Nutrients and micronutrients at risk during renal replacement therapy: a scoping review

Abstract

Purpose of review Malnutrition is frequent in patients with acute kidney injury. Nutrient clearance during renal replacement therapy (RRT) potentially contributes to this complication. Although losses of amino acid, trace elements and vitamins have been described, there is no clear guidance regarding the role of micronutrient supplementation. Recent findings A scoping review was conducted with the aim to review the existing literature on micronutrients status during RRT: 35 publications including data on effluent losses and blood concentrations were considered relevant and analysed. For completeness, we also included data on amino acids. Among trace elements, negative balances have been shown for copper and selenium: low blood levels seem to indicate potential deficiency. Smaller size water soluble vitamins were found in the effluent, but not larger size liposoluble vitamins. Low blood values were frequently reported for thiamine, folate and vitamin C, as well as for carnitine. All amino acids were detectable in effluent fluid. Duration of RRT was associated with decreasing blood values. Summary Losses of several micronutrients and amino acids associated with low blood levels represent a real risk of deficiency for vitamins B1 and C, copper and selenium: they should be monitored in prolonged RRT. Further Research is urgently required as the data are insufficient to generate strong conclusions and prescription recommendations for clinical practice.

ESPEN micronutrient guideline

“…In a recent systematic review of 2344 publications, no reference was found about the effect of systemic inflammation on the levels on chromium [102]. However, low chromium levels have been described since the 1970s during acute illness (burns, trauma, and infected patients) with abnormalities in glucose metabolism [80,103].…”

Altered Serum Acylcarnitines Profile after a Prolonged Stay in Intensive Care

“…Secondary carnitine deficiencies may occur in vegetarians, in some clinical situations or as consequences of some drugs therapies (i.e., zidovudine, cyclosporine). Critically ill patients are at risk of carnitine deficiency, due to clinical conditions, supports or treatments [ 4 ], such as prolonged undernutrition, prolonged total parenteral nutrition (commercial formulations do not contain carnitine), prolonged continuous renal replacement therapy (loss of carnitine in the effluent) or valproate treatment (carnitine used for urinary excretion of drug derivates) [ 3 , 5 ]. Reports about carnitine levels in critically ill patients are rare.…”

Serum micronutrient levels in critically ill patients receiving continuous renal replacement therapy: A prospective, observational study

“…Deficiency of these essential micronutrients may be associated with impaired biochemical function and, thus, potentially poor clinical outcomes in critically ill patients. Therefore, it is important to further characterize this potential problem in order to design evidence‐based strategies to replace the lost micronutrients in these patients 7–9 …”

“…Therefore, it is important to further characterize this potential problem in order to design evidence-based strategies to replace the lost micronutrients in these patients. [7][8][9] The aim of this study was to prospectively determine serum concentrations of vitamin B 6 , folic acid and vitamin C, chromium, copper, ceruloplasmin (copper-carrying protein), selenium, and zinc in critically ill patients receiving CRRT treatment.…”