The Journal of pediatrics
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The Journal of pediatrics · Apr 1998
Intravenous correction of neonatal hypomagnesemia: effect on ionized magnesium.
Neonatal hypomagnesemia is defined as total magnesium (TMg) < or = 0.65 mmol/L (1.6 mg/dl). However, magnesium (Mg) deficiency and sufficiency overlap at serum values of 0.57 to 0.74 mmol/L (1.4 to 1.8 mg/dl). We hypothesized that (1) some infants with TMg < or = 0.65 mmol/L (1.6 mg/dl) have normal ionized Mg values (normal neonatal range 0.40 to 0.56 mmol/L (0.97 to 1.36 mg/dl)); (2) the dose (6.0 mg of elemental Mg/kg) used to correct hypomagnesemia does not lead to elevation of ionized Mg; (3) after intravenous magnesium sulfate infusion, ionized calcium increases in patients with low baseline ionized Mg and decreases in patients with normal baseline ionized Mg. ⋯ (1) Measurement of ionized Mg should prevent overdiagnosis and treatment of hypomagnesemia. (2) The dose used in this study is safe. (3) Ionized Mg concentrations are inversely correlated to the response of ionized Ca concentrations to an Mg load.