Selenium supplementation for critically ill adults

Relationship Between Selenium Trace and Patient Outcome After Open-Heart Surgery

Background

Acute stress response to heart surgery can cause major morbidity in patients. The trace of selenium is useful for preventing heart damage. Although the trend of selenium changes is of high importance for body balance, the usefulness of routine use and effectiveness of this element for patients under open-heart surgery is still unclear.

Objectives

This study aimed at assessing serum selenium level before and after open-heart surgery and the relationship between selenium trace and patient outcome.

Methods

This prospective analytical study was performed on 100 patients undergoing open-heart surgery using cardiopulmonary bypass (CPB). In all patients, the serum level was measured at a predetermined time (before surgery and one and two days after surgery). Then, the relationship between serum selenium and patient outcome was assessed.

Results

The mean serum selenium level in patients on admission was 72.90 ± 14.62 μg/L, one day after surgery was 71.20 ± 15.84 μg/L, and two days after surgery was 71.54 ± 15.97 μg/L. Serum selenium levels were inversely and significantly associated with age (r = -0.183; P = 0.034, 013) duration of surgery (r = -221 and P = 0.014), duration of intensive care unit stay (r = 0.204, P = 0.021), and duration of CPB (r = 0.223, P = 013).

Conclusions

Based on this study’s results, a low level of selenium can affect patients’ outcomes after open-heart surgery.

The Effect of High-dose Parenteral Sodium Selenite in Critically Ill Patients following Sepsis: A Clinical and Mechanistic Study

INTRODUCTION

Severe sepsis and septic shock is characterized by inflammation and oxidative stress. Selenium levels have been reported to be low due to loss or increased requirements during severe sepsis and septic shock. We investigated the effect of high-dose parenteral selenium administration in septic patients.

METHODS

A prospective, randomized control clinical trial was performed in septic patients. After randomization, patients in selenium group received high-dose parenteral sodium selenite (2 mg intravenous [IV] bolus followed by 1.5 mg IV continuous infusion daily for 14 days) plus standard therapy and the control group received standard therapy. The primary endpoint was mortality at 28 days. Changes in the mean levels of high mobility group box-1 (HMGB-1) protein and superoxide dismutase (SOD), duration of vasopressor therapy, incidence of acute renal failure, and 60 days' mortality were secondary endpoints.

RESULTS

Fifty-four patients were randomized into selenium group (n = 29) and control group (n = 25). There was no significant difference in 28-day mortality. No significant difference between the two groups with respect to the average levels of HMGB-1 protein and SOD at any point in time over the course of 14 days had observed.

CONCLUSION

In early administration within the first 6 h of sepsis diagnosis, our study demonstrated that high-dose parenteral selenium administration had no significant effect either on 28-day mortality or the mean levels of HMGB-1 and SOD (Trial Registration: IRCT201212082887N4 at WHO Clinical Trial Registry, August 29, 2014).

Serum selenium levels in patients with respiratory diseases: a prospective observational study

BACKGROUND

Serum selenium levels are lower in critically ill patients as compared with healthy controls. However, there is no data about the difference in serum selenium levels depending on the severity of lung diseases. We aimed to identify the factors associated with low serum selenium levels in critically ill patients with respiratory diseases.

METHODS

A prospective study was performed in 83 patients with respiratory diseases who had admitted to the intensive care unit (ICU) and general wards. We obtained systemic inflammatory markers, nutritional indicators and prognostic factors as the explanatory variables for the outcome of low serum selenium levels.

RESULTS

Serum selenium levels on admission were lower by 28% in the ICU group as compared with the general ward group (70.0±26.4 and 97.9±20.8 ng/mL, respectively, P<0.001). Low serum selenium levels had a correlation with malnutrition represented by decreases in levels of lymphocyte (R(2)=0.107, P=0.005) and albumin (R(2)=0.174, P<0.001). In addition, low serum selenium levels were associated with an increase in baseline C-reactive protein (CRP) (R(2)=0.059, P=0.041) and APACHE II scores (R(2)=0.209, P<0.001). Lower albumin levels (P=0.032) and higher APACHE II scores (P=0.046) showed a significant correlation with lower serum selenium levels on multivariate analysis.

CONCLUSIONS

Low serum selenium levels in patients with respiratory diseases have a significant correlation with poor nutritional status and prognosis on admission.

