Oxalate, Urine (Sendout)

General Information

Lab Name

Oxalate, URN

Lab Code

RUOXL

Epic Ordering

Oxalate, Urine (Sendout)

External Test Id

OXU

Description

Useful For:

Monitoring therapy for kidney stones using 24-hour urine collections
Identifying increased urinary oxalate as a risk factor for stone formation
Diagnosis of primary or secondary hyperoxaluria

Patient Preparation: Patients should avoid Vitamin C supplements for 48 hrs prior to and during collection.

Ordering Note: A timed 24-hour urine collection is the preferred specimen for measuring and interpreting this urinary analyte. Random collections normalized to urinary creatinine may be of some clinical use in patients who cannot collect a 24-hour specimen, typically small children. Random samples will be reported under Reference Laboratory Test 1 (SEND1).

Synonyms

OXU, Urine Oxalate

Components

Code	Name
ROXPT	Oxalate/24 hr (mmol/24 h), URN
ROXLPT	Oxalate/24hr, URN
ROXINT	INTERVAL
ROXLTV	Total Volume

Interpretation

Method: Enzymatic
Reference Range: See individual components

Ordering & Collection

Specimen Type

Urine

Collection

Collect urine for 24 hours in a timed urine collection container with no metal cap or glued insert.

Preferred: Add 5 mL of diazolidinyl urea (Germall, Mayo T822) as a preservative at start of collection. Specimens without preservative are acceptable if they are refrigerated during and after collection.
Specimen pH should be between 4.5 and 8 and will stay in this range if kept refrigerated. Specimens with pH >8 may indicate bacterial contamination, and testing will be cancelled. Do not attempt to adjust pH as it will adversely affect results.
Mayo Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens
Note: The addition of preservative must occur at the start of collection or application of temperature controls must occur during and after collection. All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Handling Instructions

Outside Laboratories:

Mix urine well and measure the volume. Record the total volume and collection interval (required).
Transfer 10 mL urine to a screw-cap plastic aliquot vial. Refrigerate.

Quantity

requested: 10 mL urine
minimum: 4 mL urine

Processing

Processing

Mix urine well. Measure and record the total volume. Ensure that the collection interval and total volume is also noted on the requisition.
Transfer 10 mL urine to a screw-cap plastic aliquot vial. Refrigerate.

Sendouts:

Order Mayo Test code: OXU.
For random samples, batch the order to MayoAccess, add test code ROXUR, and delete test OXU.

Stability: Refrigerated (preferred): 14 days; Frozen: Unacceptable, Ambient: Unacceptable.

Performance

LIS Dept Code

Sendouts Mayo Lab (RF) (MARF)

Performing Location(s)

Sendout	Mayo Clinic Laboratories 800-533-1710 200 First Street Southwest Rochester, MN 55901

Frequency

Performed: Monday through Saturday. Report Available: 3-5 days.

Available STAT?

Billing & Coding

CPT codes: 83945
LOINC: 14862-7
Interfaced Order Code: UOW1847