Prevention of Early Neonatal Hypocalcemia in Low Birth Weight Infants with Continuous Calcium Infusion: Effect on Serum Calcium, Phosphorus, Magnesium, and Circulating Immunoreactive Parathyroid Hormone and Calcitonin

摘要

Summary: This study was conducted in 41 premature infants during the first 48 hr of life to investigate the effect of a constant calcium infusion on serum calcium, phosphorus, magnesium, immunoreactive parathyroid hormone (iPTH), and immunoreactive calcitonin (iCT) in low birth weight infants (LBW). The infants were divided into two comparable groups. A control group (group I) included 16 infants who received a 10% glucose solution; a calcium group (group II) included 25 infants who received a 10% glucose solution with calcium gluconate, the amount of mineral calcium perfused being 35 mg/kg/day or 1.7 mg/kg/day. No overall adverse effects were observed in the infants receiving the Ca infusion.In the first group, mean serum Ca level decreased rapidly during the first 24 hr of life from 8.9 ± 0.7 mg/100 ml to 6.79 ± 1.07 mg/100 ml at 22–26 hr (P group II at 10–14 hr and 22–26 hr (P group II from 22–48 hr. Mean serum iPTH levels increased in both groups from 1–3 hr to 44–48 hr (P P group I, mean serum iCT levels decreased during the second day of life, whereas in group II there was no further significant change in mean serum iCT.These data suggest that the administration of a continuous intravenous perfusion of calcium can prevent early neonatal hypocalcemia in low birth weight infants without depressing the parathyroid activity in the majority of the infants. They also indicate that the hypercalcitoninemia which is observed during the neonatal period is not closely dependent upon the serum Ca level; however, the finding of negative correlations between serum Ca and serum iCT levels suggests that the elevated serum iCT levels have a depressive effect upon serum Ca in low birth weight infants.Speculation: The use of a prophylactic continuous calcium infusion has been advocated to prevent early neonatal hypocalcemia of low birth weight infants. In the normal adult calcium infusion is known to depress the parathyroid function and may stimulate the secretion of calcitonin. We wished to determine the effects of early continuous calcium infusion on serum parathyroid hormone and calcitonin levels in low birth weight infants.