Patient Preparation

 

Collect

Plasma Separator Tube (PST) or Serum Separator Tube (SST) AND random urine. Also acceptable: 24 hour urine. 

Specimen Preparation

Allow serum tube to clot completely at room temperature. Separate from cells ASAP or within 2 hours. Transfer 1 mL serum or plasma to an ARUP Standard Transport Tube. (Min: 0.2 mL) AND Transfer one 3 mL aliquot of urine to an ARUP Standard Transport Tube. (Min: 0.5 mL) Also acceptable: Urine specimens previously preserved with 6M HCl, boric acid, or 5 percent NaOH. 

Storage/Transport Temperature

Refrigerated. 

Unacceptable Conditions

Specimens obtained through catheters, used to infuse hyperalimentation fluid. Specimens with potassium oxalate/sodium fluoride, citrate, or EDTA as anticoagulants. 

Remarks

Patient age and sex are required for calculation. 

Stability

Ambient: 48 hours; Refrigerated: 1 week; Frozen: 3 months 

By report

The CKD-EPI equation for non-African American individuals is used to calculate the estimated glomerular filtration rate (GFR). To estimate the GFR for African Americans, multiply the provided GFR result by 1.16.

The CKD-EPI equation is validated in individuals 18 years of age and older. However, the equation is less accurate in patients with extremes of muscle mass, restriction of dietary protein, ingestion of creatine, extra-renal metabolism of creatinine, or treatment with medications that affect renal tubular creatinine secretion.

GFR Categories in Chronic Kidney Disease (CKD)
GFR Category	GFR (mL/min/1.73 square meters)	Interpretation
G1	90 or greater	Normal or high*
G2	60-89	Mild decrease*
G3a	45-59	Mild to moderate decrease
G3b	30-44	Moderate to severe decrease
G4	15-29	Severe decrease
G5	14 or less	Kidney failure
*In the absence of evidence of kidney damage, neither GFR category G1 nor G2 fulfill the criteria for CKD (Kidney Int Suppl 2013;3:1-150)

If a 24-hour urine collection is submitted, 24-hour calculations will not be performed. If 24-hour calculations are required, refer to test code 0050203 Albumin-Creatinine Ratio, Urine.

View Hotline History

82043, 82570, 82565

Component Test Code*	Component Chart Name	LOINC
0020025	Creatinine, Serum or Plasma	2160-0
0020207	Creatinine, Urine - per volume	2161-8
0026634	Calculated GFR	62238-1
0050583	Albumin - mg/dL	30003-8
0050678	Albumin/Creatinine Ratio	14958-3

* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.