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Lab Dept:
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Chemistry
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Test Name:
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CREATININE CLEARANCE, SERUM AND URINE
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General Information
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Lab Order Codes:
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CRCL - for more information on urine creatinine, see Creatinine, Timed Urine test listing.
CREA - Please order a blood creatinine within the urine collection period. See Creatinine, blood test listing for more information on creatinine. A blood creatinine within 10 days will be used, however, one closest to the urine collection period is preferred.
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CPT Codes:
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82575 - Creatinine clearance
81050 - Urine timed measurement
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Test Includes:
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Serum creatinine and urine creatinine (24 hour collection), Creatinine clearance [1.73(m²)]/body surface area (m²)] x [volume of urine (mL)/total time (min)] x [urine creatinine (mg/dL)/serum creatinine (mg/dL)] = mL/min/1.73 m² (standard surface area).
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Logistics
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Test Indications:
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Renal function test to estimate glomerular filtration rate (GFR); evaluate renal function in small or wasted tubules; follow possible progression of renal disease; adjust dosages of medications in which renal excretion is pivotal (eg, aminoglycosides, methotrexate, cisplatin).
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Lab Testing Sections:
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Chemistry
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Phone Numbers:
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MIN Lab: 612-813-6280
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STP Lab: 651-220-6550
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Test Availability:
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Daily, 24 hours
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Turnaround Time:
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1 day
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Special Instructions:
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A 24-hour collection bottle with no preservative can be obtained from the lab. Refrigerate the specimen during and after collection. A 24 hour collection is preferred. Reference ranges have not been established for collection periods shorter than 24 hours.
A blood creatinine must be ordered within the 24-hour urine collection period. Patient height and weight as well as starting and ending date and time of urine collection are required for the test and must be documented electronically or on the proper request form.
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Specimen
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Specimen Type:
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Urine and blood
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Container:
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Blood: Green top tube or microtainer
Urine: Plastic leakproof container (No preservative). Urine GUARD® collection container is preferred for a timed urine sample.
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Draw Volume:
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Blood: 0.6 mL in green top (lithium heparin) tube or microtainer
Alternate tube: Red top tube
Urine: Submit an entire 24-hour urine collection
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Processed Volume:
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Serum/plasma: 0.2 mL
Urine: Aliquot from 24 hour collection
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Collection:
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Blood: Routine venipuncture
Urine: For timed urine collections, empty the bladder, discard the voided sample, and note the start time. Collect all urine voided for the specified time period. At the end of the period, note the finishing time, add the last voided sample to the container by emptying the bladder. Bring the refrigerated container to the lab. Make sure all specimens submitted to the laboratory are properly labeled with the patient’s name, medical record number and date of birth.
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Special Processing:
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Lab Staff: Urine: Mix, measure and record the 24-hour urine volume. Result the patient height and weight into the computer system. Aliquot a specimen for urine creatinine testing.
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Patient Preparation:
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Avoid cephalosporins. Have patient drink water before the clearance is begun, and continue good hydration throughout the clearance. If possible, drugs should be stopped beforehand.
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Sample Rejection:
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Mislabeled or unlabeled specimens
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Interpretive
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Reference Range:
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All ages: 70 - 130 mL/min/1.73m²
Note: The above reference range is based on a 24 hour collection. Reference ranges have not been established for collection periods shorter than 24 hours.
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Critical Values:
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N/A
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Limitations:
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Drugs may interfere with urinary assays.
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Methodology:
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EZCR Flex® reagent cartridge insert sheet PN 717270.003, issue date 2011-03-07 Rev C
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References:
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CREA Flex® reagent cartridge insert sheet (2010-01-21) Rev J PN 717033.002 - US
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Clinical Significance, Dade Behring Inc., Glasgow Business Community, Mailbox 531, P.O. Box 6101, Newark, Delaware 19714
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Jacobs & DeMott Laboratory Test Handbook (2001) Lexi-Comp, Inc, Hudson, OH, 5th Edition
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Biorad Liquichekÿ Unassayed Chemistry Control (Human) product insert, Irvine, CA
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Biorad Liquichekÿ Urine Chemistry Control Product insert, Bio-Rad Laboratories, Irvine, CA 92618
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Updates:
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2/4/2013: Method update, previously listed as Alkaline Picrate/Kinetic
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