Hematocrit

Question 1

Hematocrit used along with several lab tests to evaluate?

Answer 1

RBCs

- screen for anemia (decrease) and polycythemia (increase)

Question 2

Hematocrit value represents?

Answer 2

percentage of RBCs in whole blood //

• Hct affected by size of RBCs - can look like a lot of RBCs but maybe they are just huge (high Hct and macrocytic)
• Hct also affected by volume of blood (think dehydration)

Question 3

Hct values must always be evaluated in conjunction with?

Answer 3

MCV, mean corpuscular volume

• average volume of a red blood cell aka SIZE
• macrocytic, normocytic, microcytic

Question 4

If you are severely dehydration what will happen to your Hct value?

Answer 4

when dehydrated, blood volume decreases, therefore Hct increases.

Question 5

During pregnancy, what will happen to your Hct value?

Answer 5

during pregnancy, Hct value will go down as the blood volume increases (hemodilution)

Question 6

In the case of acute hemorrhage, what will happen to the Hct value?

Answer 6

Hct value will remain the same.

but as they recover, the blood volume increases and Hct decreases significantly.

Question 7

Hct has a close relationship with which count?

As the Hct value increases, what happens to the other count?

Answer 7

RBC count aka lab measurement of total number of RBC’s in a cubic millimeter of blood.

Hct value increases and so does RBC count.

Question 8

Normal Hct value?

women, men, newborns, elderly

Answer 8

women: 36-48%
men: 42-52%
newborns: 44-64%
>60 yo declines

Question 9

What will cause a false elevated reading of Hct value?

Answer 9

• prolonged venous stasis due to tourniquet left on too long

- including the buffy coat in the reading

Question 10

What will cause a false depressed reading of Hct value?

Answer 10

failure to invert the tube after drawing blood

Question 11

What will cause reading the results to be difficult due to the unclear RBC/plasma junction?

Answer 11

waiting more than an hr after centrifuging to read results