Hematocrit (HCT) or Packed Cell Volume (PCV)
● Hematocrit is the volume of packed red cells in a
particular specimen of blood calculated as a percentage of total volume of blood.
● Hematocrit (HCT) and packed cell volume (PCV) are used to
measure red blood cell mass.
● It is generally a part of the complete blood count (CBC)
test.
● The PCV test measures how much of the blood consists of
cells.
● Hematocrit may be measured by centrifugation or automated
methods.
● A PCV of 40% means that there are 40 millilitres of cells
in 100 millilitres of blood.
Hematocrit (HCT)
● A calculated value obtained from modern automated
hematology analyzers.
● It is the product of the mean cell volume (MCV) and the
red blood cell (RBC) count, both of which are directly measured by the
analyzer.
● The formula used to calculate the HCT is as follows:
HCT = (MCV x RBC count)÷10
Packed cell volume (PCV)
● This is a directly measured value obtained from
centrifuging blood in a micro-hematocrit tube in a micro-hematocrit centrifuge.
● The PCV is measured as the height of the red cell column
in a micro-hematocrit tube after centrifugation.
● It is the quickest and most readily available measure of
the red blood cell component of blood
Normal Ranges of Packed cell volume (PCV)
● Male adult: 42 –
52%
● Female adult:
35 - 47%
● Pregnant females:
33- 38%
● New born: 42- 64%
● 1 – 5 year: 31
- 44%
● 5 – 10 year: 35
– 44%
● 11 – 18 year:
37 – 48% (male), 34 – 44% (female)
Indications of Packed cell volume (PCV)
● Hematocrit shows that a patient has anemia, erythrocytosis,
or changes in plasma volume.
● Hematocrit value is used as a cutoff to determine the
amount of requirement for transfusion.
Interpretation of Packed cell volume (PCV)
● Hematocrit is raised with an increase in the number of red
blood cells or a decrease in plasma volume.
● Hematocrit falls in decreased erythropoiesis or hemolysis
and hemorrhage where plasma volume is increased.
Increased Levels of Packed cell volume (PCV)
● Polycythemia vera
● Burns
● COPD
● Congenital heart disease
● Dehydration
● Eclampsia
Decreased Levels of Packed cell volume (PCV)
● Anemia
● Hemoglobinopathy
● Bone marrow failure
● Hemorrhage
● Hemolytic reaction
● Normal pregnancy
● Multiple myeloma
● Leukemia or lymphoma
● Nutritional deficiencies of iron or vitamin (B12 or
folate) and mineral deficiencies
● Recent or long-term blood loss
Interfering Factors of Packed cell volume (PCV)
Altitude:People living
in high altitudes have a high HCT.
Pregnancy: Hemodilution
of pregnancy causes decreased HCT.
Age: Lower HCT is
seen in men and women over the age of 60.
Dehydration: Severe
dehydration causes a false increase in HCT.
Nursing Implications of Packed cell volume (PCV)
● Manage fatigue avoid complications of anemia, maintain adequate
nutrition, maintain adequate perfusion, and encourage compliance with
prescribed therapy.
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