Low versus standard calorie and protein feeding and renal dysfunction in ventilated adults with shock: a NUTRIREA-3 post hoc analysis

Intensive Care Medicine: Published: 16 April 2026

Purpose

The optimal intake of artificial nutrition in critically ill patients remains unclear. While calorie and protein intakes affect glomerular function in patients with chronic kidney disease, their relation to renal function at the acute phase of intensive care is insufficiently documented. We aimed to study associations of a low-calorie and low-protein diet with renal outcomes in critically ill patients.

Methods

This post hoc analysis of the NUTRIREA-3 randomized-controlled trial included 3036 mechanically ventilated patients with shock. Calorie and protein intakes during the first 7 days were either low (6 kcal/kg and 0.2–0.4 g protein/kg/d) or standard (25 kcal/kg and 1.0–1.3 g protein/kg/d). The primary outcome was the incidence of acute kidney disease (AKD) during the ICU stay (up to ICU discharge or day 90 after inclusion, whichever occurred first).

Results

AKD during the ICU stay occurred in 669 (44.6%) low-group patients and 691 (46.1%) standard-group patients (hazard ratio, 0.97; 95% CI 0.88–1.07; P = 0.53). The highest urea level and the urea level at ICU discharge were significantly lower in the low group (P = 0.002). No differences were found for renal replacement therapy requirements or other renal outcomes. The results were similar in patients with early kidney dysfunction, severe organ failures, or end-stage chronic kidney disease.

Conclusion

In critically ill patients with shock, early low-calorie and low-protein nutrition for 7 days was not associated with worse renal outcomes or mortality compared to standard feeding, even in patients with preexisting renal dysfunction.