HEMA LAB - MIDTERM RBC COUNT

RBC count, r.b.c., erythrocyte count, red corpuscle count, and red cell enumeration

What are the synonyms for red cell count?

Number of red cells in one cubic millimeter of blood

What does a red cell count determine?

4.5-5.9 million/mm³ or 4.5-5.9 × 10¹²/L

What is the normal RBC count for males?

4.0-5.2 million/mm³ or 4.0-5.2 × 10¹²/L

What is the normal RBC count for females?

4.0-6.2 million/mm³ or 4.0-6.2 × 10¹²/L

What is the normal RBC count for newborn infants?

Lower oxygen content stimulates bone marrow to produce more red cells

Why does the RBC count increase at high altitude?

Increased oxygen content causes bone marrow to produce fewer red cells

Why may RBC count decrease at sea level after descending from high altitude?

Increased body fluid dilutes the red cells

Why may RBC count decrease during pregnancy?

Fluid loss concentrates the red cells

Why may RBC count increase in severe burns?

Anemia and leukemia

What conditions are associated with a low RBC count?

Polycythemia vera and dehydration

What conditions are associated with a high RBC count?

Oligocythemia

What is the term for a red cell count below normal that the manual describes as seldom used?

Erythrocytosis

What is the term for a red cell count above normal?

Isotonic for RBCs, economical, easy to prepare, preservative, high specific gravity, stable, buffered, non-allergenic, and non-corrosive

What are the ideal characteristics of an RBC diluting fluid?

Hayem, Gower, Toisson, Bethel, Formol-Citrate (Dacie), NSS, and 3.8% sodium citrate

What RBC diluting fluids are listed in the manual?

Volume in the bulb (constant) divided by volume of blood used (variable)

What is the formula for calculating the dilution factor?

200

What is the RBC dilution factor when 0.5 volume of blood is mixed with a bulb volume of 100?

20

What is the WBC dilution factor when 0.5 volume of blood is mixed with a bulb volume of 10?

Average number of RBCs × dilution factor × depth factor ÷ area counted

What is the general formula for calculating RBC count?

Average number of RBCs × 10,000, or add four zeros

What is the shortcut formula for RBC count when the dilution factor is 200?

Million/mm³ in conventional units or ×10¹²/L in SI units

What are the conventional and SI reporting units for RBC count?