Nutritional management of patients treated with continuous renal replacement therapy

Abstract Continuous renal replacement therapy (CRRT), along with prolonged intermittent renal replacement therapies, represents the primary choice in critically ill patients with acute kidney injury or end-stage renal disease due to better hemodynamic stability, with efficient fluid removal and metabolic control. Nutritional support is also greatly facilitated by a more efficient volume and azotemic control, however, with some limitations. Determination of energy expenditure can be confounded by CRRT, and buffers used in CRRT fluids can be metabolized and contribute to the carbohydrate load. More specifically, glucose and calorie balance may be disrupted, affecting glycemic control and calorie intake. Amino acids, vitamins, and trace elements can be lost selectively and in variable proportions, leading to negative nutrient balance. Electrolytes need to be monitored and replaced with strict protocols. Nutritional losses can be supplemented, which may improve clinical outcomes. An understanding of these mechanisms is essential to allow for a better combination of CRRT and nutritional support.