Acute kidney disease (AKD) -which includes acute kidney injury (AKI) e and chronic kidney disease (CKD) are highly prevalent among hospitalized patients, including those in nephrology and medicine wards, surgical wards, and intensive care units (ICU), and they have important metabolic and nutritional consequences.Moreover, in case kidney replacement therapy (KRT) is started, whatever is the modality used, the possible impact on nutritional profiles, substrate balance, and nutritional treatment processes cannot be neglected.The present guideline is aimed at providing evidence-based recommendations for clinical nutrition in hospitalized patients with AKD and CKD. Due to the significant heterogeneity of this patient population as well as the paucity of high-quality evidence data, the present guideline is to be intended as a basic framework of both evidence and -in most cases -expert opinions, aggregated in a structured consensus process, in order to update the two previous ESPEN Guidelines on Enteral (2006) and Parenteral (2009) Nutrition in Adult Renal Failure. Nutritional care for patients with stable CKD (i.e., controlled protein content diets/low protein diets with or without amino acid/ketoanalogue integration in outpatients up to CKD stages four and five), nutrition in kidney transplantation, and pediatric kidney disease will not be addressed in the present guideline.

Introduction Nutrition is an important part of treatment in critically ill children. Clinical guidelines for nutrition adaptations during continuous renal replacement therapy (CRRT) are lacking. We collected and evaluated current knowledge on this topic and provide recommendations. Methods Questions were produced to guide the literature search in the PubMed database. Results Evidence is scarce and extrapolation from adult data was often required. CRRT has a direct and substantial impact on metabolism. Indirect calorimetry is the preferred method to assess resting energy expenditure (REE). Moderate underestimation of REE is common but not clinically relevant. Formula‐based calculation of REE is inaccurate and not validated in critically ill children on CRRT. The nutrition impact of nonintentional calories delivered as citrate, lactate, and glucose during CRRT must be considered. Quantifying nitrogen balance is not feasible during CRRT. Protein delivery should be increased by 25% to compensate for losses in the effluent. Fats are not removed by CRRT and should not be adapted during CRRT. Electrolyte disturbances are frequently present and should be treated accordingly. Vitamins B1, B6, B9, and C are lost in the effluent and should be adapted to the effluent dose. Trace elements, with the exception of selenium, are not cleared in relevant quantities. Manganese accumulation is of concern because of potential neurotoxicity. Conclusion Current recommendations regarding nutrition support in pediatric CRRT must be extrapolated from adult studies. Recommendations are provided, based on the weak level of evidence. Additional research on this topic is warranted.

BackgroundAn optimal nutritional approach sustained by convenient monitoring of metabolic status and reliable assessment of energy expenditure (EE) may improve the outcome of critically ill patients on extracorporeal membrane oxygenation (ECMO). We previously demonstrated the feasibility of indirect calorimetry (IC)—the standard of care technique to determine caloric targets—in patients undergoing ECMO. This study aims to compare measured with calculated EE during ECMO treatment. We additionally provide median EE values for use in settings where IC is not available.MethodsIC was performed in seven stable ECMO patients. Gas exchange was analyzed at the ventilator, and ECMO side and values were introduced in a modified Weir formula to calculate resting EE. Results were compared with EE calculated with the Harris‐Benedict equation and with the 25 kcal/kg/day ESPEN recommendation.ResultsTotal median oxygen consumption rate was 196 (Q1‐Q3 158‐331) mL/min, and total median carbon dioxide production was 150 (Q1‐Q3 104‐203) mL/min. Clinically relevant differences between calculated and measured EE were observed in all patients. The median EE was 1334 (Q1‐Q3 1134‐2119) kcal/24 hours or 18 (Q1‐Q3 15‐27) kcal/kg/day.ConclusionCompared with measured EE, calculation of EE both over‐ and underestimated caloric needs during ECMO treatment. Despite a median EE of 21 kcal/kg/day, large variability in metabolic rate was found and demands further investigation.

Background: and aims: Caloric prescription based on resting energy expenditure (REE) measured with indirect calorimetry (IC) improves outcome and is the gold standard in nutritional therapy of critically ill patients. Until now continuous renal replacement therapy (CRRT) precluded the use of IC due to several mechanisms. We investigated the impact of CRRT on V_CO 2 , V_O 2 and REE to facilitate indirect calorimetry during CRRT. Methods: In 10 critically ill ventilated patient in need of continuous veno-venous hemofiltration (CVVH) using citrate predilution we performed IC in 4 different states: baseline, high dose, baseline with NaCl predilution and without CVVH. CO 2 content of effluent fluid was measured by a point of care blood gas analyzer. Carbon dioxide production (V_CO 2) measured with IC was adapted by adding the CO 2 flow of effluent and deducing CO 2 flow in postdilution fluid to calculate a true V_CO 2. True REE was calculated with the Weir equation using the true V_CO 2. Results: CO 2 removal in effluent during baseline, high dose and NaCl predilution was respectively 24 mL/min, 38 mL/min and 23 mL/min. Together with the CO 2 delivery by the postdilution fluid this led to an adaptation of REE respectively by 34 kcal/d or 2% (p ¼ 0,002), 44 kcal/d or 3% (p ¼ 0,002) and 33 kcal/d or 2% (p ¼ 0,002). Compared to the true REE during baseline of 1935 ± 921 kcal/d, true REE during high dose was 1723 ± 752 kcal/d (p ¼ 0.65), during NaCl predilution it was 1604 ± 633 kcal/ d (p ¼ 0.014) and without CRRT it was 1713 ± 704 kcal/d (p ¼ 0.193). Conclusions: CO 2 alterations due to CVVH are clinically of no importance so no correction factor of REE is needed with or without CVVH. IC must be performed during CVVH as CVVH seems to alter metabolism. These changes may be mainly explained by the use of citrate predilution.

Background: Indirect calorimetry (IC) is the gold standard for measuring energy expenditure in critically ill patients However, continuous renal replacement therapy (CRRT) is a formal contraindication for IC use. Aims: To discuss specific issues that hamper or preclude an IC-based assessment of energy expenditure and correct caloric prescription in CRRT-treated patients. Methods: Narrative review of current literature. Results: Several relevant pitfalls for validation of IC during CRRT were identified. First, IC measures CO 2 production (VCO 2 ) and O 2 consumption to calculate resting energy expenditure (REE) with the Weir equation. VCO 2 measurements are influenced by CRRT because CO 2 is exchanged during the blood purification process. CO 2 exchange also depends on type of pre-and/or postdilution fluid(s). CO 2 dissolves in different forms with dynamic but unpredictable impact on VCO 2 . Second, the effect of immunologic activation and heat loss on REE caused by extracorporeal circulation during CRRT is poorly documented. Third, caloric prescription should be adapted to CRRT-induced in-and efflux of different nutrients. Finally, citrate, which is the preferred anticoagulant for CRRT, is a caloric source that may influence IC measurements and REE. Conclusion: Better understanding of CRRT-related processes is needed to assess REE and provide individualized nutritional therapy in this condition.