Emergency metabolic tests

Emergency metabolic tests

When a patient is admitted with a possible inborn error of intermediary metabolism, the following samples are required for metabolic studies.

The vital specimen: consider catheterisation or bladder tap

Urine at least 3 mL Random sample, frozen or on ice. No added preservative. and transport on dry ice
For amino acid profile, organic acid profile, acylglycines, orotic acid etc.

Next two most important samples

Plasma at least 1 mL Lithium Heparin (not EDTA). Contact your laboratory as the sample needs to be separated and spun down within 20 minutes, then frozen at -80 C and transport on dry ice.
For acylcarnitines, carnitine, quantitative amino acids, very long chain fatty acids, etc.
Dried blood spots at least 1 mL Whole blood Lithium Heparin (not EDTA). Spot onto all circles of 3 or 4 Guthrie cards or store at +4 C. Transport cards in a paper envelope, NOT A PLASTIC BAG. Transport whole blood on ice.
For acylcarnitine profile, galactose-1-phosphate uridyltransferase screen, DNA/PCR etc.

If the patient is hypoglycaemic

Plasma Add a request to your laboratory for free fatty acids, 3 hydroxybutyrates.

If the patient is to have a lumbar puncture

CSF at least 250 µL Collected within 1 hour of the matching plasma sample. MUST be free of red cells. Freeze and store at -80 C and transport on dry ice.
For quantitative amino acids, especially glycine or homocarnosine.