Mind the Gap: Optimizing Nutrition in Critically Ill Patients with AKI

Acute kidney injury (AKI) affects over 50% of patients in the intensive care unit and is significantly associated with progression to acute kidney disease (AKD) and chronic kidney disease (CKD), as well as increased mortality risk, making it a critical population for nutritional intervention. However, protein catabolism in critical illness is a complex process, regulated by the interplay of inflammation and anabolic resistance, such that simply increasing protein intake does not necessarily reverse muscle loss effectively. 
Two landmark large-scale randomized controlled trials—EFFORT Protein (Heyland et al., Lancet 2023) and PRECISe (Bels et al., Lancet 2024)—have challenged the conventional assumption that "higher protein dosing leads to better outcomes." Both studies demonstrated that high-dose protein not only failed to confer clinical benefit, but was potentially harmful in patients with AKI or higher disease severity, and was associated with significantly worse quality-of-life scores at 180 days. This lecture will review this key evidence and discuss why nutritional support strategies during the acute phase should follow a "go slow, not high" principle, with ESPEN's recommended target of approximately 1.3 g/kg/day serving as a relatively safe starting point, while avoiding early high-protein, high-calorie feeding in patients with AKI or multi-organ failure. In addition, the risk of trace element and vitamin deficiencies in critically ill patients and those receiving continuous renal replacement therapy (CRRT) will be discussed, emphasizing that monitoring and supplementation are as critical to comprehensive nutritional care as protein dosing itself.