METABOLIC SUPPORT: Edited by Paul E. WischmeyerIndirect calorimetry in critical illness: a new standard of care?De Waele, Elisabetha,b,c; Jonckheer, Joopb; Wischmeyer, Paul E.dAuthor Information aDepartment of Clinical Nutrition bDepartment of Intensive Care Medicine cFaculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Brussels, Belgium dDepartment of Anesthesiology and Surgery, Duke University School of Medicine, Durham, North Carolina, USA Correspondence to Elisabeth De Waele, ICU Department, UZ Brussel, 101, Laarbeeklaan, 1090 Jette, Belgium. E-mail: [email protected] Current Opinion in Critical Care: August 2021 - Volume 27 - Issue 4 - p 334-343 doi: 10.1097/MCC.0000000000000844 Buy Metrics Abstract Purpose of review Review recent literature on the role of indirect calorimetry in critical care nutrition management. Recent findings Critical illness demands objective, targeted nutritional therapy to prevent adverse effects of underfeeding/over feeding. Thus, all recent societal guidelines recommend indirect calorimetry use to determine energy needs. Very recently, indirect calorimetry technology has finally evolved to allow for accurate, simple, and routine utilization in a wider range of ICU patients. Recent data continues to confirm poor correlation between measured and equation-predicted energy expenditure emphasizing need for indirect calorimetry to be standard of care. This may be particularly true in COVID-19, where significant progressive hypermetabolism and variability in energy expenditure has been shown. Metabolic physiology can change frequently during ICU stay in response to changes in clinical condition or care. Thus, repeated longitudinal indirect calorimetry measures are needed throughout ICU stay to optimize care, with initial data showing improved clinical outcomes when indirect calorimetry targets are utilized. Summary Personalized ICU care demands objective data to guide therapy. This includes use of indirect calorimetry to determine energy expenditure and guide ICU nutrition therapy. Long-awaited new innovations in indirect calorimetry technology should finally lead to indirect calorimetry to becoming a fundamental component of modern ICU standard of care and clinical research moving forward. Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.