P414 - THE PREVALENCE OF UNDER AND OVER FEEDING WHEN PREDICTIVE EQUATIONS ARE USED TO DETERMINE ENERGY EXPENDITURE DURING THE FIRST WEEK OF ICU STAY

P414

THE PREVALENCE OF UNDER AND OVER FEEDING WHEN PREDICTIVE EQUATIONS ARE USED TO DETERMINE ENERGY EXPENDITURE DURING THE FIRST WEEK OF ICU STAY

K. Murphy^1,*, N. Kelly-Whyte¹, S. O'Connor¹, C. Twomey¹

¹Nutrition and Dietetics, Cork University Hospital, Cork, Ireland

Rationale: Indirect calorimetry (IC) is the Gold Standard for determining energy expenditure in critically ill patients¹. As IC is not readily available in clinical practice ESPEN recommend aiming for 70% of predictive equations for the first week of ICU stay to avoid potential overfeeding¹. The aim of this study is to compare the Penn State University Equation (PSU) to IC measurements taken during the first week of ICU stay to determine if aiming for 100% of PSU could lead to overfeeding (> 110% IC)² and 70% of PSU could lead to underfeeding (< 80% IC)².

Methods: IC data were collected on ventilated patients admitted to a critical care unit from June 2022 to December 2024. Measurements were taken as close as possible to day 3, 5 and 7 of ICU admission. PSU was calculated on the same day as the IC measurement. The PSU and 70% PSU were compared to IC to determine the degree of under and overfeeding.

Results: 437 IC measurements from 323 patients are included in the results (64% male, mean BMI 27.8kg/m²). Aiming for 100% of PSU would have led to over feeding on 17% of occasions. Aiming for 70% of PSU would have led to underfeeding on 86% of occasions and adequate feeding (80-110% of IC) on 14% of occasions.

Conclusion: Underfeeding is prevalent when aiming for 70% of PSU to estimate energy expenditure in critically ill patients during the first week of ICU stay. Overfeeding is not as common as expected when aiming for 100% of PSU in the same cohort. Applying best practice guidelines by using IC to measure energy expenditure ensured these ICU patients were not under or overfed.

References:         1. Singer P, Blaser AR et al. ESPEN Guideline on clinical nutrition in the intensive care unit Clin Nut 2019; 38: 48-7

        2. Heyland D K, Cahill N, et al. Optimal amount of calories for critically ill patients: depends on how you slice the cake! Crit Care Med 2011; 39: 2619-2626

Disclosure of Interest: None declared