Assessment of serum zinc, selenium, and prolactin concentrations in critically ill children

Background

In critically ill patients, there are reduced stores of antioxidants, which are associated with increased organ failure and even higher mortality. Trace elements, especially zinc and selenium, are the cornerstone of the antioxidant defense in acute systemic inflammatory response syndrome. Prolactin (PRL) is the counterregulatory stress hormone that prevents cortisol/stress-induced lymphocyte apoptosis. The aim of our study is to detect the serum levels of zinc, selenium, and PRL hormone as important immunomodulators in critically ill children and to investigate the relationship between these immunomodulators and the severity of illness.

Subjects and methods

This was a prospective study that included two groups; group 1: 50 critically ill children within 72 hours of intensive care unit admission, and group 2: 30 healthy children as controls. Blood samples were collected from the two groups for zinc, selenium, and PRL level measurement.

Results

Zinc and PRL levels were found to be decreased in critically ill children compared to control group, and these levels were inversely correlated with organ failure index and pediatric logistic organ dysfunction scores. Selenium levels were decreased in patients with sepsis and in patients with multiple organ failure.

Conclusion

Serum concentrations of zinc and PRL are generally low in critically ill children, with a greater decrease in patients with sepsis and in the presence of multiple organ failure. The levels of zinc and PRL are inversely correlated with severity of illness. Selenium levels were decreased in patients with sepsis and in patients with multiple organ failure.

Selenium supplementation for critically ill adults

BACKGROUND

Selenium is a trace mineral essential to health and has an important role in immunity, defence against tissue damage and thyroid function. Improving selenium status could help protect against overwhelming tissue damage and infection in critically ill adults. This Cochrane review was originally published in 2004 updated in 2007 and again 2015.

OBJECTIVES

The primary objective was to examine the effect of nutrition supplemented with selenium or ebselen on mortality in critically ill patients.The secondary objective was to examine the relationship between selenium or ebselen supplementation and number of infections, duration of mechanical ventilation, length of intensive care unit stay and length of hospital stay.

SEARCH METHODS

In this update, we searched the current issue of the Cochrane Central Register of Controlled Trials, the Cochrane Library (2014, Issue 5); MEDLINE (Ovid SP, to May 20, 2014), EMBASE (Ovid SP, to May 20, 2014), CAB, BIOSIS and CINAHL. We handsearched the reference lists of the newest reviews and cross-checked with our search in MEDLINE. We contacted the main authors of included studies to request any missed, unreported or ongoing studies. The latest search was performed up to 21 May 2014. The search is now from inception until 21 May 2014.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) irrespective of publication status, date of publication, blinding status, outcomes published or language. We contacted the trial investigators and authors in order to retrieve relevant and missing data.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and we resolved any disagreements by discussion. Our primary outcome measure was all-cause mortality. We performed several subgroup and sensitivity analyses to assess the effects of selenium in critically ill patients. We presented pooled estimates of the effects of intervention as risk ratios (RRs) with 95% confidence intervals (CIs). We assessed the risk of bias through assessment of trial methodological components and the risk of random error through trial sequential analysis.

MAIN RESULTS

We included six new RCTs in this review update. In total we included 16 RCTs (2084 participants) in this review. Most trials were at high risk of bias. The availability of outcome data was limited and trials involving selenium supplementation were, with the exception of one trial, small regarding sample size. Thus the results must be interpreted with caution.Thirteen trials of intravenous sodium selenite showed a statistically significant reduction in overall mortality (RR 0.82, 95% CI 0.72 to 0.93, 1391 participants, very low quality of evidence). However, the overall point estimate on mortality is primarily influenced by trials of high risk of bias. Meta-analysis of three trials of ebselen had a RR of 0.83 (95% CI 0.52 to 1.34, 693 participants, very low quality of evidence).Nine trials of intravenous sodium selenite were analysed for 28 days mortality with no statistically significant difference (RR 0.84, 95% CI 0.69 to 1.02, 1180 participants, very low quality of evidence) while three trials were analysed for 90 days mortality with similar findings (RR 0.96, 95% Cl 0.78 to 1.18, 614 participants, very low quality of evidence).Two trials of ebselen were analysed for 90 days mortality and were not found to yield any benefit (RR 0.72, 95% Cl 0.42 to 1.22, 588 participants, very low quality of evidence).For mortality among intensive care patients selenium supplementation failed to indicate any statistically significant advantage (RR 0.88, 95% CI 0.77 to 1.01, nine trials, 1168 participants, very low quality of evidence).Six trials of intravenous sodium selenite found no statistically significant difference for participants developing infection (RR 0.96, 95% CI 0.75 to 1.23, 934 patients, very low quality of evidence). Similarly, three trials of ebselen provided data for participants developing infections (pyrexia, respiratory infections or meningitis) with no obvious benefit (RR 0.60, 95% CI 0.36 to 1.02, 685 participants, very low quality of evidence).Our analyses showed no effect of selenium or ebselen on adverse events (Selenium: RR 1.03, 95% Cl 0.85 to 1.24; six trials, 925 participants ; Ebselen: RR 1.16, 95% CI 0.40 to 3.36; two trials, 588 participants, very low quality of evidence).No clear evidence emerged in favour of selenium supplementation for outcomes such as number of days on a ventilator (mean difference (MD) -0.86, 95% CI -4.39 to 2.67, four trials, 191 participants, very low quality of evidence), length of intensive care unit stay (MD 0.54, 95% CI -2.27 to 3.34, seven trials, 934 participants, very low quality of evidence) or length of hospital stay (MD -3.33, 95% Cl -5.22 to -1.44, five trials, 693 participants, very low quality of evidence).The quality of trial methodology was low. Due to high risk of bias in the included trials, results must be interpreted with caution.

