(406) Energy Administration in Acute Nutritional Therapy for ICU Patients: Use of Indirect Calorimetry

Introduction: There is still a lack of consensus regarding energy administration in acute nutritional therapy for critically ill ICU patients. We conducted a basic study on nutritional metabolic alterations during the acute phase using indirect calorimetry and found that endogenous lipid metabolism was increased during the acute phase. We report the results of our study of nutritional metabolic alterations during the acute phase in critically ill ICU patients using indirect calorimetry, and discuss how energy should be administered and the possibility of effective therapeutic intervention.

Methods: Subjects were 33 adult patients (15 with sepsis, 16 with trauma, and 2 with burns) admitted to our emergency ICU. Indirect calorimetry was performed for 72 hours after admission, and energy expenditure (EE), respiratory quotient (RQ), carbohydrate oxidation (CHO), and fatty acid oxidation (FAO) were measured. We also analyzed the relationship between these values and inflammatory parameters (PCT, CRP), nutritional parameters (PA), and various medical information.

Results: The mean value of EE was 1712 kcal/day and showed an increasing trend over time. The mean value of EE was 1712 kcal/day, and the mean values of CHO and FAO showed a maximum value at 48 hours after admission, while RQ showed a minimum value (0.64). All data on the relationship between indirect calorimetry and inflammation correlated significantly with CRP, especially with FAO (p=0.0001). FAO was significantly higher in obese (BMI≥25) than in thin (BMI≤20) subjects (p=0.0047).

Conclusions: Similar to previous studies, our results suggest that energy metabolism is enhanced in the acute phase in critically ill ICU patients, especially endogenous lipid metabolism, in accordance with the severity of illness. In acute nutritional therapy, it is useful to understand the dynamics of nutrient metabolism by utilizing indirect calorimetry, and interventions focusing on endogenous lipid metabolism may have therapeutic effects.