Red Blood Cell (RBC) Count

CPT 85041
Synonyms
  • Erythrocyte Count

Test Details

Use

Evaluate anemia and loss of red cells and suspected polycythemic condition

Limitations

Presence of cold agglutinins may result in falsely low RBC counts.

Methodology

Automated cell counter

Additional Information

Decrease in RBC count may be the result of red cell loss by bleeding or hemolysis (intravascular or extravascular), failure of marrow production (due to a broad variety of causes), or may be secondary to dilutional factors (eg, intravenous fluids). Increase in RBC count may be the result of primary polycythemia (polycythemia vera) or secondary polycythemia (hypoxemia of lung or cardiovascular disease, increased erythropoietin production associated with renal cyst, renal cell carcinoma, cerebellar hemangioblastoma, or high O2 affinity hemoglobinopathy) including stress polycythemia (hemoconcentration associated with exercise, exertion, fright, etc).

Specimen Requirements

Information on collection, storage, and volume

Specimen

Whole blood

Volume

Tube fill capacity

Minimum Volume

0.5 mL (500 μL for pediatric microtainer capillary tubes; fill tube to capacity.) (Note: This volume does not allow for repeat testing.)

Container

Lavender-top (EDTA) tube

Storage Instructions

Maintain specimen at room temperature.

Causes for Rejection

Hemolysis; clotted specimen; tube not filled with minimum volume; improper labeling; transport tubes with whole blood; specimen drawn in any anticoagulant other than EDTA; specimen diluted or contaminated with IV fluid; specimen received with plasma removed

Collection

Invert tube immediately 8 to 10 times once tube is filled at time of collection.