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Test Code LAB79 Blood Gas, Venous

Performing Laboratory

St. Louis Children's Hospital Laboratory  - Core Lab

Specimen Requirements

NOTE: SPECIMEN SHOULD ARRIVE WITHIN 10 MINUTES OF COLLECTION

Patient Preparation: None

Collection Container/Tube:

Preferred: 1.0 mL Air-tight balanced heparinized blood gas syringe

Acceptable: 3.0 mL Air-tight balanced heparinized blood gas syringe

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

Specimen Collection Volume: 1.0 mL (minimum 0.3 mL if using the 1.0 mL syringe or absolute minimum of 0.8 mL if using the 3.0 mL syringe)

Special Instructions: Mix well and send capped syringe (no needle attached) to lab immediately. Place specimen in wet ice at bedside if unable to send immediately (removing specimen from ice to send thru tube system).

 

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: 

pH Ven
   <18 years: none established
   ≥18 years:      7.32-7.43                                                                                   
pCO2 Ven
   <18 years: none established                                                               
   ≥ 18 years: 40-50 mmHg                                                              
pO2 Ven
all ages: none established                                     
HCO3 Ven  
   <18 years:            none established                                                                          
   ≥ 18 years: 20-30 mmol/L                                                

Base Excess: no reference interval(s) established

 

Critical Value:  

pH Ven (All ages): <7.20  OR  >7.60                                                             

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

Methodology

Potentiometry and Amperometry

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 mL (minimum 0.3 mL in 1.0 mL syringe or 0.8 mL in 3.0 syringe) whole blood

Specimen Stability Information:

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

82803

LOINC

pH Ven: 2746-6

pCO2 Ven: 2021-4

pO2 Ven: 2705-2

CO2 Totl ECMO: 20565-8

Last Reviewed

07/2025