mediated HaCaT keratinocyte polarization process including the recruitment of polarity regulating proteins, leading to wound repair independently of its antioxidant activity. We investigated the effects of α-Toc and other antioxidants such as Trolox, a cell-permeable α-Toc analog on the migration, proliferation, and cell polarization of HaCaT keratinocytes after wounding. We analyzed the localization and complex formation of polarity proteins, partitioning defective 3 (Par3), and atypical protein kinase C (aPKC), and aPKC activity by immunohistochemistry, immunoprecipitation analyses, and in vitro kinase assays, respectively. α-Toc but not other antioxidants enhanced the wound closure and cell polarization in HaCaT keratinocytes after wounding. α-Toc regulated the localization and complex formation of Par3 and aPKC during wound healing. Knockdown of aPKC or Par3 abrogated α-Toc-mediated promotion of the wound closure and cell polarization in HaCaT keratinocytes. Furthermore, aPKC kinase activity was significantly increased in α-Toc-treated cells through activation of phosphatidylinositol 3-kinase/Akt signaling pathway. These results suggest that α-Toc promotes HaCaT keratinocyte wound repair by regulating the aPKC kinase activity and the formation of aPKC-Par3 complex. © 2017 BioFactors, 44(2):180-191, 2018.

Effects of Selenium Supplementation on Gene Expression Levels of Inflammatory Cytokines and Vascular Endothelial Growth Factor in Patients with Gestational Diabetes

Selenium is known to exert multiple beneficial effects including anti-inflammatory actions. The aim of the study was to evaluate the effects of selenium supplementation on gene expression levels of inflammatory cytokines and vascular endothelial growth factor (VEGF) in women with gestational diabetes (GDM). This randomized double-blind, placebo-controlled trial was carried out among 40 subjects diagnosed with GDM aged 18-40 years old. Subjects were randomly allocated into two groups to receive either 200 μg/day selenium supplements (n = 20) or placebo (n = 20) for 6 weeks. Gene expression of inflammatory cytokines and VEGF were assessed in lymphocytes of GDM women with RT-PCR method. Results of RT-PCR indicated that after the 6-week intervention, compared with the placebo, selenium supplementation downregulated gene expression of tumor necrosis factor alpha (TNF-α) (P = 0.02) and transforming growth factor beta (TGF-β) (P = 0.01), and upregulated gene expression of VEGF (P = 0.03) in lymphocytes of patients with GDM. There was no statistically significant change following supplementation with selenium on gene expression of interleukin (IL)-1β and IL-8 in lymphocytes of subjects with GDM. Selenium supplementation for 6 weeks in women with GDM significantly decreased gene expression of TNF-α and TGF-β, and significantly increased gene expression of VEGF, but did not affect gene expression of IL-1β and IL-8. Clinical trial registration number http://www.irct.ir : IRCT201612045623N95.

Vitamin C and Immune Function

Vitamin C is an essential micronutrient for humans, with pleiotropic functions related to its ability to donate electrons. It is a potent antioxidant and a cofactor for a family of biosynthetic and gene regulatory enzymes. Vitamin C contributes to immune defense by supporting various cellular functions of both the innate and adaptive immune system. Vitamin C supports epithelial barrier function against pathogens and promotes the oxidant scavenging activity of the skin, thereby potentially protecting against environmental oxidative stress. Vitamin C accumulates in phagocytic cells, such as neutrophils, and can enhance chemotaxis, phagocytosis, generation of reactive oxygen species, and ultimately microbial killing. It is also needed for apoptosis and clearance of the spent neutrophils from sites of infection by macrophages, thereby decreasing necrosis/NETosis and potential tissue damage. The role of vitamin C in lymphocytes is less clear, but it has been shown to enhance differentiation and proliferation of B- and T-cells, likely due to its gene regulating effects. Vitamin C deficiency results in impaired immunity and higher susceptibility to infections. In turn, infections significantly impact on vitamin C levels due to enhanced inflammation and metabolic requirements. Furthermore, supplementation with vitamin C appears to be able to both prevent and treat respiratory and systemic infections. Prophylactic prevention of infection requires dietary vitamin C intakes that provide at least adequate, if not saturating plasma levels (i.e., 100–200 mg/day), which optimize cell and tissue levels. In contrast, treatment of established infections requires significantly higher (gram) doses of the vitamin to compensate for the increased inflammatory response and metabolic demand.

