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A B C D E F G H I J K L M N O P Q

Test Identifier Information

 
Registration CodeCORT
Method

At midnight the patient is given 1.0 mg Dexamethasone orally. At 0800 hr the next morning, blood is drawn for plasma cortisol.

Diagnostic Use / Indications

To differentiate normal subjects form those with Cushing's Syndrome.

 

Dexamethasone Suppression Test Protocol

Constituent TestsCortisol, Plasma (Plasma / Serum) ;
External PriceContact Canterbury Health Laboratories on +64 3 364 0484 or email Labinfo.
  

Specimen Collection

 
Pre-Testing Requirements

Appointment required.

No preparation. The patient need not be fasting. It is preferable for the patient to be off medication.

 

Specimen Collection Protocols

At midnight the patient is given 1.0 mg Dexamethasone orally. At 0800 hr the next morning, blood is drawn into either a plasma or serum tube. Send 0.3 mL or more blood for cortisol analysis. 

Patient Specimen2.0mL Red Top,
Sample Delivery to LabAmbient
  

Instructions for Referral to CHLabs

 
Aliquot Instructions0.1 mL or more of plasma or serum. Send for cortisol analysis.
Aliquot Transport to CHLAmbient
  

CHLabs Laboratory

 
DepartmentEndocrine Test Centre
Contact Details Email Email
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Contact Phone Number(03) 3640934 | x80934
Test AvailabilityBy arrangement only - please contact Endolab.
Turnaround TimeN/A
Interpretation

A plasma cortisol of less that 100 nmol/L virtually excludes Cushing's Syndrome. Values above 100 nmol/L should prompt further investigation. Values between 100 and 150 nmol/L are a "grey area" and are unlikely to represent Cushing's Syndrome, but require further assessment and discussion with an Endocrinologist. False positives may occur when patients are depressed, stressed or are receiving drugs such as phenytoin or chronic barbiturate treatment.  

Additional Information

For results please contact Canterbury Health Laboratories ph. 03 364 0300.

Delphic Number Test Number1102

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