Specimen Collection
SPECIMEN:
Single stool
It is preferable that patients have been on a diet containing 70-100g fat per day for at least 3 days prior to and during the collection period.
No laxatives should be given.
Stool for steatocrit testing is stable for seven days under refrigeration. If longer term storage is necessary, it should be frozen.
Specimen must not contain foreign material such as toilet paper.
Note: Labplus no longer offers the 72-hour quantitative faecal fat test
Reference Intervals
Units:
expressed as percentages (%)
Age >6 months:
|
<10%
|
normal
|
|
10-20%
|
equivocal
|
|
>20%
|
abnormal (steatorrhoea)
|
Uncertainty of measurement: 25%
Turnaround Time: Within 1 week
Assay Method
Principle:
Ratio fat:solids
Reagent:
In-house reagents
Analyser:
Manual measurement
Diagnostic Use and Interpretation
The steatocrit is a measure of the amount of fat in faeces. Fat content is expressed as a percentage, derived from the volume of fatty layer divided by the volume of liquid-free solid faecal layer after centrifugation. It is a more convenient alternative to the 72 hour faecal fat test as it requires only a single stool sample.
There is a reasonable correlation between steatocrit and 72 hour faecal fat measurements and the steatocrit has been shown to be a reliable screening test for steatorrhoea.
The traditional microscopic examination of stool for fat globules is now replaced by this steatocrit test.
INFANTS
Both term and premature infants show high and widely variable steatocrit values in the first 6mths of life ("physiologic steatorrhoea"). Human milk-fed babies' steatocrits decrease earlier than formula fed babies. In the first month of life the steatocrit may give very high values (e.g. even up to 80-100%) with no differences between feeding regimens.
References
1. Amann, S. T., S. A. Josephson, et al. (1997). "Acid steatocrit: a simple, rapid gravimetric method to determine steatorrhea." Am J Gastroenterol 92(12): 2280-4.
2. Van den Neucker, A. M., E. M. Kerkvliet, et al. (2001). "Acid steatocrit: a reliable screening tool for steatorrhoea." Acta Paediatr 90(8): 873-5.
3. Van den Neucker A, Forget P, Veneberg JA et al. Acid steatocrit during infancy. Acta Paediatr. 1996;85:1153-1155
Contact Information
Emails to
chemicalpathologist@adhb.govt.nz
will receive priority attention from the on-call chemical pathologist.
If the query concerns a specific patient please include the NHI number in your email.
If email is not a suitable option, please contact the on-call chemical pathologist via
Lablink (Auckland City Hospital ext. 22000 or 09-3078995).
Individual chemical pathologists may be contacted but will not be available at all times.
After-hours
: contact
Lablink (Auckland City Hospital ext. 22000 or 09-3078995) or hospital operator for on duty staff after hours.
Dr Samarina Musaad
(Clinical Lead)
:
SamarinaM@adhb.govt.nz
ext. 22402
Dr Cam Kyle:
CampbellK@adhb.govt.nz
ext 22052
Dr Weldon Chiu:
WeldonC@adhb.govt.nz
ext. 23427
Dr Campbell Heron:
CHeron@adhb.govt.nz
ext. 23427
Dr Sakunthala Jayasinghe:
Sakunthala@adhb.govt.nz
ext. 23427