REducing Deaths due to OXidative Stress (The REDOXS Study): Rationale and study design for a randomized trial of glutamine and antioxidant supplementation in critically-ill patients

[Nutrition practices in intensive care units: nutritionDay from 2007-2021]

In intensive care units (ICU), patients who are not able to eat or are considered at nutritional risk typically receive medical nutrition therapy based on partially contradictory guidelines as well as the strategies used in large randomized trials. The aim of this study is to analyze patient data from the nutritionDay project in intensive care to describe current clinical approaches to nutrition support worldwide, in Europe and in the group of German-speaking countries, the DACH (i.e., Germany, Austria, Switzerland) region. From 2007-2021, data of 18,918 adult patients in 1595 ICUs from 63 different countries were included in this cross-sectional study. The aim was to recruit all patients present in ICUs. Median stay in the ICU was 4 days on nutritionDay. Little difference in patient characteristics were observed between worldwide, Europe, and the DACH region. Patient were 64 years old, 40% female, 50% ventilated, 29% sedated, and 10% needed renal replacement therapy. A quarter of the patients died in hospital within 60 days and about half of the patients had been discharged home. Enteral nutrition was given twice as frequently as parenteral nutrition (48% versus 24%). Many patients received oral nutrition (39%) and a substantial number received no nutrition support (10%). Parenteral nutrition was used more frequently in Europe than in other world regions, the lowest use being observed in North America. The amount of nutrition given is very similar in all regions regardless of the nutrition route with about 1500 kcal and 60 g of protein per day. A clear association with body weight was not observed and the variation around the median was very large with half of patients receiving amounts 25% below or above the median. Upon completion of data entry, the nutritionDay project allows each ICU to download a unit report summarizing data that allows comparison with worldwide data in numeric and graphical form to permit easy benchmarking of medical nutrition therapy.

Ethics of ECPR research

The design of emergency medicine trials can raise several ethical concerns - risks may be greater, and randomisation may have to occur before consent. Research in emergency medicine is thus an illuminating context to explore the interplay between risk and randomisation, and the consequences for consent. Using a currently running trial, we describe possible concerns, considerations, and solutions to reconcile the conflicting interests of scientific inquiry, ethical principles, and clinical reality in emergency medicine research.

Bovine Immunology: Implications for Dairy Cattle

The growing world population (7.8 billion) exerts an increased pressure on the cattle industry amongst others. Intensification and expansion of milk and beef production inevitably leads to increased risk of infectious disease spread and exacerbation. This indicates that improved understanding of cattle immune function is needed to provide optimal tools to combat the existing and future pathogens and improve food security. While dairy and beef cattle production is easily the world's most important agricultural industry, there are few current comprehensive reviews of bovine immunobiology. High-yielding dairy cattle and their calves are more vulnerable to various diseases leading to shorter life expectancy and reduced environmental fitness. In this manuscript, we seek to fill this paucity of knowledge and provide an up-to-date overview of immune function in cattle emphasizing the unresolved challenges and most urgent needs in rearing dairy calves. We will also discuss how the combination of available preventative and treatment strategies and herd management practices can maintain optimal health in dairy cows during the transition (periparturient) period and in neonatal calves.

Selenium and Selenoprotein P Deficiency Correlates With Complications and Adverse Outcome After Major Trauma

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Background:

A declining selenium (Se) status constitutes a characteristic of critical illness and may affect disease course and survival. The dynamics of trauma-induced changes in biomarkers of Se status are poorly characterized, and an association with multiple organ failure (MOF) and mortality can be hypothesized. It was the aim of this study to investigate Se and selenoprotein P (SELENOP) concentrations in major trauma patients during the early posttraumatic period.

Patients and Methods:

Twenty-four patients after major trauma (ISS ≥16) were included at our level one trauma center. Se supplementation ever during the 90-day observation period was defined as an exclusion criterion. Serum samples were drawn within less than 60 min after trauma, and after 6 h, 12 h, 24 h, 48 h, and 72 h. Serum Se was analyzed by X-ray fluorescence and SELENOP concentrations by ELISA. The data were correlated to clinical parameters, occurrence of MOF defined by MOF and APACHE II score, lung injury defined by Horowitz index and clinical outcome (90-days survival).

Results:

Serum Se and SELENOP concentrations of the trauma patients were significantly below the average of healthy European subjects (mean ±SD; Se, 41.2±8.1 vs. 84.7±23.3 μg/L, P < 0.001; SePP, 1.5±0.3 vs. 4.3±1.0 mg/L, P < 0.001). A strong deficit was present already at the first time point (Se; 33.6±10.5 μg/L, SELENOP: 1.4±0.5 mg/L). The clinical scores collectively showed an inverse relation between health status and Se biomarkers. Patients who did not survive the 90-day observation period exhibited significantly lower initial post-trauma Se status than the surviving patients (mean±SD; Se, 24.7±7.2 vs. 39.2±8.4 μg/L, P<0.05; SePP, 1.1±0.4 vs. 1.6±0.4 mg/L, P<0.05).

Conclusion:

Very low Se and SELENOP concentrations occur fast after major trauma and are associated with poor survival odds. These findings support the notion that early Se substitution may constitute a meaningful adjuvant treatment strategy in trauma patients.

The Relevance of Selenium Status in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune and inflammatory disease that can cause joint damage. Among the environmental risk factors, diet plays an important role because it can aggravate or attenuate inflammation. Selenium (Se) is considered an essential trace element since it is a structural component of antioxidant enzymes; however, its concentration can be affected by diet, drugs and genetic polymorphisms. Studies have reported that RA patients have a deficient diet in some food groups that is associated with parameters of disease activity. Furthermore, it has been shown that there is an alteration in serum Se levels in this population. Although some clinical trials have been conducted in the past to analyze the effect of Se supplementation in RA, no significant results were obtained. Contrastingly, experimental studies that have evaluated the effect of novel Se nanoparticles in RA-induced models have shown promising results on the restoration of antioxidant enzyme levels. In particular, glutathione peroxidase (GPx) is an important selenoprotein that could have a modulating effect on inflammation in RA. Considering that RA patients present an inflammatory and oxidative state, the aim of this review is to give an overview of the current knowledge about the relevance of Se status in RA.

Volume Resuscitation in Patients With High-Voltage Electrical Injuries

Volume resuscitation of patients with high-voltage electrical injuries (>1000 V) is a more complex challenge than standard burn resuscitation. High voltages penetrate deep tissues. These deep injuries are not accounted for in resuscitation formulae dependent on percentage of cutaneous burn. Myonecrosis occurring from direct electrical injury and secondary compartment syndromes can result in rhabdomyolysis, compromising renal function and urine output. Urine output is the primary end point, with a goal of 1 mL/kg/h for adult patients with high-voltage electrical injuries. As such, secondary resuscitation end points of laboratory values, such as lactate, base deficit, hemoglobin, and creatinine, as well as hemodynamic monitoring, such as mean arterial pressure and thermodilution techniques, can become crucial in guiding optimum administration of resuscitation fluids. Mannitol and bicarbonates are available but have limited support in the literature. High-voltage electrical injury patients often develop acute kidney injury requiring dialysis and have increased risks of chronic kidney disease and mortality. Continuous venovenous hemofiltration is a well-supported adjunct to clear the myoglobin load that hemodialysis cannot from circulation.

