Transient hyperammonemia of the preterm infant

Area of Science:

• Neonatology
• Biochemistry

Background:

• Preterm infants (34-36 weeks gestation) can develop severe illness within 48 hours of birth.
• Symptoms include respiratory distress progressing to deep coma requiring ventilatory support.

Observation:

• Five preterm infants presented with overwhelming illness and extremely high plasma ammonia levels (844-7640 µg/dL).
• Urea-cycle enzyme activity in liver tissue was normal in three infants, including the one who died.

Findings:

• Four infants treated with exchange transfusion and peritoneal dialysis showed ammonia normalization (<150 µg/dL) within 72 hours.
• These four infants achieved normal growth and development after protein challenge.

Implications:

• Transient hyperammonemia of unknown cause may be a common neonatal condition.
• Early diagnosis and aggressive intervention are crucial for favorable outcomes in affected infants.