The solubility of calcium and phosphorus in neonatal total parenteral nutrition solutions

ABSTRACT. Precipitation of calcium phosphate in neonatal total parenteral nutrition (TPN) solutions remains a significant problem. Whereas numerous studies have attempted to estab-lish guidelines for maximum concentrations of various combi-nations that can be mixed, differences in study design and reliance upon subjective visual assessment severely limit their applicability. The purpose of this study was to quantitatively determine calcium and phosphate compatibility in commonly used neonatal TPN solutions containing a final concentration of either 1 or 2 % amino acids. The final dextrose concentra-tion was 10%. Electrolytes, heparin, and pediatric vitamins and trace minerals were also added. Calcium gluconate (10%) and potassium phosphate (mono and dibasic) were added by cali-brated micropipetors. Calcium concentrations ranged from 5 to 60 mEq/L and phosphate from 5 to 40 mM/L with a minimu