(470) Energy Requirements in Ventilated Surgical-Trauma Critically Ill Patients With Acute Kidney Injury

Introduction: There is a paucity of literature regarding the effect of acute kidney injury (AKI) on resting energy expenditure (REE). We hypothesized that there is no difference in REE in critically ill ventilated patients with AKI and those without. The aim of this study was to characterize REE as determined by indirect calorimetry (IC) of ventilated surgical-trauma critically ill patients who developed AKI versus those who did not. We further explored the REE in relation to gender, age group and BMI.

Methods: Critically ill ventilated adults whose REE was measured by IC were eligible for inclusion. We excluded pediatric, pregnant, and incarcerated patients, those with a history of quadriplegia, paraplegia, or cystic fibrosis. We also excluded patients with a respiratory quotient outside the normal range and those admitted to the MICU on or following the date of the metabolic cart. Those with major burns defined as ≥ 20% TBSA, with PN orders on or following the date IC was performed, admitted with a tracheostomy, discharged, expired while on mechanical ventilator support or without nutrition prescription were also excluded.

Results: Out of 794 patients screened, 180 were included (AKI= 84, no AKI= 96) with mean age 54 years, BMI 30.5, APACHE II score 21 and SAPS II score 48. Mean overall measured REE was 1730 kcal with no statistical difference between the 2 groups (1642 vs 1665 kcal/day, p=0.380) for AKI vs no AKI respectively.
There was a statistically significant difference in REE between males and females but not within gender group (1806 vs 1425 kcal/day, p< 0.0001; 1804 vs 1839, p= 0.956; 1401 vs 1401, p= 0.8372) for AKI vs no AKI respectively. REE was statistically different between those 18-65 vs > 65 years old but not within age group (1768.4 vs 1427.7 kcal/day, p= 0.0016; 1484 vs 1371, p= 0.272; 1785 vs 1751, p= 0.7354) for AKI vs no AKI respectively. Non-obese REE was statistically different from obese but not within BMI class for AKI vs no AKI (1500 vs 1841 kcal/day, p < 0.0001; 1606 vs 1666, p= 0.477; 1761 vs 1648 p= 0.536).

Conclusions: We found no difference in measured REE in the ventilated surgical-trauma critically ill patients with AKI and those without. Gender, age, and obesity class had an impact on REE, but AKI did not influence within-groups energy difference.