Hematocrit Determination (Worksheet #5 | M) Flashcards
What is hematocrit (what is its component)?
It is the volume of packed red blood cells (PRBCs) after the centrifugation of a blood sx
What is the other term for Hct?
Packed cell volume (PCV) and erythrocyte volume fraction (EVF)
How is Hct reported (what are the units used)?
1) Percent (%)
2) Cell volume percent (CV%)
3) Volume percent (vol%)
What are the contributions (and advantages) of Hct determination?
It is one of the: 1) simplest 2) most accurate and 3) valuable tests in hematological investigation
What is more useful than RBC count when it comes to detecting cases of anemia?
Hct determination
What are the values (or components) needed for the manual computation of RBC indices?
From the values of:
1) RBC count
2) Hemoglobin level
3) Hematocrit level
What are the 2 methods of Hct determination?
1) Clay Adam’s Microhematocrit Method
2) Wintrobe Method (Macrohematocrit Method)
What are the materials needed for Clay Adam’s method?
1) EDTA blood
2) Capillary tube (blue or red)
3) Sealing clay
4) Microhct centrifuge
5) Microhct reader
6) Disposable sterile blood lancet
What is the process (or steps) of Clay Adam’s method?
1) Fill around 3/4 of the capillary tube w/ blood
2) Seal one end of the capillary tube w/ sealing clay (about 3 mm)
3) Centrifuge the blood at 10,000 rpm for 4 - 5 mins using a microhct centrifuge
4) Determine the lvl of PRBCs using a microhct reader
What are the characteristics of red capillary tube (used in Clay Adam’s method)?
1) It is heparinized
2) It has a red colored ring at the top of the capillary tube
What is the purpose of red capillary tube (in Clay Adam’s method)?
It is heparinized which is responsible for the anticoagulation of blood
What are the characteristics of blue capillary tube (used in Clay Adam’s method)?
1) It is non-heparinized
2) It has a blue colored ring at the top of the capillary tube
What is the purpose of blue capillary tube (in Clay Adam’s method)?
It is non-heparinized to not provide contribution to the anticoagulant properties of EDTA tube
What is the depth of sealing to the capillary tube (for Clay Adam’s method)?
about 3 mm
What is the rpm for centrifuging blood using a microhct centrifuge?
10,000 rpm
What is the time for centrifuging blood using a microhct centrifuge?
4 - 5 mins
What is used to determine the lvl of PRBCs?
Microhct reader
What is utilized in Wintrobe method?
This method utilizes a wintrobe tube
How many are the calibrations of a Wintrobe tube (used in Wintrobe method)?
2
What are the 2 types of calibrations of Wintrobe tube?
1) 0 to 10
2) 10 to 0
* upwards
What is the purpose of Wintrobe tube having 0 to 10 calibration?
It is used for ESR
What is the purpose of a Wintrobe tube having a 10 to 0 calibration?
It is used for Hct
What is the anticoagulant of choice for Wintrobe method?
Double oxalate
What is the process (or steps) of Wintrobe method?
1) Fill the Wintrobe tube w/ blood using a Pasteur pipette
2) Centrifuge the tube at 3,000 rpm for 30 mins
3) Read the volume of PRBCs
4) Compute for the Hct lvl using the formula
What should be used to fill the Wintrobe tube w/ blood (in Wintrobe method)?
Pasteur pipette
What is the rpm in centrifuging the tube (in Wintrobe method)?
3,000 rpm
What is the time duration for centrifugation of tube (in Wintrobe method)?
30 mins
What is the formula used for computing the Hct lvl (in Wintrobe method)?
Hematocrit (%) = height of PRBCs / height of whole blood used X 100
What are the normal values (in CU) of Hct for male and female?
1) Male: 40 - 54 %
2) Female: 35 - 49 %
What are the normal values (in SI) of Hct for male and female?
1) Male: 0.40 - 0.54 L/L
2) Female: 0.35 - 0.49 L/L
What is the conversion factor for computing the normal values of Hct?
0.01
