95.3k views
5 votes
A subject has a metabolic study performed with the following results:O2300 ml/minCO2270 ml/minIf the subject's 24-hour urinary nitrogen (UN) is 22 g/24 hours, what is the approximate REE?

User Molbdnilo
by
8.6k points

1 Answer

1 vote

Final answer:

Using the Weir equation, the calculated REE was negative, indicating an error in the metabolic study measurements or data reporting. The REE should be recalculated with accurate data.

Step-by-step explanation:

To calculate the subject's Resting Energy Expenditure (REE), we primarily need to know the oxygen consumption (VO₂) and carbon dioxide production (VCO₂), as well as the urinary nitrogen excretion since the Weir equation includes these variables. The Weir equation is as follows:

REE (kcal/day) = (VO₂ (L/day) × 3.941) + (VCO₂ (L/day) × 1.106) − (UN (g/day) × 2.17)

First, we need to convert the subject's VO₂ and VCO₂ from ml/min to L/day:



  • VO₂ = 300 ml/min × 60 min/hr × 24 hr/day × (1 L/1000 ml) = 4.32 L/day


  • VCO₂ = 270 ml/min × 60 min/hr × 24 hr/day × (1 L/1000 ml) = 3.888 L/day

With the urinary nitrogen (UN), we have 22 g/24 hours already in the correct units for the formula. Plugging these values into the Weir equation gives:

REE = (4.32 × 3.941) + (3.888 × 1.106) - (22 × 2.17)

REE = 17.00832 + 4.300928 - 47.74

REE = 21.309248 - 47.74

REE = -26.430752 kcal/day (which does not make physiological sense)

We expected a positive caloric value. If these were the numbers provided by the metabolic study, there would likely be a mistake either in the measurements obtained during the study or in the reporting of these values. The REE should be recalculated with verified data measurements.

User MicFin
by
7.2k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.