Packed Cell Volume PCVHaematocrit It is defined as

Packed Cell Volume (PCV)/Haematocrit.

• It is defined as the percentage of blood volume that is constituted by erythrocytes. • Wintrobes method • In Males 45% (40 -50%) • In Females 42%(37 -45%)

Variation in PCV Increases in : • Polycythaemia (increase in RBC Count) • Burns, Sweating , Diarrhea (Hemoconcentration –Relative increase) • High Altitude • Males. • Newborn babies. PCV viscosity peripheral resistance BP

Decreases in: • Anaemia ( a decrease in RBC Count). bone marrow depression. • Females. • Pregnancy. • Fluid transfusions (Hemodilution. Relative decrease).

Swollen RBC’s in venous blood (due to chloride shift) -- PCV of venous blood is 3% greater than that of arterial blood.

• Simple screening test for Anaemia. • Enable the calculation of absolute values. (blood indices).

Plasma color • Deep yellow plasma -----jaundice. • Slight reddish colour ---hemolytic anemia. • White color --- presence of lipid

Serum • The clear liquid part of the blood that remains after blood cells and clotting factors have been removed

ESR ( Erythrocyte Sedimentation Rate) The rate at which the RBC’s sediments due to the gravity , when anticoagulated blood is allowed to stand in a vertical tube for 1 hour. Westergren’s tube.

Normal values: • Males : 1 to 4 mm at the end of 1 st hr • Females : 5 to 10 mm at the end of 1 st hr Prognostic value

Increase in: • Pregnancy( in fibrinogen and globulin) • Women( RBC) • Anaemia • Acute and chronic infection • Cancerous condition

Decrease in: • Polycythaemia • Sickle cell anaemia

Rouleaux Formation

Blood loses its stability and the RBC’s pile one over the other.

Factors affecting ESR: • Size of Rouleaux. • fibrinogen, globulin. • Temperature. • Shape of the cell. • viscosity. • Position of the pipette.