Abstract 17372: Comparison of Resting Energy Expenditure With Energy Intake in Neonates With Hypoplastic Left Heart Syndrome Following Stage 1 Palliation

Abstract

Introduction: Nutrition provision and fluid administration following cardiac surgery in neonates impacts ventilator-dependent days, intensive care unit length of stay and diuretic administration. Resting energy expenditure (REE) in neonates following stage 1 palliation (S1P) for hypoplastic left heart syndrome (HLHS) has been poorly characterized and is essential to the provision of optimal nutrition. Methods: We continuously measured REE from postoperative day (POD) 0 through 7 following S1P in n=22 infants using an in-line, indirect calorimetric device (E-COVX moduleTM, GE Healthcare). Artifactual REE values were identified and filtered according to a predefined algorithm. Energy intake (EI) was abstracted from a detailed nutrition record. Results: There were no complications related to REE measurement, and 7.4% of measurements were found to be artifactual and excluded. Mean REE was 35.9 ± 10.1 kcal/kg/day on POD 0 and increased by an average of 3.1 ± 0.2 kcal/kg/day each day between POD 0 and 7 (A). Current recommended dietary allowance (RDA) estimates propose energy needs to be 108 kcal/kg/day in these patients. From POD 0-1, EI was less than REE by 18.5±4.3 kcal/kg/day, as fluid intake was primarily comprised of blood products (46.8±7.4%) and flushes (24.5±1.9%, B). From POD 2-7, EI exceeded REE by 22.6±4.4 kcal/kg/day (cumulative amount of 111 ± 7.7 kcal/kg/day over a 5 day period, C). EI from carbohydrates was disproportionately high (69.1±6.2%), and that from protein remained low (7.6±1.2% of calories, 1.53±0.3 g/kg/day, C). Conclusions: Following S1P, EI correlates poorly with measured REE, which is significantly lower than RDA estimates. This may result in excessive fluid and calorie administration in this fluid-sensitive population. Continuous measurement of REE is safe to perform and should be considered in neonates following cardiac surgery. A future trial comparing restricted EI to estimated EI in postoperative neonates is necessary.