Nutritional Support for Patients with Acute Kidney Injury: How Much Protein is Enough or Too Much?

Acute kidney injury occurs commonly in critically ill patients and is associated with increased morbidity and mortality in the ICU. The hypermetabolic and hypercatabolic state that occurs in ICU patients with acute kidney injury is distinctly different than other forms of renal failure such as chronic kidney disease and requires an approach to nutrition that supports protein synthesis to prevent severe muscle wasting and malnutrition. Protein restriction does not appear to offer metabolic advantages or decrease urea generation in AKI associated with critical illness, but does result in a more negative nitrogen balance with potential to compromise lean muscle mass and nutrition status. The metabolic studies available provide insight into appropriate calorie and protein requirements for critically ill patients with AKI.