Optimal energy provision early in ICU stay for critically ill patients receiving parenteral nutrition.

Background: Literature on optimal energy provision via parenteral nutrition (PN) is limited and the evidence quality is low. The purpose of this study is to determine if there is a difference in outcomes in adult critically ill patients when receiving lower vs higher calorie provision via PN early in intensive care unit (ICU) stay.

Methods: Adult patients initiated on PN within the first 10 days of ICU stay from May 2014 to June 2021 were included in this retrospective study. The primary outcome was to determine the impact of lower (<20 kcal/kg/day) vs higher (>25 kcal/kg/day) calorie provision on all-cause, in-hospital mortality. Secondary outcomes were to determine the impact of calorie provision on hospital or ICU length of stay and incidence of complications.

Results: This study included 133 patients: a lower calorie provision group (n = 77) and a higher calorie provision group (n = 56). There was a significant difference in all-cause, in-hospital mortality between the lower and the higher calorie provision groups (36.36% and 17.86%, respectively; P = 0.02). However, upon a multivariate analysis of death at discharge, the specific calorie provision group did not affect the probability of death at hospital discharge. The secondary outcomes were not significantly different between groups.

Conclusion: When comparing lower calorie provision with higher calorie provision in adult critically ill patients receiving PN early within their ICU stay, there were no differences in outcomes after controlling for significant confounders. Future larger prospective studies should further evaluate optimal caloric provision via PN in this population.