Nitrogen, Total, 24 Hour, Urine
Use
This test is useful for assessing nutritional status (protein malnutrition), assessment of protein nutrition and nitrogen balance in hospitalized patients, evaluating protein catabolism, and determining nitrogen balance when used in conjunction with 24-hour fecal nitrogen measurement. It measures total urinary nitrogen excretion, which is key in evaluating protein catabolism and nutritional status. Urinary nitrogen excretion within normal range indicates adequate nutrition; moderate deviations may reflect stress or trauma; significant deviations may occur in severe stress states such as trauma, sepsis, or burns, with therapeutic goals targeting a positive nitrogen balance of 4 to 6 g nitrogen/24 hours. Citations: Mayo Clinic Labs overview pages ([mayocliniclabs.com](https://www.mayocliniclabs.com/test-catalog/Overview/607705?utm_source=openai)).
Special Instructions
Not provided.
Limitations
Urine samples with visible blood may exhibit a positive bias due to nitrogen from hemoglobin, and nitrogen lost from wounds, burns, or sputum must be included in balance studies. Measurement of both urine and fecal nitrogen is necessary for accurate nitrogen balance estimation. Citations: ([mayocliniclabs.com](https://www.mayocliniclabs.com/test-catalog/Overview/607705?utm_source=openai)).
New York Approved
Methodology
Other
Biomarkers
Nitrogen, Total, U
Analyte
LOINC Codes
- 2660‑9
- 13362‑9
- 28009‑9
- 2660‑9
Result Turnaround Time
1-8 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
10 mL
Minimum Volume
2 mL
Container
Plastic, 10‑mL urine tube
Collection Instructions
Collect urine for 24 hours; no preservative; refrigerated is preferred.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 7 days |
| Frozen | 3 years |