Presented at the Neonatal Society 2007 Autumn Meeting.

Gupta N, Mills S, Okonkwo O, Kempley S

Neonatal Unit, Royal London Hospital, Whitechapel, London, UK
Barts and the London, Queen Mary’s School of Medicine and Dentistry, London, UK

Background: Uncertainty remains over whether extremely premature babies should be given high fluid volumes to maintain hydration or should be restricted to reduce the incidence of patent ductus arter iosus (PDA), chronic lung disease (CLD) and necrotising enterocolitis (NEC) (1). Sodium intake should be minimal in the first days of life until natriuresis commences (2).

Aims: 1. To determine the fluid input for extremely premature infants in the first week of life likely to achieve an “ideal” weight loss of 6% from birth weight. 2. To compare the fluid and sodium administration in infants of various gestational age groups.

Methods: A retrospective audit of fluid balance and sodium input was performed for 84 premature infants admitted from Dec 2005 to May 2007. Infants were divided into 4 gestation groups: 23-25, 26-27, 28-29 and 30-32 weeks. At least 20 patients were studied in each group, including only those surviving beyond the first week of life. Detailed information on the volume of fluid and sodium input, serum sodium and weight change was obtained for the first 7 days of life. Outcomes of PDA, CLD and NEC were recorded. For each gestation group, the fluids needed to achieve an “ideal” weight profile were calculated by the formula:

Ideal fluid input = Actual input – (weight change – ideal weight change)

Results: The most premature infants received more fluid and more sodium per kg body weight than the more mature groups. For babies of 23-25 weeks gestation, this amounted to 5.5 mmol/kg of sodium in the first 3 days. Complications of PDA, CLD and NEC were also more common in this group. Infants with these complications had higher water and sodium input than unaffected counterparts, but on logistic regression analysis, only gestation and weight loss remained as predictors of PDA and CLD.

Conclusions: The most immature infants received more sodium and more water than required to achieve ideal weight loss and minimise complications. We have produced guidance on ideal fluid intake, which together with rigorous sodium restriction, may help with postnatal fluid balance and adaptation.

Acknowledgements:

References
1. Bell EF, Acarregui MJ. Restricted versus Liberal water intake for preventing morbidity and mortality in preterm infants. Cochrane Review. In Cochrane Library 2001;(3):CD000503
2. Modi N. Management of fluid balance in the very immature neonates. Arch Dis Child Fetal Neonatal Ed 2004;89:F108-111