Clonidine Suppression Test (Four-hour)
Also known as: Adrenaline, Plasma, Epinephrine, Plasma, Noradrenaline, Plasma, Norepinephrine, Plasma, Plasma Catecholamines
Use
Diagnose pheochromocytoma and those paragangliomas that may secrete epinephrine, norepinephrine, or both. Such tumors may cause paroxysmal or persistent hypertension. Investigation of hypertensive patients, especially younger individuals, particularly when hypertension is paroxysmal, suggesting pheochromocytoma.2
Special Instructions
Not provided.
Limitations
While elevated plasma levels are clinically useful, false negatives can occur if the specimen is drawn during an uneventful period. False positives are also common due to conditions like cold and hypoglycemia. Numerous drugs affect plasma norepinephrine levels, potentially skewing results.
Methodology
Mass Spectrometry
Biomarkers
Catecholamines, Total, Plasma
AnalyteEpinephrine, Plasma
AnalyteNorepinephrine, Plasma
Analyte
LOINC Codes
- 1606-3 - Norepineph pre 300 ug CLN PO Plas-mCnc
- 1464-7 - Epineph pre 300 ug CLN PO Plas-mCnc
- 1388-8 - FCA Fract pre 300 ug CLN PO Plas-mCnc
- 1604-8 - Norepineph 2h p 300 ug CLN PO Plas-mCnc
- 1462-1 - Epineph 2h p 300 ug CLN PO Plas-mCnc
- 16558-9 - Catechols 2h p chal Plas-mCnc
- 1605-5 - Norepineph 3h p 300 ug CLN PO Plas-mCnc
- 1463-9 - Epineph 3h p 300 ug CLN PO Plas-mCnc
- 16559-7 - Catechols 3h p chal Plas-mCnc
- 12528-6 - Norepineph 4h p chal Plas-mCnc
- 16821-1 - Epineph 4h p chal Plas-mCnc
- 12524-5 - Catechols sp4 p chal Plas-mCnc
- 1606-3 - Norepineph pre 300 ug CLN PO Plas-mCnc
- 1464-7 - Epineph pre 300 ug CLN PO Plas-mCnc
- 1388-8 - FCA Fract pre 300 ug CLN PO Plas-mCnc
- 1604-8 - Norepineph 2h p 300 ug CLN PO Plas-mCnc
- 1462-1 - Epineph 2h p 300 ug CLN PO Plas-mCnc
- 16558-9 - Catechols 2h p chal Plas-mCnc
- 1605-5 - Norepineph 3h p 300 ug CLN PO Plas-mCnc
- 1463-9 - Epineph 3h p 300 ug CLN PO Plas-mCnc
- 16559-7 - Catechols 3h p chal Plas-mCnc
- 12528-6 - Norepineph 4h p chal Plas-mCnc
- 16821-1 - Epineph 4h p chal Plas-mCnc
- 12524-5 - Catechols sp4 p chal Plas-mCnc
Result Turnaround Time
2-4 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
One tube (3 mL) each for baseline, two-hour, three-hour, and four-hour specimens
Minimum Volume
One tube (2.2 mL) each for baseline, two-hour, three-hour, and four-hour specimens
Container
Chilled lavender-top (EDTA) tube
Collection Instructions
Draw blood in chilled lavender-top (EDTA) tube, mix thoroughly. Centrifuge at 4°C. Transfer plasma to plastic tubes. Freeze at -20°C and ship frozen. Prelabel tubes as 'baseline,' 'two-hour,' 'three-hour,' and 'four-hour.' Submit separate frozen specimens for each test requested.
Patient Preparation
Avoid smoking, walnuts, bananas, and certain medications one week before collection. Use an indwelling heparinized catheter to minimize catecholamine elevation due to venipuncture. Remain recumbent during collection. Draw baseline blood 30 minutes after catheter insertion, administer clonidine (0.3 mg) orally, collect repeat specimens two and three hours thereafter.
Storage Instructions
Freeze
Causes for Rejection
Specimen not drawn in correct tube; plasma not received frozen; thawed specimen; inadequate patient preparation
Other tests from different labs that may be relevant