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Test Code LAB114 Potassium

Useful For

  • Monitoring renal function, fluid, and electrolyte balance
  • Decreased levels are seen in reduced dietary intake, excessive loss due to diarrhea, prolonged vomiting, or increased renal excretion.
  • Increased levels are seen in dehydration, shock, severe burns, diabetic ketoacidosis, and retention by the kidneys.

Methodology

Ion-Selective Electrode (ISE)

Performing Laboratory

Bozeman Health Laboratory Services

Specimen Requirements

Specimen Type: Plasma or serum
Container/Tube: Light-green top (lithium heparin gel), red top, or gold top
Specimen Volume: 1 mL
Specimen Minimum Volume: 0.5 mL

Collection Instructions:  Spin down and separate serum/plasma from cells within 2 hours.

Specimen Rejection:

  1. Hemolyzed samples will be rejected.
  2. Grossly lipemic samples may be rejected.   Ultrafuge samples before analysis if possible.

Additional Information

  • Hemolyzed specimen may give incorrectly elevated potassium results. Intracellular potassium concentration is 30-fold to 50-fold greater than that of extracellular serum or plasma.
  • Gross lipemia causes pseudohyponatremia.  Samples should be cleared by ultracentrifugation.

Specimen Transport Temperature

Ambient/Refrigerated

Specimen Stability

Specimen Type Temperature Time
Plasma or Serum Ambient 2 weeks
  Refrigerated 2 weeks
  Frozen 1 year

Reference Values

3.4-5.1 meq/L

Critical values (automatic call-back): <3.0 meq/L or >6.5 meq/L

Day(s) Test Set Up

Monday through Sunday

Test Classification and CPT Coding

84132