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Test Code LAB3033 Sodium, Whole Blood

Performing Laboratory

St. Louis Children's Hospital Laboratory  - Core Lab

Specimen Requirements

Patient Preparation: None

Collection Container/Tube:

Preferred: Air-tight balanced heparinized blood gas syringe

Acceptable: Heparinized Capillary blood gas tube or green microtainer

Submission Container/Tube: May not be received from outside facility

Specimen Collection Volume: 1.0 mL (minimum 0.3 mL)

Special Instructions: Mix well and send to lab immediately. If collecting in capillary blood gas tube be sure to add flea to mix.

Sample Rejection

Mislabled or unlabeled specimens 

Clotted specimens

Logistics

Test Availability: Monday-Sunday

Cut-off time: None, performed as received

Turnaround Time: Same Day; 30 minutes from receipt in lab

Reference Values

Reference Interval: 

all ages: 135-145 mmol/L                                                                  

Critical Value: 

all ages: <120  OR  >160 mmol/L                                                            

Critical results will be called back automatically initially and every 24 hours thereafter.

Methodology

Ion-Selective Electrode (ISE)

Limitations

  • NA

Additional Information

FOR SLCH CORE LABORATORY USE ONLY

Lab Processing Instructions: DO NOT SPIN give specimen directly to blood gas bench

Processed Volume: 1.0 (minimum 0.3 mL) whole blood

Analyte Stability:

Specimen Type Temperature Time
Whole Blood (unprocessed)  Ambient 24 hours
Plasma/Serum (processed) Refrigerated      not acceptable   
  Ambient  not acceptable
  Frozen  not acceptable   

Test Classification and CPT Code

84295

LOINC

2951-2

Last Reviewed

07/2025