Lab Information Manual

Laboratory:

Clinical Biochemistry (METABOLIC)

Test Name:

OXALATE – Random (Oxalate/Creatinine Ratio) - (U)

Test Code: OXU

Clinical Information:

Test Indications: OXALATE/CREATININE RATIO
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 Instructions:
For children, height (cm) and weight (kg) must be recorded on requisition.
For 24 hours before patient should not take large doses (>2 g orally/24 hours) of vitamin C. Ingestion of ascorbic acid may falsely elevate the measured urinary oxalate excretion

Collection protocol:
• Collect first-morning urine

Collection Devices:

Preferred Device:

1 - Urine Collection Container, Random 100 mL

Urine Collection Container, Random 100 mL
Manufacturer: Starplex Scientific Inc. (Etobicoke, ON)

Catalogue #: 3008-1

- Samples cannot be refridgerated prior to aliquoting

Specimen Required:

Urine: 10.0 mL

Pediatric Urine: 5.0 mL

Referral:

Refer to JA110-50-01B Random Urine Processing Flow Chart

Specimen Stability:

Refrigerated: 14 Days

Frozen: 14 Days

Requisition:

_SH Urine Testing Requisition (R250-10-95)

Reference Values:

AGE GROUPS             Reference Ranges (Oxalate µmol/mmol creatinine)
0 - 1 mo:                       500
2 - 6 mo:                       500
7 - 12 mo:                     375
13 mo - 6 y:                  190
7 - 10 y:                        125
> 10 y:                         100

Method of Analysis: Enzymatic

Availability:

Within 2 Weeks