Monitoring the clinical introduction of a glutamine and antioxidant solution in critically ill trauma and burn patients

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.

Thiamine use is associated with better outcomes for traumatic brain injury patients

Background

Traumatic brain injury (TBI) is a global health concern that often leads to poor prognosis. We designed this study to explore whether thiamine use is associated with a better prognosis of TBI.

Methods

TBI patients selected from the Medical Information Mart for Intensive Care-III database were included in the study. Univariate and multivariate Cox regression analyses were performed to examine the relationship between thiamine use and mortality in TBI patients. Propensity score matching (PSM) was utilized to generate balanced cohorts of the non-thiamine use group and the thiamine use group. Subgroup analysis was performed in the cohort after PSM to verify the association between thiamine use and mortality in TBI patients across different stratifications.

Results

The incidence of thiamine use in TBI was 18.3%. The thiamine use group had a lower 30-day mortality rate (p < 0.001), a longer length of ICU stay (p < 0.001), and a longer length of hospital stay (p < 0.001) than the non-thiamine use group, both in the primary cohort before PSM and the cohort after PSM. A multivariate Cox regression analysis confirmed that thiamine use was independently associated with mortality (OR = 0.454, p < 0.001) after adjusting for confounding effects. In the cohort after PSM, the subgroup analysis showed that thiamine use is associated with lower mortality in TBI patients with a Glasgow Coma Scale (GCS) score of < 13, but it is not associated with mortality in TBI patients whose GCS score is ≥13.

Conclusion

Thiamine supplementation is effective in improving the outcome of TBI, except in cases of mild TBI. The optimal thiamine supplementation strategy for TBI is worthwhile to be explored in future studies.

Patient-centred outcomes are under-reported in the critical care burns literature: a systematic review

BACKGROUND

Developments in the care of critically ill patients with severe burns have led to improved hospital survival, but long-term recovery may be impaired. The extent to which patient-centred outcomes are assessed and reported in studies in this population is unclear.

METHODS

We conducted a systematic review to assess the outcomes reported in studies involving critically ill burns patients. Randomised controlled trials (RCTs) and cohort studies on the topics of fluid resuscitation, analgesia, haemodynamic monitoring, ventilation strategies, transfusion targets, enteral nutrition and timing of surgery were included. We assessed the outcomes reported and then classified these according to two suggested core outcome sets.

RESULTS

A comprehensive search returned 6154 studies; 98 papers met inclusion criteria. There were 66 RCTs, 19 clinical studies with concurrent controls and 13 interventional studies without concurrent controls. Outcome reporting was inconsistent across studies. Pain, reported using the visual analogue scale, fluid volume administered and mortality were the only outcomes measured in more than three studies. Sixty-six studies (67%) had surrogate primary outcomes. Follow-up was poor, with median longest follow-up across all studies 5 days (IQR 3-28). When compared to the suggested OMERACT core outcome set, 53% of papers reported on mortality, 28% reported on life impact, 30% reported resource/economic outcomes and 95% reported on pathophysiological manifestations. Burns-specific Falder outcome reporting was globally poor, with only 4.3% of outcomes being reported across the 98 papers.

CONCLUSION

There are deficiencies in the reporting of outcomes in the literature pertaining to the intensive care management of patients with severe burns, both with regard to the consistency of outcomes as well as a lack of focus on patient-centred outcomes. Long-term outcomes are infrequently reported. The development and validation of a core outcome dataset for severe burns would improve the quality of reporting.

