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HelpTest Code LAB16 Electrolyte Panel
Performing Laboratory
St. Louis Children's Hospital Laboratory - Chemistry
Specimen Requirements
Note: This test includes analysis of: Sodium; Postassium; Chloride; and CO2 (carbon dioxide)
Patient Preparation: None
Collection Container/Tube:
Preferred: Mint green-top lithium heparin (MNTGRN LiHep) tube
Acceptable: Green samplette/microtainer, plain red-top tube, or Gold SST gel tube
Submission Container/Tube: If collected in a microtainer or plain red-top tube aliquot processed sample into a plastic vial for transport (labeling with specimen type).
Specimen Collection Volume: 1.0 mL (minimum 0.6 mL)
Special Instructions: Send to lab promptly
Sample Rejection
Mislabled or unlabeled specimens
Logistics
Test Availability: Monday-Sunday
Cut-off time: None, performed as received
Turnaround Time: Same Day; 2 hours from receipt in performing lab
Reference Values
Reference Interval: See individual test listings
Critical Value: See individual test listings
Any Critical result will be called back automatically initially
Methodology
Ion-Selective Electrode (ISE)
Limitations
- Hemolysis can interfere with Potassium concentrations
Additional Information
FOR SLCH CORE LABORATORY USE ONLY
Lab Processing Instructions: Centrifuge to separate within 2 hours of collection. If specimen is collected in microtainer or plain red-top tube aliquot sample into a Roche false-bottom tube for testing (labeling aliquot with specimen type).
Processed Volume: 0.3 mL plasma/serum
Analyte Stability:
| Specimen Type | Temperature | Time |
|---|---|---|
| Whole Blood (unprocessed) | Ambient | 2 hours |
| Plasma/Serum (processed) | Refrigerated (preferred) | * |
| Ambient | * | |
| Frozen | * | |
| *See individual test listings for processed stability for individual analyte needed | ||
NOTE: if specimen is received in plain, red-top or serum gel tube, check if LIS order is for serum or plasma. If order is for "Lytes Plas" cancel and re-order as "Lytes Ser".
Test Classification and CPT Code
80051
LOINC
| Sodium | 2951-2 |
| Potassium | 2823-3 |
| Chloride | 2075-0 |
| CO2 Totl | 1962-0 |
Last Reviewed
06/2025