Acute oliguric renal failure in hypoxic neonates born at full term

Abstract

Acute renal failure (ARF) is a frequent clinical condition in neonatal intensive care units (NICU). The leading cause of neonatal ARF is perinatal asphyxia (PS). The aim of this study was to examine the relationship between the degree of PS and the severity of ARF in term neonates. A prospective survey of 31 term neonates with Ps and but without congenital malformations or sepsis was performed in NICU of the regional Hospital of Gynaecology and Obstetrics in Belgrade (average number of deliveries about 6000 per year). ARF was diagnosed in the first 7 days of life when plasma creatinine was above 133 mumol/L for at least 48 hours while maternal renal function was normal. The degree of PS was determined according to Apgar score (AS) at 1 min. The severe PS was defined as AS < 3 and moderate PS as AS 4-6. Twenty neonates (64%) had oliguric ARF with urine output of 0.37 +/- 0.16 ml/kg/h while the others had nonoliguric ARF with urine output of 2.4 +/- 0.7 ml/kg/h. Most of neonates with oliguric ARF (65%) had severe perinatal asphyxia while in those with nonoliguric ARF moderate perinatal asphyxia predominated (73%). During hypoxic-ischaemic events many organs are injured, and the most vulnerable ones are kidneys and central nervous system. Our results showed a strong connection between perinatal asphyxia and A, which was in accordance with the results of other studies. Neonates with severe perinatal asphyxia had serious impairment of renal function, which was confirmed with strong correlation between Apgar score and plasma creatinine. In neonates with oliguric ARF, but not in those with nonliguric ARF, the highly positive linear correlations were found between AS and urinary output (r = 0.77; p < 0.01), plasma creatinine (r = 0.78; p < 0.01), fractional excretion of sodium (r = 0.76; p < 0.01), and index of renal failure (r = 0.80; p < 0.01). Only in oliguric neonates with severe perinatal asphyxia (31%) the outcome was fatal. We conclude that in tgerm neonates with severe perinatal asphyxia oliguric ARF was the predominant type of ARF. There is a good prediction of the severity of oliguric ARF according to the degree of perinatal asphyxia determined by Apgar score at 1 min.