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Test Code LAB7856 Calcium Ionized, 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 (arterial or venous collection)

Acceptable: Heparinized Capillary blood gas tube 

Submission Container/Tube: May not be received from outside facility unless order as 'Calcium Ionized' that is collected in red-top tube.

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.

If specimen is to be collected and sent from outside facility, sample may be collected in a plain, red-top tube or gold/red SST tube. Specimens collected in red top tubes are stable for up to 4 hours as long as the tube top has not been opened or removed.

 

Sample Rejection

Mislabled or unlabeled specimens 

Clotted specimens

Specimens collected in Mint Green-top LiHep tubes or microtainers

Logistics

Test Availability: Monday-Sunday

Cut-off time: None, performed as received

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

Reference Values

Reference Interval: 

< 24 hours: 4.50-5.75 mg/dL                                                 
24 hours - 4 days: 4.15-5.40 mg/dL
4 days - 6 months: 4.85-5.80 mg/dL
6 - 30 months: 4.60-5.50 mg/dL
30 months - 18 years: 4.45-5.25 mg/dL
≥ 18 years: 4.50-5.10 mg/dL

Critical Value: 

All ages:  <2.60  OR  >6.80 mg/dL                                                            

Critical test 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 30 minutes
Plasma/Serum (processed) Refrigerated      not acceptable   
  Ambient  not acceptable
  Frozen  not acceptable   

 

Test Classification and CPT Code

82330

LOINC

12180-6

Last Reviewed

07/2025