Effects of perinatal asphyxia and myoglobinuria

Thirty four consecutive neonates with birth asphyxia or respiratory problems were examined in the first week of life to clarify the relation between neonatal myoglobinuria and acute renal failure. Investigations included determination of creatinine clearance, fractional sodium excretion, and N-acetyl-13-D glucosaminidase index as an indicator of tubular injury. The infants' gestational ages ranged from 29 to 41 weeks (mean 36 weeks). Fifteen infants did not have myoglobinuria on the first day of life (group A); myoglobinuria was mild in eight infants (group B) and severe in eleven (group C). Two infants in group B and seven in group C developed acute renal failure (47%). Ten infants in group C (91%) had severe asphyxia, five of whom (45%) also suffered neonatal seizures and intracranial haemorrhage. We suggest that myoglobin derived from muscle breakdown in asphyxiated infants may lead to acute renal failure secondary to a reduction in renal blood flow, or to tubular damage.