Emerging Evidence on Neutrophil Motility Supporting Its Usefulness to Define Vitamin C Intake Requirements

Establishing intake recommendations for vitamin C remains a challenge, as no suitable functional parameter has yet been agreed upon. In this report, we review the emerging evidence on neutrophil motility as a possible marker of vitamin C requirements and put the results in perspective with other approaches. A recent in vitro study showed that adequate levels of vitamin C were needed for this function to work optimally when measured as chemotaxis and chemokinesis. In a human study, neutrophil motility was optimal at intakes ≥250 mg/day. Interestingly, a Cochrane review showed a significant reduction in the duration of episodes of common cold with regular vitamin C intakes in a similar range. Additionally, it was shown that at a plasma level of 75 µmol/L, which is reached with vitamin C intakes ≥200 mg/day, incidences of cardiovascular disease were lowest. This evidence would suggest that daily intakes of 200 mg vitamin C might be advisable for the general adult population, which can be achieved by means of a diverse diet. However, additional studies are warranted to investigate the usefulness of neutrophil motility as a marker of vitamin C requirements.

When Is It Appropriate to Use Glutamine in Critical Illness?

Glutamine is a nonessential amino acid, which under trauma or critical illness can become essential. A number of historic small single-center randomized controlled trials (RCTs) have demonstrated positive treatment effects on clinical outcomes with glutamine supplementation. Meta-analyses based on these trials demonstrated a significant reduction in hospital mortality, intensive care unit (ICU) length of stay (LOS), and hospital LOS with intravenous (IV) glutamine. Similar results were not noted in 2 large multicenter RCTs (REDOXS and MetaPlus) assessing the efficacy of glutamine supplementation in ventilated ICU patients. The REDOXS trial of 40 ICUs randomized 1223 ventilated ICU patients to glutamine (IV and enteral), antioxidants, both glutamine and antioxidants, or placebo. The main conclusions were a trend toward increased 28-day mortality and significant increased hospital and 6-month mortality in those who received glutamine. The MetaPlus trial of 14 ICUs, which randomized 301 ventilated ICU patients to glutamine-enriched enteral vs an isocaloric diet, noted increased 6-month mortality in the glutamine-supplemented group. Newer RCTs have focused on specific populations and have demonstrated benefits in burn and elective surgery patients with glutamine supplementation. Whether larger studies will confirm these findings is yet to be determined. Recent American Society for Parenteral and Enteral Nutrition guidelines recommend that IV and enteral glutamine should not be used in the critical care setting based on the moderate quality of evidence available. We agree with these recommendations and would encourage larger multicenter studies to evaluate the risks and benefits of glutamine in burn and elective surgery patients.

Chronic wound repair and healing in older adults: current status and future research

Older adults are more likely to have chronic wounds than younger people, and the effect of chronic wounds on quality of life is particularly profound in this population. Wound healing slows with age, but the basic biology underlying chronic wounds and the influence of age-associated changes on wound healing are poorly understood. Most studies have used in vitro approaches and various animal models, but observed changes translate poorly to human healing conditions. The effect of age and accompanying multimorbidity on the effectiveness of existing and emerging treatment approaches for chronic wounds is also unknown, and older adults tend to be excluded from randomized clinical trials. Poorly defined outcomes and variables; lack of standardization in data collection; and variations in the definition, measurement, and treatment of wounds also hamper clinical studies. The Association of Specialty Professors, in conjunction with the National Institute on Aging and the Wound Healing Society, held a workshop, summarized in this article, to explore the current state of knowledge and research challenges, engage investigators across disciplines, and identify research questions to guide future study of age-associated changes in chronic wound healing.

Chronic wound repair and healing in older adults: current status and future research

The incidence of chronic wounds is increased among older adults, and the impact of chronic wounds on quality of life is particularly profound in this population. It is well established that wound healing slows with age. However, the basic biology underlying chronic wounds and the influence of age-associated changes on wound healing are poorly understood. Most studies have used in vitro approaches and various animal models, but observed changes translate poorly to human healing conditions. The impact of age and accompanying multi-morbidity on the effectiveness of existing and emerging treatment approaches for chronic wounds is also unknown, and older adults tend to be excluded from randomized clinical trials. Poorly defined outcomes and variables, lack of standardization in data collection, and variations in the definition, measurement, and treatment of wounds also hamper clinical studies. The Association of Specialty Professors, in conjunction with the National Institute on Aging and the Wound Healing Society, held a workshop, summarized in this paper, to explore the current state of knowledge and research challenges, engage investigators across disciplines, and identify key research questions to guide future study of age-associated changes in chronic wound healing.

