Urea Nitrogen Clearance

CERNER / EPIC MNEMONIC: U/UREA CLR
POE DESCRIPTION: URT UREA CLEARANCE; U/UREA CLR
CPT CODE: 84545
TEST INFORMATION: Test includes blood urea nitrogen, urine urea nitrogen, urine urea clearance.
DAYS PERFORMED: Specimen accepted daily
TURNAROUND TIME: 24-48 hours
SPECIAL INSTRUCTIONS: Blood urea should be ordered and sent to the laboratory during urine collection. This test is part of the Basic Metabolic Panel and the Comprehensive Metabolic Panel. For timed urine collection, instru t the patient to void at the beginning of the collection period and discard the specimen. Give patient two glasses of water. Give patient two more glasses of water one hour after test is started. After approximately 12 hours (midway in the collection), the blood specimen should be drawn. Collect all urine including the final specimen voided at the end of the collection period. Containers must be labeled with patient`s full name, room number, date and time collection started, and the date and time collection finished.
CONTAINER TYPE:

SST tube; plastic 24-hour urine container, no preservative (Chemistry bottle #1)

SPECIMEN REQUIREMENTS: Blood (serum), 12- or 24-hour urine colleciton
MINIMUM VOLUME: 4 mL blood (2 mL serum); submit entire urine collection to the laboratory.
HANDLING INSTRUCTIONS: Refrigerate urine during collection.
REFERENCE RANGE: Maximum clearance: 62-95 mL/minute; standard clearance: 42-65 mL/minute (80% to 135% of normal)
TEST SYNONYM(S):Urea Clearance; UUN Clearance