The Impact of Selenium Supplementation on Trauma Patients-Systematic Review and Meta-Analysis

This study aimed to assess current evidence regarding the effect of selenium (Se) supplementation on the prognosis in patients sustaining trauma. MEDLINE, Embase, and Web of Science databases were searched with the following terms: “trace element”, “selenium”, “copper”, “zinc”, “injury”, and “trauma”. Seven studies were included in the meta-analysis. The pooled results showed that Se supplementation was associated with a lower mortality rate (OR 0.733, 95% CI: 0.586, 0.918, p = 0.007; heterogeneity, I² = 0%). Regarding the incidence of infectious complications, there was no statistically significant benefit after analyzing the four studies (OR 0.942, 95% CI: 0.695, 1.277, p = 0.702; heterogeneity, I² = 14.343%). The patients with Se supplementation had a reduced ICU length of stay (standard difference in means (SMD): −0.324, 95% CI: −0.382, −0.265, p < 0.001; heterogeneity, I² = 0%) and lesser hospital length of stay (SMD: −0.243, 95% CI: −0.474, −0.012, p < 0.001; heterogeneity, I² = 45.496%). Se supplementation after trauma confers positive effects in decreasing the mortality and length of ICU and hospital stay.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Clinical Sequelae From Overfeeding in Enterally Fed Critically Ill Adults: Where Is the Evidence?

Enteral energy delivery above requirements (overfeeding) is believed to cause adverse effects during critical illness, but the literature supporting this is limited. We aimed to quantify the reported frequency and clinical sequelae of energy overfeeding with enterally delivered nutrition in critically ill adult patients. A systematic search of MEDLINE, EMBASE, and CINAHL from conception to November 28, 2018, identified clinical studies of nutrition interventions in enterally fed critically ill adults that reported overfeeding in 1 or more study arms. Overfeeding was defined as energy delivery > 2000 kcal/d, > 25 kcal/kg/d, or ≥ 110% of energy prescription. Data were extracted on methodology, demographics, prescribed and delivered nutrition, clinical variables, and predefined outcomes. Cochrane "Risk of Bias" tool was used to assess the quality of randomized controlled trials (RCTs). Eighteen studies were included, of which 10 were randomized (n = 4386 patients) and 8 were nonrandomized (n = 223). Only 4 studies reported a separation in energy delivery between treatment groups whereby 1 arm met the definition of overfeeding, which reported no between-group differences in mortality, infectious complications, or ventilatory support. Overfeeding was associated with increased insulin administration (median 3 [interquartile range: 0-41.8] vs 0 [0-30.6] units/d) and upper-gastrointestinal intolerance in 1 large RCT and with duration of antimicrobial therapy in a small RCT. There are limited high-quality data to determine the impact of energy overfeeding of critically ill patients by the enteral route; however, based on available evidence, overfeeding does not appear to affect mortality or other important clinical outcomes.

Evaluation of plasma oxidative stress, with or without antioxidant supplementation, in superficial partial thickness burn patients: a pilot study

BACKGROUND

Oxidative stress is one of the main causes of pathophysiological alterations observed during burn injury. The present pilot study aimed to determine whether a specific oral antioxidant supplementation could in any way influence free radical blood values in patients affected by superficial partial thickness burns.

MATERIALS AND METHODS

Plasma oxidants and plasma antioxidant capacity were analysed in 20 superficial partial thickness burn patients for a 2-week period; patients were randomly divided into two groups, one of which was supported with a specifically designed oral antioxidant formula (Squalene 100 mg, Vitamin C 30 mg, Coenzyme Q10 10 mg, Zinc 5 mg, Beta Carotene 3.6 mg, Bioflavonoids 30 mg, Selenium 55 mcg) administered daily, starting from the day of admission, for the whole study period.

RESULTS

No significant differences were found in plasma oxidants and plasma antioxidant capacity between the two groups of patients.

CONCLUSIONS

These results did not reflect any significant benefits of an antioxidant oral supplementation at usual dosages when considering oxidative plasmatic values of superficial partial thickness burn patients.

Biphasic changes (overreduction and overoxidation) of plasma redox status and clinical implications in early stage of severe burns

PURPOSE

Although the changes of redox status in the early stage of severe burns are considered to be associated with the disease progression, whereas antioxidant therapy cannot improve the prognosis, the characteristics and mechanisms of dynamic change of redox status related with the disease progression deserve further study.

METHODS

Blood redox potential (ORP) values (ΔORP value was adopted), plasma uric acid (UA) levels, and the inflammation-related indicators of 67 burn patients were dynamically monitored in the early stage.