Safety and efficacy of adding intravenous N-acetylcysteine to parenteral L-alanyl-L-glutamine in hospitalized patients undergoing surgery of the colon: a randomized controlled trial

BACKGROUND

Colon surgery can cause systemic inflammatory response syndrome (SIRS). There is a recent trend towards the use of antioxidant agents in the prevention or alleviation of the severity of postoperative SIRS, but its use is controversial as studies have shown conflicting results.

OBJECTIVES

Investigate the efficacy and tolerability of perioperative intravenous administration of N-acetylcysteine (NAC) as an antioxidant and anti-inflammatory agent in patients undergoing colon surgery.

DESIGN

Randomized, double-blinded, and controlled clinical trial.

SETTING

Surgical critical care unit in Egypt.

PATIENTS AND METHODS

Sixty patients who required admission to the ICU following colon surgery were enrolled in the study between July 2015 and October 2016. Eligibility included the need for parenteral nutrition for at least 5 days due to failure of or contraindication to enteral nutrition. Patients were randomly allocated using a computer-generated list to a loading dose of NAC followed by continuous infusion started one hour prior to induction, and continued over 48 hours, or to the control group, who received the same volume of dextrose 5%. Allocation was concealed using opaque, sealed envelopes under pharmacy control. The researcher, the anesthesiologist, the surgeon, and patients were blinded to the treatment allocation.

MAIN OUTCOME MEASURES

Clinical and laboratory evaluation for manifestations of SIRS, serum levels of tumor necrosis factor alpha and malondialdehyde, and occurrence of side effects in the study group.

SAMPLE SIZE

60 patients with mean (SD) ages of 56 (15.1) years in the study group (n=30) and 57.7 (12.3) years in the control group (n=30).

RESULTS

There was a significant difference in the mean serum level of ALT (22.6 (9.9) U/L in the study group vs. 31.1 (17.8) U/L in the control group, P=.028) after treatment with NAC, but differences between the groups in the serum level of tumor necrosis factor alpha and malondialdehyde after treatment were not significant. Serum levels of malondialdehyde increased in both groups after treatment P<.001. There was no statistically significant difference from baseline or between the groups after treatment in other clinical data and laboratory parameters following NAC administration, and only 6.6% of the patients in the study group experienced mild side effects.

CONCLUSIONS

Preoperative administration of NAC is safe, but its efficacy as an antioxidant and anti-inflammatory agent was not statistically significant and requires further investigation in a larger sample.

LIMITATIONS

Single-center study, small sample size, and short duration of NAC administration.

CLINICAL TRIALS REGISTRY

NCT03589495.

CONFLICT OF INTEREST

None.

Effects of different ascorbic acid doses on the mortality of critically ill patients: a meta-analysis

BACKGROUND

Low levels of ascorbic acid (AA) have been detected in critically ill patients in which AA supplementation leads to promising outcomes. However, the ability of AA to reduce mortality in critically ill patients remains controversial. In this study, we have performed a meta-analysis to evaluate the effects of AA dose on the mortality of critically ill adults.

METHODS

Electronic databases were searched for trials in which AA had been intravenously administered to critically ill patients regardless of the dose or the co-administration of antioxidant agents. The predefined primary outcome included all-cause mortality at final follow-up.

RESULTS

The included trials enrolled a total of 1210 patients. Intravenous (IV) AA doses of 3-10 g/d reduced the mortality of critically ill patients (OR 0.25; 95% CI (0.14-0.46); p < 0.001; I2 = 0.0%), while low (< 3 g/d) and high AA doses (≥ 10 g/d) had no effect (OR 1.44; 95% CI (0.79-2.61); p = 0.234; I2 = 0.0% versus OR 1.12; 95% CI (0.62-2.03); p = 0.700; I2 = 0.0%). AA was associated with a decreased duration of vasopressor support and mechanical ventilation, but did not influence fluid requirement or urine output during the first 24 h of admission. The number of patients suffering from acute kidney injury and the length of intensive care unit or hospital stays were also unaffected by the AA.

CONCLUSION

Intravenous AA reduces the duration of vasopressor support and mechanical ventilation; 3-10 g AA results in lower overall mortality rates. Given the limitations of the primary literature, further studies are required to fully clarify the effectiveness of AA during the management of critically ill patients.

The Renal Safety of L-Carnitine, L-Arginine, and Glutamine in Athletes and Bodybuilders

One of the major concerns about taking amino acid supplements is their potential adverse effects on the kidney as a major organ involved in the metabolism and excretion of exogenous substances. The aim of this study is to review available data about renal safety of the most prominent amino acid supplements including L-arginine, glutamine and also L-carnitine as well as creatine (as amino acid derivatives) in athletes and bodybuilders. The literature was searched by keywords such as "L-carnitine", "L-arginine", "glutamine", and "kidney injury" in databases such as Scopus, Medline, Embase, and ISI Web of Knowledge. Articles published from 1950 to December 2017 were included. Among 3171, 5740, and 1608 records after primary search in the relevant databases, 8, 7, and 5 studies have been finally included, respectively, for L-carnitine, L-arginine, and glutamine in this review. Arginine appears to have both beneficial and detrimental effects on kidney function. However, adverse effects are unlikely to occur with the routine doses (from 3 to >100 g/day). The risks and benefits of L-carnitine on the athletes' and bodybuilders' kidney have not been evaluated yet. However, L-carnitine up to 6000 mg/day is generally considered to be a safe supplement at least in healthy adults. Both short-term (20-30 g within a few hours) and long-term (0.1 g/kg four times daily for 2 weeks) glutamine supplementation in healthy athletes were associated with no significant adverse effects, but it can cause glomerulosclerosis and serum creatinine level elevation in the setting of diabetic nephropathy. Creatine supplementation (ranged from 5 to 30 g/day) also appears to have no detrimental effects on kidney function of individuals without underlying renal diseases. More clinical data are warranted to determine the optimal daily dose and intake duration of common supplemental amino acids associated with the lowest renal adverse effects in sportsmen and sports women.

Trace element repletion following severe burn injury: A dose-finding cohort study

BACKGROUND & AIMS

Major burn patients are characterized by large exudative losses of Cu, Se and Zn. Trace element (TE) repletion has been shown to improve clinical outcome. Having increased the TE doses over time, the study aimed at analysing if our repletion protocol corrected TE plasma concentrations and if the necessity for continuous renal replacement therapy (CRRT) might increase the TE needs.

METHODS

Retrospective analysis of prospectively collected data in burn patients requiring intensive care (ICU) between 1999 and 2015.