Efficacy of Glutamine-Enriched Nutrition Support for Patients With Severe Acute Pancreatitis: A Meta-Analysis

BACKGROUND

Plasma glutamine (Gln) level has been negatively correlated with the severity of severe acute pancreatitis (SAP). Although Gln is widely used today, the results of individual randomized controlled trials of Gln-enriched nutrition support for patients with SAP are conflicting.

METHODS

PubMed, EMBASE, HighWire, Cochrane Central Register of Controlled Trials, Wanfang, China Journals Full-Text Database, and the Chinese Biomedical Literature Database were searched. Literature published before June 2014 was searched. Randomized controlled trials investigating the comparison of conventional and Gln-enriched nutrition support were included; a random effect model using Rev Man 5.2 software was chosen to complete this meta-analysis. The count data were analyzed using the risk ratio (RR) and 95% confidence interval (CI), and the measurement data were analyzed using the standard mean difference or weighted mean difference and 95% CI. Heterogeneity analyses were conducted by I(2) test; publication bias analyses were conducted by Begg test.

RESULTS

Ten studies were eventually chosen for analysis, including 218 patients who received conventional methods (control group) and 215 patients who received Gln-enriched nutrition support (experimental group). Compared with the control group, Gln is helpful in elevating the albumin level, decreasing C-reaction protein (standard mean difference = 1.01, -1.89; 95% CI: 0.50 to 1.51, -3.23 to -0.56; P < .05), decreasing the incidence of infectious complication and mortality (RR = 0.62, 0.36; 95% CI: 0.46 to 0.83, 0.16 to 0.83; P < .05), and shortening the hospital stay length (weighted mean difference [WMD] = -3.89; 95% CI: -4.98 to -2.81; P < .05) without increasing expenses (WMD = -0.16; 95% CI: -1.34 to 1.02; P > .05). Intravenous infusion manifested more advantages by decreasing the incidence of infectious complications and mortality.

CONCLUSIONS

Gln-enriched nutrition support is superior to conventional methods for SAP, and intravenous infusion may be a better choice for drug administration.

Micronutrients, Arginine, and Glutamine: Does Supplementation Provide an Efficient Tool for Prevention and Treatment of Different Kinds of Wounds?

Significance: Wound-healing complications are a clinical problem with a considerable socioeconomic burden. Since several nutrients play a physiological role in wound healing, supplementation of these nutrients may improve wound healing. Recent Advances: Oral nutritional supplements and enteral formulas providing arginine, glutamine, and micronutrients such as ascorbic acid and zinc should improve the healing of pressure ulcers (PU) and the healing of surgical, traumatic, and burned wounds. Is their efficacy proved from clinical intervention trials? Critical Issues: Formulas that are rich in energy, protein, arginine, vitamin C, and zinc can improve PU healing, whereas their efficacy for PU prevention is less clear. High-dose supplementation of vitamin C, zinc, and pantothenic acid may improve the healing of surgical wounds in healthy subjects. Arginine lowers the risk of fistulas in patients undergoing elective surgery due to gastrointestinal cancer. However, formulations also enriched with n-3-fatty acids and ribonucleic acids lower the risk of several wound complications, thus being more effective than isolated arginine. Glutamine and antioxidant micronutrients (vitamin C and E, zinc, selenium, and copper) can improve the healing of surgical, traumatic, and burned wounds. Future Directions: Considerable evidence suggests that formulations, indicated especially for critically ill patients, support the healing of PU and the healing of surgical and burned wounds. However, their optimal composition with regard to the dose of individual components has to be determined in future studies. Further well-designed trials should investigate the impact of certain nutrients for the prevention of PU and for the healing of surgical wounds in healthy subjects.

