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HelpTest Code K Potassium
Specimen and Container/Tube
Specimen Type: Plasma
Preferred Specimen: Li-Heparin Mint Green Top
Other Acceptable specimens: Serum/Gold Top, Serum/Red Top
Volume
Preferred Volume: 0.5 mL
Minimum Volume: 0.2 mL
Specimen Stability
|
Storage Temperature |
Stability |
|
Room temperature |
14 days |
|
Refrigerated |
14 days |
|
Frozen |
stable |
Collection Instructions
Collect specimen per standard laboratory collection procedures.
Specimen Handling and Transport Instructions
UCMC Onsite Instructions:
Collect specimen per standard collection procedure and send to laboratory immediately.
UCMC Offsite and UC MedLab Outreach Instructions:
- Samples should be centrifuged within 2 hours of collection.
- Centrifuge specimens at >2500 x g for 10 minutes at room temperature.
- Aliquot sample into plastic transport tube containing a minimum of 0.2 mL of specimen.
- Samples must be sent room temperature at 15-25oC.
Rejection Criteria
- Common specimen rejected situations include: incorrect specimen type, insufficient volume, missing or incomplete specimen identifiers, incorrect specimen transport, or specimens outside stability limits.
- Specimens that are clotted or grossly hemolyzed.
- Specimens that were transported unspun/whole blood and draw time is greater than 6 hours.
Reference Values
|
Test |
Age |
Sex |
Reference Range |
|
Potassium |
All |
All |
3.5-5.0 mmol/L |
Note: Reference range based on in-house studies, recommendations from Tietz Textbook of Clinical Chemistry, and Roche product literature.
Critical Values
|
Analyte |
Unit |
Low |
High |
Age |
|
Potassium |
mmol/L |
< 2.8 |
≥ 6.0 |
All |
Turnaround Time
Turnaround times are relative to the time the specimen is received in the test laboratory.
STAT Turnaround Time: 1 hour
Routine Turnaround Time: 4 hours
Testing Schedule: 24/7
Clinical Indications
Potassium, as one of the principal intracellular cations in the body, is a major contributor to tissue osmotic pressure and is the prime determinant of the cell resting membrane potential.
Test Components
Potassium
Methodology
Ion Specific Electrode Method (ISE) (Roche Diagnostics)
CPT Codes
84132
LOINC Codes
2823-3
Synonyms/Keyword Search
K
Additional Information
- Results should always be assessed in conjunction with patient's medical history, clinical examination and other findings.
- Release of potassium from as few as 0.5 % of the erythrocytes (from specimen collection) can increase the plasma level by 0.5 mmol/L.
- Hyperkalemia may be seen with anuria or urinary obstruction, tissue damage, violent muscle contraction, adrenal insufficiency, diabetes mellitus, leukemia, hyperparathyroidism, congestive heart failure (less common), metabolic acidosis and heat stroke.
- Hypokalemia may be seen with prolonged diarrhea or vomiting, diuretic administration, mineralocorticoid excess, familial periodic paralysis, renal tubular acidosis, Bartter’s syndrome, acute intermittent porphyria, congestive heart failure, and Reye’s syndrome.
- Patients with WBC >100 K/uL and have a diagnosis of chronic lymphocytic leukemia (CLL) have the potential to have falsely elevated potassium when drawn in lithium heparin plasma separator tubes. Therefore patients should be drawn in a Serum Gold Top or Red Top tube using the order code SSTCP for CMP for chronic lymphocytic leukemia (CPNL FOR CLL PATIENTS ONLY) , or SSTKP for BMP for chronic lymphocytic leukemia (KPNL FOR CLL PATIENTS ONLY)
- Also included in Basic Metabolic Panel KPNL, Comprehensive Metabolic Panel CPNL, ER Panel I STKG, Renal Function Panel RPNL, and Electrolyte Panel LYTS
Last Review Date
5/6/2025