INCLUSION CRITERIA

Admission on day 1, full treatment, burned surface area (TBSA) ≥20% and ≥1 TE plasma determination during the stay. Four groups were constituted according to protocol changes. Period 1 (P1): 1999-2000, P2: 2001-2005, P3: 2006-2010, P4: 2011-2015. Changes consisted in increasing TE repletion doses and duration. Demographic data, daily TE intakes and weekly plasma concentrations were retrieved for the first 21 ICU-days. Data as median (IQR).

RESULTS

139 patients completed the criteria, aged 37 (28) years, burned on 35 (25) % TBSA. As a result of prescription, Cu, Se and Zn intakes increased significantly between P1 and P4, resulting in normalization of plasma Cu (16 μmol/l) since P3 and Zn (13.5 μmol/l) since P2. Median plasma Se were above reference range (1400 nmol/l) during P3 and P4. CRRT patients required higher doses of Cu for maintenance within normal ranges.

CONCLUSION

This dose finding study shows that the latest repletion protocol is safe and normalizes Cu and Zn concentrations. Se doses result in supra-normal Se concentrations, suggesting prescription reduction. CRRT patients are at high risk of Cu depletion and require specific monitoring.

Assessment of the innate immune response in the periparturient cow

The transition period is the most critical phase in the life of high yielding dairy cows. Within a few weeks, cows are submitted to many challenges (physiological, nutritional, psychological, management) that require prompt and effective adaptive responses. The immune system is involved in this process, and many changes of the cow's immune system components have been observed around calving. Cows are considered to be immunosuppressed in late lactation, and available data suggest that the immune system is dysregulated around parturition. Significant attention has been focused on modification of cellular functions (e.g. the reduction of phagocytosis and diapedesis), but growing interest concerns the components of the innate immune system, which often exhibits increased responses such as susceptibility to inflammatory events and the related acute phase response (APR). Systemic inflammation plays a significant role in early lactation, affects many liver functions and has been associated with the impairment of cow performance (i.e. reduced feed intake, milk yield, fertility, welfare). The assessment of variations in immune-metabolic indices offers opportunities to predict the onset of the health troubles and to anticipate the proper therapies needed to guarantee health, good welfare and fertility in the following lactation. The frequency of diseases (metabolic and infectious) before calving is rare, but several clues suggest that various metabolic and immune variations can begin during the dry period. Interesting preliminary results encourage this perspective and possible candidates are suggested.

Efficacy of commercial formulas in comparison with home-made formulas for enteral feeding: A critical review

Background: In several disease conditions, patients must inevitably be nourished by enteral feeding (EF). Though in many countries, commercial formulas are routinely used for EF, in Iran still home-made formulas are commonly employed as commercial formulas are not covered by insurance. This may pose patients to malnutrition and bring about further costs. The aim of this study was to evaluate the efficacy of EF commercial formulas in comparison with home-made formulas and thus to make further evidence for insurance policy-making

Methods: Medline, Cochrane, Embass and Center for Review & Dissemination (CRD) as well as IranDoc and SID databases were searched. Keywords included formula, ICU, and enteral nutrition or tube feeding. No clinical trial study on the efficacy of EF formulas was found. Therefore, the compositions of available formulas and their cost-effectiveness were evaluated based on the clinical guidelines of scientific bodies such as American Society for Parenteral and Enteral Nutrition (ASPEN), European Society for Parenteral and Enteral Nutrition (ESPEN) and relative articles available in PubMed. In addition, the expert opinions were also taken into consideration.

Results: Domestic commercial formulas seemed to less merit dietary recommended intakes, i.e. the amount of some nutrients were much higher, and some others were much lower than the recommended values. The amount of several micronutrients including vitamins B1, B6, C, D and K, as well as iron, calcium and magnesium were not sufficient to meet the body needs in most commercial formulas upon receiving 2000 kilocalories and less.

Conclusion: Clinical studies on the efficacy of commercial formulas in comparison with home-made formulas are needed. Meanwhile, making suitable conditions for increasing the diversity of artificial nutrition products in the market would help clinical nutritionists to make better choices according to their patients conditions and to reduce the costs, as well.

Glutamine prevents oxidative stress in a model of portal hypertension

AIM

To evaluate the protective effects of glutamine in a model of portal hypertension (PH) induced by partial portal vein ligation (PPVL).

METHODS

Male Wistar rats were housed in a controlled environment and were allowed access to food and water ad libitum. Twenty-four male Wistar rats were divided into four experimental groups: (1) control group (SO) - rats underwent exploratory laparotomy; (2) control + glutamine group (SO + G) - rats were subjected to laparotomy and were treated intraperitoneally with glutamine; (3) portal hypertension group (PPVL) - rats were subjected to PPVL; and (4) PPVL + glutamine group (PPVL + G) - rats were treated intraperitoneally with glutamine for seven days. Local injuries were determined by evaluating intestinal segments for oxidative stress using lipid peroxidation and the activities of glutathione peroxidase (GPx), endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) after PPVL.

RESULTS

Lipid peroxidation of the membrane was increased in the animals subjected to PH (P < 0.01). However, the group that received glutamine for seven days after the PPVL procedure showed levels of lipid peroxidation similar to those of the control groups (P > 0.05). The activity of the antioxidant enzyme GTx was decreased in the gut of animals subjected to PH compared with that in the control group of animals not subjected to PH (P < 0.01). However, the group that received glutamine for seven days after the PPVL showed similar GTx activity to both the control groups not subjected to PH (P > 0.05). At least 10 random, non-overlapping images of each histological slide with 200 × magnification (44 pixel = 1 μm) were captured. The sum means of all areas, of each group were calculated. The mean areas of eNOS staining for both of the control groups were similar. The PPVL group showed the largest area of staining for eNOS. The PPVL + G group had the second highest amount of staining, but the mean value was much lower than that of the PPVL group (P < 0.01). For iNOS, the control (SO) and control + G (SO + G) groups showed similar areas of staining. The PPVL group contained the largest area of iNOS staining, followed by the PPVL + G group; however, this area was significantly smaller than that of the group that underwent PH without glutamine (P < 0.01).

CONCLUSION

Treatment with glutamine prevents gut mucosal injury after PH in rats.

Amelioration of energy metabolism by melatonin in skeletal muscle of rats with LPS induced endotoxemia

In the literature, few studies have investigated the effects of melatonin on energy metabolism in skeletal muscle in endotoxemia. We investigated the effects of melatonin on tissue structure, energy metabolism in skeletal muscle, and antioxidant level of rats with endotoxemia. We divided rats into 4 groups, control, lipopolysaccharide (LPS) (20 mg/kg, i.p., single dose), melatonin (10 mg/kg, i.p., three times), and melatonin + LPS. Melatonin was injected i.p. 30 min before and after the 2nd and 4th hours of LPS injection. Antioxidant status was determined by glutathione (GSH) measurement in the blood. Muscle tissue was stained using modified Gomori trichrome (MGT), succinic dehydrogenase (SDH), and cytochrome oxidase (COX) and histological scored. Also the sections were then stained with hematoxylin and eosin. The stained sections were visualized and photographed. Creatine, creatine phosphate, adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP) levels were investigated using high performance liquid chromatography (HPLC) in muscle tissue. In the Melatonin + LPS group, blood GSH levels were increased compared with the LPS group (P<0.01). Melatonin reduced myopathic changes in the LPS group according to the histopathologic findings. In addition, ATP values were increased compared with the LPS group (P<0.05). Our findings showed melatonin treatment prevented muscle damage by increasing ATP and GSH levels in rats with LPS induced endotoxemia.

