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Test Code LAB114 Potassium, Plasma

Performing Laboratory

Barnes-Jewish Hospital Laboratory

Methodology

Indirect Ion-Selective Electrode (ISE)

Literature Reference:

Package insert: ISE/Na,K,Cl. Roche Corporation, 08/2017.

Specimen Requirements

Note: This test is also available as part of LAB15 Basic Metabolic Panel (BMP); LAB17 Comprehensive Metabolic Panel (CMP); LAB16 Electrolyte Panel, Plasma; and LAB19 Renal Function Panel. 

 

Specimen Type: Plasma

Container/Tube: Mint-green top (lithium heparin)
Specimen Volume: Full tube

 

Day(s) Test Set Up

Monday through Sunday
Turnaround Time:
STAT: 1 hour after receipt in laboratory
Routine: 2 to 4 hours after receipt in laboratory

Test Classification and CPT Coding

84132

Reference Values

PLASMA

3.3-4.9 mmol/L

Critical result (automatic call-back): ≤2.5 mmol/L or ≥6.2 mmol/L

Note: If serum is submitted and tested the reference intervals are as follows.

 

SERUM

3.6-5.2 mmol/L

Critical result (automatic call-back): ≤2.5 mmol/L or ≥6.2 mmol/L

Literature Reference:

1. Cheng S, Schindler E, Scott MG. Disorders of Water Electrolyte, and Acid-Base Metabolism. In Tietz textbook of Clinical Chemistry 6th ed: Chapter 60, P. 1324, Elsevier, St. Louis, MO 2018.

2. Schindler E, Brown S and Scott MG. Electrolytes and Blood Gases. In Tietz Textbook of Clinical Chemistry 6th ed: Chapter 35, P. 604, Elsevier, St. Louis, MO 2018.

3. Zou J, Nolan DK, LaFiore AR, Scott MG. Estimating the effects of hemolysis on Potassium and LDH Laboratory Values. Clin Chem 2013; 421:60.

4. Abraham B, Fakhar I, et.al. Pseudohyperkalemia in a leukemic patient. Clin Chem 2008; 54:449.

Specimen Transport Temperature

Ambient

Additional Information

For BJH Laboratory Use Only

Alternate Tube: 
1 dark green-top (lithium heparin) tube
1 red-top tube

Laboratory Processing Instructions:

Test performed in BJH Core Lab.  Processed by automated line for delivery to the Cobas 8000. Completed specimens are stored refrigerated for 5 days. 

Test performed in South County Siteman and Ambulatory Cancer Building Lab.  Centrifuge sample and deliver to the Cobas.  Completed specimens are stored refrigerated for 5 days.  

Note: If a red-top tube is received, reorder as Potassium, Serum. This is required because serum reference intervals differ. Serum reference intervals will print on report.

Special Instructions

See Analyte Stability Chart under General Information for a complete list.

LOINC Code Information

Name LOINC Code
Potassium 2823-3