Abstract
BACKGROUND: There is controversy over the optimal energy delivery in intensive care units (ICUs). In this study, we aimed to evaluate the association between different caloric adequacy assessed by a weight-based equation and short-term clinical outcomes in a cohort of critically ill patients. METHODS: This is a secondary analysis of a cluster-randomized controlled trial (N = 2,772). The energy requirement was estimated as 25 kcal/kg of body weight. The study subjects were divided into three groups according to their caloric adequacy as calculated by the mean energy delivered from days 3 to 7 of enrollment divided by the estimated energy requirements: (1) received < 70% of energy requirement (hypocaloric), (2) received 70-100% of energy requirement (normocaloric), and (3) received > 100% of energy requirement (hypercaloric). Cox proportional hazards models were used to analyze the association between caloric adequacy and 28-day mortality and time to discharge alive from the ICU. RESULTS: A total of 1,694 patients were included. Compared with normocaloric feeding, hypocaloric feeding significantly increased the risk of 28-day mortality (hazard ratio [HR] = 1.590, 95% confidence interval [CI]: 1.162-2.176, p = 0.004), while hypercaloric feeding did not. After controlling for potential confounders, the association remained valid (adjusted HR = 1.596, 95% CI: 1.150-2.215, p = 0.005). The caloric adequacy was not associated with time to discharge alive from the ICU in the unadjusted and the adjusted models. CONCLUSION: Energy delivery below 70% of the estimated energy requirement during days 3-7 of critical illness is associated with 28-day mortality. CLINICAL TRIAL REGISTRATION: [https://www.isrctn.com/ISRCTN12233792], identifier [ISRCTN12233792].