Test Code: 4541CPT: 82565
|Use||Measurements of creatinine are used in the diagnosis and treatment of renal disease.|
|Clinical Utility||Serum creatinine measurements prove 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. Both serum creatinine and BUN are used to differentiate prerenal and postrenal (obstructive) 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.
An increase in serum BUN without concomitant increase of serum creatinine is key to identifying prerenal azotemia. With postrenal azotemia, both serum BUN and creatinine rise, but the rise is disproportionately greater for BUN.
|Intended Patient Population||18+ and Older Adult Males & Females|
|Patient Preparation||None Specified|
|Tube||Red, Green, Tiger|
|Volume||4mL Whole Blood (1mL Serum/Plasma)|
|Min Sample Volume||0.1 mLs|
|Reference Ranges||CREA - M ≥ 18 yrs old; 0.70-1.30 mg/dL
CREA - F ≥ 18 yrs old; 0.60-1.20 mg/dL
eGFR - M & F ≥ 18 yrs old; ≥ 60 mL/Min/1.73m^2
|Analytical Measurement Range||0.20-30.00 mg/dL|
|Critical Values||≥ 10.0 mg/dL|
|Test Methodology||Quantitative Enzymatic|
|Test Turnaround Time||1 Day|
|Limitations||Creatinine ratios to urea nitrogen can be affected by reduced renal blood flow. Cephalosporin antibiotics can lead to significant false-positive values if samples are drawn within four hours of a dose.2 Ceatinine is not reliable in the presence of cefoxitin therapy for several renal disease. Lipemia, hemolysis, and bilirubin may interfere.3,4|
|Specimen Stability||7 Days RT
7 Days RF
|Reject Criteria||Gross Hemolysis|
|Laboratory Developed Test (LDT)||Yes|