Nutrition in ICU Patients with Acute Kidney Injury

Patients with acute kidney injury (AKI) are vulnerable, and nutrition care should take into account the stage of AKI based on the KDIGO system and the use of renal replacement therapy. In AKI stage 1, often observed during the first days in the ICU, preventive measures like volume optimization, blood pressure support, avoidance of hyperglycemia, and nephrotoxic drugs should be accompanied by progressive nutrition with an individualized protein supply adapted to the kidney’s excretory function. During AKI stage 3 with renal replacement therapy, nutrition to the target is possible, but losses of electrolytes, vitamins, and macro- and micronutrients need to be compensated for. These losses are typically proportional to effluent flow during continuous renal replacement therapy. After discontinuation of the renal replacement therapy, kidney function has often not returned to normal, and an approach similar to handling patients with chronic kidney disease with a diet restricted in protein and electrolytes will be necessary, together with oral bicarbonate and phosphate-binding substances.