Protein Requirements: Refocusing on an Essential Nutrient

ICU-acquired muscle weakness is associated with poor outcomes in critically ill patients. Current international guidelines suggest introducing early nutritional support to limit energy and protein debt and mitigate muscle loss. A protein target of 1.3 g/kg/day should be reached progressively up to day 4 in the acute phase of critical illness. In patients receiving kidney replacement therapy (KRT), the protein target should be raised to 1.3–1.5 g/kg/d and 1.5–1.7 g/kg/d for intermittent and continuous KRT, respectively. In the post-acute or rehabilitation phase, the association of high protein intake and physical exercise may be beneficial.