Hematology

Question 1

What is anemia defined as?

Answer 1

reduction in Hct or Hb concentration

Question 2

When is blood transfusion recommended before surgery?

Answer 2

Hb<8

Hct <30

Question 3

S/S of anemia?

Answer 3

• nonspecific: headache, fatigue, N/V
• conjunctival pallor
• hypotension and tachycardia

Question 4

what are some historical findings to consider in patients with anemia?

Answer 4

• bleeding (melena, recent trauma/sx, hematemesis)
• chronic illnesses (e.g. renal failure)
• alcoholism (folate, vit B12 def, iron def)
• fam hx of hemophilia, G6PD deficiency, thalassemia

Question 5

how many points does 1 unit of packed RBC increase for Hb? for Hct?

Answer 5

increases Hb level by 1 point

increases Hct by 3 points

Question 6

what is pseudoanemia?

Answer 6

decrease in H&H secondary to dilution (i.e. secondary to acute volume infusion or overload)

Question 7

if H/H reveals anemia, what are the next tests to obtain to determine cause of anemia?

Answer 7

reticulocyte count

and mean corpuscular volume (MCV)

Question 8

why is the reticulocyte count important in evaluating anemia?

Answer 8

indicates whether effective erythropoeisis is occurring in the bone marrow
-reticulocytes are immature RBC befroe they leave the bone marrow

Question 9

where is erythropoietin made?

Answer 9

in the kidney

this is why renal failure may cause anemia

Question 10

for platelet transfusions, how much does 1 unit raise platelet count by?

Answer 10

1,000

Question 11

what is a normal reticulocyte index? what is abnormal, and what does this indicate?

Answer 11

• normal is less than 2% and implies inadequate RBC production by bone marrow
• abnormal is greater than 2% and implies excessive RBC destruction or blood loss, so then the bone marrow is responding to increased RBC requirements

Question 12

what MCV value is considered a microcytic anemia ?

Answer 12

MCV less than 80

Question 13

what MCV value is considered macrocytic anemia?

Answer 13

MCV greater than 100

Question 14

what MCV value is considered normocytic anemia?

Answer 14

MCV between 80-99

Question 15

what is the most common cause of microcytic anemia?

Answer 15

iron deficiency anemia

Question 16

what are some DDx for causes of macrocytic anemia ?

Answer 16

Vitamin B12 and folate deficiencies

liver disease

Question 17

what are some DDx for causes of microcytic anemia?

Answer 17

iron deficiency anemia
thalassemias
anemia of chronic dz
sideroblastic anemia- lead poisoning, alcohol poisoning, pyridoxine deficiency

Question 18

what are some DDx for normocytic anemias?

Answer 18

aplastic anemia
bone marrow fibrosis
tumor
anemia of chronic dz (chronic inflammation, malignancy) 
renal failure (decreased epo production)

Question 19

if the reticulocyte index is greater than 2, what should you do?

Answer 19

suspect blood loss- look for a source of bleeding

suspect hemolysis

Question 20

What are the iron studies in iron deficiency anemia?

Answer 20

decreased serum ferritin (and serum iron)
high TIBC/transferrin levels
high RDW

Question 21

in elderly patients with iron deficiency anemia, you should suspect what?

Answer 21

GI blood loss (esp colon cancer!!)

Question 22

what is the treatment of iron deficiency microcytic anemia?

Answer 22

oral iron replacement (ferrous sulfate)

parenteral iron replacement (rarely necessary)

Question 23

what is thalassemias?

Answer 23

inherited disorders characterized by inadequate production of either the alpha or beta-globin chain of Hb
*classified according to the chain that is deficient

Question 24

why do chronic diseases cause anemia (normocytic)?

Answer 24

the release of inflammatory cytokines has a suppressive effect on erythropoiesis

Question 25

treatment for anemia of chronic dz?

Answer 25

do NOT give iron. the anemia is mild and well-tolerated. just treat the underlying process

Question 26

what are the main dietary sources of vitamin B12?

Answer 26

meat and fish

Question 27

where is Vit B12 stored?

Answer 27

in the liver

Question 28

what does Vit B12 bind to?

Answer 28

intrinsic factor (which is produced by gastric parietal cells) and is absorbed by the terminal ileum

Question 29

what is pernicious anemia?

Answer 29

lack of intrinsic factor (so B12 can't bind it and be absorbed) --> leading to B12 deficiency and macrocytic anemia *diagnose by antibodies against intrinsic factor

Question 30

hypersegmented neutrophils seen in a blood smear is diagnostic for what?

Answer 30

Vit B12 def (macrocytic anemia)

Question 31

what clinical symptom is often seen in B12 deficient patients?

Answer 31

neuropathy and other neurologic dz

Question 32

how are serum methylmalonic acid and homocysteine levels in B12 deficiency?

Answer 32

both are elevated (because they are precursors in excess with no cofactor to do the conversion)

Question 33

what is treatment for B12 deficiency?

Answer 33

parenteral therapy- cyanocobalamin (Vit B12) IM injection once a month

Question 34

what is the main dietary source of folate?

Answer 34

green vegetables

Question 35

schistocytes (fragmented RBC) suggest what?

Answer 35

intravascular hemolysis

Question 36

spherocytes (or helmet cells) suggest what?

Answer 36

extrvascular hemolysis

Question 37

Heinz bodies are seen in what?

Answer 37

G6PD deficiency

Question 38

haptoglobin levels are high/low in hemolytic anemia?

Answer 38

LOW- bc haptoglobin binds to Hb, so its absence means that Hb was destroyed

Question 39

what is normal platelet count?

Answer 39

150k-400k