Specimen Requirements

Laboratory Orders

1. Laboratory orders DEX1600 for 1600 day after dexamethasone administration.

2. Laboratory orders DEX2300 for 2300 day after dexamethasone administration.

Patient Preparation

Administer 1 mg of dexamethasone orally to patient at 2300.

Note: Laboratory does not supply dexamethasone.

Specimen Collection

Submit only 1 of the following specimens:

Plasma

Draw blood in a green-top (lithium heparin) tube at 1600 and 2300 the day following dexamethasone and sedative administration. (Hemolyzed specimen is not acceptable.) Spin down, separate within 2 hours of draw, and send 2 mL of lithium heparin plasma.

Note: 1. Indicate plasma.

2. Label specimens appropriately (as plasma and with corresponding draw time [1600 and 2300]).

3. Plasma cortisol levels will be reported for specimens drawn at 1600 and 2300 of the day following dexamethasone ingestion.

Serum
Draw blood in a gold-top serum gel tube at 1600 and 2300 the day following dexamethasone and sedative administration. (Hemolyzed specimen is not acceptable.) Spin down, separate within 2 hours of draw, and send 2 mL of serum.

Note: 1. Indicate serum.

2. Label specimens appropriately (as serum and with corresponding draw time [1600 and 2300]).

3. Serum cortisol levels will be reported for specimens drawn at 1600 and 2300 of the day following dexamethasone ingestion.