Postinjury Inflammation and Organ Dysfunction

The development of organ dysfunction (OD) is related to the intensity and balance between trauma-induced simultaneous, opposite inflammatory responses. Early proinflammation via innate immune system activation may cause early OD, whereas antiinflammation, via inhibition of the adaptive immune system and apoptosis, may induce immunoparalysis, impaired healing, infections, and late OD. Patients discharged with low-level OD may develop the persistent inflammation-immunosuppression catabolism syndrome. Although the incidence of multiple organ failure has decreased over time, it remains morbid, lethal, and resource intensive. However, single OD, especially acute lung injury, remains frequent. Treatment is limited, and prevention remains the mainstay strategy.

Pediatric Multiple Organ Dysfunction Syndrome: Promising Therapies

OBJECTIVE

To describe the state of the science, identify knowledge gaps, and offer potential future research questions regarding promising therapies for children with multiple organ dysfunction syndrome presented during the Eunice Kennedy Shriver National Institute of Child Health and Human Development Workshop on Pediatric Multiple Organ Dysfunction Syndrome (March 26-27, 2015).

DATA SOURCES

Literature review, research data, and expert opinion.

STUDY SELECTION

Not applicable.

DATA EXTRACTION

Moderated by an expert from the field, issues relevant to the association of multiple organ dysfunction syndrome with a variety of conditions were presented, discussed, and debated with a focus on identifying knowledge gaps and research priorities.

DATA SYNTHESIS

Summary of presentations and discussion supported and supplemented by relevant literature.

CONCLUSIONS

Among critically ill children, multiple organ dysfunction syndrome is relatively common and associated with significant morbidity and mortality. For outcomes to improve, effective therapies aimed at preventing and treating this condition must be discovered and rigorously evaluated. In this article, a number of potential opportunities to enhance current care are highlighted including the need for a better understanding of the pharmacokinetics and pharmacodynamics of medications, the effect of early and optimized nutrition, and the impact of effective glucose control in the setting of multiple organ dysfunction syndrome. Additionally, a handful of the promising therapies either currently being implemented or developed are described. These include extracorporeal therapies, anticytokine therapies, antitoxin treatments, antioxidant approaches, and multiple forms of exogenous steroids. For the field to advance, promising therapies and other therapies must be assessed in rigorous manner and implemented accordingly.

Optimizing the Dose of Glutamine Dipeptides and Antioxidants in Critically Ill Patients: A Phase I Dose-Finding Study

BACKGROUND

Supplementation with glutamine and antioxidants may be associated with an improvement in clinical outcomes, but the optimal dose of these substrates is unknown. The purpose of this study was to determine the safety of high doses of glutamine combined with antioxidants in critically ill patients.

METHODS

We conducted a single-center, open-label, dose-escalating clinical trial. Mechanically ventilated adult patients with clinical evidence of hypoperfusion were sequentially enrolled to 1 of 5 groups. Group 1 (n = 30): no supplementation; group 2 (n = 7): 0.35 g/kg/d of glutamine IV; group 3 (n = 7): same as group 2 plus 15 g/d of glutamine and 150 microg of selenium enterally; group 4 (n = 7): same as group 2 plus 30 g/d of glutamine and 300 microg of selenium enterally; and group 5 (n = 7): same as group 4 plus an additional 500 microg of selenium IV. After enrollment, nutrients were started as soon as possible. All patients were fed enterally according to clinical practice guidelines.

RESULTS

The primary outcomes for this study were change in sequential organ function assessment (SOFA) score and safety parameters. Secondary outcomes included whole blood glutathione (GSH), thiobarbituric acid reactive substances (TBARS), and blood cells' mitochondrial DNA/nuclear DNA ratio (RATIO). There were no adverse events attributable to the study nutrients, and the maximum and Delta SOFA did not differ across groups. In group 2, a significant decrease in GSH levels was observed (p = .03). With subsequent groups, the slopes straighten out and the p values are no longer significant, suggesting a greater preservation of GSH levels with escalating doses. In group 2, the slope of the line representing TBARS was horizontal. With subsequent groups, the slopes decrease, and by group 5, this decrease reaches statistical significance (p = .03), suggesting a greater reduction in oxidative stress with the higher doses in group 5. The difference in slopes across all groups describing the mitochondrial RATIO is statistically significant (p = .001), again suggesting that, with higher doses, there is increased mitochondrial function.

CONCLUSIONS

The doses of glutamine and antioxidants tested in this study seem to be safe and may have positive effects on some mechanistic endpoints. A larger trial will be necessary to confirm their therapeutic effects.

Nutrition: A Primary Therapy in Pediatric Acute Respiratory Distress Syndrome

Appropriate nutrition is an essential component of intensive care management of children with acute respiratory distress syndrome (ARDS) and is linked to patient outcomes. One out of every two children in the pediatric intensive care unit (PICU) will develop malnutrition or have worsening of baseline malnutrition and present with specific micronutrient deficiencies. Early and adequate enteral nutrition (EN) is associated with improved 60-day survival after pediatric critical illness, and, yet, despite early EN guidelines, critically ill children receive on average only 55% of goal calories by PICU day 10. Inadequate delivery of EN is due to perceived feeding intolerance, reluctance to enterally feed children with hemodynamic instability, and fluid restriction. Underlying each of these factors is large practice variation between providers and across institutions for initiation, advancement, and maintenance of EN. Strategies to improve early initiation and advancement and to maintain delivery of EN are needed to improve morbidity and mortality from pediatric ARDS. Both, over and underfeeding, prolong duration of mechanical ventilation in children and worsen other organ function such that precise calorie goals are needed. The gut is thought to act as a "motor" of organ dysfunction, and emerging data regarding the role of intestinal barrier functions and the intestinal microbiome on organ dysfunction and outcomes of critical illness present exciting opportunities to improve patient outcomes. Nutrition should be considered a primary rather than supportive therapy for pediatric ARDS. Precise nutritional therapies, which are titrated and targeted to preservation of intestinal barrier function, prevention of intestinal dysbiosis, preservation of lean body mass, and blunting of the systemic inflammatory response, offer great potential for improving outcomes of pediatric ARDS. In this review, we examine the current evidence regarding dose, route, and timing of nutrition, current recommendations for provision of nutrition to children with ARDS, and the current literature for immune-modulating diets for pediatric ARDS. We will examine emerging data regarding the role of the intestinal microbiome in modulating the response to critical illness.