RESULTS

Compared with healthy persons, the results revealed the biphasic changes of redox status in the early stage after burns, and both of them were closely related to the prognosis of severe burns. Overreduction status and overoxidation status were related to the dynamic changes of plasma UA level and the inflammation-related indicators of severe burns. In addition, the change of ΔORP value was found to associate with the traditional prognostic markers.

CONCLUSIONS

This study firstly revealed the excessive, biphasic changes of redox status and clinical implications in the early stage of severe burns, providing a new viewpoint for early pathological changes of severe burns and will be helpful for corresponding early treatment. ΔORP value also appears to be a potential early prognostic marker.

The clinical role of glutamine supplementation in patients with multiple trauma: a narrative review

Glutamine is considered an essential amino acid during stress and critical illness. Parenteral glutamine supplementation in critically ill patients has been shown to improve survival rate and minimise infectious complications, costs and hospital length-of-stay. However, glutamine supplementation in patients receiving enteral nutrition and the best method of administration are still controversial. The purpose of this article is to provide a narrative review of the current evidence and trials of enteral and parenteral glutamine supplementation in multiple trauma patients. A search in PubMed and EMBASE was conducted and relevant papers that investigated the effect of enteral or parenteral glutamine supplementation in patients with multiple trauma were reviewed. Although recent nutritional guidelines recommend that glutamine supplementation should be considered in these patients, further well-designed trials are required to provide a confirmed conclusion. Due to the inconclusive results of enteral glutamine supplementation trials in patients receiving enteral nutrition, future trials should focus on intravenous glutamine supplementation in patients requiring enteral nutrition and on major clinical outcome measures (e.g. mortality rate, infectious complications).

Hemorrhagic shock and surgical stress alter distribution of labile zinc within high- and low-molecular-weight plasma fractions

Zinc ions (Zn) are essential for tissue repair following injury or stress. We hypothesize that during such stresses Zn is redistributed to labile pools in plasma components. Here we tested this hypothesis using a novel assay to monitor labile Zn in plasma in hemorrhagic shock. Adult rats in the shock group (S group) underwent hemorrhage and resuscitation. Blood samples were drawn at baseline and at 1, 4, and 24 h. The surgical control group (SC group) was anesthetized and instrumented, but not bled. Albumin, total Zn, and labile Zn levels were assayed in plasma. Binding capacity for Zn was assessed in high- and low-molecular-weight pools. Significant decreases in total Zn were observed by 24 h, in both S and SC groups. Albumin levels were significantly reduced in the S group at 1 and 4 h but restored at 24 h; significant changes were not observed in other groups. In whole plasma, labile Zn levels were stable initially in the S and SC groups, but declined at 24 h. In the high-molecular-weight pool, marked and significant impairment of binding was noted throughout all time periods following the shock period in the S group. Such changes were observed in the SC group of less intensity and duration. These experiments suggest that shock alters affinity of plasma proteins for Zn, promoting delivery to peripheral tissues during periods of increased Zn utilization.

Randomized controlled trial comparing antioxidant-enriched enteral nutrition with immune-enhancing enteral nutrition after esophagectomy for cancer: a pilot study

PURPOSE

The objective of this study was to compare the effects of two types of enteral supplements, an antioxidant-enriched enteral nutrition (AeEN) and an immune-enhancing enteral nutrition (IeEN), on the nutrition, immunoinflammatory response, antioxidant capacity and clinical outcomes in patients after esophagectomy for cancer.

METHODS

Patients (n = 20) undergoing esophagectomy for cancer were randomized in this single-center, open-label study. Two types of enteral supplements were used for 5 days before surgery and 7 days after surgery. The circulating levels of nutritional markers, immunoinflammatory markers, oxidative stress markers, and the antioxidant capacity were compared throughout the perioperative period, and the patients' clinical outcomes were also compared.

RESULTS

The circulating levels of nutritional markers decreased after surgery, but the changes were not significantly different between the AeEN group and the IeEN group throughout the perioperative period. Surgery increased the immunoinflammatory markers, and the levels were not significantly different between the groups after surgery. Surgery also increased the levels of oxidative stress markers, but there were no significant differences between the groups throughout the study period.

