bloodindiceshaemato-2103211419012227.pdf

Red cell indices

1. RED BLOOD CELL
INDICES
Dr. JILSHA

2. CONTENTS
•Introduction
•Mean corpuscular volume
•Mean corpuscular haemoglobin
•Mean corpuscular haemoglobin
concentration.
•Red Cell Distribution width
•Colour Index

3. INTRODUCTION
•The values of Hemoglobin, Packed Cell
Volume (PCV) and Total RBC count are used to
calculate red cell volume and red cell
hemoglobin content and concentration. These
are called Red Blood Cell indices.

4. INTRODUCTION
•The commonly estimated indices are :
oMean Cell Volume (MCV)
oMean Cell Hemoglobin (MCH)
oMean Cell Hemoglobin Concentration (MCHC)
oRed Cell Distribution Width (RDW)
•Determination of these indices are is of
considerable clinical importance and is
widely used in the classification of
anemia.

5. MEAN CORPUSCULAR VOLUME
(MCV)
•MCV is the average volume of an RBC
expressed in femtoliters(1 fL= 10-15 L).
•If the PCV and number of red cells per liter
are known, MCV is calculated as follows :
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6. MCV
•The factor 10 is introduced to convert the
hematocrit reading in % from volume of
packed red cells per 100 mL to volume per
liter.
•For example if the hematocrit is 40% and the
red cell count is 5 million, then MCV is :
��??????=
40×10
5
= 80 fL

7. MCV
•Normal value : MCV in adults in between
78 fLto 96 fL.
APPLIED ASPECT
MCVis the index of the size of red cells. It depicts whether
the red cells are Microcytic, Normocytic or Macrocytic.
If the MCV is less than 78 FL, the cells are microcytic. If it is
greater than 96 FL, the cells are macrocytic.

8. MEAN CORPUSCULAR
HEMOGLOBIN (MCH)
•MCH is the averageweight of hemoglobin
content in an RBC.
•It is expressed in picograms(1pg = 10 –12 g)
•It is calculated as follows :
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��(
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)×10
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9. MCH
•For example, if the hemoglobin content is 14 g/dl
and the RBC count is 5 million:
���=
14×10
5
= 28 pg.
•Normal value : Normal range is 27 –33 pg
APPLIED ASPECT
MCH will be as high as 50 pgin macrocytic anemia or as low
as 20 pgor less in microcytic hypochromic anemia

10. MEAN CORPUSCULAR HEMOGLOBIN
CONCENTRATION (MCHC)
•It is the average hemoglobin concentration
per unit volume of packed red cells.
•It is expressed as g/dl or percent.
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)
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11. MCHC
•For example, if the Hbconcentration is 15 g/dl and
PCV is 45 %
����=
15
45
×100=33.3%
•Normal value : between 33-37 g/dl or %
APPLIED ASPECT
MCHC above 40% indicateserror in instrument or manual
method as 37% is the limit for hemoglobin solubility .
Inhypochromic anemias, the Hbconcentration is reduced and
values as low as 20 –25% are present.

12. RED CELL DISTRIBUTION WIDTH
(RDW)
•It is a measurement derived from the RBC
distribution curve generated on automated
hematology analyserand is an indicator of
variation in RBC size within a blood sample.
•It is used along with other indices to describe
the population of RBCs.

13. RDW
•It is calculated as follows :
�������������????????????�
��??????
×100
•It is expressed in percentage.
•Normal range is 11-15%

14. COLOUR INDEX (CI)
•It refers to the ratio of Hbto RBC.
•For calculating CI, Hbof 14.8 g/dl is taken as
100% and RBC count of 5 million/mm
3
is taken
as 100 %
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•For eg., if Hbis 14.8 g/dl and RBC count is 4.5
million/mm
3
then 4.5*100 = 90%, so,
CI = 100/90 = 1.11