Anti-Inflammatory Effect of Taurine in Burned Patients

PURPOSE

Burn induced inflammatory response can be mediated by reactive oxygen metabolites and accompanied by multiple organ dysfunction. Taurine has protective effects against various inflammatory conditions. The aim of this study was to determine the effect of Taurine supplement in thermal burn victims.

METHODS

Thirty patients with severe thermal burns were enrolled in this randomized double-blinded clinical trial. These patients were randomly divided into two equal groups (namely Control and Taurine groups), where both received isocaloric and isonitrogenous formula. One group was supplemented with 50 mg/kg of Taurine per day for a duration of 10 days. Blood samples were obtained to measure Interleukin-10 (IL-10), high-sensitivity C-reactive protein (hs-CRP), and Tumor Necrosis Factor alpha (TNF-α) levels at the beginning and the end of the study.

RESULTS

Change in serum level of IL-10 in Taurine group was more than Control group [-13.60(-31.40, -10.40) compared to -4.00(-20.00, -0.20) respectively; P = 0.030]. This change was significant in patients with more than 30% TBSA of burn [-14.20(-31.40, -10.40) compared to -2.40(-9.60, 0.40) respectively; P = 0.013]. As for the hs-CRP and TNF-α levels, the difference between the two groups were not significant.

CONCLUSION

Based on the results obtained, Taurine supplement showed a positive outcome on anti-inflammatory cytokine IL-10 in all burn patients. This effect was even more significant in patients with higher percentage of burn area. Taurine had no significant effect on the inflammatory marker hs-CRP and the pro-inflammatory cytokine TNF-α level. For a more thorough verification, measurement of a wider range of inflammatory cytokines in more frequent time intervals are suggested.

The Association Between Nutritional Adequacy and Long-Term Outcomes in Critically Ill Patients Requiring Prolonged Mechanical Ventilation: A Multicenter Cohort Study

OBJECTIVE

To examine the association between short-term nutritional adequacy received while in the ICU and long-term outcomes including 6-month survival and health-related quality of life in critically ill patients requiring prolonged mechanical ventilation.

DESIGN

Retrospective analysis of data prospectively collected in the context of a multicenter randomized controlled trial.

SETTING

An international sample of ICUs.

PATIENTS

Adult patients who were mechanically ventilated for more than 8 days in the ICU.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Nutritional adequacy was obtained from the average proportion of prescribed calories received over the amount prescribed during the first 8 days. Survival status and health-related quality of life as assessed using the Short-Form 36 v2 were obtained at 3- and 6 months post ICU admission. Of the 1,223 patients enrolled in the randomized controlled trial, 475 met the inclusion criteria for this study. At 6-month follow-up, 302 of the 475 patients (64%) were alive. Survival time in those who received low nutritional adequacy was significantly shorter than those who received high nutritional adequacy while adjusting for important covariates (adjusted hazard ratio, 1.7; 95% CI, 1.1-2.6). At 3-month follow-up, a 25% increase in nutritional adequacy was associated with improvements in Physical Functioning and Role Physical of 7.3 (p = 0.02) and 8.3 (p = 0.004) points, respectively. At 6-month follow-up, adjusted increases in Physical Functioning and Role Physical scores for every 25% increase in nutrition adequacy became smaller and were no longer statistically significant (adjusted estimate for Physical Functioning = 4.2, p = 0.14; for Role Physical = 3.2, p = 0.25).

CONCLUSIONS

Greater amounts of nutritional intake received during the first week in the ICU were associated with longer survival time and faster physical recovery to 3 months but not 6 months post ICU discharge in critically ill patients requiring prolonged mechanical ventilation. Current recommendations to underfeed critically ill patients may cause harm in some long-stay patients.

Nutritional support in critical illness and recovery

An adequate nutritional status is crucial for optimum function of cells and organs, and for wound healing. Options for artificial nutrition have greatly expanded in the past few decades, but have concomitantly shown limitations and potential side-effects. Few rigorous randomised controlled trials (RCTs) have investigated enteral or parenteral nutritional support, and evidence-based clinical guidance is largely restricted to the first week of critical illness. In the early stages of critical illness, whether artificial feeding is better than no feeding intervention has been given little attention in existing RCTs. Expected beneficial effects of various forms of early feeding interventions on rates of morbidity or mortality have generally not been supported by results of recent high-quality RCTs. Thus, whether nutritional interventions early in an intensive care unit (ICU) stay improve outcomes remains unclear. Trials assessing feeding interventions that continue after the first week of critical illness and into the post-ICU and post-hospital settings are clearly needed. Although acute morbidity and mortality will remain important safety parameters in such trials, primary outcomes should perhaps, in view of the adjunctive nature of nutritional intervention in critical illness, be focused on physical function and assessed months or even years after patients are discharged from the ICU. This Series paper is based on results of high-quality RCTs and provides new perspectives on nutritional support during critical illness and recovery.

Safety and Dose Escalation Study of Intravenous Zinc Supplementation in Pediatric Critical Illness

BACKGROUND

Critically ill children have low plasma zinc (pZn), correlating with organ failure. Since Zn influences inflammation, immune function, and glucose control, Zn supplementation is a plausible therapeutic modality. We sought to determine a safe dose of intravenous (IV) Zn to restore pZn in critically ill children.

METHODS

Stepwise dose escalation study of IV Zn supplementation at a tertiary children's hospital. All children (<10 years) admitted to the pediatric intensive care unit with a Pediatric Risk of Mortality III score >5, or ≥1 new organ failure were eligible. After consent, patients were sequentially enrolled into 4 dosing groups: (1) no zinc, (2) Zn250: 250 mcg/kg/d ZnSO4, (3) Zn500: 500 mcg/kg/d ZnSO4, or (4) Zn750: 750 mcg/kg/d ZnSO4 ZnSO4 was administered 3 times daily for 7 days. pZn was measured at baseline, end of first ZnSO4 infusion, 1 hour postinfusion, and 7 hours postinfusion on day 1, then daily through days 2-7. Interleukin-6 (IL-6), C-reactive protein (CRP), and lymphocyte subsets were measured on days 1 and 3. Glucose was measured 3 times daily for 7 days.

RESULTS

Twenty-four patients were enrolled. Baseline demographics were similar among groups. Baseline pZn was low in all patients (mean [SD], 41.8 [16.0] mcg/dL). pZn increased over the study period in supplemented groups; however, mean pZn in the Zn750 group exceeded the 50th percentile. pZn was not associated with IL-6, CRP, or lymphocyte subsets among groups. Degree of hyperglycemia did not differ among groups. No patient had a study-related adverse event.

CONCLUSIONS

IV zinc supplementation at 500 mcg/kg/d restores pZn to near the 50th percentile and is well tolerated.

Pharmaconutrition with selenium in critically ill patients: what do we know?

