Metabolic Profiles of Critically Ill COVID-19 Patients: A Comparative Analysis of Energy Expenditure

The COVID-19 pandemic has placed a substantial strain on healthcare systems, particularly in managing critically ill patients. Accurate measurement of energy expenditure (EE) is essential for optimal nutritional support and improved clinical outcomes in these patients. Indirect calorimetry (IC) is the preferred method for assessing EE, though its application in critically ill COVID-19 patients has been underexplored. This study aims to evaluate EE in critically ill patients with and without COVID-19 to identify potential differences that may influence nutritional strategies.

A retrospective observational study was conducted at a large tertiary university hospital, comparing calorimetry data from critically ill patients with and without COVID-19. Data collected included resting energy expenditure, energy expenditure per kilogram, and respiratory exchange ratio (RQ) using IC. 

The study included 95 critically ill patients, with 61 non-COVID-19 patients and 34 COVID-19 patients. COVID-19 patients had significantly lower Simplified Acute Physiology Score (SAPS) II compared to non-COVID-19 patients. Although no significant differences in overall energy needs were observed between the two groups or within the COVID-19 group, there was a trend toward lower energy needs in COVID-19 patients. Significant differences in respiratory quotient were found among COVID-19 patients, particularly between those with and without pulmonary thromboembolism, with the latter group exhibiting lower RQ values.

This study suggests that while overall EE may not significantly differ between critically ill COVID-19 and non-COVID-19 patients, differences in substrate utilization could influence nutritional support strategies. These findings underscore the need for individualized nutritional interventions, particularly for critically ill patients with COVID-19.