AUTHORS' CONCLUSIONS

Despite publication of a number of trials, the current evidence to recommend supplementation of critically ill patients with selenium or ebselen remains disputed. Trials are required which overcome the methodological inadequacies of the reviewed studies, particularly in relation to sample size, design and outcomes.

[Adjuvant treatment of sepsis: what is known?]

BACKGROUND

Recent decades have been characterized by a large number of trials for registration of new drugs or indication approvals in the field of sepsis. Modern anti-inflammatory drugs or interventions are intended to correct the overwhelming dysregulation of inflammatory and coagulation pathways seen particularly in the early phase of sepsis. Immunostimulatory therapies are also being studied in order to correct immunoparalysis, which develops later in the course of sepsis as a compensatory mechanism.

CURRENT STUDY RESULTS

Recombinant activated protein C, drotrecogin α, was conditionally approved and later withdrawn from the market by the producer because the initially observed beneficial effect could not be confirmed. The efficacy and safety of antithrombin, which, like drotrecogin α, also modulates inflammation and coagulation as an endogenous anticoagulant could not be confirmed when used for treating sepsis. As sepsis leads to disseminated intravascular coagulation which may be counteracted by antithrombin, new guidelines recommend antithrombin as a treatment option in this subgroup of sepsis patients. Intravenous administration of immunoglobulin, enteral administration of immunomodulating substances as immunonutrition, and the substitution of selenium, all showed some effectiveness in small heterogeneous studies, but their efficacy was not confirmed in large high-quality trials. Intensive glycemic control, which was temporarily recommended for acutely ill patients, increased the risk for adverse hypoglycemia in several clinical trials so that blood glucose target levels have been redefined and guidelines now no longer ask for normalization of blood glucose values with insulin.

CONCLUSION AND OUTLOOK

None of the new drugs, however, has successfully become established as a new standard of care. In the future, studies of novel sepsis therapies may succeed better if suitable biomarkers allow for patient selection, reflecting key pathophysiologic mechanisms that are targeted by the innovative drugs.

Adjuvant selenium supplementation in the form of sodium selenite in postoperative critically ill patients with severe sepsis

INTRODUCTION

Plasma selenium (Se) concentrations are reduced in critically ill surgical patients, and lower plasma Se concentrations are associated with worse outcomes. We investigated whether adjuvant Se supplementation in the form of sodium selenite could improve outcomes in surgical patients with sepsis.

METHODS

In this retrospective study, all adult patients admitted to a 50-bed surgical ICU with severe sepsis between January 2004 and April 2010 were included and analysed according to whether they had received adjuvant Se supplementation, which was given at the discretion of the attending physician. When prescribed, Se was administered in the form of sodium selenite pentahydrate (Na2SeO3∙5H2O), in which 100 μg of Se corresponds to 333 μg of sodium selenite. A bolus of sodium selenite corresponding to 1,000 μg of Se was injected intravenously through a central venous line for 30 minutes, followed by infusion of 1,000 μg/day for 24 hours for 14 days until ICU discharge or death. We performed logistic regression analysis to investigate the impact of adjuvant Se supplementation on hospital mortality.

