Anemia

Question 1

Cytopenia

Answer 1

non-specific term for a reduction in the number of a cellular component of blood

Question 2

Anemia

Answer 2

low hemoglobin concentration in blood

Question 3

Thrombocytopenia

Answer 3

low number of platelets in blood

Question 4

Leukopenia

Answer 4

low number of white cells in blood

Question 5

Neutropenia

Answer 5

low number of neutrophils (absolute neutrophil count or ANC <1.5)

Question 6

Pancytopenia

Answer 6

reduction of all three cell lines (anemia, thrombocytopenia, neutropenia)

Question 7

3 principles in considering blood count

Answer 7

Principle #1: a patient’s cell count is low (where is the problem?). Principle #2: consider the other cell counts (is this an isolated abnormality?). DIFFERENTIAL DIAGNOSIS: plan further diagnostic tests. Principle #3: consider the patient(how urgently do tests need to be done?)

Question 8

Normal life cycle of blood cells

Answer 8

Produced in bone marrow; released into peripheral blood; normal lifespan: RBC: 120d, pt: 7-10d, neut: 6-8h; senescence (RBC destroyed by spleen, pt consumed in clots or destroyed by spleen, neut consumed or apoptosis)

Question 9

What causes blood cell numbers to be low?

Answer 9

Bone marrow not working; or Peripheral problems, namely: Sequestered (engulfed by abnormally large spleen, or diluted in large blood volume); Consumption or loss (bleeding (RBC and pt), immune function (pt and neut), severe infection (neut))

Question 10

What is likely causing pancytopoenia?

Answer 10

The more cell lines affected, the more likely it is bone marrow problem. Also see more immature cells released

Question 11

Anemia

Answer 11

It’s not a diagnosis, just a condition - investigate. Hb < normal (130g/L for male, 120 for female). Symptoms depend on severity, rapidity of onset, age, comorbid contitions

Question 12

General signs and symptoms of anemia

Answer 12

Quite nonspecific, so hard to ID sometimes. Fatigue; SOB & tachypnea (increased respiratory rate); Tachycardia (increased heart rate); decreased exercise tolerance; dizzy or lightheaded; worsening of pre-existing ischemic state (ie. patient with underlying coronary artery disease getting chest pain).

Question 13

Anemia classification approaches

Answer 13

1. According to the MCV 2. According to the bone marrow response (reticulocyte count) 3. According to pathologic category: decreased production, increased loss or destruction, Sequestration

Question 14

MCV approach

Answer 14

MCV < 80fL is microcytic anemia; MCV 80 - 100 fL is normocytic anemia; MCV > 100 is macrocytic anemia. But remember these are not mutually exclusive!

Question 15

Microcytic anemia causes

Answer 15

iron deficiency; anemia of chronic; disease; Thalassemia trait (and disease); sideroblastic anemia; lead poisoning (last 2 less so)

Question 16

Macrocytic anemia causes

Answer 16

B12 or folate deficiency; liver disease, EtOH; high reticulocyte count; alcohol; Myelodysplasia; anemia from hypothyroidism (more rare)

Question 17

Iron deficiency

Answer 17

(MCV 60s to normocytic!) Not enough iron to make heme

Question 18

Thalassemia trait or disease

Answer 18

(MCV 60-70s) Not enough globin chains to make Hb. Trait is “carrier” state, milder. Due to mutations in genes for a and ß glob in chains

Question 19

Anemia of chronic disease

Answer 19

(MCV 75-85) Iron present but not readily available for use

Question 20

VitaminB12/folate deficiency; Myelodysplasia, Drugs (chemotherapy, HIV drugs)

Answer 20

Impaired DNA synthesis; nuclear maturation and cytoplasm maturation are mismatched

Question 21

Alcoholism, Liver disease, TSH

Answer 21

Altered/increased lipid content in cell membrane: redundant membrane

Question 22

Reticulocytes

Answer 22

(young RBC, some remnants of nucleus still there) Contain residual protein synthesis machinery; have not achieved final compact red cell size

Question 23

Reticulocyte count

Answer 23

Underused test. Consider ordering it if unexplained anemia. Should be about 1% normally, but should be high if you are responding to EPO

Question 24

Normal response to anemia

Answer 24

Kidney detects low O2, release EPO, bone marrow produces new RBC (reticulocytes)

Question 25

Low reticulocyte count

Answer 25

abnormal marrow; deficiency of food for red cells (need iron and vitamin B12); low metabolic state; low erythropoietin because of renal failure. Marrow can’t respond!

Question 26

High reticulocyte count

Answer 26

bleeding, hemolysis. Marrow is responding BUT red cells being lost or destroyed faster than they can be replaced

Question 27

Anemia by pathologic category

Answer 27

Increased loss or destruction: LOSS = Bleeding (obvious or occult) DESTRUCTION = Hemolysis (red cells being destroyed in the body). Sequestration (and dilution): dilutional = pregnancy, large IV boluses; sequestration = cells sequestered in the spleen (not so relevant to red cells). Decreased production: BIG category (mostly bone marrow)

Question 28

Summary: initial investigation of anemia

Answer 28

1. MCV based: Microcytic: ferritin, +/- Hemoglobinopathy investigation; Macrocytic: B12/folate, liver enzymes, TSH. 2. Consider a Blood film: Confirms cell count abnormalities and may offer important clues if you have no idea what is going on, other cell lines are also down or if hemolysis is suspected. 3. Reticulocyte count (is the marrow working?). 4. Serum ferritin: assess iron stores

Question 29

Summary of pathologic category

Answer 29

picture

Question 30

Summary for classifications of anemia

Answer 30

table

Question 31

Summary framework for diagnosis

Answer 31

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