Identifying a target group for selenium supplementation in high-risk cardiac surgery: a secondary analysis of the SUSTAIN CSX trial.

BACKGROUND: Recent data from the randomized SUSTAIN CSX trial could not confirm clinical benefits from perioperative selenium treatment in high-risk cardiac surgery patients. Underlying reasons may involve inadequate biosynthesis of glutathione peroxidase (GPx3), which is a key mediator of selenium's antioxidant effects. This secondary analysis aimed to identify patients with an increase in GPx3 activity following selenium treatment. We hypothesize that these responders might benefit from perioperative selenium treatment. METHODS: Patients were selected based on the availability of selenium biomarker information. Four subgroups were defined according to the patient's baseline status, including those with normal kidney function, reduced kidney function, selenium deficiency, and submaximal GPx3 activity. RESULTS: Two hundred and forty-four patients were included in this analysis. Overall, higher serum concentrations of selenium, selenoprotein P (SELENOP) and GPx3 were correlated with less organ injury. GPx3 activity at baseline was predictive of 6-month survival (AUC 0.73; p = 0.03). While selenium treatment elevated serum selenium and SELENOP concentrations but not GPx3 activity in the full patient cohort, subgroup analyses revealed that GPx3 activity increased in patients with reduced kidney function, selenium deficiency and low to moderate GPx3 activity. Clinical outcomes did not vary between selenium treatment and placebo in any of these subgroups, though the study was not powered to conclusively detect differences in outcomes. CONCLUSIONS: The identification of GPx3 responders encourages further refined investigations into the treatment effects of selenium in high-risk cardiac surgery patients.

What the clinician needs to know about medical nutrition therapy in critically ill patients in 2023: A narrative review.

Medical nutrition therapy (MNT) represents an essential element in the medical care of critically ill patients admitted to an intensive care unit (ICU). Increasing awareness exists that energy and nutrients not only preserve body structures such as lean body/muscle mass but also represent promising therapeutic elements to target the profound metabolic, inflammatory, endocrinologic, and immunologic alterations occurring during critical illness. However, despite intense research activities for years, diverse aspects of MNT such as the optimal timing, dosing, and composition of energy and macronutrient supply, as well as the role of micronutrients, are still an issue of debate resulting from strong heterogeneity in methods and findings of respective studies. These discrepancies are also reflected in diverging recommendations of international clinical nutrition guidelines for specific topics. In addition, implementing targeted, personalized MNT strategies in routine clinical practice underlies difficulties and challenges resulting from disease-specific issues and/or organizational, structural, and educational aspects. This narrative review aims to summarize the most recent evidence relevant to clinical practice on selected aspects of MNT in adult patients in the ICU and to provide guidance for implementing evidence-based approaches for adequate energy and nutrient supply in the ICU setting.

Administration of vitamin D and its metabolites in critically ill adult patients: an updated systematic review with meta-analysis of randomized controlled trials.

BACKGROUND: The clinical significance of vitamin D administration in critically ill patients remains inconclusive. The purpose of this systematic review with meta-analysis was to investigate the effect of vitamin D and its metabolites on major clinical outcomes in critically ill patients, including a subgroup analysis based on vitamin D status and route of vitamin D administration. METHODS: Major databases were searched through February 9, 2022. Randomized controlled trials of adult critically ill patients with an intervention group receiving vitamin D or its metabolites were included. Random-effect meta-analyses were performed to estimate the pooled risk ratio (dichotomized outcomes) or mean difference (continuous outcomes). Risk of bias assessment included the Cochrane tool for assessing risk of bias in randomized trials. RESULTS: Sixteen randomized clinical trials with 2449 patients were included. Vitamin D administration was associated with lower overall mortality (16 studies: risk ratio 0.78, 95% confidence interval 0.62-0.97, p = 0.03; I2 = 30%), reduced intensive care unit length of stay (12 studies: mean difference - 3.13 days, 95% CI - 5.36 to - 0.89, n = 1250, p = 0.006; I2 = 70%), and shorter duration of mechanical ventilation (9 studies: mean difference - 5.07 days, 95% CI - 7.42 to - 2.73, n = 572, p < 0.0001; I2 = 54%). Parenteral administration was associated with a greater effect on overall mortality than enteral administration (test of subgroup differences, p = 0.04), whereas studies of parenteral subgroups had lower quality. There were no subgroup differences based on baseline vitamin D levels. CONCLUSIONS: Vitamin D supplementation in critically ill patients may reduce mortality. Parenteral administration might be associated with a greater impact on mortality. Heterogeneity and assessed certainty among the studies limits the generalizability of the results. TRIAL REGISTRATION: PROSPERO international prospective database of systematic reviews (CRD42021256939-05 July 2021).