Improvements of metabolic imbalances after enteral sodium bicarbonate supplementation in infants of very low birth weight (VLBW).

Abstract

One of the main points of clinical care is the catch-up growth of VLBW infants especially those of small gestational age (SGA). The required high amounts of protein are often not tolerated [1]. Metabolic imbalances due to immaturities of protein metabolism are described [2, 3] also in infants SGA feeding amounts of proteins comparable to mature newborns [4]. Remarkable signs of overloading by proteins are the elevation of amino acid and the bile acid concentrations in the serum [3, 5, 6]. In some of those cases [7] late metabolic acidosis (LMA) is to be seen. There is evidence in the literature that sodium bicarbonate influences nitrogen [8] and ionic balances [9] in newborn animals without any signs of acidosis, besides its simple buffer function. The aim of this study was to control changes of metabolic imbalances after bicarbonate supplementation before development of acidosis in predisposed infants. Therefore we determined parameters, which were significantly changed with LMA [6] during two feeding schedules: firstly, during bolus supplementation in infants feeding (2.0 +/- 0.4) g/kg BW.d protein and secondly during chronic supplementation of bicarbonate to (3.0 +/- 0.4) g/kg BW.d protein. In relation to the improvement of the nitrogen balance in growing lambs [7] we supposed comparable effect of bicarbonate on metabolic imbalances caused by protein overloading.