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Cortisol, Unconjugated, urine
|Method||Tandem Mass Spectrometry|
|Collection Instructions||Obtain container from Specimen Receiving. Report any medications that the patient is taking.|
|Container type||24 hour urine collection container
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|Amount to Collect||Entire 24 hour urine output|
|Sample type||24 hour urine collection|
|Preferred volume||2 mL urine|
|Min. Volume||0.5 mL urine|
|Processing notes||Freeze aliquot from well mixed collection at -20C. Include any information regarding medication the patient is taking. Order Quest # 11280X.|
|Units||µg/24 hours (mcg/24 hours)|
|Synonyms||Free cortisol; Cortisol, free; Free F; Free hydroxycorticoids|
|Turn around times||Test performed Monday-Saturday. Turnaround time: 2-5 days.|
|Additional information||To convert µg/d to nmol/d (SI units) multiply by 2.76.
Urinary creatinine is assayed as a measure of the completeness of urine collection. If the total creatinine excretion is not within normal limits for the patient's age and sex (see entry for Creatinine) and the patient has normal renal function, the urine collection is probably incomplete and the result is invalid.
Because of cyclical excretion and problems with urine collection, it is recommended that assays be repeated on at least two consecutive 24 hour samples: "normalization" of excretion per gram of urinary creatinine cannot correct for incomplete collection (Orth, DN. NewEngl J Med. 1995; 332:791).
|Last Updated||3/24/2013 7:48:09 PM|