Plasma catecholamine levels in children.

While blood norepinephrine and epinephrine levels are well established in adults, literature data concerning concentrations in young children are conflicting. This situation prompted us to assay plasma catecholamines in 86 healthy subjects aged two days to fifteen years using a sensitive high-performance liquid chromatography technique with electrochemical detection. Norepinephrine and epinephrine concentrations remained elevated up until 24 months of age, then dropped progressively to adult levels between 24 and 36 months, with fluctuations. These fluctuations, which reflect the sensitivity of children to environmental factors, prevented demonstration of any catecholaminergic secretory abnormality by blood assays in subjects under two years of age. Urinary assays, for which established values exist, are the only applicable procedure in such patients.