Cobalt, Urine (Sendout)

Reference Values:

Interpretation:

Concentrations of 2.0 mcg/specimen or more indicate excess exposure. There are no Occupational Safety and Health Administration blood or urine criteria for occupational exposure to cobalt.

Prosthesis wear is known to result in increased circulating concentration of metal ions. In a patient with a cobalt-based implant, modest increase (2-4 mcg/specimen) in urine cobalt concentration is likely to be associated with a prosthetic device in good condition. Excessive exposure is indicated when urine cobalt concentration is above 5 mcg/specimen, consistent with prosthesis wear. Urine concentrations above 20 mcg/specimen in a patient with a cobalt-based implant suggest significant prosthesis wear. Increased urine trace element concentrations in the absence of corroborating clinical information do not independently predict prosthesis wear or failure.

Cautions:

Specimen collection procedures for cobalt require special specimen collection tubes, rigorous attention to ultraclean specimen collection and handling procedures, and analysis in an ultraclean facility. Unless these precautions are taken, elevated urine cobalt results may be an incidental and misleading finding.

Metal-free urine collection procedures must be followed (see Trace Metals Analysis Specimen Collection and Transport).

Patient Preparation: High concentrations of gadolinium and iodine are known to interfere with most metals tests. If either gadolinium- or iodine-containing contrast media has been administered, a specimen should not be collected for 96 hours.

Collection:

• Collect urine for 24 hours in a preservative-free amber polyethylene 24-hr urine collection container (with no metal caps or glued inserts).
• Refrigeration during collection is preferred, but not required.
• Specimen must be refrigerated within 4 hours of completion of 24-hr collection.
• Refer to Mayo Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for acceptable collection conditions.

Outside Laboratories: Mix specimen well. Measure and record total volume. Aliquot 10 mL urine (min 0.5 mL) into a Mayo metal-free screw-capped vial (T173) and refrigerate.

• Note: Mayo T173 is recommended, but not required.

Stability: Refrigerated (Preferred): 28 days; Frozen: 28 days; Ambient: 28 days.

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Mix specimen well. Measure and record total volume. Aliquot 10 mL urine (min 0.5 mL) into a Mayo metal-free screw-capped vial (T173) and refrigerate.

• Note: Mayo T173 is recommended, but not required.

Login: SEND1-;REFRIG

• RSNDT1: MAYO
• RSTYP1: URN
• RTSRQ1: ;Cobalt (Mayo test COU)

Sendouts:

• Order Mayo Test: COU.
• Enter the collection interval and total volume in MayoAccess.

Stability: Refrigerated (Preferred): 28 days; Frozen: 28 days; Ambient: 28 days.

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.