Specimen Collection

Sample stability:

• 7 days at 15-25 ^o C
• 7 days at 2-8 ^o C
• 1 year at -20 ^o C

4.5 mL Adult PST Blood (Preferred)

0.5 mL Paediatric Micro-PST Blood (Preferred)

5 mL Adult Heparin Blood

4 mL Adult Plain Blood

5 mL Adult SST Blood

0.5 mL Paediatric Microsample Blood

0.5 mL Paediatric Micro-heparin Blood
Reference Intervals

urea (mmol/L)
Neonate:	1.0 - 4.0
1 month - 1 yr:	1.4 - 5.4
1 yr - 4 yr:	1.8 - 5.4
Adult:	3.2 - 7.7

Uncertainty of Measurement: 6%

Turnaround Time: Within 3 hours
Assay Method

Principle : Enzymatic

Reagents: Roche Urea Kit

Analyser: Cobas c702

Diagnostic Use and Interpretation

Plasma urea may be used as a rough index of renal function, although creatinine is a better index of glomerular filtration.

Urea is synthesised in the liver from amino acids and its level is dependent on protein intake. Urea rises proportionately more than creatinine in dehydration or pre-renal uremia.

Contact Information

The chemical pathology team can be reached via email: chemicalpathologist@adhb.govt.nz or via Lablink (09) 307 4949 ext 22000 or 09-3078995

Emails will receive priority attention from the on-call chemical pathologist. Include the patients NHI.

After-hours: contact Lablink (Auckland City Hospital ext. 22000 or 09-3078995) or hospital operator for on duty staff after hours .

• Dr Samarina Musaad (Clinical Lead) : SamarinaM@adhb.govt.nz ext. 22402
• Dr Cam Kyle : CampbellK@adhb.govt.nz ext 22052
• Dr Weldon Chiu : WeldonC@adhb.govt.nz ext. 23427
• Dr Campbell Heron : CHeron@adhb.govt.nz ext. 23427
• Dr Sakunthala Jayasinghe Saku.Jayasinghe@adhb.govt.nz
• Dr Owen Yi WenyiYi@adhb.govt.nz

Last updated at 11:42:03 16/01/2026