Selenium is a component of selenoproteins with antioxidant, anti-inflammatory, and immunomodulatory properties. Systemic inflammatory response syndrome (SIRS), multiorgan dysfunction (MOD), and multiorgan failure (MOF) are associated with an early reduction in plasma selenium and glutathione peroxidase activity (GPx), and both parameters correlate inversely with the severity of illness and outcomes. Several randomized clinical trials (RCTs) evaluated selenium therapy as monotherapy or in antioxidant cocktails in intensive care unit (ICU) patient populations, and more recently several meta-analyses suggested benefits with selenium therapy in the most seriously ill patients. However, the largest RCT on pharmaconutrition with glutamine and antioxidants, the REducing Deaths due to Oxidative Stress (REDOXS) Study, was unable to find any improvement in clinical outcomes with antioxidants provided by the enteral and parenteral route and suggested harm in patients with renal dysfunction. Subsequently, the MetaPlus study demonstrated increased mortality in medical patients when provided extra glutamine and selenium enterally. The treatment effect of selenium may be dependent on the dose, the route of administration, and whether administered with other nutrients and the patient population studied. Currently, there are few small studies evaluating the pharmacokinetic profile of intravenous (IV) selenium in SIRS, and therefore more data are necessary, particularly in patients with MOD, including those with renal dysfunction. According to current knowledge, high-dose pentahydrate sodium selenite could be given as an IV bolus injection (1000-2000 µg), which causes transient pro-oxidant, cytotoxic, and anti-inflammatory effects, and then followed by a continuous infusion of 1000-1600 µg/d for up to 10-14 days. Nonetheless, the optimum dose and efficacy still remain controversial and need to be definitively established.

The Japanese guidelines for the management of sepsis

This is a guideline for the management of sepsis, developed by the Sepsis Registry Committee of The Japanese Society of Intensive Care Medicine (JSICM) launched in March 2007. This guideline was developed on the basis of evidence-based medicine and focuses on unique treatments in Japan that have not been included in the Surviving Sepsis Campaign guidelines (SSCG), as well as treatments that are viewed differently in Japan and in Western countries. Although the methods in this guideline conform to the 2008 SSCG, the Japanese literature and the results of the Sepsis Registry Survey, which was performed twice by the Sepsis Registry Committee in intensive care units (ICUs) registered with JSICM, are also referred. This is the first and original guideline for sepsis in Japan and is expected to be properly used in daily clinical practice.

This article is translated from Japanese, originally published as “The Japanese Guidelines for the Management of Sepsis” in the Journal of the Japanese Society of Intensive Care Medicine (J Jpn Soc Intensive Care Med), 2013; 20:124–73. The original work is at http://dx.doi.org/10.3918/jsicm.20.124.

[Intensive care unit acquired weakness. Pathogenesis, treatment, rehabilitation and outcome]

The diagnosis of intensive care unit acquired weakness (ICUAW) in the setting of neurological rehabilitation is steadily increasing. This is due to the fact that the intensive care of patients with sepsis or after cardiac or abdominal surgery is improving. A longer duration of respiratory weaning and comorbidities frequently complicate rehabilitation. Clinically, patients present with a flaccid (tetra) paresis and electrophysiological studies have shown axonal damage. Besides involvement of peripheral nerves, muscle can also be affected (critical illness myopathy) leading to ICUAW with inconstant myopathic damage patterns found by electrophysiological testing. Mixed forms can also be found. A specific therapy for ICUAW is not available. Early mobilization to be initiated on the intensive care unit and commencing neurological rehabilitation improve the outcome of ICUAW. This review highlights the current literature regarding the etiology and diagnosis of ICUAW. Furthermore, studies about rehabilitation and outcome of ICUAW are discussed.

Glutamine supplementation for critically ill adults

BACKGROUND

Glutamine is a non-essential amino acid which is abundant in the healthy human body. There are studies reporting that plasma glutamine levels are reduced in patients with critical illness or following major surgery, suggesting that glutamine may be a conditionally essential amino acid in situations of extreme stress. In the past decade, several clinical trials examining the effects of glutamine supplementation in patients with critical illness or receiving surgery have been done, and the systematic review of this clinical evidence has suggested that glutamine supplementation may reduce infection and mortality rates in patients with critical illness. However, two recent large-scale randomized clinical trials did not find any beneficial effects of glutamine supplementation in patients with critical illness.

OBJECTIVES

The objective of this review was to:1. assess the effects of glutamine supplementation in critically ill adults and in adults after major surgery on infection rate, mortality and other clinically relevant outcomes;2. investigate potential heterogeneity across different patient groups and different routes for providing nutrition.

SEARCH METHODS

We searched the Cochrane Anaesthesia Review Group (CARG) Specialized Register; Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (2013, Issue 5); MEDLINE (1950 to May 2013); EMBASE (1980 to May 2013) and Web of Science (1945 to May 2013).

SELECTION CRITERIA

We included controlled clinical trials with random or quasi-random allocation that examined glutamine supplementation versus no supplementation or placebo in adults with a critical illness or undergoing elective major surgery. We excluded cross-over trials.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted the relevant information from each included study using a standardized data extraction form. For infectious complications and mortality and morbidity outcomes we used risk ratio (RR) as the summary measure with the 95% confidence interval (CI). We calculated, where appropriate, the number needed to treat to benefit (NNTB) and the number needed to treat to harm (NNTH). We presented continuous data as the difference between means (MD) with the 95% CI.

MAIN RESULTS

Our search identified 1999 titles, of which 53 trials (57 articles) fulfilled our inclusion criteria. The 53 included studies enrolled a total of 4671 participants with critical illness or undergoing elective major surgery. We analysed seven domains of potential risk of bias. In 10 studies the risk of bias was evaluated as low in all of the domains. Thirty-three trials (2303 patients) provided data on nosocomial infectious complications; pooling of these data suggested that glutamine supplementation reduced the infectious complications rate in adults with critical illness or undergoing elective major surgery (RR 0.79, 95% CI 0.71 to 0.87, P ＜ 0.00001, I² = 8%, moderate quality evidence). Thirty-six studies reported short-term (hospital or less than one month) mortality. The combined rate of mortality from these studies was not statistically different between the groups receiving glutamine supplement and those receiving no supplement (RR 0.89, 95% CI 0.78 to 1.02, P = 0.10, I² = 22%, low quality evidence). Eleven studies reported long-term (more than six months) mortality; meta-analysis of these studies (2277 participants) yielded a RR of 1.00 (95% CI 0.89 to 1.12, P = 0.94, I² = 30%, moderate quality evidence). Subgroup analysis of infectious complications and mortality outcomes did not find any statistically significant differences between the predefined groups. Hospital length of stay was reported in 36 studies. We found that the length of hospital stay was shorter in the intervention group than in the control group (MD -3.46 days, 95% CI -4.61 to -2.32, P < 0.0001, I² = 63%, low quality evidence). Slightly prolonged intensive care unit (ICU) stay was found in the glutamine supplemented group from 22 studies (2285 participants) (MD 0.18 days, 95% CI 0.07 to 0.29, P = 0.002, I² = 11%, moderate quality evidence). Days on mechanical ventilation (14 studies, 1297 participants) was found to be slightly shorter in the intervention group than in the control group (MD - 0.69 days, 95% CI -1.37 to -0.02, P = 0.04, I² = 18%, moderate quality evidence). There was no clear evidence of a difference between the groups for side effects and quality of life, however results were imprecise for serious adverse events and few studies reported on quality of life. Sensitivity analysis including only low risk of bias studies found that glutamine supplementation had beneficial effects in reducing the length of hospital stay (MD -2.9 days, 95% CI -5.3 to -0.5, P = 0.02, I² = 58%, eight studies) while there was no statistically significant difference between the groups for all of the other outcomes.

