[Restricted intake of sodium in newborn infants with very low birth weight in the first days of life]

Abstract

A prospective study on the amount of sodium administered in the first five days of life in a group of 18 low-birth-weight infants is presented. Their mean birth weight, and gestational age were 1.150 gm., and 28.8 weeks. Patients were cared for in radiant warmers, and protected with a plastic blanket. Minimum amount of sodium necessary to maintain a normal plasma sodium concentration was given. Mean daily sodium and free water given was 0.96 mEq/kg/day, and 108.4 ml/kg/day, respectively. In day 5, there was a mean accumulated body weight loss of ten per cent. This group of patients were compared with a similar group in whom plastic blanket was not used, and who received a sodium intake of 1.5 mEq/kg/day. In this latter group of patients there was a higher incidence of hypernatremia (p less than 0.005). The incidence of hyponatremia was similar in both groups. Daily sodium intake might be very low, in infants of very-low-birth-weight if a negative weight balance is allowed in the first days of life.