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Test Code WBC White Blood Cell (WBC) Count, Blood

Additional Codes

St. Luke's Compendium Code (Iatric): L100.0190

Performing Laboratory

St. Lukes Hospital Laboratory

Methodology

Automated Flow-Through Cytometry

Specimen Requirements

Draw blood in a lavender-top (EDTA) tube(s), and send 1 mL of EDTA whole blood. If there is a delay in transport of >8 hours, make 4 to 5 blood smears within 2 hours of draw. Forward promptly at ambient temperature.
Note:  1. If specimen will not arrive at St. Luke’s Hospital Laboratory the same day as drawn, refrigerate specimen. Transport at ambient temperature. Do not place EDTA whole blood directly on top of an ice pack.

2. Label slides with patient’s full name (first and last) and date and time of collection.

Reference Values

0-1 week:  9.0-30.0 K/µL

1-2 weeks:  5.0-20.0 K/µL

2 weeks-1 year:  5.0-15.5 K/µL

1-4 years:  4.0-12.0 K/µL

>4 years:  4.0-10.0 K/µL

Critical value (automatic call-back):  ≤0.9 K/µL

Interfering Substances:

Lipemia, hemolysis, abnormal RBC morphology, and cold agglutinins may interfere with testing.

Day(s) Test Set Up

Monday through Sunday

Test Classification and CPT Coding

CPT: 85048

LOINC: 6690-2