Introduction to Anaemia

Question 1

What is the definition of anaemia?

Answer 1

Reduced total red cell mass

Question 2

What are the two main surrogate markers used to measure total red cell mass?

Answer 2

Haemoglobin concentration and haematocrit

Question 3

What would be a normal Hb level for each of the following groups: a) men? b) adult females and children aged 6-14 years? c) pregnant females and children aged 6 months to 6 years?

Answer 3

a) > 130g/L b) > 120g/L c) > 110g/L

Question 4

What is the haematocrit?

Answer 4

The ratio or percentage of the whole blood sample that is made up of red cells if the sample was left to settle

Question 5

What are some rarer situations where Hb and haematocrit are not good markers of anaemia?

Answer 5

Early on in a severe, rapid bleed and in haemodilution

Question 6

Aside from red cell indices, what are some further investigations which could be done to assess for anaemia?

Answer 6

Blood film, reticulocyte count and other additional tests depending on clinical findings

Question 7

What blood test is the most useful tool in distinguishing between nuclear and cytoplasmic deficits?

Answer 7

Mean cellular volume (MCV)

Question 8

If Hb and MCV are low, what is this known as? You should consider a problem with what?

Answer 8

Microcytic anaemia / haemoglobinisation of the red blood cell

Question 9

If Hb is low and MCV is high what is this known as? You should consider a problem with what?

Answer 9

Macrocytic anaemia / maturation of the red blood cell

Question 10

In terms of the pathophysiology of anaemia, it can be due to what two things?

Answer 10

Decreased production of red blood cells or increased loss/destruction of red blood cells

Question 11

What happens to the reticulocyte count if the cause of an anaemia is decreased production of red blood cells?

Answer 11

It is low

Question 12

What happens to the reticulocyte count if the cause of an anaemia is increased loss or destruction of red blood cells?

Answer 12

It is high

Question 13

What are the two subgroups of causes which come under ‘decreased production of red blood cells’?

Answer 13

Hypoproliferative (reduced erythropoiesis) or a maturation abnormality which causes ineffective erythropoiesis

Question 14

Impaired haemoglobinisation is caused by a defect where?

Answer 14

Cell cytoplasm

Question 15

Impaired red cell division and maturation is caused by a defect where?

Answer 15

Cell nucleus

Question 16

What are the two main causes of increased loss/destruction of red blood cells?

Answer 16

Bleeding and haemolysis

Question 17

What is haemolysis? What is the compensatory mechanism to this?

Answer 17

Premature red cell destruction in the circulation / increased red cell production in the bone marrow

Question 18

What are reticulocytes?

Answer 18

Red blood cells which have just left the bone marrow

Question 19

How do reticulocytes appear different to mature erythrocytes?

Answer 19

They are larger and they stain deep purple/red known as ‘polychromasia’

Question 20

Why do reticulocytes stain deep purple/red?

Answer 20

They still contain some RNA

Question 21

Reticulocyte count is a marker of what?

Answer 21

Red cell production

Question 22

If there are increased reticulocytes, this indicates what?

Answer 22

Either blood is being lost or the patient is haemolysing

Question 23

Reticulocytosis can be a sign of both blood loss and haemolysis. What other factors would point more towards a diagnosis of haemolysis?

Answer 23

Increased red cell breakdown products e.g. unconjugated serum bilirubin and urinary urobilinogen

Question 24

What is the result of producing increased red cell breakdown products?

Answer 24

Anaemia and jaundice, sometimes splenomegaly

Question 25

Why can anaemia be asymptomatic?

Answer 25

Since a slowly falling Hb can be compensated for by a rise in 2,3-DPG causing a shift of the oxygen dissociation curve to the right to allow oxygen to be more readily given up to the tissues

Question 26

What are the main non-specific symptoms of anaemia?

Answer 26

Tiredness, headache, faintness, breathlessness

Question 27

What are the main non-specific signs of anaemia?

Answer 27

Pallor, tachycardia, systolic murmur