RESULTS

Adjuvant Se was administered to 413 (39.7%) of the 1,047 patients admitted with severe sepsis. Age and sex were similar between patients who received adjuvant Se and those who did not. Compared with patients who did not receive adjuvant Se supplementation, patients who did had higher scores on the Simplified Acute Physiology Score II, a greater prevalence of cancer upon admission to the ICU and were more commonly admitted after abdominal surgery. Compared with patients who did not receive adjuvant Se, patients who did had higher hospital mortality rates (46% versus 39.1%; P = 0.027), and longer median (interquartile range (IQR)) ICU stays (15 days (6 to 24) versus 11 days (4 to 24); P = 0.01) and hospital lengths of stay (33 days (21 to 52) versus 28 days (17 to 46); P = 0.001). In multivariable analysis, adjuvant Se supplementation was not independently associated with favourable outcome (odds ratio = 1.19, 95% confidence interval = 0.86 to 1.65; P = 0.288).

CONCLUSIONS

In this retrospective analysis of a large cohort of surgical ICU patients with severe sepsis, adjuvant Se supplementation in the form of sodium selenite had no impact on in-hospital death rates after adjustment for confounders.

[Calories, proteins - what does the intensive care patient need?]

It is increasingly recognized that the nutrition of critically ill patients is a highly complex activity with many unanswered questions. Much research has been performed showing that early enteral nutrition helps to avoid complications. In addition, it has already been shown that the calorie goal as the sole diet goal rather plays a minor role, if one pays attention to sufficient supply of proteins. The diet of the different patient groups with their very individual physiological conditions and their very different diseases are another difficile question in nutritional therapy. The question about the best access path currently appears clearly to be the way of enteral nutrition. Although there seems to be no clear advantage to the gastric or jejunal route, the gastric tube is apparently used more often in clinical practice due to the ease of placement. Reflux control is also currently controversially discussed. To assess the intestinal transport capacity, control of reflux is inevitable, but the amount of reflux that should be considered as cut-off criteria is still unclear. The field of immunonutrition or the substitution of selenium, glutamine, and other substances requires further research. The goal of this article is to provide the reader with a review of the current literature concerning nutritional needs of intensive care patients.

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.

Effect of parenteral selenium supplementation in critically ill patients: a systematic review and meta-analysis

BACKGROUND

It is currently unclear whether parenteral selenium supplementation should be recommended in the management of critically ill patients. Here we conducted a systematic review and meta-analysis to assess the efficacy of parenteral selenium supplementation on clinical outcomes.

METHODS/PRINCIPAL FINDINGS

Randomized trials investigating parenteral selenium supplementation administered in addition to standard of care to critically ill patients were included. CENTRAL, Medline, EMBASE, the Science Citation Index, and CINAHL were searched with complementary manual searches. The primary outcome was all-cause mortality. Trials published in any language were included. Two authors independently extracted data and assessed trial quality. A third author was consulted to resolve disagreements and for quality assurance. Twelve trials were included and meta-analysis was performed on nine trials that recruited critically ill septic patients. These comprised 965 participants in total. Of these, 148 patients (30.7%) in the treatment groups, and 180 patients (37.3%) in control groups died. Parenteral selenium treatment significantly reduced all-cause mortality in critically ill patients with sepsis (relative risk [RR] 0.83, 95% CI 0.70-0.99, p = 0.04, I(2) = 0%). Subgroup analyses demonstrated that the administration schedule employing longer duration (RR 0.77, 95% CI 0.63-0.94, p = 0.01, I(2) = 0%), loading boluses (RR 0.73, 95% CI 0.58-0.94, p = 0.01, I(2) = 0%) or high-dose selenium treatment (RR 0.77, 95% CI 0.61-0.99, p = 0.04, I(2) = 0%) might be associated with a lower mortality risk. There was no evidence of adverse events.

CONCLUSIONS/SIGNIFICANCE

Parenteral selenium supplementation reduces risk of mortality among critically ill patients with sepsis. Owing to the varied methodological quality of the studies, future high-quality randomized trials that directly focus on the effect of adequate-duration of parenteral selenium supplementation for severe septic patients are needed to confirm our results. Clinicians should consider these findings when treating this high-risk population.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 2011; CRD42011001768.

Lower whole blood selenium level is associated with higher operative risk and mortality following cardiac surgery

PURPOSE

The authors intended to test their hypothesis that a low blood selenium level is associated with higher mortality, morbidity, and increased inflammatory response following cardiac surgery.

