1. Prepared by: Yasser M. EL-dahdouh
Red Blood Cell Indices
Prepared by:
Yasser M. EL-dahdouh

2. Red Blood Cell Indices
They are also called red cell absolute values or erythrocyte indices.
Red blood cell indices are measurements that describe the size and oxygen- carrying protein( hemoglobin) content of red blood cells.
The indices are used to help in the differential diagnosis of anemia.

3. **The relationships between the hematocrit, the hemoglobin, and the red blood cells are converted to red blood cell indices through mathematical formulas. ** The indices include these measurements: 1- Mean corpuscular volume ( MCV). 2- Mean corpuscular hemoglobin ( MCH). 3- Mean corpuscular hemoglobin concentration ( MCHC).

4. MCV “ Mean corpuscular volume “
** is the average volume of the RBCs in femtoliters( fl ), or 10^-15 L. MCV = HCT(%) * 10/ RBCs count (10^-12/L ) ** Cells of normal size ( MCV is 80 – 100 fl )are called normocytic, Smaller cells are microcytic, Larger cells are macrocytic.

5. These size catedories are used to classify anemia.
* Normocytic anemia have normal size cells and a normal MCV.
* Microcytic anemia have small cells and a decreased MCV.
* Macrocytic anemia have large cells and a increased MCV.
Example:
Hct= 45%, RBCs count= 5.0 * 10^12/L,
MCV= 45 * 10 / 5.0 = 90fl.

6. MCH “ Mean corpuscular hemoglobin”
** is the average weight of Hb in an RBC, expressed in the units of picograms ( pg) or
( 10^-12g).
MCH= Hb(g/dl) * 10 / RBCs count ( 10^12/L).
** Reference range ( 28 – 32 pg ).
** The MCH is not generally considered in the classification of anemia.

7. Example:
Hb= 16 g/dl.
RBCs connt= 5.0 * 10^12/L.
MCH= 16.0 * 10 / 5.0= 32.0 pg

8. MCHC
** is the average concentration of Hb in each individual erythrocyte.
** The units used are gram per deciliter ( formerly referred to as a percentage ).
MCHC= Hb(g/dl) * 100 / Hct (%)
** Reference range ( 32 – 37 g/dl ).
* Hypo chromic cells are less than 32 g/dl.
* Hyper chromic cells are greater than 37g/dl.
*Values of normo chromic cells range from 32 to 37 g/dl.

9. Anemia: a variety of condition in which a person blood can not carry as much oxygen as it should due to a decreased number or size of red blood
cells.
Hypochromic: a descriptive term applied to a red blood cell with a decreased concentration of Hb.
Hyperchromic: a descriptive term applied to a red blood cell with a increased concentration of
Hb.