CONCLUSIONS

The results of this pilot study suggest that AeEN and IeEN have a similar effect on nutrition, the immunoinflammatory response, antioxidant capacity and clinical outcomes after esophagectomy for cancer. These findings, therefore, warrant further studies on a larger scale.

Review of Intravenous Selenium Infusions for the Critically III Patient

Attempts to improve mortality for patients with sepsis, severe sepsis, systemic inflammatory response syndrome, and septic shock continue to challenge health care professionals. This review will explore how the antioxidant, and possibly pro-oxidant, properties of selenium may benefit critically ill patients. Literature examining improvements in clinical outcomes from intravenous (IV) selenium infusion therapy will be discussed. Although there is not an overwhelming amount of knowledge about IV selenium and its effect on morbidity and mortality, this review will outline recent research evaluating the use of IV selenium infusions and its potential to decrease morbidity and mortality for different critically ill patient populations.

Glutamine randomized studies in early life: the unsolved riddle of experimental and clinical studies

Glutamine may have benefits during immaturity or critical illness in early life but its effects on outcome end hardpoints are controversial. Our aim was to review randomized studies on glutamine supplementation in pups, infants, and children examining whether glutamine affects outcome. Experimental work has proposed various mechanisms of glutamine action but none of the randomized studies in early life showed any effect on mortality and only a few showed some effect on inflammatory response, organ function, and a trend for infection control. Although apparently safe in animal models (pups), premature infants, and critically ill children, glutamine supplementation does not reduce mortality or late onset sepsis, and its routine use cannot be recommended in these sensitive populations. Large prospectively stratified trials are needed to better define the crucial interrelations of “glutamine-heat shock proteins-stress response” in critical illness and to identify the specific subgroups of premature neonates and critically ill infants or children who may have a greater need for glutamine and who may eventually benefit from its supplementation. The methodological problems noted in the reviewed randomized experimental and clinical trials should be seriously considered in any future well-designed large blinded randomized controlled trial involving glutamine supplementation in critical illness.

Selenium supplementation in the critically ill

Selenium (Se) is an essential trace element with antioxidant, immunological, and anti-inflammatory properties, which are attributed to its presence in selenoproteins, as the 21st amino acid selenocysteine. These selenoenzymes are involved in redox signaling, antioxidant defense, thyroid hormone metabolism, and immune responses. Dietary intakes differ considerably between geographical regions, due to variability of the Se food content, leading to differences in dietary reference intakes and toxicity cautions. Critical illness with systemic inflammatory response syndrome (SIRS) is characterized by Se depletion with high morbidity and mortality. Se status correlates well with clinical outcome in SIRS and may be useful as an early predictor of survival. Several investigators have evaluated the benefits of Se supplementation for the critically ill, either as monotherapy or in an antioxidant micronutrient combination. Pharmaconutrition, with high-dose Se (from 500-1600 µg/d) involving an initial loading bolus, followed by continuous infusion, appears to be safe and efficacious, with evidence that it can improve clinical outcome by reducing illness severity, infectious complications, and decreasing mortality in the intensive care unit (ICU). We now have a clearer understanding of the pharmacokinetics of the initial and transient pro-oxidant effect of an intravenous bolus of selenite and the antioxidant effect of continuous infusion. Better biomarkers to ascertain optimum Se requirements for individual patients are now needed, and clinical practice guidelines need improvement. Nevertheless, sufficient evidence is available to consider initiating high-dose intravenous Se therapy routinely in critically ill SIRS patients, immediately on admission to the ICU.

