Laboratory Approach to Hematology

Question 1

H&H

Answer 1

Hemoglobin and hematocrit

Question 2

CBC definition, what about “with diff”?

Answer 2

A set of tests of red and white blood cells that includes number, size and distrubution, and hemoglobin/hematocrit

The diff is a WBC differential count, or what types of wbc a patient has prevalent amounts of

Question 3

reference range for RBC count male and female

Answer 3

males - 4.5-6x10^6 cells/uL

females - 4-5.5x10^6 cells/uL

Question 4

Hematocrit

Answer 4

The percentage of RBC’s that makeup whole blood

Question 5

Reference range for hematocrit male and female

Answer 5

male 39-49%

female 35-45%

Question 6

Hemoglobin structure, how many o2 molecules can it carry?

Answer 6

4 chains a1 and 2, b1 and 2, each with a heme group containing an iron atom, it can carry 4 o2 molecules

Question 7

Hgb A vs Hgb F vs Hgb AS vs Hgb SS

Answer 7

• A is 90% of normal human hemoglobin
• F is fetal hemoglobin that has a higher carrying capacity than HgbA useful for fetal development, it drops drastically 3 months after birth
• AS is sickle cell trait
• SS is sickle cell disease

Question 8

As a rule of thumb, hematocrit is typically ___ to hemoglobin

Answer 8

3x

Question 9

Reference range for hemoglobin male and female

Answer 9

male - 13.8-18 g/dL

female - 12.1-15.1 g/dL

Question 10

2 examples of situations that increase hematocrit and decrease it (volume contraction and volume expansion)

Answer 10

Dehydration increases, pregnancy can decrease

Question 11

If an anemic patient is dehydrated, they will have a ____ H&H

Answer 11

normal appearing

Question 12

A hypervolemic patient will have a falsely low H&H, which might be mistaken for

Answer 12

Anemia

Question 13

A patient with acute active hemorrhage will have a ___ H&H

Answer 13

normal, serum and RBC’s are being lost together

Question 14

Thrombocytes are derived from this organ, while clotting factors are derived from this organ

Answer 14

Bone marrow, liver

Question 15

Name the 4 red cell indices

Answer 15

1) Mean corpuscular volume
2) Mean corpuscular hemoglobin
3) mean corpuscular hemoglobin conc.
4) red cell distribution width

Question 16

Mean corpuscular volume (MCV) function and reference range

Answer 16

Determines presence of macrocytic or microcytic anemia by measuring the avg size of an RBC, reference range being 80-100fL

Question 17

Common causes of macrocytosis (2)

Answer 17

• folate or B12 deficiency

- acoholism or liver disease

Question 18

Common causes of microcytosis (2)

Answer 18

• Chronic iron deficiency

- blood loss

Question 19

Mean corpuscular hemoglobin (MCH) function

Answer 19

Measures the weight of hemoglobin in avg RBC, correlates very closely with MCV andis redundant

Question 20

Mean corpuscular hemoglobin concentration (MCHC) function

Answer 20

Avg conc of hemoglobin in the average RBC, correlates with degree of chromasia (redness of RBC)

Question 21

Anisocytosis

Answer 21

Presence of RBC’s with varying sizes

Question 22

Polkiocytosis

Answer 22

Presence of RBC’s with varying shapes

Question 23

Red cell distribution width (RDW) function

Answer 23

Measure of variation in RBC size, with deficiency anemias tending to have higher RDW’s

Question 24

Reticulocyte count function, what do we want to see it look like on an anemic patient?

Answer 24

A measure of reticulocytes in the blood, indicative of functioning bone marrow
-If patient is anemic want to see high count to indicate bone marrow is working to replenish

Question 25

Serum ferritin test function, what is it most sensitive test for?

Answer 25

A measure of the intracellular protein that stores iron in the body to be mobilized in times of need, most sensitive test for iron deficiency

Question 26

Total Iron Binding Capacity test function, what does increased and decreased values indicate?

Answer 26

TIBC measures the blood capacity to bind iron with transferrin, if increased indicative of iron deficiency anemia, if normal or decreased could indicate hemolytic anemia or pernicious anemia

Question 27

Haptoglobin test function and what does a decrease or increase indicate?

Answer 27

Measures a blood glycoprotein that binds free hemoglobin, increased indicates inflammation or infection, decreased indicates hemolysis because the majority of it is bound to the free heme iron (it indirectly is measuring heme iron this way)

Question 28

Prothrombin time (PT)/INR test function, what does a low or high value indicate?

Answer 28

Measures time it takes blood to clot (while compensating for a standardized unit) to measure extrinsic clotting factors, low indicates prone to clots, high indicates prone to bleed

Question 29

Activated partial thromboplastin time (aPTT) test function, what does a low or high value indicate?

Answer 29

Measures time it takes blood to clot to measure intrinsic clotting factors, low indicates prone to clots, high indicates prone to bleed

Question 30

C reactive protein levels can help…

Answer 30

….detect inflammation

Question 31

MCV calculation

Answer 31

Hct x 10/RBC

Question 32

MCH calculation

Answer 32

Hgb x10/RBC

Question 33

MCHC calculation

Answer 33

Hgb x100/Hct