Electrolyte and Mineral Homeostasis After Optimizing Early Macronutrient Intakes in VLBW Infants on Parenteral Nutrition.

Abstract

The aim of the present study was to evaluate electrolyte and mineral homeostasis in very-low-birth-weight (VLBW) infants who received high protein and energy intakes with a unique standardized parenteral nutrition solution containing electrolytes and minerals from birth onward. Prospective cohort study in 102 infants with birth weight <1250 g. The evolution of plasma biochemical parameters was described during the first 2 weeks of life. During the first 3 days of life, mean parenteral intakes were 51 ± 8 kcal · kg · day with 2.7 ± 0.4 g · kg · day of protein, 1.1 ± 0.2 mmol · kg · day of sodium and potassium, and 1.3 ± 0.2 mmol · kg · day of calcium and phosphorus. Afterwards, most nutritional intakes (parenteral and enteral) met growth requirements. No infant developed a hyperkalemia >7 mmol/L, and a hypernatremia >150 mmol/L occurred only in 15.7% of the infants. In contrast, hyponatremia <130 mmol/L and hypokalemia <3 mmol/L occurred in 30.4% and 8.8% of the infants, respectively. The initial neonatal metabolic acidosis rapidly resolved in most infants and only 2.0% developed a base deficit >10 mmol/L after day 3 of life. Early hypocalcemia <1.8 mmol/L occurred in 13.7% of the infants. In contrast, hypophosphatemia <1.6 mmol/L occurred in 37.3% and hypercalcemia >2.8 mmol/L occurred in 12.7% of the infants. Increasing early protein and energy intakes in VLBW infants in the first week of life improves electrolyte homeostasis. It also increases the phosphorus requirements with a calcium-to-phosphorus ratio ≤1.0 (mmol/mmol) and the potassium and sodium requirements to avoid the development of a refeeding-like syndrome. These data suggest that the parenteral nutrition guidelines for VLBW infants for the first week of life need to be revised.