Equations because you suck at this

What equation tells you the average RBC size derived from a RBC histogram?

• MCV (Mean Cell Volume)

What is the equation for MCV?

• (HCT % / RBC count) x 10

What value from the MCV indicates microcytic anemia?

• < 80 fl

What value from the MCV indicates normocytic anemia?

• 80 - 100 fl

What value from the MCV indicates macrocytic anemia?

• > 100 fL

What equation measures the variability in the size of RBC, and measures anastomosis?

• RDW

What is the equation for RDW?

• (sd x 100) / mean size

What is the normal range for the RDW?

• 11.5 - 14.5%

What is the equation for hematocrit (HCT)?

• (RBC x MCV) / 10

What equation represents the mean weight of Hgb per erythrocyte and is expressed in (pg)?

• MCH (Mean Cell Hemoglobin)

What is the formula for MCH?

• (Hgb x 10) / RBC count

What range for the MCH represents hypochromic anemia?

• < 26 pg

What range for the MCH represents normochromic anemia?

• 26 - 34 pg

What range for the MCH represents hyperchromic anemia?

• > 34 pg

What equation is used to correct a WBC formula when nRBC are present?

• (# WBC x 100) / (nRBC + 100)

Give an example of using a Corrected WBC count equation?

• WBC = 9.0 × 10⁹/L (uncorrected)

• nRBC/100 WBC = 17

• (9.0 × 10⁹/L x 100) / (17 + 100) = 7.6 × 10⁹ / L

When should you perform a corrected WBC count?

• when the number of nRBCs is > 5 per 100 RBC

What is a Relative Count?

• % of a particular white blood cell from the white blood cell differential

What is an Absolute Count?

• depicted by #

• determined by multiplying relative count(%) by the total WBC from the print out (relative count x total WBC)

• OR hemogram/ 100

What is the equation for the reticulocyte count?

• (number of reticulocytes / 1000 RBC) x 100

What is the normal range for Reticulocyte counts?

• 0.5 - 1.5%

Calculate the reticulocyte count if 24 retics were present.

• (24 reticulocytes / 1000 RBC) x 100

• Retic count: 2.4%

What are corrected reticulocyte counts?

• compares patient hematocrit with normal hematocrit values

What equation is used to calculate corrected reticulocyte count?

• (Patient retic % x Patient Hct %) / 45%

What is the equation for the Reticulocyte Production Index (RPI)?

• ((Reticulocyte count % x (Patient HCT % / 45%)) / (Retic maturation time)

Solve for Reticulocyte production index.

Patient retic count: 7.8%

Patient Hct: 30%

for the Hct of 30% the maturation time is 2 days.

• (7.8 x (30/45)) / 2

• RPI = 2.6

What number for RPI means that there is adequate bone marrow response?

• > 3

What equation measures the actual number of reticulocytes in 1 liter of blood?

• absolute retic count

What is the equation for the absolute retic count?

• (reticulocytes % x RBC count) / 100

What is the normal range for absolute reticulocyte count?

• 20 - 115 × 10⁹ /L