The effect of hemodynamically significant patent ductus arteriosus on acute kidney injury and systemic hypertension in extremely low gestational age newborns

Background: Acute kidney injury (AKI) in preterm neonates is becoming an increasingly recognized morbidity in the neonatal intensive care unit neonatal intensive care unit (NICU), yet its epidemiology, delineation and relation to numerous toxic exposures and common morbidities such as systemic hypertension is just evolving. With a frequency of the patent ductus arteriosus (PDA) as high as 70% in preterm infants born before 28-week gestation, the role of the hemodynamically significant PDA (hs-PDA) remains unclear. Objective: To determine if AKI and systemic hypertension is more common in extremely low gestational age newborns (ELGAN) with hs PDA compared to ELGAN with no or non-hs PDA using modified AKIN and Neonatal Risk, Injury, Failure, Loss of Kidney Function, and End-stage (N-RIFLE) scoring systems. Methods: This was a retrospective cohort study of infants <= 28 weeks gestational age born between 2010 and 2016 who had echocardiographic PDA evaluation completed for hemodynamical significance as well as serial serum creatinine and urine output measurement documented, needed for the two AKI scoring systems: modified AKIN (based on serial serum creatinine) and N-RIFLE (using urine output data). Blood pressure measurements and therapy were evaluated during the hospitalization and on the day of NICU discharge. Baseline characteristics and outcome variables were compared between the hs-PDA and no or non-hs PDA using unpaired t-tests for continuous variables and chi square tests for categorical data. Results: One hundred fifty-one infants were eligible of which 110 had hs-PDA. Infants with hs-PDA were smaller (777 versus 867 g, p = .026), less mature (25.8 versus 26.4 weeks, p = .023) and had greater exposure to nephrotoxic drugs (14 versus 9.4 days, p = .001). Other clinical and demographic variables were similar between the two groups. The overall incidence of AKI was not different between the hs-PDA and no PDA or non-hs PDA groups when evaluated by the acute kidney injury network (AKIN) or N-RIFLE staging; however, preterm newborns with hs-PDA demonstrated a trend towards increased risk of AKI injury (12.7 versus 0.02%, p = .06). The N-RIFLE and AKIN scoring systems demonstrated very poor degree of agreement (kappa = 0.00853) in our study. There was no difference in the rates of hypertension during the hospitalization as well as on the day of NICU discharge. Conclusion: Preterm neonates with hs-PDA had similar rates of AKI and hypertension as neonates with no or non-hs PDA.