PCV

Packed Cell Volume (PCV) & Blood Indices

DETERMINATION OF HEMATOCRIT (PACKED CELL VOLUME-PCV)

Methods

Microhaematocrit Method
Materials and instruments

Hematocrit (Hct) or Packed Cell Volume (PCV):

4. Microhematocrit reader

Microhematocrit Procedure

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)%.

BLOOD INDICES

Introduction and PrincipleThe 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.


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

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 1 0 = fL RCBNormal range 80-100fL. So the RBC’s are normocytic .Value less than 80 fl RBC’s are microcytic e.g. iron deficiency anemiaValue more than 1o0 fl RBC’s are macrocytic e.g. pernicious anemia

2-Mean Corpuscular hemoglobin (MCH):

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 100 PCV = %Normal value is 31-36% so the RBC’s are normochromic.If MCHC is less than 31% so the RBC s are hypochromic.