Catecholamine Fractionation, Free, Plasma
Centralized Core Laboratory:Chemistry
Purple top (EDTA- with sodium metabisulfite solution) tube
Sent to Reference laboratory
High- Pressure Liquid Chromatography (HPLC)
Draw 20 mL of blood into two chilled tubes. Separate plasma in a refrigerated centrifuge within 30 minutes of draw. Freeze 7 mL of plasma immediately.
Unless the purpose of the measurement is drug monitoring, discontinue any epinephrine, norepinephrine, or dopamine for at least 12 hours before specimen draw. Discontinue drugs that release epinephrine, norepinephrine, or dopamine or hinder their metabolism for at least 1 week before obtaining the specimen. If this is not possible for medical reasons contact the laboratory. Refrain from tobacco and drinking caffeinated beverages for at least 4 hrs. before specimen draw. Drawing from a catheter is required. Have patient rest for 30 min. in the supine position. Then withdraw and discard a minimum of 3mL of blood to remove saline out of the catheter.
Days Peformed: Mon-Fri 9:00AM
Call laboratory to make sure they have proper tubes for collection and to verify collection requirements.
OC Power Word:
Supine: 70-750 pg/mL
Standing: 200-1700 pg/mL
Supine: undetectable-110 pg/mL
Standing: undectable-140 pg/mL
< 30 pg/mL ( no postural change)
Unconjugated norepinephrine,epinephrine, and dopamine