Dexamethasone Suppression Cushings

Overview

  • EPIC Code:
  • LAB2404
  • Soft Test Code:
  • DSTC1
Alternate Names
  • Cushings
  • Dexamethasone Suppression for Cushings
Included Tests

8 AM Cortisol


Specimen Collection & Preparation

Patient Preparation

Patient should discontinue taking Biotin, Vitamin B7, or Vitamin H 48 hours before getting blood drawn.


Specimen Requirements:

-OR-

1.0 mL Serum in a SST Gold Top Tube
Minimum Volume:
0.2 mL Serum*

* This volume does not allow for repeat testing

Specimen Information:

Cushing’s Syndrome Method
 
1.  A dose of 1 mg of Dexamethasone is to be given to the patient at 11:00 P.M.
2.  Request an 8:00 A.M. Cortisol to be drawn the next morning.


Processing Instructions:

Specimens are stable 48 hours unspun


Transport and Storage:
  • Ambient (18-24°C): 24 Hours
  • Refrigerated (2-8°C): 4 Days
  • Frozen (-20° C or colder): 12 Months

Clinical Interpretation

Reference Range:

0.0 - 1.8 ug/dL


Test Comments:

In the screen for Cushing’s Syndrome, the Cortisol level will not be suppressed if the disease is present.

Patients taking vitamin supplements containing high doses of biotin (>5 mg/day) may have falsely increased test results generated.


Methodology:
  • Chemiluminescence (CL)
Documentation

Two methods are acceptable for Dexamethasone Suppression Testing. 
    The first one is used primarily as a screening test for Cushing’s Syndrome (Test Code DSTC1)
    The second is used on psychiatric patients to diagnose depression (Test Code DST)


Production Schedule

Sites Performed
  • Parkview Regional Medical Center
Days Performed
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Departments
  • Chemistry
Turn Around Time

Same day/next day


Coding & Compliance

CDM

01483972


CPT Coding

82533