Calculating nutritional needs by indirect calorimetry in critcally ill patients

Nutritional assessment and support in the Intensive Care Unit (ICU) is difficult to measure due to the varying levels of metabolic activity/demand in patients. Traditionally, total energy expenditure (TEE) is measured using the Harris‐Benedict equation, which utilizes weight, height, and age to determine TEE, however, in the ICU these values may not be optimal. In this study, we utilize indirect calorimetry to measure patients resting energy expenditures (REE) to calculate individual nutritional demands. We monitored patients'oxygen consumption (VO2), carbon dioxide production (VCO2), respiratory quotient (RQ) and blood biochemistries daily throughout the patients ICU stay and assessed for under/over‐feeding by calculating REE. 75% of all patients required alterations in their nutritional support when calculated by indirect calorimetry. Traditional TEE calculations, in general, overestimated caloric needs resulting in overfeeding of most ICU patients. In conclusion, indirect calorimetry and daily monitoring of patients allows for optimal nutritional support preventing any detrimental effects from under/over‐feeding.