Nutrition and Chronic Wounds

Significance: Nutrition is one of the most basic of medical issues and is often ignored as a problem in the management of our chronic wound patients. Unfortunately, malnutrition is widespread in our geriatric patients even in nursing homes in developed countries. Attention to basic nutrition and providing appropriate supplements may assist in the healing of our chronic wounds. Recent Advances: Recent research has revealed the epidemiology of malnutrition in developed countries, the similarities to malnutrition in developing countries, and some of the physiologic and sociologic causes for this problem. More information is now available on the biochemical effects of nutrient deficiency and supplementation with macronutrients and micronutrients. In some cases, administration of isolated nutrients beyond recommended amounts for healthy individuals may have a pharmacologic effect to help wounds heal. Critical Issues: Much of the knowledge of the nutritional support of chronic wounds is based on information that has been obtained from trauma management. Due to the demographic differences of the patients and differences in the physiology of acute and chronic wounds, it is not logical to assume that all aspects of nutritional support are identical in these patient groups. Before providing specific nutritional supplements, appropriate assessments of patient general nutritional status and the reasons for malnutrition must be obtained or specific nutrient supplementation will not be utilized. Future Directions: Future research must concentrate on the biochemical and physiologic differences of the acute and chronic wounds and the interaction with specific supplements, such as antioxidants, vitamin A, and vitamin D.

The use of a specialised amino acid mixture for pressure ulcers: a placebo-controlled trial

OBJECTIVE

To compare pressure ulcer healing rates in patients supplemented with a specialised amino acid mixture containing (beta)-hydroxy (beta)-methylbutyrate (HMB), arginine and glutamine, and standard oral nutritional supplements versus patients supplemented with oral nutritional supplements and a placebo mixture.

METHOD

Twenty-three inpatients with stage II, III or IV pressure ulcers in an acute care hospital were randomised to recieve (A) a HMB, arginine and glutamine mixture twice daily alongside oral nutritional supplements (n=11) or (B) standard nutritional care alongside oral nutritional supplements (n=12) for 2 weeks. Pressure ulcers were measured weekly for area, depth and Pressure Ulcer Scale for Healing (PUSH) scores. The proportion of viable tissue was determined based on area of wound tracing. Weekly laboratory tests were performed to measure C-reactive protein and pre-albumin levels. This trial is registered at http://ClinicalTrials.gov under NCT01090076.

RESULTS

There was no difference between anthropometrical measurements, biochemical parameters and nutritional intake pre- and post- study. Wound area did not decrease significantly in the short term for both groups. The proportion of viable tissues increased within 2 weeks on HMB, arginine and glutamine supplementation (p=0.02). PUSH scores showed significant improvement within 1 week of supplementation for the experimental group (p=0.013).

CONCLUSION

The use of specialised amino acid does not appear to reduce wound size and PUSH scores but may improve tissue viability after 2 weeks. Further confirmation on a larger scale is required to determine the benefits of supplementing additional HMB, arginine and glutamine in patients with pressure ulcers.

Immunonutrition as an adjuvant therapy for burns

BACKGROUND

With burn injuries involving a large total body surface area (TBSA), the body can enter a state of breakdown, resulting in a condition similar to that seen with severe lack of proper nutrition. In addition, destruction of the effective skin barrier leads to loss of normal body temperature regulation and increased risk of infection and fluid loss. Nutritional support is common in the management of severe burn injury, and the approach of altering immune system activity with specific nutrients is termed immunonutrition. Three potential targets have been identified for immunonutrition: mucosal barrier function, cellular defence and local or systemic inflammation. The nutrients most often used for immunonutrition are glutamine, arginine, branched-chain amino acids (BCAAs), omega-3 (n-3) fatty acids and nucleotides.

OBJECTIVES

To assess the effects of a diet with added immunonutrients (glutamine, arginine, BCAAs, n-3 fatty acids (fish oil), combined immunonutrients or precursors to known immunonutrients) versus an isonitrogenous diet (a diet wherein the overall protein content is held constant, but individual constituents may be changed) on clinical outcomes in patients with severe burn injury.

SEARCH METHODS

The search was run on 12 August 2012. We searched the Cochrane Injuries Group's Specialised Register, The Cochrane Library, MEDLINE (OvidSP), Embase (OvidSP), ISI WOS SCI-EXPANDED & CPCI-S and four other databases. We handsearched relevant journals and conference proceedings, screened reference lists and contacted pharmaceutical companies. We updated this search in October 2014, but the results of this updated search have not yet been incorporated.

SELECTION CRITERIA

Randomised controlled trials comparing the addition of immunonutrients to a standard nutritional regimen versus an isonitrogenated diet or another immunonutrient agent.

