Nutritional assessment and support in acute kidney injury.

PURPOSE OF REVIEW

Acute kidney injury (AKI) in the ICU is associated with an increased risk of protein-energy wasting (PEW), a major negative prognostic factor. This review illustrates recently published data and guidelines concerning nutritional problems in AKI, pointing out complexities and peculiarities of the syndrome.

RECENT FINDINGS

The main goals of nutritional support in AKI on renal replacement therapy (RRT) are to ensure the provision of adequate amounts of nutrients, to prevent PEW, to promote tissue reparation, to support the immune system, and possibly to reduce mortality. The enteral route should be preferred, even though parenteral nutrition is often required to target nutritional needs. Special attention should be paid both to the impact of RRT on macronutrient and micronutrient losses, and to the risk of complications. In fact, due to both the acute loss of the kidneys' homeostatic function, and the frequent need of RRT, patients with AKI are especially prone to hypoglycemia and hyperglycemia, hypertriglyceridemia, fluid balance alterations, electrolyte and acid-base derangements.

SUMMARY

This review highlights the most recent concepts and recommendations for nutritional support in AKI, stressing the need for a close integration between adequate nutrition and RRT in this clinical condition, with the aim of carefully tailoring both therapies on patients' changing needs. Recent findings about the renoprotective role of some nutrients (glutamine, omega-3 fatty acids) are also discussed.