Background: Current definitions of acute kidney injury (AKI) are not sufficiently sensitive to identify all newborns with AKI during the first week of life.
Methods: To determine whether the rate of decline of serum creatinine (SCr) during the first week of life can be used to identify newborns with AKI, we reviewed the medical records of 106 term neonates at risk of AKI who were treated with hypothermia for hypoxic ischemic encephalopathy (HIE).
Results: Of the newborns enrolled in the study, 69 % showed a normal rate of decline of SCr to ≥50 % and/or reached SCr levels of ≤0.6 mg/dl before the 7th day of life, and therefore had an excellent clinical outcome (control group). Thirteen newborns with HIE (12 %) developed AKI according to an established neonatal definition (AKI-KIDGO group), and an additional 20 newborns (19 %) showed a rate of decline of SCr of <33, <40, and <46 % from birth to days 3, 5, or 7 of life, respectively (delayed rise in estimated SCr clearance group). Compared to the control group, newborns in the other two groups required more days of mechanical ventilation and vasopressor drugs and had higher gentamicin levels, more fluid overload, lower urinary epidermal growth factor levels, and a prolonged length of stay.
Conclusions: The rate of decline of SCr provides a sensitive approach to identify term newborns with AKI during the first week of life.
Keywords: Acute kidney injury; Biomarkers; Epidermal growth factor; Neonate; Serum creatinine.