Effect of intravenous GLutamine supplementation IN Trauma patients receiving enteral nutrition study protocol (GLINT Study): a prospective, blinded, randomised, placebo-controlled clinical trial

Background Trauma patients are characterised by alterations in the immune system, increased exposure to infectious complications, sepsis and potentially organ failure and death. Glutamine supplementation to parenteral nutrition has been proven to be associated with improved clinical outcomes. However, glutamine supplementation in patients receiving enteral nutrition and its best route are still controversial. Previous trials have been limited by a small sample size, use of surrogate outcomes or a limited period of supplementation. The aim of this trial is to investigate if intravenous glutamine supplementation to trauma patients receiving enteral nutrition is associated with improved clinical outcomes in terms of decreased organ dysfunction, infectious complications and other secondary outcomes. Methods/design Eighty-eight critically ill patients with multiple trauma receiving enteral nutrition will be recruited in this prospective, triple-blind, block-randomised, placebo-controlled clinical trial to receive either 0.5 g/kg/day intravenous undiluted alanyl-glutamine or intravenous placebo by continuous infusion (24 h/day). Both groups will be receiving the same standard enteral nutrition protocol and the same standard intensive care unit care. Supplementation will continue until discharge from the intensive care unit, death or a maximum duration of 3 weeks. The primary outcome will be organ-dysfunction evaluation assessed by the pattern of change in sequential organ failure assessment score over a 10-day period. The secondary outcomes are: the changes in total sequential organ failure assessment score on the last day of treatment, infectious complications during the ICU stay, 60-day mortality, length of stay in the intensive care unit and body-composition analysis. Discussion This study is the first trial to investigate the effect of intravenous alanyl-glutamine supplementation in multiple trauma patients receiving enteral nutrition on reducing severity of organ failure and infectious complications and preservation of lean body mass. Trial registration number This trial is registered at http://www.clinicaltrials.gov. NCT01240291.

Thiamine supplementation in the critically ill

PURPOSE OF REVIEW

To summarize the properties of thiamine and evaluate current evidence on thiamine status and supplementation, for different populations of critically ill patients.

RECENT FINDINGS

Thiamine, in the form of thiamine pyrophosphate, is a critical co-factor in the glyocolysis and oxidative decarboxylation of carbohydrates for energy production. Different studies have shown that critical illness in adults and children is characterized by absolute or relative thiamine depletion, which is associated with an almost 50% increase in mortality. Thiamine deficiency should be suspected in different clinical scenarios such as severe sepsis, burns, unexplained heart failure or lactic acidosis, neurological disorder in patients with previous history of alcoholism, starvation, chronic malnutrition, long-term parenteral feeding, hyperemesis gravidarum, or bariatric surgery. Nonetheless, thiamine supplements are not routinely given to critically ill patients. Clinicians should be able to suspect and recognize risk factors for the occurrence of severe neurological disorders secondary to thiamine deficiency, as early treatment can prevent the appearance of permanent neurological damage.

SUMMARY

Symptoms and signs associated with thiamine deficiency lack sensitivity and specificity in critically ill patients. Consequently, depletion is frequently unrecognized and underdiagnosed by clinicians. Potentially deleterious consequences of thiamine depletion should be avoided by early and appropriate supplementation.

Tolerability and efficacy of a low-volume enteral supplement containing key nutrients in the critically ill

BACKGROUND & AIMS

To compare early supplementation with antioxidants and glutamine using a low-volume enteral supplement containing key nutrients to an energy adjusted standard elementary diet and to investigate its effect on clinical efficacy and tolerability in critically ill patients with sepsis/SIRS. The primary endpoints were length of stay in the ICU and sufficient enteral feed.

METHODS

This was a randomized, prospective, single-blind, controlled study in 58 critically ill patients (56.9% male, mean age 46.7 years, mean APACHE II score 21.6). They received either a low-volume enteral supplement containing key nutrients or a diluted standard nutrition solution. After 10 or 14 days inflammatory parameters, catecholamine need, and maximal enteral delivery were determined.

RESULTS

Patients receiving a low-volume enteral supplement containing key nutrients did not reach sufficient enteral feed more often than controls (76 vs. 62%, respectively, p = 0.17). The difference in vitamin E and selenium uptake was higher in the treatment group than controls (12.4 vs. 3.7 and 54.7 vs. 16.3, respectively, p ≤ 0.011). Parameters such as fever, antibiotic treatment, artificial ventilation, and death were comparable. This was also true for days of ICU or hospital stay (33 ± 23 and 49 ± 34 days, respectively).