AUTHORS' CONCLUSIONS

This review found moderate evidence that glutamine supplementation reduced the infection rate and days on mechanical ventilation, and low quality evidence that glutamine supplementation reduced length of hospital stay in critically ill or surgical patients. It seems to have little or no effect on the risk of mortality and length of ICU stay, however. The effects on the risk of serious side effects were imprecise. The strength of evidence in this review was impaired by a high risk of overall bias, suspected publication bias, and moderate to substantial heterogeneity within the included studies.

Oxidative Stress and Therapeutic Development in Lung Diseases

Oxidative stress has many implications in the pathogenesis of lung diseases. In this review, we provide an overview of Reactive Oxygen Species (ROS) and nitrogen (RNS) species and antioxidants, how they relate to normal physiological function and the pathophysiology of different lung diseases, and therapeutic strategies. The production of ROS/RNS from endogenous and exogenous sources is first discussed, followed by antioxidant systems that restore oxidative balance and cellular homeostasis. The contribution of oxidant/antioxidant imbalance in lung disease pathogenesis is also discussed. An overview of therapeutic strategies is provided, such as augmenting NO bioactivity, blocking the production of ROS/RNS and replacement of deficient antioxidants. The limitations of current strategies and failures of clinical trials are then addressed, followed by discussion of novel experimental approaches for the development of improved antioxidant therapies.

Glutamine and antioxidants in the critically ill patient: a post hoc analysis of a large-scale randomized trial

BACKGROUND

The recent large randomized controlled trial of glutamine and antioxidant supplementation suggested that high-dose glutamine is associated with increased mortality in critically ill patients with multiorgan failure. The objectives of the present analyses were to reevaluate the effect of supplementation after controlling for baseline covariates and to identify potentially important subgroup effects.

MATERIALS AND METHODS

This study was a post hoc analysis of a prospective factorial 2 × 2 randomized trial conducted in 40 intensive care units in North America and Europe. In total, 1223 mechanically ventilated adult patients with multiorgan failure were randomized to receive glutamine, antioxidants, both glutamine and antioxidants, or placebo administered separate from artificial nutrition. We compared each of the 3 active treatment arms (glutamine alone, antioxidants alone, and glutamine + antioxidants) with placebo on 28-day mortality. Post hoc, treatment effects were examined within subgroups defined by baseline patient characteristics. Logistic regression was used to estimate treatment effects within subgroups after adjustment for baseline covariates and to identify treatment-by-subgroup interactions (effect modification).

RESULTS

The 28-day mortality rates in the placebo, glutamine, antioxidant, and combination arms were 25%, 32%, 29%, and 33%, respectively. After adjusting for prespecified baseline covariates, the adjusted odds ratio of 28-day mortality vs placebo was 1.5 (95% confidence interval, 1.0-2.1, P = .05), 1.2 (0.8-1.8, P = .40), and 1.4 (0.9-2.0, P = .09) for glutamine, antioxidant, and glutamine plus antioxidant arms, respectively. In the post hoc subgroup analysis, both glutamine and antioxidants appeared most harmful in patients with baseline renal dysfunction. No subgroups suggested reduced mortality with supplements.

CONCLUSIONS

After adjustment for baseline covariates, early provision of high-dose glutamine administered separately from artificial nutrition was not beneficial and may be associated with increased mortality in critically ill patients with multiorgan failure. For both glutamine and antioxidants, the greatest potential for harm was observed in patients with multiorgan failure that included renal dysfunction upon study enrollment.

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.

Assessment of plasma and red cell trace element concentrations, disease severity, and outcome in patients with critical illness

PURPOSE

The purpose of the study is to examine the value of both plasma and red cell trace element measurements when assessing nutritional status in patients with critical illness.

MATERIALS AND METHODS

A total of 125 patients who were admitted to intensive care unit with evidence of systemic inflammatory response as per Bone's criteria were recruited. Venous blood samples were obtained from all on admission and, in 31 of the 125 patients, on approximately days 4 and 7. Copper, zinc, and selenium concentrations were measured in plasma and erythrocytes and results related to mortality and patient outcome measures.

RESULTS

A total of 125 critically ill patients were recruited; 81 (66%) were male, the median age was 60 (range, 18-100), and the medical/surgical proportion was 55/70 (44%/56%). The median (lower and upper 2.5th percentile) Acute Physiology and Chronic Health Evaluation II score, Sequential Organ Failure Assessment score, and length of stay and mortality were 21 (16-26), 7 (4-9) 3.7 days (1.5-11.1) and 19%, respectively. Plasma zinc and selenium concentrations were significantly lower on admission compared with reference intervals, whereas copper was increased. Normal plasma glutathione peroxidase activity suggested selenium status was adequate on admission; erythrocyte concentrations of glutathione peroxidase and trace elements were normal, suggesting adequate nutritional status 1 to 2 months before admission. Only plasma zinc and selenium were inversely associated with C-reactive protein (rs = -0.266, P = .004, rs = -0.322, P < .001, respectively). Compared with survivors, albumin (P < .001) concentrations were significantly lower in the nonsurvivor group. No significant difference of plasma selenium and zinc between survivors and nonsurvivors was found, although plasma selenium concentrations tended to be lower (P = .04). On multivariate logistic regression analysis of the significant variables, none was independently associated with mortality.

CONCLUSION

The altered plasma concentrations of zinc, selenium, and copper in patients with critical illness were primarily due to the effects of the systemic inflammatory response and do not reliably indicate their status.

A randomized trial of glutamine and antioxidants in critically ill patients

BACKGROUND

Critically ill patients have considerable oxidative stress. Glutamine and antioxidant supplementation may offer therapeutic benefit, although current data are conflicting.

METHODS

In this blinded 2-by-2 factorial trial, we randomly assigned 1223 critically ill adults in 40 intensive care units (ICUs) in Canada, the United States, and Europe who had multiorgan failure and were receiving mechanical ventilation to receive supplements of glutamine, antioxidants, both, or placebo. Supplements were started within 24 hours after admission to the ICU and were provided both intravenously and enterally. The primary outcome was 28-day mortality. Because of the interim-analysis plan, a P value of less than 0.044 at the final analysis was considered to indicate statistical significance.

