Nutritional Support in Acute Kidney Injury

Abstract

Protein-energy wasting (PEW) is particularly common in patients with acute kidney injury (AKI). It is correlated, at least in part, with specific factors of the reduction of renal function and is associated with significant increase in mortality and morbidity. In this clinical condition, the optimal nutritional support remains an open question due to its qualitative composition in terms of macro- and micronutrients. In fact, data on critically ill patients have confirmed that nutritional support targeting the real protein and energy needs is associated with improvement of clinical outcome. However, data available in AKI patients are still scarce. AKI is characterized by increased risk of both under- and overfeeding because of the coexistence of many factors that can influence the evaluation of nutrient needs, such as a rapid change in body weight due to alterations in fluid balance, loss of nutrients during renal replacement therapy (RRT), and the presence of hidden calories in the RRT (ie, calories derived from anticoagulants and/or from solutions used in the different dialysis methods). As AKI comprises a highly heterogeneous group of patients, with oscillatory nutrient needs during patients’ clinical course, nutritional requirements should be frequently reassessed, individualized, and carefully integrated with RRT. Nutrient needs in patients with AKI can be difficult to estimate and should be directly measured, especially in the intensive care unit setting. This review contains 4 figures, 3 tables and 104 references Keywords: Malnutrition In ICU Patients, Acute Kidney Injury, Nutritional Support, Indirect Calorimetry, Resting Energy Expenditure, Lipid Oxidation Rate, Glucose Oxidation Rate, Micronutrients