Nitrogen, Total, Feces
Test Mnemonic
NITF
CPT Codes
- 84999 - QTY (1)
LOINC ®
16141-4
Performing Laboratory
Mayo Clinic Dpt of Lab Med & Pathology
FDA Category
Laboratory Developed Test
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 5 g | Stool | Mayo Stool collection container | Frozen | Submit entire collection of a 24, 48, 72, or 96 hour timed specimen. Must contain at least 5 grams of stool. Barium and boric acid interfere with the test. |
Minimum Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 2.5 g | From a 24, 48, 72, or 96 hour collection |
Stability
| Environmental Condition | Description |
|---|---|
| Ambient | 7 days |
| Refrigerated | 7 days |
| Frozen | Preferred |
Days Performed
Tue, Fri
Turnaround Time
2 - 6 days
Methodology
| Name | Description |
|---|---|
| Dumas Combustion |
Reference Range
| Nitrogen Total Feces | |||||
|---|---|---|---|---|---|
| Sex | Age From | Age To | Type | Range | Range Unit |
| Years | 15 Years | Normal | Not Established | 16 Years | 99 Years | Normal | 1 - 2 | g/24 hrs |
Special Info
Send ENTIRE STOOL COLLECTION in a Mayo stool container (Supply T291). Include collection period and weight of entire collection with the sample. Call Client Services at 800-628-6816 or 216-444-5755 for stool containers.
Clinical Info
Average fecal nitrogen excretion is approximately 2 g/day, but fecal nitrogen excretion is highly variable, especially in conditions resulting in excessive protein catabolism. Significantly abnormal excretion rates, resulting in negative nitrogen balance, may be associated with severe stress due to multiple trauma, head injury, sepsis, or extensive burns. Elevated values >2.5 g total fecal nitrogen/24 hours are usually found in cases of chronic progressive pancreatitis. The goal with therapy for a depleted person is a positive nitrogen balance of 4 to 6 g nitrogen/24-hours. Measurement of both urine and fecal nitrogen is necessary for the accurate determination of nitrogen balance.