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HelpTest Code Billings Clinic: 4216 Sodium + Potassium, Plasma or Serum
Performing Laboratory
Billings Clinic Laboratory: Chemistry
Useful For
- Evaluation of electrolyte balance, cardiac arrhythmia, muscular weakness, hepatic encephalopathy, and renal failure
- Potassium should be monitored during treatment of many conditions but especially in diabetic ketoacidosis and any intravenous therapy for fluid replacement.
- Sodium assays are important in assessing acid-base balance, water balance, water intoxication, and dehydration.
Methodology
A-LYTE® Integrated Multisensor Technology (IMT)
Specimen Requirements
Submit only 1 of the following specimens:
Serum or plasma should be physically separated from cells as soon as possible with a maximum limit of two hours from the time of collection.
Plasma
- Draw blood in a green-top (lithium heparin) tube(s).
- Spin down and send 1.0 mL of heparinized plasma frozen.
Serum
- Draw blood in a plain, red-top tube(s) or a serum gel tube(s).
- Spin down and send 1.0 mL of serum frozen
Storage/Stability
| Specimen Type | Temperature | Time |
| Plasma, Serum | Refrigerated | 7 days |
| Frozen (preferred) | 30 days |
Reject Due To
- Hemolysis
Reference Values
See individual test listings.
Day(s) Test Set Up
Daily
Test Classification and CPT Coding
84132 - potassium
84295 - sodium
LOINC Code Information
| Reporting Name | LOINC Code |
| Sodium | 2951-2 |
| Potassium | 2823-3 |
Profile/Testing Information
| Profile Information: | |
| Potassium |
Sodium |
Interferences
- Hemolyzed samples may give incorrect elevated potassium. Intracellular potassium concentration is 30–50 times greater than that of extracellular serum or plasma.
- Samples exposed to benzalkonium salts present in certain blood catheter devices will cause falsely elevated sodium and potassium measurements.
- Iron at 1 g/dL increases the potassium result in serum/plasma at 2.69 mmol/L (2.69 mEq/L) by 17% and 4.54 mmol/L (4.54 mEq/L) by 11%.