Usefulness of Emerging Markers in the Early Detection of Renal Dysfunction in Term Neonates With Perinatal Asphyxia

Arunima Bhardwaj, Surinder Singh, Arvind Sood, Jagjit Singh Chahal

Abstract

Aim: To study the usefulness of urinary N-acetyl-β-glucosaminidase (NAG), fractional excretion of sodium (FeNa), and Renal Failure Index (RFI) as early markers of renal dysfunction in term neonates with perinatal asphyxia

Materials and Methods: This prospective, case–control study included 50 term neonates with perinatal asphyxia and 50 nonasphyxiated matched neonates as controls. Asphyxia was graded based on the Apgar score, and hypoxic-ischemic encephalopathy (HIE) staging was done. Blood and urinary parameters including urinary NAG were estimated in all the neonates, and RFI and FeNa were calculated. The renal parameters were compared between the cases and controls and in different stages of HIE among the cases.

Results: Acute kidney injury (AKI) was noted in 62% of the cases. Of these, 62.5% of the neonates had prerenal injury, and 37.5% of the neonates had intrinsic renal injury. Blood urea and serum creatinine levels were significantly high in the cases than in the controls (P < .001) after 48 hours of life. Urinary NAG estimated before 48 hours of life was also significantly different between the cases and controls (P < .001). The severity of renal involvement was correlated with the severity of asphyxia and HIE staging. Urinary NAG, FeNa, and RFI increased with increasing grades of asphyxia.

Conclusions: AKI is common in term neonates with perinatal asphyxia. Urinary NAG, FeNa, and RFI along with the conventional markers of renal dysfunction can be used for the early diagnosis of kidney injury in perinatal asphyxia.