Creatinine, Plasma

Overview

Department

Biochemistry

Test Code

PCRN

Synonyms

CRN, plasma

Availability

Monday - Sunday, testing routinely available out of hours

Turnaround Time

1 hour urgent - 2 hours routine

Stability – Add test

24 hours

Specimen Requirements

Specimen

Serum

Plasma

Preferred

6 mL Plain Red-Top

Acceptable

4 mL Li-Heparin Green-Top

Specimen Transportation

Pediatric Requirements

600 µL Li-Heparin Microtainer

Aliquot Requirements

Sample

Plasma

Serum

Preferred Volume

100 µL

Minimum Volume

Aliquot Transportation

Clinical Information

Reference Intervals

Creatinine µmol/L
0 - 1 mth	20 - 60
>1 mth - 2 yr	20 - 50
>2 yrs - 4 yrs ,	20 - 60
>4 yrs - 6yrs	25 - 65
>6 yrs - 10yrs	25 - 70
>10 yrs - 15 yrs	40 - 80
Male >15yr + Adult	50 - 110
Female >15 yr + Adult	45 - 90

CKD-EPI calculation for eGFR

Reference range: 80 - 120 mL/min/1.73 m2

Female

Crn ≤62 eGFR (ml/min) = 144 x [Crn(µmol/L)/0.7]-0.329 x [0.993] Age.

Crn >62 eGFR (ml/min) = 144 x [Crn(µmol/L)/0.7]-1.209 x [0.993] Age.

Male

Crn ≤80 eGFR (ml/min) = 141 x [Crn(µmol/L)/0.9]-0.411 x [0.993] Age.

Crn >80 eGFR (ml/min) = 141 x [Crn(µmol/L)/0.9]- 1.209 x [0.993] Age.

Children < 16 years- no calculation done

Interpretation

Estimated GFR is only reliable under steady state conditions (stable Creatinine >4 days).

Caution should be used in interpretation in non-Caucasians, extremes of body weight, pregnancy, oedematous subjects, low Creatinine (<0.06mmol/L) and other complex cases.

GFR declines by 1 ml/min/year over 40 years.

Test Method

Classical Jaffe Reaction using Abbott reagents on the Abbott ci8200 analyser.

eGFR routinely reported on all valid samples. Calculated using the plasma creatinine and CKD-EPI calculation.

Advanced Notice

Not required

Patient Preparation