Fluid intake in the first week of life: effect on morbidity and mortality in extremely low birth weight infants (less than 900 grams)

Abstract

This study was carried out to determine whether lower fluid intake in extremely low birth weight preterm infants < 900 
grams birth weight is associated with reduced incidence of PDA and BPD without affecting mortality. Retrospective 
chart review of two cohorts treated in the same NICU over a 5-year period. The high fluid intake cohort was managed 
with liberal fluid intakes starting at 155 mL/kg/day. The low fluid cohort was managed starting with 125 mL/kg/day. We 
compared the rates of mortality and the morbidities of PDA and BPD in these cohorts using ANOVA, chi-square, or the 
Student t test. One hundred and sixty one infants were admitted during two periods. After exclusion 113 infants were 
studied; 75 infants in high fluid intake group and 38 in low fluid intake group. The two groups were statistically 
different in their cumulative weekly fluid intake and the peak daily intake. We found no difference in mortality, PDA, 
BPD (by either of two definitions), ventilator days, or hospital stay. We were not able to demonstrate any association 
between fluid intake and mortality or morbidity in this retrospective analysis. The concept of fluid balance may be a 
more appropriate way to think about fluid intake in ELBW infants rather than absolute fluid intake.