Renal failure in asphyxiated neonates

A prospective case controlled study was conducted in the NICU of a tertiary level referral teaching hospital to determine the incidence of renal failure in asphyxiated neonates and to correlate severity and type of renal failure with Apgar score and hypoxic ischemic encephalopathy (HIE) grading of the neonates. Ninety-eight neonates were enrolled 70 asphyxiated babies and 28 healthy controls. Renal functions were assessed using urinary output, urine microscopy, biochemical parameters and sonographic findings. Babies having renal failure were managed on a protocolised plan and followed up till 6 months of age to detect any residual impairment. Blood urea and serum creatinine were significantly higher in asphyxiated babies compared to the control group. Biochemical derangements correlated well with HIE staging and Apgar scores. There was no significant difference in urine output in the control and the study group as significant oliguria was seen in only 7 of the 70 asphyxiated babies and the output did not correlate with severity of asphyxia. Serum sodium level and fractional excretion of sodium showed significantly different values in the asphyxiated babies compared to control. Of the 70 asphyxiated babies 33 (47.1 %) had renal failure, which was of the non-oliguric type in 78 % cases and oliguric type in 22 % cases. Sonographic abnormalities were seen more often in oliguric babies and was associated with a bad prognosis. Renal parameters normalized in all neonates by 6 months of age. Mortality was higher in babies with oliguric renal failure. We conclude that renal failure is a significant problem in asphyxiated neonates with majority of babies having nonoliguric failure. Severity of renal function abnormality correlates well with degree of asphyxia. Oliguria, hyponatremia and abnormal sonographic scan are bad prognostic signs in renal failure secondary to birth asphyxia.