Analysis index

4 ml EDTA-plasma, divide plasma as soon as possible (Stability in plasma at4°C – 8°C: 2 days). In case of longer storage or postal shipping, please freeze plasma.

The evaluation of metanephrine and normetanephrine in plasma can be used for screening of pheochromocytomas/paragangliomas. To avoid false-positive results, blood extraction should be done in an empty-stomached patient after resting in supine position for 20 – 30 minutes, via a previously inserted venous catheter. Due to the uniform use of frozen EDTA-plasma, glutathione tubes are no longer required.

2 – 3 days before the test, coffee, tea, nicotine, alcohol, chocolate, banana, eggs and nuts should be avoided. As far as reasonable, all medication should be discontinued 7 – 14 days prior to test. Theophylline, MAO-inhibitors, phenothiazine, methyldopa, and levodopa can be responsible for an increased catecholamine release for up to 2 weeks and should definitely be discontinued. Diuretics, alpha- and beta-receptor blockers, vasodilators, calcium-antagonists, angiotensin-II-antagonists and ACE-inhibitors, Clonidine (Catapressan®) should also be discontinued where possible. A strong sympathicus stimulation through hypoglycemia, physical exertion or increased intracranial pressure can also lead to increased catecholamine release.

Adrenalin
Adults < 90 ng/l
3 – 15 years of age < 464 ng/l

Noradrenalin
Adults < 460 ng/l
3 – 15 years of age < 1251 ng/l

Dopamine
Adults < 30 ng/l
3 – 15 years of age < 60 ng/l

Suspicion of secondary hypertension, diagnosis and progress checks of pheochromocytoma or pheochromocytoma-paraganglioma-syndrome, screening in case of MEN 2A, neurofibromatosis type 1, Hippel-Lindau syndrome and Incidentaloma. Neuroblastomas (in connection to vanillic acid and homovanillylmandelic acid), ganglioneuroma

It has to be mentioned, that missing catecholamine release does not rule out pheochromocytoma/paraganglioma, as there are asecretory variants, which appear especially at a higher age. Furthermore, dopamine production should be considered in clinically unapparent pheochromocytomas/paragangliomas, hence dopamine or its degradation product 3-methoxytyramine (only in plasma) should be determined.