Turnaround times
The quoted turnaround time is from sample receipt in the laboratory, to results authorisation in the Laboratory Information Management system. The times do not include transport of specimen to the laboratory or the administrative process to print and post/email reports. Service users must allow for transport and reporting time when ordering tests.
Clinical background:
A raised urinary oxalate can result in the formation of renal stones which are predominantly composed of the sparingly soluble salt of calcium oxalate. Causes of hyperoxaluria include ingestion of oxalate rich foods, increased GI absorption of oxalate when there is severe fat malabsorption and rarely inherited disorders of metabolism such as primary oxaluria. An oxalate is commonly measured in urine in the investigation of renal calculi.
Specimen container paediatric:
Plain universal container (randome urine sample)
Specimen container adult:
Plain universal container for random urine sample, or acid-rinsed bottle for 24 hour urine collection
Minimum volume paediatric:
1 mL
Minimum volume adult:
2 mL
Special requirements:
For external users: samples must be acidified to pH<2.
Patient should refrain from excess vitamin C for at least 48h prior to collection.
Interpretation:
An increased excretion of oxalate can be attributed to increases in:
• Ingestion of oxalate rich foods, e.g. rhubarb.
• Formation of oxalate due to metabolic defects such as in primary hyperoxaluria
• Absorption of oxalate in a number of gastrointestinal disorders that produce severe fat malabsorption including patients with inflammatory bowel disease, ileal resection, and pancreatic insufficiency.
Reference ranges:
24h urine (mmol/24h)
Adult male: 0.08 – 0.49 mmol/24 hrs
Adult female: 0.04 – 0.32 mmol/24 hrs
Children: 0.14-0.42 mmol/24 hrs
Random urine (mmol/mmol creatinine)
<1 yr: 0.015 – 0.260
1-4 yrs: 0.011 – 0.120
5-11 yrs: 0.006 – 0.150
>12 yrs: 0.002 – 0.083
<1 yr: 0.015 – 0.260
1-4 yrs: 0.011 – 0.120
5-11 yrs: 0.006 – 0.150
>12 yrs: 0.002 – 0.083