Acute kidney injury in asphyxiated neonates and its correlation to hypoxic ischemic encephalopathy staging

Abstract

Background: Acute kidney injury (AKI) is a common consequence of perinatal asphyxia, occurring in up to 56% of these neonates. It is important to recognize AKI in asphyxiated neonates to facilitate administration of appropriate fluids and electrolytes to improve their outcome. Objectives: To determine the incidence of AKI in asphyxiated neonates and its correlation with severity of hypoxic-ischemic encephalopathy (HIE). Methods: 135 term neonates were enrolled - 90 asphyxiated and 45 healthy neonates. AKI was diagnosed when serum creatinine was >1.5 mg/dl regardless of the rate of urine output (UOP). Neonates with AKI were managed as per standard protocol. Results: Of the 90 asphyxiated neonates, 68 (75.6%) had AKI including 58 (85.3%) neonates with pre-renal AKI and 10 (14.7%) with intrinsic AKI. Out of the 68 AKI, 22 (32.36%) had oliguric AKI and 46 (67.64%) had non-oliguric AKI. Levels of blood urea and serum creatinine were significantly higher in asphyxiated neonates as compared to healthy controls (p<0.001). There was no significant difference in UOP in control and study groups. Sonographic abnormalities were seen mostly in oliguric babies and indicated bad prognosis. Mortality was higher in babies with oliguric AKI. Conclusions: Perinatal asphyxia is an important cause of neonatal AKI. The majority had non-oliguric AKI and responded well to fluid challenge. Abnormalities in the renal function correlate well with the severity of HIE. Intrinsic AKI, oliguria, hyponatremia, reduced creatinine clearance, and abnormal sonographic scan suggest bad prognosis in neonatal AKI secondary to perinatal asphyxia.