Dexamethasone Suppression Test

Overview

  • EPIC Code:
  • LAB2287
  • Soft Test Code:
  • DST
Alternate Names
  • Dexamethasone Suppresion for Depression
  • DST
Included Tests

Baseline Cortisol; 4 PM Cortisol; 11 PM 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 for each draw
Minimum Volume:
0.2 mL Serum*

* This volume does not allow for repeat testing

Collection Instructions:

Depression Method 
1. Request a baseline Cortisol to be drawn before dosage is given.
2.  A dose of 1 mg of Dexamethasone is to be given to the patient at 11:00 P.M.
3. Request a 4:00 P.M. and 11:00 P.M. Cortisol to be drawn the next day. Minor variations from these times (+ / - 1 hour) will not affect the performance of the test.


Processing Instructions:

Specimens 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:

Refer to Interpretive Results


Test Comments:

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/1 to 2 days


Coding & Compliance

CPT Coding

82533 x 3