METHODS

A single-center clinical survey was conducted on 197 consecutive patients undergoing on-pump operation in Debrecen, Hungary. Blood samples for whole blood selenium analysis were taken immediately before the surgery. Their risk profiles were evaluated according to the EuroSCORE. The outcome parameters were as follows: 30-day mortality, incidence of systemic inflammatory response syndrome, and cardiac and renal dysfunction. The main laboratory outcome variables were the postoperative concentrations of C-reactive protein and cardiac troponin I.

RESULTS

The mean blood selenium level was significantly lower in non-survivors 102.2 ± 19.5 μg/L compared with survivors 111.1 ± 16.9 μg/L (p = 0.047), and the mean age, EuroSCORE values, and troponin concentrations were significantly higher in the non-survivors. To exclude these potential confounders a logistic regression model was fitted to our data, with mortality as the outcome and the EuroSCORE, the degree of troponin elevation, and selenium concentration as explanatory variables. This model revealed that a lower selenium level was a minor but apparently existing risk factor for postoperative mortality.

CONCLUSION

Further examinations are required to clarify the question that remained unanswered in this study: the role of low selenium in the causality chain leading to higher postoperative 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.

[Immunonutrition after trauma]

Immunonutrition may be superior to standard clinical nutrition in specific clinical situations. After severe trauma, an enteral immuno-enhancing diet, enriched with arginine, omega-3 fatty acids, and nucleotides, decreases infectious complications. During acute respiratory distress syndrome, a continuous enteral diet with high-dose omega-3 fatty acids, gamma-linolenic acid, and antioxidants improved clinical outcome. Glutamine should be administered enterally or parenterally whenever total parenteral nutrition is indicated.

Echinacea purpurea along with zinc, selenium and vitamin C to alleviate exacerbations of chronic obstructive pulmonary disease: results from a randomized controlled trial

WHAT IS KNOWN AND OBJECTIVE

Upper respiratory tract infections (URTI) frequently cause exacerbations of chronic-obstructive pulmonary disease (COPD). Stimulation of the innate immune system may provide an early defence against such infections. The objective of this study was to determine whether Echinacea purpurea (EP) along with micronutrients may alleviate COPD exacerbations caused by acute URTI.

METHODS

This was a double-blind, randomized, placebo-controlled trial in COPD patients with acute URTI. Patients were given ciprofloxacin for 7 days and additionally one tablet per day of EP, of EP along with zinc, selenium and ascorbic acid (EP+), or of placebo until day 14. Serum levels of TNF α and interleukins 1β, 6 and 10 were measured before and after treatment. Until week 4 post-end of treatment, all patients had to daily report on COPD symptoms in diaries.

RESULTS AND DISCUSSION

In total, 108 mostly male patients with a mean age of 65·8 years (40-81 years) were enrolled. Patients of the three treatment arms did not vary significantly in baseline characteristics. EP+, but not EP resulted in significantly less severe and shorter exacerbation episodes following URTI as compared with placebo suggesting a synergistic effect of Echinacea and micronutrients. Large variations in biomarkers in-between and within groups were unrelated to treatment. Study medication was safe and well tolerated with overall 15 adverse events one of which was serious. Among those, sleeping disorders were most frequent and likely related to the underlying disease.

WHAT IS NEW AND CONCLUSION

The combination of EP, zinc, selenium and vitamin C may alleviate exacerbation symptoms caused by URTI in COPD. Further studies are warranted to investigate the interactions among Echinacea, zinc, selenium and vitamin C.

Trace element loss in urine and effluent following traumatic injury

BACKGROUND

Few data are available to establish recommendations for trace element supplementation during critical illness. This study quantified the loss of several elements and assessed the adequacy of manganese and selenium in parenteral nutrition (PN).

METHODS

Men with traumatic injuries were grouped by renal status: adequate (POLY; n = 6), acute failure with continuous venovenous hemofiltration (CVVH; n = 2), or continuous venovenous hemodiafiltration (CVVHD; n = 4). PN supplied 300 microg/d manganese and 60 microg/d selenium. Urine and effluent (from artificial kidneys) were collected for 3 days and analyzed for boron, manganese, nickel, and silicon using inductively coupled plasma atomic emission spectrometry, and for selenium using atomic absorption spectrometry.

