Indirect calorimetry in canopy mode in healthy subjects: performances of the Q-NRG device compared to the Deltatrac II

This study aimed to evaluate the agreement between the Q-NRG device in canopy mode and the Deltatrac II, which has long been considered the Gold Standard for Indirect Calorimetry in clinical practice, while its production has ceased. 

Sixty-one healthy volunteers underwent two consecutive assessments using both the Q-NRG and Deltatrac II in random order, under standardized conditions, including fasting, controlled environment, and consistent body position.

The results revealed that the Q-NRG performed similarly to the Deltatrac II, with energy expenditure (EE) measurements of 1816±361 kcal/day for Q-NRG and 1809±260 kcal/day for Deltatrac II (p=0.803). A significant positive correlation was found between the two devices (ρ=0.78, p<0.01), though the Q-NRG slightly overestimated EE with a bias of 7 ± 227 kcal/day. 

These findings confirm the Q-NRG’s accuracy in canopy mode, validating its clinical application for measuring Energy Expenditure in spontaneously breathing patients.

This study highlights the Q-NRG’s potential for broader use in both routine and critical care settings, providing a reliable, user-friendly solution for assessing metabolic rate across diverse clinical environments.