(465) Evaluation of Parenteral Nutrition Protein Dose in Critically Ill Patients With Acute Kidney Injury

Introduction: Consensus guidelines suggest high protein doses in critically ill patients. However, recent literature has signaled harm in those with acute kidney injury (AKI) that receive higher doses (≥2.2 g/kg/day) compared to usual doses (≤1.2 g/kg/day). This evaluation compared outcomes of those receiving above versus below the median protein dose (high protein [HP] vs. low protein [LP]) in total parenteral nutrition (TPN) formulas.

Methods: This retrospective cohort study included critically ill adult patients with TPN initiated and a concurrent diagnosis of an AKI at a single academic medical center between February 1, 2016 and November 31, 2023. Patients were excluded if they had TPN prior to ICU admission or if renal replacement therapy was initiated prior to or on the day of TPN initiation. The primary outcome was 60-day mortality, which was compared using a multivariate logistic regression. Secondary outcomes included duration of TPN, mechanical ventilation, and ICU and hospital length of stay.

Results: Seventy-four patients met the inclusion criteria. The median protein dose was 1.4 g/kg/day, of which 36 patients received less than and 38 received greater or equal to divide the cohorts of LP and HP. Baseline characteristics were similar, apart from the LP group having more patients admitted to the cardiovascular ICU (44.4% vs. 15.8%, p=0.007), higher sequential organ failure assessment score (median 7.5 vs. 6, p=0.54), longer time from ICU admission to TPN initiation (median 4.4 vs. 2.7 days, p=0.67), and less severe malnutrition diagnosis (11.1% vs. 21.1%, p=0.246). After adjustment for these covariates, 60-day mortality was nonsignificant (LP 30.6% vs. HP 29%, adjOR 0.91 [95% CI 0.30-2.7], p=0.861). Duration of TPN, mechanical ventilation, and ICU and hospital stays were also nonsignificant.

Conclusions: Patients with AKI receiving higher protein doses in TPN formulas did not have higher 60-day mortality, durations of mechanical ventilation, or hospital durations compared to usual protein doses. While this evaluation may be underpowered to detect a difference in these outcomes, the results may also signal no increase in harm with usual protein doses, strengthening the argument that high protein doses may be unnecessary in critically ill patients with AKI.