CONCLUSIONS

The low-volume enteral supplement containing key nutrients was well tolerated and led to a better vitamin E and selenium supply. However, it did not affect length of ICU or hospital stay. Further studies are necessary to determine which disease-specific subgroups may benefit from this supplementation or which group may be harmed.

Congestive heart failure: where homeostasis begets dyshomeostasis

Despite today's standard of care, aimed at preventing homeostatic neurohormonal activation, one in every five patients recently hospitalized with congestive heart failure (CHF) will be readmitted within 30 days of discharge because of a recurrence of their symptoms and signs. In light of recent pathophysiological insights, it is now propitious to revisit CHF with a view toward complementary and evolving management strategies. CHF is a progressive systemic illness. Its features include: oxidative stress in diverse tissues; an immunostimulatory state with circulating proinflammatory cytokines; a wasting of soft tissues; and a resorption of bone. Its origins are rooted in homeostatic mechanisms gone awry to beget dyshomeostasis. For example, marked excretory losses of Ca2+ and Mg2+ accompany renin-angiotensin-aldosterone system activation, causing ionized hypocalcemia and hypomagnesemia that lead to secondary hyperparathyroidism with consequent bone resorption and a propensity to atraumatic fractures. Parathyroid hormone accounts for paradoxical intracellular Ca2+ overloading in diverse tissues and consequent systemic induction of oxidative stress. In cardiac myocytes and mitochondria, these events orchestrate opening of the mitochondrial permeability transition pore with an ensuing osmotic-based destruction of these organelles and resultant cardiomyocyte necrosis with myocardial scarring. Contemporaneous with Ca2+ and Mg2+ dyshomeostasis is hypozincemia and hyposelenemia, which compromise metalloenzyme-based antioxidant defenses, whereas hypovitaminosis D threatens Ca2+ stores needed to prevent secondary hyperparathyroidism. An intrinsically coupled dyshomeostasis of intracellular Ca2+ and Zn2+, representing pro-oxidant and antioxidant, respectively, is integral to regulating the mitochondrial redox state; it can be uncoupled by a Zn2+ supplement in favor of antioxidant defenses. Hence, the complementary use of nutriceuticals to nullify dyshomeostatic responses involving macro- and micronutrients should be considered. Evolving strategies with mitochondria-targeted interventions interfering with their uptake of Ca2+ or serving as selective antioxidant or mitochondrial permeability transition pore inhibitor may also prove efficacious in the overall management of CHF.

Nutritional support of the pediatric trauma patient

Of all the interventions available to aid recovery of the injured child, few have the power of proper nutritional support. Healing after trauma depends not only on restoration of oxygen delivery, but on "substrate delivery," or provision of calories to support metabolic power and specific nutrients to allow rebuilding of injured tissue. Failure to deliver adequate substrate to the cells is revealed as another form of shock. Nutritional interventions after trauma are most effective when informed by the specific ways that children diverge physiologically (metabolic rate, biomechanics, physiological response to trauma) from adults. This review describes these responses and outlines a general strategy for safely delivering energy and specific substrates to protect and heal injured children, regardless of body size and type of injury.

Uncoupling the coupled calcium and zinc dyshomeostasis in cardiac myocytes and mitochondria seen in aldosteronism

