The trace element selenium is of high importance for many of the body’s regulatory and metabolic functions. Balanced selenium levels are essential, whereas dysregulation can cause harm. A rapidly increasing number of studies characterizes the wide range of selenium dependent functions in the human body and elucidates the complex and multiple physiological and pathophysiological interactions of selenium and selenoproteins. For the majority of selenium dependent enzymes, several biological functions have already been identified, like regulation of the inflammatory response, antioxidant properties and the proliferation/differentiation of immune cells. Although the potential role of selenium in the development and progression of cardiovascular disease has been investigated for decades, both observational and interventional studies of selenium supplementation remain inconclusive and are considered in this review. This review covers current knowledge of the role of selenium and selenoproteins in the human body and its functional role in the cardiovascular system. The relationships between selenium intake/status and various health outcomes, in particular cardiomyopathy, myocardial ischemia/infarction and reperfusion injury are reviewed. We describe, in depth, selenium as a biomarker in coronary heart disease and highlight the significance of selenium supplementation for patients undergoing cardiac surgery.

Critical illness is characterized by a loss of commensal flora and an overgrowth of potentially pathogenic bacteria, leading to a high susceptibility to nosocomial infections. Probiotics are living non-pathogenic microorganisms, which may protect the gut barrier, attenuate pathogen overgrowth, decrease bacterial translocation and prevent infection. The purpose of this updated systematic review is to evaluate the overall efficacy of probiotics and synbiotic mixtures on clinical outcomes in critical illness. Computerized databases from 1980 to 2016 were searched. Randomized controlled trials (RCT) evaluating clinical outcomes associated with probiotic therapy as a single strategy or in combination with prebiotic fiber (synbiotics). Overall number of new infections was the primary outcome; secondary outcomes included mortality, ICU and hospital length of stay (LOS), and diarrhea. Subgroup analyses were performed to elucidate the role of other key factors such as probiotic type and patient mortality risk on the effect of probiotics on outcomes. Thirty trials that enrolled 2972 patients were identified for analysis. Probiotics were associated with a significant reduction in infections (risk ratio 0.80, 95 % confidence interval (CI) 0.68, 0.95, P = 0.009; heterogeneity I 2 = 36 %, P = 0.09). Further, a significant reduction in the incidence of ventilator-associated pneumonia (VAP) was found (risk ratio 0.74, 95 % CI 0.61, 0. 90, P = 0.002; I 2 = 19 %). No effect on mortality, LOS or diarrhea was observed. Subgroup analysis indicated that the greatest improvement in the outcome of infections was in critically ill patients receiving probiotics alone versus synbiotic mixtures, although limited synbiotic trial data currently exists. Probiotics show promise in reducing infections, including VAP in critical illness. Currently, clinical heterogeneity and potential publication bias reduce strong clinical recommendations and indicate further high quality clinical trials are needed to conclusively prove these benefits.

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.

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

The Global Leadership Initiative on Malnutrition (GLIM) approach to malnutrition diagnosis is based on assessment of three phenotypic (weight loss, low body mass index, and reduced skeletal muscle mass) and two etiologic (reduced food intake/assimilation and disease burden/inflammation) criteria, with diagnosis confirmed by fulfillment of any combination of at least one phenotypic and at least one etiologic criterion. The original GLIM description provided limited guidance regarding assessment of inflammation and this has been a factor impeding further implementation of the GLIM criteria. We now seek to provide practical guidance for assessment of inflammation in support of the etiologic criterion for inflammation. A GLIM-constituted working group with 36 participants developed consensus-based guidance through a modified-Delphi review. A multi-round review and revision process served to develop seven guidance statements. The final round of review was highly favorable with 99 % overall "agree" or "strongly agree" responses. The presence of acute or chronic disease, infection or injury that is usually associated with inflammatory activity may be used to fulfill the GLIM disease burden/inflammation criterion, without the need for laboratory confirmation. However, we recommend that recognition of underlying medical conditions commonly associated with inflammation be supported by C-reactive protein (CRP) measurements when the contribution of inflammatory components is uncertain. Interpretation of CRP requires that consideration be given to the method, reference values, and units (mg/dL or mg/L) for the clinical laboratory that is being used. Confirmation of inflammation should be guided by clinical judgement based upon underlying diagnosis or condition, clinical signs, or CRP.