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Laboratory Test Reference Guide

Laboratory Information

Test Name

Urea (Blood Gas)

Specimen Collection

Specimen Collection and Transport Protocols

Remove at least 3 mL of blood to waste prior to collecting the blood sample from a line

Adult Specimen

1.0 mL blood in an adult blood gas syringe or 0.5 mL in a paediatric blood gas syringe

Paediatric Specimen

0.5 mL blood in a paediatric blood gas syringe

Test Information



Test Availability

Mon - Sun, 24hrs

Laboratory Turnaround Time

30 minutes


Blood gas analyser - Thames only

Unit of measurement


Reference interval

Reference interval applies from age onward

0 day: 1 - 4 mmol/L

1 month: 1.4 - 5.4 mmol/L

1 year: 1.8 - 5.4 mmol/L

4 years: 3.2 - 7.7 mmol/L

Uncertainty of measurement

+/- 10%

Minimum Volume

0.3 mL collected into a paediatric blood gas syringe

Electronic Information

Registration Code