RESULTS

There was a trend toward increased mortality at 28 days among patients who received glutamine as compared with those who did not receive glutamine (32.4% vs. 27.2%; adjusted odds ratio, 1.28; 95% confidence interval [CI], 1.00 to 1.64; P=0.05). In-hospital mortality and mortality at 6 months were significantly higher among those who received glutamine than among those who did not. Glutamine had no effect on rates of organ failure or infectious complications. Antioxidants had no effect on 28-day mortality (30.8%, vs. 28.8% with no antioxidants; adjusted odds ratio, 1.09; 95% CI, 0.86 to 1.40; P=0.48) or any other secondary end point. There were no differences among the groups with respect to serious adverse events (P=0.83).

CONCLUSIONS

Early provision of glutamine or antioxidants did not improve clinical outcomes, and glutamine was associated with an increase in mortality among critically ill patients with multiorgan failure. (Funded by the Canadian Institutes of Health Research; ClinicalTrials.gov number, NCT00133978.).

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).

Disease-specific nutrition therapy: one size does not fit all

INTRODUCTION

The delivery of adequate nutrition is an integral part of the care of the critically ill surgical patient, and the provision of nutrition may have a greater impact on outcome than many other therapies commonly employed in the treatment of certain disease states.

METHODS

A review of the existing literature was performed to summarize the evidence for utilizing disease-specific nutrition in critically ill surgical patients.

RESULTS

Enteral nutrition, unless specifically contraindicated, is always preferable to parenteral nutrition. Methodological heterogeneity and conflicting results plague research in immunonutrition, and routine use is not currently recommended in critically ill patients.

CONCLUSION

There is currently insufficient evidence to recommend the routine initial use of most disease-specific formulas, as most patients with the disease in question will tolerate standard enteral formulas. However, the clinician should closely monitor for signs of intolerance and utilize disease-specific formulas when appropriate.

[Immunonutrition in intensive care medicine]

The review presents the concept of immunonutrition in enteral and parenteral nutrition of the critically ill. The present indications for supplementing immune enhancing and anti-inflammatory substances are summarized and discussed in accordance with the recent literature and guidelines.

Antioxidant micronutrients in the critically ill: a systematic review and meta-analysis

INTRODUCTION

Critical illness is characterized by oxidative stress, which is a major promoter of systemic inflammation and organ failure due to excessive free radical production, depletion of antioxidant defenses, or both. We hypothesized that exogenous supplementation of trace elements and vitamins could restore antioxidant status, improving clinical outcomes.

METHODS

We searched computerized databases, reference lists of pertinent articles and personal files from 1980 to 2011. We included randomized controlled trials (RCTs) conducted in critically ill adult patients that evaluated relevant clinical outcomes with antioxidant micronutrients (vitamins and trace elements) supplementation versus placebo.

RESULTS

A total of 21 RCTs met inclusion criteria. When the results of these studies were statistically aggregated (n = 20), combined antioxidants were associated with a significant reduction in mortality (risk ratio (RR) = 0.82, 95% confidence interval (CI) 0.72 to 0.93, P = 0.002); a significant reduction in duration of mechanical ventilation (weighed mean difference in days = -0.67, 95% CI -1.22 to -0.13, P = 0.02); a trend towards a reduction in infections (RR= 0.88, 95% CI 0.76 to 1.02, P = 0.08); and no overall effect on ICU or hospital length of stay (LOS). Furthermore, antioxidants were associated with a significant reduction in overall mortality among patients with higher risk of death (>10% mortality in control group) (RR 0.79, 95% CI 0.68 to 0.92, P = 0.003) whereas there was no significant effect observed for trials of patients with a lower mortality in the control group (RR = 1.14, 95% 0.72 to 1.82, P = 0.57). Trials using more than 500 μg per day of selenium showed a trend towards a lower mortality (RR = 0.80, 95% CI 0.63 to 1.02, P = 0.07) whereas trials using doses lower than 500 μg had no effect on mortality (RR 0.94, 95% CI 0.67 to 1.33, P = 0.75).

CONCLUSIONS

Supplementation with high dose trace elements and vitamins may improve outcomes of critically ill patients, particularly those at high risk of death.

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.

A systematic literature review and meta-analysis of randomized clinical trials of parenteral glutamine supplementation

BACKGROUND & AIMS

Glutamine supplementation has been associated with reduced mortality, infections and hospital length of stay in critically ill patients and patients undergoing major surgery. We carried out a meta-analysis to examine randomized clinical trial (RCT)-based evidence of these effects.

METHODS

Based on a systematic database search, RCTs published since 1990 were included if they evaluated the effect of parenteral glutamine supplementation against a background of parenteral nutrition. Enteral (tube) feeding in a proportion of patients was allowable. Information on RCT methodology, quality and outcomes was extracted. Random effects meta-analysis followed the DerSimonian-Laird approach.

RESULTS

Forty RCTs were eligible for meta-analysis. Parenteral glutamine supplementation was associated with a non-significant 11% reduction in short-term mortality (RR = 0.89; 95% CI, 0.77-1.04). Infections were significantly reduced (RR = 0.83; 95% CI, 0.72-0.95) and length of stay was 2.35 days shorter (95% CI, -3.68 to -1.02) in the glutamine arms. Meta-analysis results were strongly influenced by one recent trial. An element of publication bias could not be excluded.

CONCLUSION

Parenteral glutamine supplementation in severely ill patients may reduce infections, length of stay and mortality, but substantial uncertainty remains. Unlike previous meta-analyses, we could not demonstrate a significant reduction in mortality.

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.

Pharmacologically dosed oral glutamine reduces myocardial injury in patients undergoing cardiac surgery: a randomized pilot feasibility trial

BACKGROUND AND OBJECTIVE

Glutamine (GLN) has been shown to protect against in vitro and in vivo myocardial injury. In humans, perioperative ischemia/reperfusion (I/R) injury during cardiac surgery is associated with higher morbidity and mortality. The objective of this safety and feasibility pilot trial was to determine if pharmacologically dosed, preoperative oral GLN attenuates myocardial injury in cardiac surgery patients.

METHODS

Patients undergoing elective cardiac surgery, requiring cardiopulmonary bypass, were enrolled in a randomized, double-blind pilot trial to receive 25 g twice of oral alanyl-glutamine (GLN; n = 7) or maltodextrin (CONT; n = 7) daily for 3 days preoperatively. Serum troponin (TROP I), creatine kinase (CK-MB), and myoglobin (MG) were measured at multiple perioperative time points. Clinical outcomes were also recorded and assessed.

RESULTS

GLN therapy significantly decreased TROP I levels at 24, 48, and 72 hours postoperatively (all P < .05) vs CONT. GLN also reduced CK-MB at 24 and 48 hours (P < .05, P < .001) vs CONT. MG was reduced at 24 hours vs control (P = .0397). GLN also significantly reduced pooled clinical complications vs CONT (P = .03).

CONCLUSION

This pilot study showed that pharmacologically dosed oral GLN therapy prior to cardiac surgery was safe, well tolerated, and feasible. GLN therapy reduced myocardial injury and clinical complications in this small randomized, blinded feasibility trial. These data indicate that a larger trial of preoperative GLN therapy in patients undergoing cardiac surgery is needed to confirm clinical benefit.