RESULTS

POLY manganese and selenium excretion averaged (standard deviation [SD]) 7.9 (3.3) microg/d and 103.5 (22.4) microg/d, respectively. All elements except selenium were detected in dialysate (prior to use). CVVHD effluent contained 3.5 and 7.3 times more manganese and nickel than CVVH ultrafiltrate, respectively. Loss of manganese averaged 2.6%, 21%, and 73% of PN amounts for POLY, CVVH, and CVVHD groups, respectively.

DISCUSSION

Minimal loss of manganese compared with the amount in PN suggests that excessive amounts are retained. POLY patients excreted more selenium than was in PN, indicating negative balance. POLY losses of boron and silicon were less than that published for healthy adults, reflecting less than typical intake, whereas loss during CVVH was in the normal reference range, possibly because of added intake from boron contamination of replacement fluids. All patients lost more nickel than amounts published for healthy adults.

CONCLUSIONS

Current guidelines of 60-100 microg/d of parenteral manganese may be excessive for trauma patients. The uptake of manganese and nickel from contaminants in CVVHD dialysate should be investigated.

Effects of high doses of selenium, as sodium selenite, in septic shock: a placebo-controlled, randomized, double-blind, phase II study

INTRODUCTION

Sepsis is associated with the generation of oxygen free radicals and (lacking) decreased selenium plasma concentrations. High doses of sodium selenite might reduce inflammation by a direct pro-oxidative effect and may increase antioxidant cell capacities by selenium incorporation into selenoenzymes. We investigated the effects of a continuous administration of high doses of selenium in septic shock patients.

METHODS

A prospective, multicentre, placebo-controlled, randomized, double-blind study was performed with an intention-to-treat analysis in severe septic shock patients with documented infection. Patients received, for 10 days, selenium as sodium selenite (4,000 microg on the first day, 1,000 microg/day on the nine following days) or matching placebo using continuous intravenous infusion. The primary endpoint was the time to vasopressor therapy withdrawal. The duration of mechanical ventilation, the mortality rates in the intensive care unit, at hospital discharge, and at 7, 14, 28 and 180 days and 1 year after randomization, and adverse events were recorded.

RESULTS

Sixty patients were included (placebo, n = 29; selenium, n = 31). The median time to vasopressor therapy withdrawal was 7 days in both groups (95% confidence interval = 5-8 and 6-9 in the placebo and selenium groups, respectively; log-rank, P = 0.713). The median duration of mechanical ventilation was 14 days and 19 days in the placebo and selenium groups, respectively (P = 0.762). Mortality rates did not significantly differ between groups at any time point. Rates of adverse events were similar in the two groups.

CONCLUSION

Continuous infusion of selenium as sodium selenite (4,000 microg on the first day, 1,000 microg/day on the nine following days) had no obvious toxicity but did not improve the clinical outcome in septic shock patients. Trial Registration = NCT00207844.

Low serum alpha-tocopherol and selenium are associated with accelerated apoptosis in severe sepsis

During sepsis, a severe systemic disorder, micronutrients often are decreased. Apoptosis is regarded as an important mechanism in the development of often significant immunosuppression in the course of the disease. This study aimed to investigate alpha-tocopherol and selenium in reference to apoptosis in patients with sepsis. 16 patients were enrolled as soon as they fulfilled the criteria of severe sepsis. 10 intensive care patients without sepsis and 11 healthy volunteers served as controls. alpha-Tocopherol, selenium and nucleosomes were measured in serum. Phosphatidylserine externalization and Bcl-2 expression were analyzed in T-cells by flow cytometry. Serum alpha-tocopherol and selenium were decreased in severe sepsis but not in non-septic critically ill patients (p < 0.05). Conversely, markers of apoptosis were increased in sepsis but not in critically ill control patients: Nucleosomes were found to be elevated 3 fold in serum (p < 0.05) and phosphatidylserine was externalized on an expanded subpopulation of T-cells (p < 0.05) while Bcl-2 was expressed at lower levels (p < 0.05). The decrease of micronutrients correlated with markers of accelerated apoptosis. Accelerated apoptosis in sepsis is associated with low alpha-tocopherol and selenium. The results support the investigation of micronutrient supplementation strategies in severe sepsis.

