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HelpTest ID NITF Nitrogen, Total, Feces
Useful For
Determining nitrogen balance, when used in conjunction with 24-hour urine nitrogen measurement
Assessing nutritional status (protein malnutrition)
Evaluating protein catabolism
Method Name
Dumas Combustion
Reporting Name
Nitrogen, Total, FSpecimen Type
FecalContainer/Tube: Stool container (Supply T291)
Specimen Volume: Entire collection (24, 48, 72, or 96 hour)
Collection Instructions:
1. Entire collection must be submitted which should contain at least 5g to 10 g of feces.
2. See Stool Collection Information Sheet in Special Instructions
Additional Information:
1. Length of collection period is required.
2. Barium and boric acid interfere with test procedure.
Specimen Minimum Volume
2.5 g
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Fecal | Frozen (preferred) | |
| Ambient | 7 days | |
| Refrigerated | 7 days | |
Clinical Information
Nitrogen is a key component of proteins. Nitrogen balance is the difference between the amount of nitrogen ingested and the amount excreted in the urine and feces. A majority of nitrogen is excreted as urea in the urine, however, fecal nitrogen can account for 30% to 50% of total nitrogen excretion.
A patient who is in negative nitrogen balance is catabolizing muscle protein to meet the metabolic requirements of the protein catabolism and,therefore, urine and fecal nitrogen may be increased due to stress, physical trauma, surgery, infections, burns, and 11-oxysteroid or thyroxine use. Testosterone and growth hormone have anabolic effects on protein synthesis and may decrease urine and fecal nitrogen.
In the course of chronic progressive pancreatitis, as the pancreas is destroyed, serum amylase and lipase may revert to normal. However, excessive fecal nitrogen levels persist and are used as an indicator of pancreatic atrophy.
Reference Values
<16 years: not established
≥16 years: 1-2 g/24 hours
Cautions
Send ENTIRE STOOL COLLECTION (must contain at least 5 g of feces) frozen on dry ice in Mayo Medical Laboratories approved container.
Measurement of both urine and fecal nitrogen is necessary for the accurate determination of nitrogen balance.
Specify length of collection period (duration of either 24, 48, 72, or 96 hour) for entire stool specimen.
During nitrogen balance studies, nitrogen lost from exuding wounds, such as burns, and from copious sputum must be included in the patient's evaluation.
Day(s) Performed
Tuesday, Friday; 11 a.m.
Report Available
1 dayPerforming Laboratory
Mayo Medical Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.CPT Code Information
84999