Test Code LAB4069 CREATININE, URINE 24 HOUR
Specimen Type
24 hour urine collection
Specimen Volume
50 mL
Minimum Volume
1 mL
Turnaround Time
STAT: 1 hour
Routine: 4 hours
Test Schedule
Daily
Sample Stability
Room Temp: 2 days
Refrigerated: 6 days
Frozen: 6 months
Method
Photometric
Reference Ranges
Collection Period hours
Volume mL
Creatinine, Urine g/24h
Male 1.0-2.4
Female 0.7-1.6
CPT Codes
82570
Specimen Processing
Invert 24 hour urine container several times to mix the specimen.
Aliquot 50 mL of a well-mixed 24-hour urine collection into a leakproof plastic urine container.
Aliquot 5 mL into a transparent red top tube.
Record collection time and total volume.
Freeze 50ml Specimen Aliquot.
Collection Instructions
Collect a 24-hour urine in a 24-hour dark plastic urine container without preservatives. Refrigerate during collection. Record collection dates and start/stop times. Deliver to the laboroatory on ice.
The following are acceptable preservatives: 6N hydrochloric acid and boric acid.
Specimen Rejection
Any urine contaminated with fecal material.
Clinical Information
The 24-hour urine creatinine sample is useful for the calculation of creatinine clearance, a measure of kidney function, when used in conjunction with serum creatinine. By comparing the creatinine urine with the level in blood, the creatinine clearance test estimates the glomerular filtration rate (GFR). GFR is a measure of how well the kidneys are functioning.