A Comparative Study of Renal Parameters and Serum Calcium Levels in Birth Asphyxiated Neonates and Normal Neonates

Abstract

Background and Objectives: Acute renal failure is a frequent clinical condition in neonatal intensive care units. The leading cause of neonatal acute renal failure is perinatal asphyxia. Early recognition of acute renal failure is particularly important in asphyxiated neonates, in whom a stable biochemical milieu is vital, because it facilitates the administration of appropriate fluid and electrolyte replacement. This study was done to determine the incidence of renal failure and its correlation with severity of asphyxia. Methods: 45 term neonates born with Apgar score of < 7 at 5 minutes after the birth are selected as cases and 45 term normal neonates as controls. All asphyxiated neonates (as per World Health Organization definition) with clinical features of Hypoxic ischemic encephalopathy are staged by Sarnat and Sarnat staging. The relevant blood and urine investigations done at 24, 48 and 72 hours of life and urine output was monitored. The babies were managed according to standard protocol. The renal indices were calculated after 48 and 72 hours. Results: The incidence of renal failure was significantly higher among cases (66.67%, 30 of 45 cases). All cases had non oliguric (100%) renal failure -11 (24.44%) cases had intrinsic renal failure. The renal parameters were higher among cases and correlated with the severity of asphyxia. Hyponatremia was seen in cases and its severity correlated with asphyxia severity. The serum calcium level was lower among cases and severity of hypocalcaemia correlated with severity of asphyxia. Fractional excretion of sodium (FeNa) was higher among cases and 11 cases had value more than 3. Renal failure Index was higher among cases and 12 cases had value more than 4. Interpretation and Conclusions: Perinatal asphyxia is an important cause of renal failure in the neonatal period. Acute renal failure in birth asphyxia is predominantly Pre renal failure and depends on the severity of asphyxia. Renal failure in birth asphyxia is predominantly non-oliguric, monitoring of urine output for renal failure alone does not help to identify renal failure. The renal parameters should be monitored and if possible the renal indices should be calculated to identify pre-renal and intrinsic renal failure.