hematology

Question 1

what percentage of blood loss results in orthostatic hypotension?

Answer 1

15% or greater

Question 2

at what GFR is erythropoietin supply starting to be diminished?

Answer 2

less than 49

Question 3

what are results of a normal h/h blood smear?

Answer 3

hgb 14-18
hct 42-52
MCV 80-100
MCHC 31-37
MCH 25-35
TIBC 250-410
Serum Ferritin 20-400
Serum Iron 50-175

Question 4

what does MCV measure? What is normal value?

Answer 4

Mean Corpuscular Volume: average size of RBCs. 80-100 is normal with 100 indicating macrocytic anemia, and 80-100 indicating a normocytic anemia and less than 80 indicating microcytic anemia

Question 5

what does MCHC measure? What is normal value?

Answer 5

Mean Corpuscular Hgb Concentration: measure of average color of RBCs. 31-37 is normal.

Question 6

What does MCH measure? What is normal value?

Answer 6

Mean Corpuscular Hemoglobin: indirect measure of color of RBCs. Decreased values mean pale or hypochromic RBCs. 25-35 is normal.

Question 7

What constitutes reticulocytosis? When is this seen?

Answer 7

> 2.5% of total RBC count. Elevation is seen when bone marrow is stimulated into producing RBCs–is elevated with supplementation of iron, folate, or B12 (after deficiency), after acute bleeding, hemolysis, leukemia, and with EPO treatment. CHRONIC BLEEDING DOES NOT CAUSE ELEVATION DUE TO COMPENSATION

Question 8

what does TIBC measure? What is normal value?

Answer 8

Total Iron Binding Capacity: Measure of available transferrin that is left unbound to iron (Transferrin is used to transport iron in the body). Normal is 250-410.

Question 9

What is serum ferritin? What is normal value?

Answer 9

The storage form of iron. Produced in intestines and stored in spleen, liver, and bone marrow–MOST SENSITIVE test for iron-deficiency anemia. Normal is 20-400.

Question 10

What are lab values of a microcytic, hypochromic anemia with elevated RDW? What is common cause?

Answer 10

MCV low, less than 80, MCH low, less than 31, RDW elevated, over 15%
Reduced H/H and RBCs
Iron deficiency anemia is most common cause–small cells due to insufficient hgb so new cells are smaller than old cells yielding elevated RDW

Question 11

What does RDW measure? When is it elevated?

Answer 11

Red Cell Distribution Width: Measure of variability of size of RBCs. Is elevated in iron-deficiency anemia and thalassemia

Question 12

What are reticulocytes (stabs)? What is normal level?

Answer 12

Immature RBCs that still have nuclei. Normal is 0.5-2.5% of total RBC count

Question 13

What are three major causes of anemia?

Answer 13

Blood loss: Acute from hemorrhage or chronic from gastritis, menorrhagia, GI malignancy etc.
Reduced RBC production: Nutrition issues (Vit B12 folic acid iron deficiency), Anemia of chronic disease, bone marrow suppression, use of certain drugs (PPIs)
Premature destruction: Hemolysis, shortened RBC lifespan

Question 14

What are lab values of a normocytic, normochromic anemia with normal RDW? What are common causes?

Answer 14

MCV normal at 80-100
MCHC normal at 31-37
RDW normal at 11.5-15%
Reduced H/H and RBCs
Acute blood loss or anemia or chronic disease--cells that are made under ordinary conditions with sufficient hemoglobin

Question 15

What are lab values of microcytic, hypochromic anemia with normal RDW? What are common causes?

Answer 15

MCV low less than 80
MCHC low less than 31
RDW normal 12.5-15%
Caused by alpha or beta thalassemia minor

Question 16

what ethnic groups are at risk for alpha thalassemia minor?

Answer 16

Alpha: Asian, African (A, A A)

Question 17

what ethnic groups are at risk for beta thalassemia minor?

Answer 17

Beta: African, Mediterranean, Middle Eastern (B, A, M, M E)

Question 18

What are lab values of a macrocytic, normochromic anemia with elevated RDW? What is common cause?

Answer 18

MCV high >100
MCHC normal at 31-37
RDW high >15%
Most common cause pernicious anemia, dietary induced vitamin B12 deficiency, folate deficiency–abnormally large cells due to altered RNA: DNA ratio

Question 19

What drugs can cause macrocytosis? (elevation in MCV without anemia

Answer 19

carbamazepine, valproic acid, phenytoin, alcohol, AZT

Question 20

What is the most common cause of anemia in elderly?

Answer 20

Anemia of chronic disease, Fe, Pernicious

Question 21

What is the most important source of the body’s iron supply?

Answer 21

recycled iron from aged rbcs.

Question 22

How do you instruct patients to take Iron?

Answer 22

on an empty stomach, with OJ or vitamin C

Question 23

What are the symbols for male female pregnancy and death in a genogram? What about male or female with disease?

Answer 23

Male=square
female=circle
pregnancy=triangle
death=x-out
with disease, blacked out

Question 24

What is the gold standard test to diagnose hemoglobinopathies such as sickle cell, thalassemias?

Answer 24

hemoglobin electrophoresis

Question 25

What foods are high in Folate?

Answer 25

broccoli, spinach, legumes, chickpeas, lentils

Question 26

What foods are high in vitamin B12?

Answer 26

meat fish dairy eggs

Question 27

What does elevated reticulocyte count indicate in anemia?

Answer 27

anemia due to blood loss or destruction

Question 28

What does decreased reticulocyte count indicate in anemia?

Answer 28

anemia due to reduced RBC production

Question 29

What happens to RDW as MCV decreases in a microcytic anemia?

Answer 29

RDW increases

Question 30

What happens to RDW as MCV increases in macrocytic anemia?

Answer 30

RDW decreases