In nitrogen balance calculations, which value is commonly added to urinary nitrogen excretion to account for insensible losses?

In nitrogen balance calculations, which value is commonly added to urinary nitrogen excretion to account for insensible losses?

• A. 2 g
• B. 6 g
• C. 4 g
• D. 8 g

Answer: (C)

In nitrogen balance work, not all nitrogen losses are captured in urine. Insensible losses—through skin, sweat, and respiration—occur daily and are not routinely measured. For adults, a typical estimate for these insensible losses is about 4 grams of nitrogen per day. Therefore, when calculating total daily nitrogen losses, you add approximately 4 g to the measured urinary nitrogen excretion to account for these unmeasured losses. The other values would under- or over-estimate the insensible losses, so 4 g is the standard estimate.

In nitrogen balance work, not all nitrogen losses are captured in urine. Insensible losses—through skin, sweat, and respiration—occur daily and are not routinely measured. For adults, a typical estimate for these insensible losses is about 4 grams of nitrogen per day. Therefore, when calculating total daily nitrogen losses, you add approximately 4 g to the measured urinary nitrogen excretion to account for these unmeasured losses. The other values would under- or over-estimate the insensible losses, so 4 g is the standard estimate.