Creatinine, Plasma/Serum

Test Code

CREAT1

Alias/See Also

Serum/Plasma creatinine, Creatinine

Includes

Creatinine, eGFR Non Black, eGFR Black

Preferred Specimen

1.0 mL plasma (0.5 mL minimum)

Transport Container

PST (light green top). Red top and SST also acceptable

Specimen Stability

Room temperature: 1 day, Refrigerated: 7 days, Frozen: 3 months

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Grossly hemolyzed specimens are unacceptable.

Reference Range

Age	Female	Male
Adult (>18 years):	0.55-1.20 mg/dL	0.70-1.30 mg/dL
Pediatric:
0 – 30 days	0.50 - 0.90	0.50 - 1.20
1 – 11 months	0.40 - 0.60	0.40 - 0.70
1 – 3 years	0.40 - 0.70	0.40 - 0.70
4 – 6 years	0.50 - 0.80	0.50 - 0.80
7 – 9 years	0.50 - 0.90	0.60 - 0.90
10 – 12 years	0.60 - 1.00	0.60 - 1.00
13 – 15 years	0.70 - 1.10	0.60 - 1.20
16 – 18 years	0.80 - 1.20	0.80 - 1.40

Clinical Significance

The serum creatinine level is increased in renal disease. Measurement of serum creatinine is useful in evaluation of kidney glomerular function and in monitoring renal dialysis. However, the serum level is not sensitive to early renal damage and responds more slowly than blood urea nitrogen (BUN) to hemodialysis during treatment of renal failure. The serum creatinine together with serum BUN is used to differentiate pre-renal, renal and post-renal (obstructive) azotemia since an elevated BUN with only slight to moderate elevation of creatinine suggests pre-renal or post-renal azotemia. Serum creatinine varies with the subject’s age, body weight, and sex. It is sometimes low in subjects with relatively small muscle mass, cachetic patients, amputees, and in older persons. A serum creatinine level that would usually be considered normal does not rule out the presence of impaired renal function.

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.