OBJECTIVES: To characterize 3 different types of neonatal renal morbidities amongst Neonatal Intensive Care Unit (NICU) patients: AKI (Acute kidney injury, KDIGO criteria); Bilateral Congenital Anomalies of the Kidneys and Urinary Tracts (CAKUT, using sonographic findings of bilateral structural anomalies); Transient elevation of serum creatinine (TESCr, at least one Jaffe-based SCr≥1.1mg/dL after age 1 day which normalized within 3 months). And identify independent risk factors for mortality amongst NICU neonates with renal disease.
METHODS: Retrospective cross-sectional study of all neonates (age<30d) born or treated during 2005 at Schneider Children`s Medical Center who had > 2 serum creatinine (SCr) tests after the age of 48 hours. Demographic, gestational features, renal parameters, comorbidities, mortality and survival (up to 31.12.2016) were compared. Univariate and multivariate analyses compared the 3 renal morbidity groups with an NICU control group.
RESULTS: The 673 study neonates had an average gestational age of 35.1±4.1 weeks, birth weight of 2378±888g and male prevalence of 57.1%. The groups included: AKI: 183 (27.2%) AKI, bilateral CAKUT: 12, TESCr: 65 (9.7%) and 414 (61.5%) controls. The AKI group differed from the rest, including: lower birth weight and gestational age. During follow-up 41 (6.1%) neonates died, of which 30 died during the neonatal hospitalization.
A mortality rate of 13.8% vs 3.1% was seen in AKI vs control neonates by univariate analysis (p<0.001). Multivariate analysis did not identify AKI as a significant independent risk factor for mortality. However, a SCr≥1.1mg/dL was independently associated with mortality (OR=4.69, 95% CI=2.33-9.43; p<0.001), as well as congenital heart diseases (OR=3.77, 95% CI=1.84-7.73; p<0.001). The ROC AUC for these 2 parameters was 0.795.
CONCLUSIONS: Neonates characterized by their renal morbidity subtypes differ significantly from controls. A Jaffe-based SCr≥1.1 mg/dL, but not AKI, was found as an independent risk factor for mortality among NICU neonates.
