TESTING FOR INBORN-ERRORS OF METABOLISM IN THE ACUTELY ILL NEWBORN

The differential diagnosis of the acutely ill newborn should include i nborn errors of metabolism along with much more common conditions such as sepsis and hypoxemia. Testing recommendations, which can take plac e simultaneously with other studies, are presented for the evaluation of inborn errors in acutely ill newborns. Initial hospital-based tests include arterial blood gases, glucose, electrolytes, urinalysis, comp lete blood count, and cultures. The results from these initial tests a re used to categorize the clinical presentation into one of several ca tegories, and each category in turn sen es to direct further testing i n an efficient manner. Definitive diagnosis often requires referral to a pediatric specialist, as well as testing available only through ref erence and research laboratories. Transfer to a tertiary care facility may be advisable when evidence for an inborn error is found.