Related Experiment Videos
Feeding the low-birthweight infant: orally or parenterally?: II. Corrected bromide space in parenterally supplemented
Insights
Parenteral supplementation in neonates may lead to increased weight gain due to water retention, not tissue growth. This study measured extracellular water to assess fluid shifts in supplemented versus orally fed infants.
Area of Science:
- Neonatal nutrition
- Fluid and electrolyte balance
- Growth and development
Background:
- Faster weight gain in parenterally supplemented neonates was previously observed.
- This enhanced growth was hypothesized to be due to water retention rather than tissue accretion.
Purpose of the Study:
- To test the hypothesis that parenteral supplementation leads to water retention.
- To investigate changes in extracellular water in neonates receiving different feeding strategies.
Main Methods:
- Ten neonates were randomly assigned to receive either 67 cal/dl formula feeding or oral 100 cal/dl formula feeding supplemented parenterally.
- Extracellular water was estimated using corrected bromide space (CBS) within 19 hours of birth and between days 7-28 postpartum.
- Total daily water and protein intake were monitored.
Main Results:
- Parenteral supplementation was associated with increased CBS, indicating water retention or shifts.
- Neonates receiving parenteral supplementation regained birthweight faster and showed higher rates of weight gain.
- Lower arterial pH was also associated with larger CBS and parenteral supplementation.
Conclusions:
- Parenteral supplementation may result in significant water retention in neonates.
- Observed faster weight gain in supplemented neonates might be attributed to water accumulation.
- Further studies are needed to confirm these findings and differentiate between water and tissue accretion.
Abstract:
Previously published data suggested that the faster rate of weight gain observed in parenterally supplemented neonates compared to their orally fed peers might be attributable to water retention rather than to more rapid tissue accretion. The present study was designed to test that hypothesis by observing changes in extracellular water, estimated as corrected bromide space (CBS). Ten neonates with a mean birthweight of 1,250 gm (range, 800 to 1,980 gm) and a mean gestational age of 31 weeks (range, 24 to 38 weeks) were randomly assigned to a 67 cal/dl formula feeding or an oral 100 cal/dl formula feeding supplemented parenterally with dextrose and amino acids. CBS was estimated within 19 hours of birth and between the 7th and 28th postnatal days. Mean total daily water and protein intakes during the intervening period were similar for orally fed and supplemented neonates, but the latter took significantly less orally and received more parenterally. CBS increased in all but one of the supplemented neonates whereas two of four orally fed babies had decreasing values and one had stable values. Shorter times before regaining birthweight, faster rates of weight gain, and lower arterial pH were associated with larger CBS as well as with parenteral supplementation. These data suggest that parenteral supplementation may result in water retention and/or shifts from the intracellular to the extracellular space. Previously reported earlier and greater mean daily weight gains in supplemented babies may be related to water accumulation rather than tissue accretion, but definitive conclusions must await further studies, including concomitant estimates of total and extracellular body water.