Fluid overload and mortality are associated with acute kidney injury in sick near-term/term neonate

Acute kidney injury (AKI) is common and portends mortality in several neonatal cohorts. Fluid overload is independently associated with poor outcomes in children and adults but has not been extensively studied in neonates.

Between February 2010 and May 2011, we followed 58 neonates who met the following criteria: birth weight >2,000 g, gestational age ≥ 34 weeks, 5-min Apgar ≤ 7, and parental consent. Serum creatinine (SCr) was measured daily for first 4 days of life. AKI was defined as a rise in SCr of > 0.3 mg/dl or persistent SCr above 1.5 mg/dl.

AKI was present in 9/58 (15.6 %) neonates and was associated with higher birth weight, being male, lower 5-min Apgar scores, lower cord pH, delivery room intubation, and absence of maternal pre-eclampsia. Percent weight accumulation at day 3 of life was higher in those with AKI [median=8.2, interquartile range (IQR) =4.4-21.6)] than without AKI (median= -4 (IQR= -6.5 to 0.0) (p<0.001). Infants with AKI had lower survival rates than those without AKI [7/9 (72 %) vs. 49/49 (100 %) (p<0.02)].

AKI incidence in this neonatal population is similar to other neonatal cohorts. Near-term/term infants with AKI have a higher mortality rate and a net positive fluid balance over the first few days of life.