DATA COLLECTION AND ANALYSIS

Two review authors were responsible for handsearching, reviewing electronic search results and identifying potentially eligible studies. Three review authors retrieved and reviewed independently full reports of these studies for inclusion. They resolved differences by discussion. Two review authors independently extracted and entered data from the included studies. A third review author checked these data. Two review authors independently assessed the risk of bias of each included study and resolved disagreements through discussion or consultation with the third and fourth review authors. Outcome measures of interest were mortality, hospital length of stay, rate of burn wound infection and rate of non-wound infection (bacteraemia, pneumonia and urinary tract infection).

MAIN RESULTS

We identified 16 trials involving 678 people that met the inclusion criteria. A total of 16 trials contributed data to the analysis. Of note, most studies failed to report on randomisation methods and intention-to-treat principles; therefore study results should be interpreted with caution. Glutamine was the most common immunonutrient and was given in seven of the 16 included studies. Use of glutamine compared with an isonitrogenous control led to a reduction in length of hospital stay (mean stay -5.65 days, 95% confidence interval (CI) -8.09 to -3.22) and reduced mortality (pooled risk ratio (RR) 0.25, 95% CI 0.08 to 0.78). However, because of the small sample size, it is likely that these results reflect a false-positive effect. No study findings suggest that glutamine has an effect on burn wound infection or on non-wound infection. All other agents investigated showed no evidence of an effect on mortality, length of stay or burn wound infection or non-wound infection rates.

AUTHORS' CONCLUSIONS

Although we found evidence of an effect of glutamine on mortality reduction, this finding should be taken with care. The number of study participants analysed in this systematic review was not sufficient to permit conclusions that recommend or refute the use of glutamine. Glutamine may be effective in reducing mortality, but larger studies are needed to determine the overall effects of glutamine and other immunonutrition agents.

Immunonutrition: Role in Wound Healing and Tissue Regeneration

Significance: The role of immunonutrition in wound healing has been an area of both interest and controversy for many years. Although deficiencies in certain nutrients have long been known to impair healing, supplementation of specific immune modulating nutrients has not consistently yielded improvements in wound healing. Still, the prospect of optimizing nutrition to assist the immune system in wound repair bears great significance in both medical and surgical fields, as the costs of wound care and repair cannot be ignored. Recent Advances: Recent studies have rekindled efforts to elucidate the roles of specific immunonutrients, and we now have a better understanding of the conditionally essential role of various nutrients such as arginine, which becomes essential in certain clinical situations such as for the trauma patient or patients at high risk for malnutrition. Immunonutrition in its current formulation usually includes supplementation with arginine, glutamine, omega-3 fatty acids, vitamins, and trace minerals, and its use has often been associated with decreased infectious complications and sometimes with improvements in wound healing. Critical Issues: A key to understanding the role of immunonutrition in wound healing is recognizing the distinct contributions and importance of the various elements utilized. Future Directions: Critical areas for future study include identifying the specific populations, timing, and ideal composition of immunomodulating diets in order to optimize the wound healing process.

Extracellular micronutrient levels and pro-/antioxidant status in trauma patients with wound healing disorders: results of a cross-sectional study

Background

Disorders in wound healing (DWH) are common in trauma patients, the reasons being not completely understood. Inadequate nutritional status may favor DWH, partly by means of oxidative stress. Reliable data, however, are lacking. This study should investigate the status of extracellular micronutrients in patients with DWH within routine setting.

Methods

Within a cross-sectional study, the plasma/serum status of several micronutrients (retinol, ascorbic acid, 25-hydroxycholecalciferol, α-tocopherol, β-carotene, selenium, and zinc) were determined in 44 trauma patients with DWH in addition to selected proteins (albumin, prealbumin, and C-reactive protein; CRP) and markers of pro-/antioxidant balance (antioxidant capacity, peroxides, and malondialdehyde). Values were compared to reference values to calculate the prevalence for biochemical deficiency. Correlations between CRP, albumin and prealbumin, and selected micronutrients were analyzed by Pearson’s test. Statistical significance was set at P < 0.05.

