Podcast
Questions and Answers
If a patient's hematocrit is found to be 62%, which of the following conditions might be suspected?
If a patient's hematocrit is found to be 62%, which of the following conditions might be suspected?
- Menstruation
- Dehydration (correct)
- Anemia
- Overhydration
A researcher is studying a population in a high-altitude environment. How would you expect their hematocrit levels to compare to a population at sea level?
A researcher is studying a population in a high-altitude environment. How would you expect their hematocrit levels to compare to a population at sea level?
- Approximately the same, as altitude has no impact on hematocrit.
- Slightly lower due to acclimatization.
- Significantly lower due to decreased oxygen availability.
- Significantly higher due to the body's adaptation to lower oxygen levels. (correct)
Why is it important to allow the alcohol used to sterilize the thumb to dry completely before performing the lancet prick for a hematocrit test?
Why is it important to allow the alcohol used to sterilize the thumb to dry completely before performing the lancet prick for a hematocrit test?
- To avoid diluting the blood sample with alcohol, which could alter the hematocrit reading. (correct)
- To prevent hemolysis of red blood cells.
- To ensure the lancet doesn't rust.
- To minimize the risk of infection.
During a hematocrit procedure, what would be the most likely consequence of not properly sealing one end of the capillary tube before centrifugation?
During a hematocrit procedure, what would be the most likely consequence of not properly sealing one end of the capillary tube before centrifugation?
A researcher obtains a hematocrit reading that is slightly higher than normal for a healthy adult male. Which factor could potentially account for this elevated result?
A researcher obtains a hematocrit reading that is slightly higher than normal for a healthy adult male. Which factor could potentially account for this elevated result?
Why are heparinized capillary tubes used for hematocrit determination?
Why are heparinized capillary tubes used for hematocrit determination?
How would severe burns likely affect a patient's hematocrit level, and why?
How would severe burns likely affect a patient's hematocrit level, and why?
How does the principle of capillarity contribute to obtaining a blood sample in the hematocrit procedure?
How does the principle of capillarity contribute to obtaining a blood sample in the hematocrit procedure?
A newborn's hematocrit level is typically higher than that of an adult. What is the primary physiological reason for this difference?
A newborn's hematocrit level is typically higher than that of an adult. What is the primary physiological reason for this difference?
A phlebotomist consistently records lower-than-expected hematocrit values for patients. What procedural error is most likely causing this issue?
A phlebotomist consistently records lower-than-expected hematocrit values for patients. What procedural error is most likely causing this issue?
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)
Synonymous with Hematocrit, it refers to the volume of red blood cells after centrifugation.
Centrifugation
Centrifugation
The process of separating blood components by spinning the blood sample at high speed.
Normal Male HCT
Normal Male HCT
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Normal Female HCT
Normal Female HCT
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Normal Newborn HCT
Normal Newborn HCT
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High Altitude & HCT
High Altitude & HCT
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Anemia & HCT
Anemia & HCT
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Polycythemia & HCT
Polycythemia & HCT
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Dehydration & HCT
Dehydration & HCT
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Study Notes
- Hematocrit (HCT) is also known as Packed Cell Volume (PCV).
- HCT is the percentage ratio of red cell volume to total blood volume.
- Hct = (RBCs volume / Total blood volume) x 100
Normal Values
- The normal HCT range for males is 44-54%.
- The normal HCT range for females is 37-47%.
- Males have a higher HCT due to testosterone, and menstruation affects HCT in females.
- The normal HCT range for newborns is 55-60% due to relative hypoxia.
Factors That Affect Hematocrit Value
- Number of RBCs in the blood affects hematocrit.
- Volume of plasma in the blood affects hematocrit.
Physiological Factors
- Age: Newborns have a high hematocrit.
- Sex: Males generally have a higher hematocrit than females.
- High Altitude: Living at high altitude can increase hematocrit due to relative hypoxia.
Pathological Factors
- Hematocrit is impacted in Anemia and Over-hydration.
- Conditions like Polycythemia and Dehydration also affects Hematocrit.
Tools
- 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, allow it to dry, and then prick it with a sterilized lancet.
- Fill the capillary tube (or 3/4 of its length) with the oozing blood, which is drawn in through capillary attraction.
- Seal one end of the tube using provided wax.
- Centrifuge the tube at 3000 revolutions per minute for 3 minutes.
- RBCs 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 align the upper limit of clear plasma to the 100% line.
- Take Hct readings directly from the scale at the upper level of RBCs.
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Description
Learn about Hematocrit (HCT), also known as Packed Cell Volume (PCV). Explore normal HCT ranges for males, females, and newborns, and factors affecting HCT values. Understand the physiological and pathological influences on hematocrit levels.