Intracellular [Ca2+]i overloading in cardiomyocytes is a fundamental pathogenic event associated with chronic aldosterone/salt treatment (ALDOST) and accounts for an induction of oxidative stress that leads to necrotic cell death and consequent myocardial scarring. This prooxidant response to Ca2+ overloading in cardiac myocytes and mitochondria is intrinsically coupled to simultaneous increased Zn2+ entry serving as an antioxidant. Herein, we investigated whether Ca2+ and Zn2+ dyshomeostasis and prooxidant to antioxidant dysequilibrium seen at 4 weeks, the pathologic stage of ALDOST, could be uncoupled in favor of antioxidants, using cotreatment with a ZnSO4 supplement; pyrrolidine dithiocarbamate (PDTC), a Zn2+ ionophore; or ZnSO4 in combination with amlodipine (Amlod), a Ca2+ channel blocker. We monitored and compared responses in cardiomyocyte free [Ca2+]i and [Zn2+]i together with biomarkers of oxidative stress in cardiac myocytes and mitochondria. At week 4 of ALDOST and compared with controls, we found (1) an elevation in [Ca2+]i coupled with [Zn2+]i and (2) increased mitochondrial H2O2 production and increased mitochondrial and cardiac 8-isoprostane levels. Cotreatment with the ZnSO4 supplement alone, PDTC, or ZnSO4+Amlod augmented the rise in cardiomyocyte [Zn2+]i beyond that seen with ALDOST alone, whereas attenuating the rise in [Ca2+]i, which together served to reduce oxidative stress. Thus, a coupled dyshomeostasis of intracellular Ca2+ and Zn2+ was demonstrated in cardiac myocytes and mitochondria during 4-week ALDOST, where prooxidants overwhelm antioxidant defenses. This intrinsically coupled Ca2+ and Zn2+ dyshomeostasis could be uncoupled in favor of antioxidant defenses by selectively increasing free [Zn2+]i and/or reducing [Ca2+]i using cotreatment with ZnSO4 or PDTC alone or ZnSO4+Amlod in combination.

Advancing from immunonutrition to a pharmaconutrition: a gigantic challenge

PURPOSE OF REVIEW

This review presents some difficulties encountered to develop and translate immunonutrition into clinical practice, and suggests moving forward to a pharmaconutrition approach.

RECENT FINDINGS

Immunonutrition suffers from inconclusive and contradictory data due to the design of many of experiments and clinical studies conducted so far. The concept of a single immunonutrient formula applicable to various types of patients has also contributed to leave the medical world in a state of uncertainty. We propose to move forward to the concept of pharmaconutrition where a disease-dedicated nutrition therapy is developed following a rigorous step-by-step procedure. Nutrients are selected according to their pharmacological properties and after an in-depth evaluation of their biological interactions when mixed together. The optimum administration schedule (i.e. dose, route, timing and duration) of the new formulae is then determined in well conducted projective clinical trials where it is administered apart from the standard nutrition to ensure full delivery of the expected doses.

SUMMARY

This review suggests moving forward to a pharmaconutrition approach where a rigorous step-by-step procedure would allow overcoming of the difficulties encountered to translate immunonutrition into clinical practice.

Selenium supplementation in the critically ill: posology and pharmacokinetics

PURPOSE OF REVIEW

To analyze current evidence for the posology and pharmacokinetics of selenium supplementation in the critically ill.

RECENT FINDINGS

Antioxidants and especially high-dose parenteral selenium may be associated with a significant reduction in mortality among critically ill patients with systemic inflammatory response syndrome (SIRS). Selenium seems to be a cornerstone of the antioxidant defense in SIRS patients. In the past few years, several clinical studies have evaluated the effect of selenium (as sodium selenite) in monotherapy or as part of a multimicronutrient approach, on relevant end points for the critically ill. However, the results from these studies have sometimes been contradictory. We now have a better understanding of the pharmacokinetics of the transient prooxidant effect of an intravenous (i.v.) bolus followed by the antioxidant effect of continuous infusion, which seems efficacious and well tolerated. Clinical confirmation of the potentially advantageous synergism between selenium and glutamine may soon be forthcoming, but the most appropriate and the optimum time of supplementation remains undetermined.

SUMMARY

This review summarizes current knowledge on selenium supplementation in the critically ill. High-dose i.v. selenite as a bolus injection plus continuous infusion appears well tolerated and optimizes selenium plasma levels and antioxidant selenoenzymes activities. Additional investigations into the posology and pharmacokinetic profile of selenium are still required. Further studies should aim to demonstrate a definitive benefit of i.v. selenite, alone or in combination, on antioxidant capacity and mortality in the critically ill.