NICU sodium administration to extremely low birth weight infants: Relationships with recommendations and growth

Objectives. To determine the amount of sodium being administered in the Neonatal Intensive Care Unit (NICU) from all sources including parenteral and enteral nutrition, medications, and intravenous solutions to extremely low birth weight (ELBW) infants—those weighing less than or equal to 1000 grams. It was hypothesized that there are variable amounts of sodium given, but those amounts are not adequate when compared to the recommendation of the American Academy of Pediatrics (AAP) (3-5 mEq/kg/d). Study design. The study design was a retrospective chart review of surviving ELBW infants admitted to and discharged from the Women and Infants\u27 Hospital (WIH) NICU in Providence, Rhode Island from January 2009 through June 2011 who were not enrolled in the NICU protein study. Information on birth weight, gestational age, length of stay, growth velocity, average protein and calorie intake per kilogram, and average sodium intake per kilogram received from all sources was collected for eleven different time points. Results. Seventy ELBW infants met the criteria for inclusion in this retrospective chart review. Comparisons of the time points showed the highest amount of sodium per kilogram to be given at Day of Life 14 (4.52 mEq/kg) and only twenty-eight infants (40%) received the minimum amount recommended by the AAP (3-5 mEq/kg) all time points were compared. When analyzed from week 2-12 (week at which true growth occurs), only eight infants (11 %) of the infants received adequate amounts. When growth velocity was compared with amount of sodium received (using 3 mEq/kg as cutoff), more growth was seen in the group given lower amounts of average sodium with the all-time points set (12.01±1.5 g/kg/day vs. 10.93±2.64 g/kg/day, p=0.034) and the same was true in the weeks 2-12 data set but no statistical significance was seen (p=0.84). Conclusions. ELBW infants are receiving large amounts of inadvertent sodium from medications and intravenous solutions. During weeks one and two of life, 88% and nearly 50% (respectively) of the sodium intake came from medications or intravenous solutions. Even with the inadvertent amounts of sodium, most of the infants received suboptimal intakes of sodium compared to recommendations by the American Academy of Pediatrics (3-5 mEq/kg). Growth velocity was compared with different levels of sodium (\u3c3 mEq/kg vs ≥3 mEq/kg). More growth was seen in the group with the lower average sodium than those receiving the higher amount of sodium. This could be explained by the morbidity level of these infants. When growth rate of the infants who had no morbidities was compared to those infants with one or more morbidities, greater growth rates were seen in the group with no morbidities (12.80±1.3 g/kg/day vs. 10.66±2.11, p=0.001)