Label Mnemonic: K
Epic code: LAB114
Downtime form: A-1a Doctor/Provider Orders - Pathology Core and Specialty Care Nursery
6240 RCP
Collection Medium:
Plasma Separator Tube 4.5 mL
Alternate Collection Media:
Call laboratory for additional acceptable specimen collection containers.
3 mL whole blood in light green top tube or ONE Microtainer® for pediatric patients.
Testing Schedule:
24 hrs/day, 7 days a week, including holidays.
Turn Around Time:
1 hour (upon receipt in laboratory)
Reference Range:
3.5 - 5.0  mEq/L

Pediatric Reference Ranges:

Age       Range    Units
<10 days  3.5-6.0  mEq/L
>10 days  3.5-5.0  mEq/L

Critical value: Adults >16 years       <2.8 mEq/L and >6.2 mEq/L
                Pediatric (0-15 years) <3.0 mEq/L and >6.5 mEq/L
Refer to BD Microtainer® Tubes product sheet for detailed sample collection instructions.

Avoid hemolysis. False elevations may occur in specimens which are not processed promptly (to separate serum from RBC's). Plasma samples drawn in heparin tubes have values slightly lower than serum.

This test is also performed in the Iowa River Landing (IRL) clinical laboratory (for specimens drawn at that site).
Test Limitations:
Icterus: No significant interference up to an I index of 60.

Hemolysis: Significant positive interference at an H index greater than 100 (approximate hemoglobin concentration: 100 mg/dL.

Lipemia (Intralipid): No significant interference up to an L index of 2000. There is poor correlation between turbidity and triglycerides concentration.
Ion Selective Electrode
CPT Code:
See also:
Potassium-Other, Body Fluid