Sign in →

Test Code LAB818 Creatinine Clearance 24 Hour, Blood and Urine

Performing Laboratory

St. Louis Children's Hospital Laboratory - Chemistry

Specimen Requirements

BOTH BLOOD AND 24 HOUR URINE COLLECTION ARE REQUIRED FOR TESTING

(NOTE: 24Hr duration is preferred collection duration of urine for testing. If other collection period is needed order as a Timed test)

Blood specimen should be obtained midway into the timed period of urine collection. However, morning blood specimens are acceptable. 

Patient Preparation: None

Collection Container/Tube:

Preferred: 

     Urine: Plain, brown-orange 24-hour urine collection container without preservatives    

     Blood: Mint green-top Lithium heparin (MNTGRN LiHep) tube

Acceptable: Blood: Green samplette/microtainer; plain red-top tube or Gold SST gel tube

Specimen Collection Volume: 

          Urine: Entire urine collection over 24 hr period required

          Blood: 2.0 mL (minimum 0.6 mL)                     

Submission Container/Tube: If specimen is coming from outside facility, mix well and measure total volume before making aliquot with a minimum of 1.0 mL of urine into a plastic, leak-proof, screw-capped tube for transport labeling with volume and duration times or send entire 24-hr urine jug.

Special Instructions: 

  1. Refrigerate urine specimen during collection
  2. Note collection start and stop dates and times on collection container
  3. Call lab at 314-454-4268 to obtain 24-hour collection jug if needed
  4. Follow instructions on "Urine Collection"

Sample Rejection

Mislabled or unlabeled specimens

Logistics

Test Availability: Monday-Sunday

Cut-off time: None, performed as received

Turnaround Time: Same Day; 2 hours from receipt in performing lab

Reference Values

Reference Interval: 

CREATININE, BLOOD  
<6 years: 0.1-0.6 mg/dL
6-13 years: 0.2-0.8 mg/dL
13-19 years  
     Males: 0.4-1.2 mg/dL
     Females: 0.4-1.0 mg/dL
≥ 19 years  
     Males: 0.8-1.3 mg/dL
     Females: 0.6-1.1 mg/dL

CREATININE, URINE: 

< 18 years: No reference intervals established                                  
≥ 18 years: 60-130 mL/min

CREATININE CLEARANCE: 

<18 years: No reference intervals established                              
≥ 18 years  
     Males: 0.8-2.2 g/24H
     Females: 0.6-1.5 g/24H

Critical Value: None established

 

Methodology

Enzymatic Colorimetric

Limitations

  • NA

Additional Information

FOR SLCH CORE LABORATORY USE ONLY

Lab Processing Instructions: 

    Urine: Mix well and measure total volume collected. Centrifuge an aliquot of the urine to clear any precipitates aliquoting cleared urine into a Roche false-bottom tube for testing.. 

    Blood: Centrifuge to separate. If specimen is collected in a microtainer or plain, red-top tube aliquot specimen into a Roche false-bottom tube for testing.

Processed Volume: minimum 0.3 mL of each urine and plasma/serum

Analyte Stability:

Specimen Type Temperature      Time
urine (without preservative)     Ambient 2 days  
  Refrigerated     3 days   
  Frozen  6 months       

 

Specimen Type Temperature      Time
Whole blood (unprocessed) Ambient 8 hours
Plasma/Serum (processed) Refrigerated (preferred) 1 month
  Ambient 5 days
  Frozen indefinitely

 

NOTE: Total volume of specimen collected and collection duration period is required. Note this information on the aliquot container label and into LIS system

If urine collection duration is <18 hours or >30 hours, the specimen should be ordered as a Timed collection (Creatinine Clearance Urine, Timed)

Test Classification and CPT Code

82575

LOINC

Creatinine in Urine:   2161-8

Creatinine, plasma:   2160-0

Volume Ur:    19153-6

Duration:       13362-9

Last Reviewed

06/2025