Collect: Serum separator tube or plasma separator tube. Also acceptable: Green (sodium or lithium heparin).
Specimen Preparation: Allow specimen to clot completely at room temperature. Separate serum or plasma from cells ASAP or within 2 hours of collection. Transfer 1 mL serum or plasma to an ARUP Standard Transport Tube. (Min: 0.6 mL)
Storage/Transport Temperature: Refrigerated.
Unacceptable Conditions: Saliva (refer to Cortisol, Saliva, ARUP test code 0080117).
Stability (collection to initiation of testing): After separation from cells: Ambient: 1 week; Refrigerated: 1 week; Frozen: 3 months
Interpretive Data:
0800 hours: 6-23 µg/dL 2000 hours: 0-9 µg/dL 8 hours post 1 mg dexamethasone given at midnight: 0-5 µg/dL 30-60 minutes post 25 units Cosyntropin I.V.: > 20 µg/dL
Note:
To convert to nmol/L, multiply µg/dL by 27.6.
CPT Code(s):
82533
Cross References:
Dexamethasone Suppression (Cortisol, Serum or Plasma)
