Table 3.

Laboratory testing that should be done in any patient suspected of having hyperammonemia

Ammonia

Glucose

Venous/arterial blood gas

Electrolytes (including calcium)

Anion gap

Blood urea nitrogen

Creatinine

Liver transaminases

Bilirubin

Albumin

Alkaline phosphatase

Lactate

Lipase (if symptoms indicate)

Blood culture

Complete blood count

Acylcarnitine profile (tandem mass spectrometry), total and free carnitine

Plasma amino acids

Save a blood sample for DNA banking and DNA testing (if genotype is not known)

Urine ketones (healthy infants should not have any)

Urine organic acids (obtained within 2 hours of presentation by any method of collection)

Urine for orotic acid