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PLEASE NOTE: Recent changes have been made to this Test


 Recent changes for Dexamethasone Suppression test

Recent changes for Dexamethasone Suppression test
DateFieldChanged FromChanged To
1st December 2023
Request Group

Cortisol

CORT

1st December 2023
Alternative names

DST

DST, Overnight DST

Collection & Request Instructions

Requesting doctor must arrange for patient to receive 1mg Dexamethasone the previous evening.

 Next morning an early morning Cortisol sample must  be taken 

 

Requesting doctor must arrange for patient to take1mg Dexamethasone at 11pm the night before blood collection.

An early morning cortisol (preferably between 8 - 9am) must be collected the following morning.

 

1st December 2023
Assay name

Cortisol; Dynamic testing

Dexamethasone Suppression test

Alternative names

Synacthen Test, Dexamethasone Test

DST

Request Group

Various

Cortisol

Preferred Container Type

SST

Lithium Heparin (with Gel)

Optional Container Type

Lithium Heparin (with Gel)

SST

Collection & Request Instructions

Endocrine consultation is suggested for dynamic testing. e.g. Short/Long Stimulation or Suppression tests using Synacthen or Dexamethasone.

All samples must be clearly marked with patient identification, time and date of sample. Sampling times must also be clearly written on request form.

Requesting doctor must arrange for patient to receive 1mg Dexamethasone the previous evening.

 Next morning an early morning Cortisol sample must  be taken 

 

Frequency

Daily

Dexamethasone Suppression test

Alternative Names:DST
Overnight DST
Laboratory:Clinical Biochemistry
Test Code:CORT
Specimen Types:Blood
Container Types:
Lithium Heparin (with Gel)
SST
Collection & Request Instructions:

Requesting doctor must arrange for patient to take1mg Dexamethasone at 11pm the night before blood collection.

An early morning cortisol (preferably between 8 - 9am) must be collected the following morning.

 

Transport Instructions between Sites and/or Laboratories:Room Temperature
Assay Frequency:Daily
Additional Notes:

A morning cortisol of  < 50 nmol/L after 1 mg dexamethasone administered overnight indicates normal suppression of the hypothalamic pituitary adrenal axis. Levels >/= 50 nmol/L may indicate hypercortisolism.

Please note that hospitalised inpatients not infrequently have an abnormal 1mg dexamethasone suppression test response. If possible, investigations should be delayed until acute illness has subsided.