Table 1.

List of examples of nutritional guidelines on COVID-19 patients referring to indirect calorimetry

Title	Authors Journal	Publication Online/Final	Statement about Indirect Calorimetry
ESPEN expert statements and practical guidance for nutritional management of individuals with SARS-CoV-2 infection	Barazzoni et al. Clinical Nutrition	March 2020 June 2020	Energy needs can be assessed using indirect calorimetry if safely available with ensured sterility of the measurement system
Nutrition Therapy in Critically Ill Patients with Coronavirus Disease (COVID-19)	Martindale et al. JPEN	May 2020 Sept 2020	While energy requirements can ideally be determined by indirect calorimetry, this technology would involve contamination of equipment and additional exposure to healthcare providers. Thus, we recommend utilizing weight-based equations instead of indirect calorimetry to estimate energy requirements as a practical matter for the COVID-19 patients.
Nutrition Support in the ICU—A Refresher in the Era of COVID-19	Micic et al. Am J Gastroenterol	July 2020 Sept 2020	Although energy expenditure is best measured by indirect calorimetry in critically ill patients, the prolonged time needed for these measures increases clinician risk for viral exposure and is contrary to the principle of “clustering care,” in which patient care is bundled to limit provider exposures. Consider indirect calorimetry if prolonged intubation (>7 days)
Nutrition of the COVID-19 patient in the intensive care unit (ICU): a practical guidance	Thibault et al. Crit Care	July 2020 July 2020	IC is the reference method to assess the energy requirements in the non-COVID-19 ICU patients Indirect calorimetry should be proposed only for patients staying for more than 10 days in the ICU or those on full parenteral nutrition (PN) to avoid overfeeding.
Easy-to-prescribe nutrition support in the intensive care in the era of COVID-19	De Watteville et al Clin Nutr Espen	July 2020 Oct 2020	Due to the lack of resources and the high risk of contagion, in- direct calorimetry (IC) measurements were not used to measure patients’ energy expenditure.
Practical guidance for the use of indirect calorimetry during COVID 19 pandemic	Singer P Clin Nutr Exp	July 2020 Oct 2020	It is mandatory to ensure health professional safety while assessing resting energy expenditure using metabolic monitors. Indirect calorimetry (IC) remains the best tool to assess resting energy expenditure in critically ill patients and ESPEN as well as ASPEN societies recommend its use.