Results

Mean concentrations of ascorbic acid (23.1 ± 15.9 μmol/L), 25-hydroxycholecalciferol (46.2±30.6 nmol/L), β-carotene (0.6 ± 0.4 μmol/L), selenium (0.79±0.19 μmol/L), and prealbumin (24.8 ± 8.2 mg/dL) were relatively low. Most patients showed levels of ascorbic acid (<28 μmol/L; 64%), 25-hydroxycholecalciferol (<50 μmol/L; 59%), selenium (≤ 94 μmol/L; 71%) and β-carotene (<0.9 μmol/L; 86%) below the reference range. Albumin and prealbumin were in the lower normal range and CRP was mostly above the reference range. Plasma antioxidant capacity was decreased, whereas peroxides and malondialdehyde were increased compared to normal values. Inverse correlations were found between CRP and albumin (P < 0.05) and between CRP and prealbumin (P < 0.01). Retinol (P < 0.001), ascorbic acid (P < 0.01), zinc (P < 0.001), and selenium (P < 0.001) were negatively correlated with CRP.

Conclusions

Trauma patients with DWH frequently suffer from protein malnutrition and reduced plasma concentrations of several micronutrients probably due to inflammation, increased requirement, and oxidative burden. Thus, adequate nutritional measures are strongly recommended to trauma patients.

Vitamin C: a wound healing perspective

Vitamin C, also known as ascorbic acid (AA), is involved in all phases of wound healing. In the inflammatory phase it is required for neutrophil apoptosis and clearance. During the proliferative phase, AA contributes towards synthesis, maturation, secretion and degradation of collagen. Deficiencies affect the maturation phase by altering collagen production and scar formation. The body strives to maintain homeostasis of AA, thereby ensuring availability for collagen synthesis. After wounding, plasma and tissue levels of AA diminish and, as a consequence, supplements may be useful for healing, although levels beyond saturation are excreted Clinicians need to be aware of both the nutritional status of patients with either acute or chronic wounds and the possibility of any AA deficiency which may hinder healing.

Intravenous glutamine for severe acute pancreatitis: A meta-analysis

AIM: To evaluate the efficacy of intravenous glutamine on the patients with severe acute pancreatitis (SAP).

METHODS: The Cochrane Library, PubMed, EMBASE, and EBM review databases were searched up to June 2012. Randomized controlled trials (RCTs) that compared non-glutamine nutrition with intravenous glutamine supplemented nutrition in patients with SAP were included. A method recommended by the Cochrane Collaboration was used to perform a meta-analysis of those RCTs.

RESULTS: Four RCTs involving a total of 190 participants were included. Analysis of these RCTs revealed the presence of statistical homogeneity among them. Results showed that glutamine dipeptide has a positive effect in reducing the mortality rate (OR = 0.26, 95%CI: 0.09-0.73, P = 0.01), length of hospital stay (weighted mean difference = -4.85, 95%CI: 6.67--3.03, P < 0.001), and the rate of complications (OR = 0.41, 95%CI: 0.22-0.78, P = 0.006). No serious adverse effects were found.

CONCLUSION: Current best evidence demonstrates that glutamine is effective for SAP. Further high quality trials are required and parameters of nutritional condition and hospital cost should be considered in future RCTs with sufficient size and rigorous design.

Nutrition and skin ulcers

PURPOSE OF REVIEW

Skin ulcerations cause significant morbidity and mortality, while driving up healthcare utilization and costs. Interventions to prevent ulcers and improve wound healing times are needed to reduce the burden on patients and healthcare systems. It has been well established that weight loss, protein-calorie malnutrition, and dehydration are risk factors for pressure ulcers. Many nutritional interventions have been studied, with studies being of variable quality and producing mixed results. This review aims to clarify the current evidence and highlights the recent advances in the area of nutrition for the prevention and management of skin ulceration.

RECENT FINDINGS

Markers for assessing nutritional status will be reviewed first, followed by a discussion on the theoretical benefit of various nutritional interventions on wound healing. Recommendations for nutrient repletion are also included. Finally, the most recent or important literature will be highlighted and the risks and benefits of supplementation are debated. There is mixed evidence for most nutritional interventions, with most studies being of poor quality with variable study designs, lack of control groups, small sample sizes, and short study lengths.

SUMMARY

Long-term randomized trials of individual nutrients and clinically relevant endpoints are needed to definitively show the benefit of additional nutritional supplementation over dietary interventions. Until those studies become available, best evidence suggests the importance of screening for malnutrition, calculating resting energy expenditure and caloric needs, and monitoring dietary intake of essential nutrients.