Podcast
Questions and Answers
What is the definition of hematocrit (HCT)?
What is the definition of hematocrit (HCT)?
- The ratio of plasma volume to total blood volume, expressed as a percentage.
- The percent ratio of red cell volume to total blood volume. (correct)
- The percentage of white blood cell volume to total blood volume.
- The concentration of hemoglobin in red blood cells.
Which of the following factors would cause an increased hematocrit (HCT) value?
Which of the following factors would cause an increased hematocrit (HCT) value?
- Menstruation
- Overhydration
- Anemia
- Dehydration (correct)
Why is hematocrit typically higher in males than in females?
Why is hematocrit typically higher in males than in females?
- Testosterone increases hematocrit levels, while menstruation decreases it in females. (correct)
- Males are more prone to overhydration.
- Males have a lower red blood cell count than females.
- Females have naturally higher plasma volumes.
A newborn's hematocrit level is found to be 58%. What is the most likely physiological reason for this?
A newborn's hematocrit level is found to be 58%. What is the most likely physiological reason for this?
In the procedure for determining hematocrit, what is the purpose of centrifuging the blood sample?
In the procedure for determining hematocrit, what is the purpose of centrifuging the blood sample?
What is the function of the heparin in the micro-capillary tube used for hematocrit determination?
What is the function of the heparin in the micro-capillary tube used for hematocrit determination?
During hematocrit measurement, if the upper limit of the plasma is set to the 100% line on the Hct scale, what does the zero line represent?
During hematocrit measurement, if the upper limit of the plasma is set to the 100% line on the Hct scale, what does the zero line represent?
A male patient has a hematocrit level of 40%. Based on the normal ranges, how would this be interpreted?
A male patient has a hematocrit level of 40%. Based on the normal ranges, how would this be interpreted?
What is the primary reason for using a sterilized lancet when collecting a blood sample for hematocrit determination?
What is the primary reason for using a sterilized lancet when collecting a blood sample for hematocrit determination?
In a patient with polycythemia, what change would you expect to see in their hematocrit level compared to the normal range?
In a patient with polycythemia, what change would you expect to see in their hematocrit level compared to the normal range?
Flashcards
Hematocrit (HCT)
Hematocrit (HCT)
The percentage of red blood cell volume in relation to the total blood volume.
Packed Cell Volume (PCV)
Packed Cell Volume (PCV)
Another name for Hematocrit, representing the volume of red blood cells after centrifugation.
Normal Hematocrit Values
Normal Hematocrit Values
Male: 44-54%. Female: 37-47%. Newborn: 55-60%.
Factors Affecting HCT
Factors Affecting HCT
Signup and view all the flashcards
Physiological Factors - HCT
Physiological Factors - HCT
Signup and view all the flashcards
Pathological Factors Affecting HCT
Pathological Factors Affecting HCT
Signup and view all the flashcards
HCT Measurement Tools
HCT Measurement Tools
Signup and view all the flashcards
Steps to Determine Hematocrit
Steps to Determine Hematocrit
Signup and view all the flashcards
Appearance After Centrifugation
Appearance After Centrifugation
Signup and view all the flashcards
Comment on HCT Result
Comment on HCT Result
Signup and view all the flashcards
Study Notes
- Hematocrit (HCT) is also known as Packed Cell Volume (PCV)
- It is the percent ratio of red cell volume to total blood volume.
- Hct = (RBCs volume / Total blood volume) x 100
- Normal HCT values for males: 44-54%
- Normal HCT values for females: 37-47%
- Hct is higher in males than females due to male testosterone and menstruation in females.
- Normal HCT values for newborns: 55-60%, due to relative hypoxia
Factors Affecting Hematocrit Value:
- Number of RBCs can affect the hematocrit
- Volume of plasma is also a factor
Physiological Factors
- Age: Hct is high in newborns
- Sex: Hct is more in males
- High altitude: Due to relative hypoxia
Pathological Factors
- Anemia and overhydration decrease Hct
- Polycythemia and dehydration increase Hct
Tools for Measuring Hematocrit
- Alcohol
- Cotton
- Sterilized Lancet
- Heparinized micro-capillary tube (red circle)
- Crista seal paste or wax
- Micro-centrifuge
- Hct scale or Hct ruler
Steps for Measuring Hematocrit
- Sterilize the thumb with alcohol, let it dry, and prick it with sterilized lancet
- Fill the capillary tube (or 3/4 of its length) with oozing blood, which is withdrawn by capillary attraction (capillarity).
- Seal one end of the tube with provided wax.
- Centrifuge the tube at 3000 revolutions per minute for 3 minutes.
- The RBCs will pack together at the bottom of the tube, while plasma remains above
- Place the lower level of RBCs on the zero line of the Hct scale and the upper limit of clear plasma on the 100% line.
- Read the Hct directly on the scale at the upper level of RBCs.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Explore hematocrit (HCT), also known as packed cell volume (PCV), which represents the percentage of red cell volume in total blood volume. Learn about normal HCT values for males, females, and newborns, along with factors affecting HCT levels, including physiological and pathological conditions. Discover the tools and steps involved in accurately measuring hematocrit.
