The patient should be fasting overnight (water and non-caffeinated soft drinks are permissible).

Plasma

1. The patient should be in a fully recumbent position (lying down) for at least 20 minutes before and during the sample collection.
2. Draw blood in a chilled EDTA tube. Invert and mix with preservatives.
3. Centrifuge and transfer the plasma to a labeled plastic transport tube.
4. Refrigerate or freeze separated plasma immediately.

Stability after plasma is separated and removed from the cells:
Frozen - 14 days
Refrigerated - 14 days
Room temperature - unstable

Heparinized plasma specimens will be rejected.

83835 - Metanephrines Frac Free (EAP 30021144)

Concentrations of normetanephrine between 146 and 487 pg/mL and metanephrine between 63 and 255 pg/mL are considered indeterminate.