Module 1: An Introduction to the Anemias

Question 1

anemia

Answer 1

reduced Hb below normal reference range

Below 140g/L in Males
below 120g/L in Females

Question 2

most anemias are accompanied by

Answer 2

low hematocrit and/or RBC count

Question 3

Polycythemia

Answer 3

RBC count (and usually also hematocrit) are increased above ref range

Question 4

2 types of anemias

Answer 4

absolute and relative

Question 5

Absolute anemia

Answer 5

hb concentration is decreased due to

• decreased absolute # of RBC in blood
• Decreased Hb inside the RBC

Question 6

Absolute anemia results in

Answer 6

decrease in oxygen carrying capacity of blood due ti decrease in red cell mass
Mild to severe hypoxia

Question 7

Symptoms of absolute anemia

Answer 7

pallor of mucous membranes
shortness of breath on mild excertion
weakness
lethargy
palpitations
headaches

Question 8

2, 3 BPG in relation to most anemias

Answer 8

level of 2, 3 BPG in red cells in increased
Oxygen dissociation curve is shifted to the right
Oxygen is release more easily and completely to hypoxic tissue

Question 9

Relative anemia

Answer 9

Hb concentration decreased by increasing plasma volume (by dilution)
No decrease in Red cell mass or any loss of oxygen carrying capacity
Often seen in third trimester pregnancy

Question 10

Only sure way of differentiating absolute from relative

Answer 10

measure red cell volume (RCV) and/or plasma volume (PV) using radioisotope techniques

Question 11

3 causes of absolute anemias

Answer 11

Decreased or Ineffective erythropoiesis (RBC production is decrease; decreased # of cells survive)

Increased Hemolysis (increased destruction or decreased survival of RBC in circulation)

Blood loss

Question 12

relation between rate of production and hemolysis/loss

Answer 12

Rate of production IS LESS THAN rate of hemolysis/loss

Question 13

Most useful classification of anemia is

Answer 13

morphologic/etiologic classification

based on red cell indices and rbc morphology

Question 14

4 types of absolute anemia

Answer 14

Hypochromic
Macrocytic
Normochromic Normocytic
Hemolytic

Question 15

Hypochromic anemia lab results

Answer 15

Red cell indices are decreased (MCV, MCH, MCHC)

Red cell morphology: Hypochromic and often microcytic

Question 16

Macrocytic anemia lab results

Answer 16

Red cell indices are variable (MCV increase, MCH variable, MCHC normal)
Red cell morphology: Macrocytic

Question 17

Normochromic normocytic anemia lab results

Answer 17

Red cell indices are normal

Red cell morphology: normal

Question 18

Hemolytic anemia lab results

Answer 18

Red cell indices are often normal

Red cell mophology: poikilocytosis (abnormal variation in shape)

Question 19

3 questions to answer for physician

Answer 19

Is an anemia present?
If yes, what kind is it?
What is its cause?

Question 20

Hemoglobin is based on

Answer 20

colorimetric measurement manually or by automated instrumentation

Question 21

Hematocrit (pcv) is based on

Answer 21

centrifugation of blood or calculated on an automated instrument

Question 22

RBC indices

Answer 22

Mean Cell Volume (MCV) indicates size

Mean Cell Hb (MCH) indicates Hb mass

Mean cell Hb concentration (MCHC) in an average RBC

RBC distribution width (RDW) which is an index of size variation which indicates amount of anisocytosis (variation in size) present

Question 23

Mean Cell volume (MCV)

Answer 23

indicates volume in femtoliters (fL; x10^-15) of an average red cell in a blood sample
From histogram or can be calculated

MCV=Hct/RBC

Normal range 80-100fL

Question 24

Normal MCV indicated

Answer 24

RBC of normal size present (normocytes present)

Question 25

Increased MCV indicates

Answer 25

at least some cells with increase volume Due to greatly increased # of young cells polychromatophilic erythrocytes (reticulocytes) or enlarged mature cells (macrocytes)

Question 26

Decreased MCV indicates

Answer 26

smaller than normal erythrocytes (microcytes) present

Question 27

Mean Cell Hemoglobin (MCH)

Answer 27

indicates weight of Hb inside an average RBC in picograms (pg; x10^-12) MCH = Hb/RBC Normal range is 27-32pg

Question 28

Mean Cell Hemoglobin Concentration (MCHC)

Answer 28

indicates the Hb concentration inside the RBC expressed as grams of Hb per L of RBC (g/L) MCHC = Hb/Hct Normal range is 320-360g/L

Question 29

Normal MCHC indicates

Answer 29

normal concentration of Hb within the RBC | Normochromic

Question 30

Decreased MCHC indicates

Answer 30

presence of red cells lacking normal amounts of Hb in blood | Hypochromia

Question 31

Increased MHCH

Answer 31

Typically erroneous because volume of RBC usually increased to accommodate greater amounts of Hb (thus MCH may be increased but MCHC remains normals due to increased volume of the cell; Term hyperchromia is NOT used) MCHC May be truly increased: Spherocytes present in blood (used term spherocytosis NOT hyperchromia), Lipemia or cold agglutinins (considered an interference)

Question 32

Red cell distribution width (RDW)

Answer 32

indicates the amount of RBC volume/size variation (anisocytosis) in a sample Obtained by calculating coefficient of variation (CV) of red cell volumes from red cell volume histogram (Expressed as %) Normal range is 11.5-14.5%

Question 33

Lab results: RDW normal MCV increased

Answer 33

Interpretation: No anisocytosis present All macrocytes

Question 34

Lab results: RDW increased MCV increased

Answer 34

Interpretation: Anisocytosis present Macrocytes and normocytes, or macrocytes, normocytes and microcytes

Question 35

Lab results: RDW Normal MCV Normal

Answer 35

Interpretation: No Anisocytosis present Normal cells

Question 36

Lab results: RDW Increased MCV Normal

Answer 36

Interpretation: Anisocytosis present Equal amounts of microcytes and macrocytes (average out to be normal)

Question 37

Lab results: RDW increased MCV decreased

Answer 37

Interpretation: Anisocytosis present Microcytes and normocytes, or microcytes, normocytes and macrocytes

Question 38

Lab results: RDW normal MCV decreased

Answer 38

Interpretation: No Anisocytosis present All microcytes

Question 39

MCV, MCH and MCHC act as quality control check on

Answer 39

RBC count, hematocrit, and Hb results

Question 40

RDW allows easier interpretation of the

Answer 40

MCV