1. Packed Cell Volume (PCV)
& Blood Indices

3. DETERMINATION OF HEMATOCRIT (PACKED CELL VOLUME-PCV)
The hematocrit or packed cell volume (PCV) determines the percentage of red blood cells (RBCs) in whole blood.
The NORMAL value for men is 42% to 52%; for women, 37% to 47%; and for newborns, 53% to 65%.
low PCV indicate medical conditions like
Anemia, leukemia
High PCV indicate medical conditions like
Dehydration, polycythemia & high altitude.

4. Methods Currently electronic method is used to measure hematocrits.
However, when hematology analyzers are not available, hematocrit determinations can be manually performed by:
Microhematocrit method
  It requires less blood and less time(commonly used)
Macrohematocrit method

5. Microhaematocrit Method
Materials and instruments
Cotton and lancet
Heparinized capillary tubes (red label at the end of the tube)
Modeling clay sealant 

6. 4. Microhematocrit reader 5. Microhematocrit centrifuge
Hematocrit (Hct) or Packed Cell Volume (PCV):

7. Microhematocrit Procedure
  To perform the microhematocrit method, you should follow the steps listed below:
1. Fill tube two-thirds to three-quarters of the heparinized capillary tube with fingertip blood.
2. Non heparinized capillary tube is used when oxalated blood is obtained.
3. Seal one end of the tube with clay. 

8. 4. Place the filled tube in the microhematocrit
4. Place the filled tube in the microhematocrit. centrifuge, with the plugged end away from the center of the centrifuge. 5. Centrifuge at a preset speed of 10,000 to 12,000 rpm for 5 minutes. 6. Place the tube in the microhematocrit reader. Read the hematocrit (PCV)%.

9. BLOOD INDICES
Introduction and Principle The red blood cell indices are used to define the size and Hb content of the single red blood cell. Types: 1.mean corpuscular volume(MCV) 2.mean corpuscular hemoglobin(MCH) 3.mean corpuscular hemoglobin concentration(MCHC%). Objectives Are used as an aid in differentiating anemia’s.

10. Information Required
1-RBC count in millions / c.mm.
2-Hb estimation in g / dL.
3-PCV estimation as %.

11. Calculations 1-Mean Corpuscular Volume (MCV):
The MCV indicates the average volume of single RBC.
Its expressed in femtoliters(fL).
PCV %
MCV =
RCB X6 /1 C.mm
PCV
= X = fL
RCB
Normal range fL. So the RBC’s are normocytic .
Value less than 80 fl RBC’s are microcytic e.g. iron deficiency anemia
Value more than 1o0 fl RBC’s are macrocytic e.g. pernicious anemia

12. 2-Mean Corpuscular hemoglobin (MCH):
Average weight of hemoglobin( Hb) in single RBC .its expressed in pigogram (pg).
Hb ( g /dl)
MCH =
RBC x 106 /1 c.mm Hb
= x 10 = pg
RBC
Normal range : pg.
If MCH is < 27 pg condition is called hypochromic

13. 3.Mean corpuscular hemoglobin concentration(MCHC%)
is the average concentration of Hb in the single red blood cell.
It is expressed as %.
Hb(g/dl)
MCHC =
PCV % Hb
= x
PCV
= %
Normal value is 31-36% so the RBC’s are normochromic.
If MCHC is less than 31% so the RBC s are hypochromic.