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Test Code CORBAS Cortisol Stimulation Baseline, LAB2385

Important Note

Cortisol Baseline is for use only as a part of the 30- or 60-minute Cortisol Stimulation Test.  To perform a 30- and/or 60-minute stimulation test, order a baseline cortisol and also order the 30- and/or 60-minute stimulation tests, as applicable.  If both 30- and 60-minute levels are to be done, order the cortisol baseline only once.


If the test requested is for a cortisol only, order the cortisol a.m. or cortisol p.m. tests, as applicable.


This test is not recommended for pregnant or nursing women.




Performing Laboratory

St. Luke's Hospital Cedar Rapids

Specimen Requirements

It is recommended that procedure be started between 0700 and 0900. Cortrosyn is available from the pharmacy or Pyxis.


Baseline - REQUIRED (30 and/or 60 minute post dose specimens must also be submitted.)




Preferred: Green-top (lithium heparin) tube

Acceptable: Gold-top tube serum gel tube or Plain red-top tube
Specimen Volume: 170 uL of plasma or serum

Stability: Keep tubes stoppered and upright at all times.  Do not use samples that have been stored at room temperature for longer than 8 hours.  Tightly cap and refrigerate specimens at 2° to 8°C if the assay is not completed within 8 hours.  Freeze samples at or below -20°C if the sample is not assayed within 48 hours.  Freeze samples only once and mix thoroughly after thawing.

Collection Instructions: A baseline cortisol is drawn, and then 0.25 mg of Cortrosyn is injected intramuscularly (IM).

Note: 1. Nursing must notify the laboratory of exact time injection was given so post dose time of draw can be set.

2. Label specimen appropriately (for baseline).

3. Assure that 30 min and/or 60 min post dose tests are ordered.




Reference Values

Baseline (AM): 4.3-22.4 mcg/dL

Cortisol 30 min:  18-20 mcg/dL

Cortisol 60 min:  Should show an approximate doubling of baseline cortisol level

Day(s) Test Set Up

Monday through Sunday

Test Classification and CPT Coding


Useful For

The ACTH stimulation test is useful in the screening of patients presumed to have adrenocortical insufficiency.