Standardized parenteral nutrition in preterm infants: early impact on fluid and electrolyte balance

Parenteral nutrition is commonly given to premature infants. It has previously been suggested that standardized parenteral nutrition (SPN) may offer nutritional advantages compared to individualized parenteral nutrition (IPN). However, whether the same level of biochemical control is assured with SPN and with IPN remains uncertain.

To compare fluid and electrolyte balance in preterm infants receiving IPN versus SPN in the first week of life.

107 infants born at <33 weeks gestation were prospectively evaluated. Serum and urinary creatinine and electrolyte concentration, urine volume, body weight, fluid, electrolyte and energy intakes were recorded daily.

40 infants received IPN and 67 SPN. Infants in IPN had significantly more water and less sodium intake than those receiving SPN. Energy and amino acid intakes were significantly lower in IPN than in SPN groups. Incidence of hypernatremia and hyponatremia was similar in both groups. Nonoliguric hyperkalemia (NOHK) was significantly more frequent in IPN than in SPN (20.0 vs. 2.9%) and mean serum K(+) peak over the first 3 days was higher in IPN than in SPN (5.63 +/- 1.05 vs. 4.91 +/- 0.78 mmol/l). Weight loss (% of birth weight) at day 7 was significantly higher in IPN than in SPN (7.7 +/- 5.8 vs. 4.2 +/- 6.5) without differences in urine output/input fluid intake ratio and glomerular renal function between the two groups.

There were no significant differences in water and sodium balance in preterm infants who received IPN versus SPN. The risk of NOHK was higher in IPN. Also, SPN significantly increased amino acid and caloric intakes, and it reduced early weight loss.