Randomised trial of glutamine and selenium supplemented parenteral nutrition for critically ill patients. Protocol Version 9, 19 February 2007 known as SIGNET (Scottish Intensive care Glutamine or seleNium Evaluative Trial)

Background

Mortality rates in the Intensive Care Unit and subsequent hospital mortality rates in the UK remain high. Infections in Intensive Care are associated with a 2–3 times increased risk of death. It is thought that under conditions of severe metabolic stress glutamine becomes "conditionally essential". Selenium is an essential trace element that has antioxidant and anti-inflammatory properties. Approximately 23% of patients in Intensive Care require parenteral nutrition and glutamine and selenium are either absent or present in low amounts. Both glutamine and selenium have the potential to influence the immune system through independent biochemical pathways. Systematic reviews suggest that supplementing parenteral nutrition in critical illness with glutamine or selenium may reduce infections and mortality. Pilot data has shown that more than 50% of participants developed infections, typically resistant organisms. We are powered to show definitively whether supplementation of PN with either glutamine or selenium is effective at reducing new infections in critically ill patients.

Methods/design

2 × 2 factorial, pragmatic, multicentre, double-blind, randomised controlled trial. The trial has an enrolment target of 500 patients. Inclusion criteria include: expected to be in critical care for at least 48 hours, aged 16 years or over, patients who require parenteral nutrition and are expected to have at least half their daily nutritional requirements given by that route.

Allocation is to one of four iso-caloric, iso-nitrogenous groups: glutamine, selenium, both glutamine & selenium or no additional glutamine or selenium. Trial supplementation is given for up to seven days on the Intensive Care Unit and subsequent wards if practicable. The primary outcomes are episodes of infection in the 14 days after starting trial nutrition and mortality. Secondary outcomes include antibiotic usage, length of hospital stay, quality of life and cost-effectiveness.

Discussion

To date more than 285 patients have been recruited to the trial from 10 sites in Scotland. Recruitment is due to finish in August 2008 with a further six months follow up. We expect to report the results of the trial in summer 2009.

Trial registration

This trial is registered with the International Standard Randomised Controlled Trial Number system. ISRCTN87144826

Time course and relationship between plasma selenium concentrations, systemic inflammatory response, sepsis, and multiorgan failure

BACKGROUND

Selenium plays an important role in defence against acute illness. We investigated, in intensive care unit (ICU) patients, the time course of plasma selenium concentrations and their relationship to systemic inflammatory response syndrome (SIRS), organ dysfunction/failure, infection, and ICU outcome.

METHODS

Plasma selenium and laboratory indices of organ dysfunction/failure, tissue inflammation, and infection were measured daily during the ICU stay in 60 consecutive ICU patients, 15 in each of four a priori defined subgroups: ICU controls (no SIRS); uncomplicated SIRS; severe SIRS; and severe sepsis/septic shock.

RESULTS

Plasma selenium concentrations were below standard values for healthy subjects (74 microg litre(-1)) in 55 patients (92%). Selenium concentrations decreased during the ICU stay in all groups, except controls, to a minimum value that was lower in patients with organ failure, particularly in those with infection. The minimum plasma selenium was inversely correlated to admission Acute Physiology and Chronic Health Evaluation II and Simplified Acute Physiology System II scores, indicators of inflammation, and the maximal degree of organ dysfunction/failure during the ICU stay. Plasma selenium was positively correlated with minimum platelet count, minimum plasma antithrombin activity, and protein C activity. In a receiver operator characteristic analysis, SAPS II score [area under the curve (AUC) = 0.903] and minimum selenium concentration (AUC = 0.867) were the strongest predictive factors for ICU mortality.

CONCLUSIONS

In critically ill surgical patients, plasma selenium concentrations are generally low with a greater decrease during the ICU stay in patients with organ failure, especially when attributed to infection. Lower plasma selenium concentrations are associated with more tissue damage, the presence of infection or organ dysfunction/failure, and increased ICU mortality.

Seleno-enzymes and seleno-compounds: the two faces of selenium

Selenium protects cells and inhibits many inflammatory cell mechanisms through antioxidant seleno-enzymes. Immunity improvement is illustrated by the study of Berger and colleagues, with reduction of nosocomial pneumonia in burnt patients under multi-trace-element supplementation. As seleno-compounds (especially sodium selenite) are pro-oxidant, however, administration above 800 μg/day may be dangerous in septic shock. Paradoxically, direct reversible pro-oxidative effects of seleno-compounds may also be beneficial for reduction of inflammation (genomic action, apoptosis), and may even be bactericidal or virucidal. These facts need to be further examined, as well as the possible dramatic drop of plasma selenoprotein P in septic shock and its role in endothelium protection.