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HelpTest Code LAB114 Potassium Level
Clinical System Name
Potassium Level
Synonyms
K
LAB114
Sample Requirements
Specimen: Whole Blood
Container(s): Lt. Green/Mint Top Lithium Heparin, Lt. Green/Lithium Heparin Microtainer, Gold SST, Gold Microtainer, Dark Green/Sodium Heparin, Red
Preferred Vol: 1.0 mL
Minimum Vol: 0.5 mL
Notes: Avoid hemolysis and contamination from IV line or tissue fluids. Method is affected by moderate to marked lipemia, hemolysis, tissue fluid from difficult finger stick, line dilution or contamination. Not affected by lithium, NH3, or sodium heparin. Red, and Gold SST tubes are acceptable, but not preferred. Warming hand or foot prior to drawing capillary sample is recommended. Potassium is leaked from cells on standing.
Processing Instructions
Reject due to: Age of Specimen, hemolysis
Spin: Y
Aliquot: Y
Storage location: Core 5 Chemistry Refrigerator
Off-site collection: Avoid hemolysis and contamination from IV line or tissue fluids. Specimen should be centrifuged within 2 hours of collection. Spin blood and transfer serum or plasma to plastic tube and refrigerate or freeze. Potassium is leaked from cells on standing.
Stability
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum or Plasma | RT |
≤ 6 w |
| Serum or Plasma | 2-8 C |
≤ 6 w |
| Serum or Plasma | -20 C or -70 C |
≤ 365 d |
Availability
| STAT | Performed | TAT |
|---|---|---|
| Y | 24/7 | 1 h |
Performing Laboratory
Seattle Children's Laboratory
Department
Department: Core Chemistry
Phone Number: 206-987-2617 (Client Services)
CPT Codes
84132
Methodology
Method: Potentiometric method by Vitros 4600
Analytical Volume: 0.02 mL + 0.03 mL dead space
Reference Range
| Age | mEq/L |
| 0 - 2 d | 3.7 - 5.9 |
| 2 d - 3 m | 3.4 - 5.6 |
| 3 m - adult | 3.5 - 5.5 |
Description
Measurement of serum potassium is used for evaluation of electrolyte imbalance, cardiac arrhythmias, muscular weakness, hepatic encephalopathy, and renal failure, and for monitoring of ketoacidosis in diabetes mellitus and intravenous fluid replacement therapy. Low potassium is common in hypertensive patients with aldosteronism, vomiting, diarrhea, alcoholism, and folic acid deficiency. High potassium values occur in rapid potassium infusion, end stage renal failure, hemolysis, trauma, Addison’s disease, metabolic acidosis, acute starvation, dehydration, and acute medical emergencies.
Critical Values
| Age | Low | High |
| 0 - 2 d |
< 3.1 mEq/L |
> 6.4 mEq/L |
| 2 d - 3 m |
< 3.1 mEq/L |
> 5.9 mEq/L |
| 3 m - adult |
< 3.1 mEq/L |
> 5.9 mEq/L |