Normal values for 24 hours are as follows: Free epinephrine and norepinephrine < 100 mcg (< 582 nmol) Total metanephrine < 1.3 mg (< 7.1 micromole), but fractionated metanephrine and normetanephrine are preferable VMA < 10 mg (< 50 micromoles), which is now rarely used HVA < 15 mg (< 82.4 micromoles), which is mainly used to detect neuroblastoma in children In pheochromocytoma, increased urinary excretion of epinephrine and norepinephrine and their metabolic products is intermittent.