Calcium, Urine, 24-Hour

Calcium, Urine 24-hour

Epic Mnemonic
Sunquest Mnemonic

LAB814
CAUB

Category

Sendouts

Methodology

Photometric

Test Performance Schedule

Daily

Result Availability

1 – 2 days

Container

24-hour Urine Container, no preservative

Volume

Pref. Vol.: Entire collection
Min. Vol.: 10.0 mL aliquot from well-mixed 24-hour specimen

NOTE: When submitting a 24-hour specimen aliquot:
• Entire urine collection must be mixed well before the aliquot is poured off
• Total volume of 24-hour collection must be measured and clearly marked on aliquot label and on test requisition

Collection Instructions

• To begin collection of timed specimen, have patient urinate, noting the date and exact time
• Discard this first portion of urine, but document date and time of voiding on the container label and test requisition as the "start" of the timed specimen
• Save all urine voided during the designated time period (usually 24 hours), including the portion voided at exact end of time period
• Document date and time of final voiding on the label and requisition as the "end" of the timed specimen
• Refrigerate during and after collection

Transportation Instructions

• Upon receipt in the laboratory, mix entire specimen well and note 24-hour volume
• Pour off a 4.0 mL urine aliquot into a separate plastic tube
• Send urine aliquot with notation of entire 24-hour urine volume on aliquot label and on requisition
• Refrigerate

Stability

• Room Temperature: Unacceptable
• Refrigerated: 72 hours
• Frozen: Acceptable

Remarks

6N HCl is an acceptable preservative for this test

CPT Codes

82340

Effective/Revised

8/19/2019

The main significance in determining urinary calcium lies in the differentiation between hypercalciuria and hypocalciuria and the differential diagnosis of nephrolithiasis.