Anaemia and polycythaemia Flashcards Preview

Y2 MCD Haem HR > Anaemia and polycythaemia > Flashcards

Flashcards in Anaemia and polycythaemia Deck (25)
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1

Define "anaemia"

A reduction in the amount of haemoglobin in a given volume of blood below what would be expected in comparison with a healthy subject of the same age and gender

2

Recall 4 MECHANISMS of anaemia

1. Reduced red cell/ Hb production
2. Pooling of red cells in large spleen
3. Blood loss
4. Reduced red cell survival

3

What is defective in microcytic anaemia? Recall 3 causes

Haemoglobin synthesis
Defects in haem synthesis: iron deficiency
Defects in globin synthesis: alpha thalassaemia, beta thalassaemia

4

What name is given to anaemia caused by abnormal haemopoiesis? What classification is it given and why?

Megaloblastic anaemia (failure of DNA synthesis)
MACROCYTIC - delay in maturation of the nucleus while the cytoplasm continues to mature and the cell continues to grow

5

What is the most common cause of megaloblastic eryhtropoiesis?

B12 deficiency

6

Recall 7 possible causes of macrocytic anaemia

1. Vit B12 def.
2. Folic acid def.
3. Recent major blood loss
4. Drugs that interfere with DNA synthesis
5. Alcohol toxicity
6. haemolytic anaemia
7. Liver disease

7

Why would haemolytic anaemia be macrocytic?

Number of reticulocytes increased, and they are 20% bigger than mature cells

8

What could be a cause of pooling of red cells in an enlarged spleen?

Portal cirrhosis

9

Recall 3 possible causes of normacytic normachromic anaemia

1. Recent blood loss
2. Failure of red cell production
3. Pooling in hypersplenism

10

Recall 3 possible causes of rec cell production failure

1. Bone marrow suppression by cancer drugs
2. Bone marrow infiltration by cancer
3. early stages of a deficiency (B12/FA/ renal fx)

11

Recall 5 hereditary causes of haemolytic anaemia

1. Protein deformation
2. Spherocytosis
3. Sickle Cell
4. Pyruvate kinase deficiency
5. G6PD deficiency

12

Recall the aetiology of hereditary spherocytosis leading to haemolytic anaemia

1. Cells lose section of membrane in spleen
2. Premature removal from spleen
3. Bone marrow responds by increasing activity --> polychromasia and reticlocytosis
4. Cells more likely to haemolyse when osmotic pressure applied

13

What is G6PD essential for in erythrocytes?

Prevention of oxidant damage

14

Recall 3 possible extrinsic oxidants that may cause G6PD deficiency

1. Drugs
2. Broad beans
3. Napthalene (moth balls)

15

Who is most at risk of G6PD deficiency and why?

Hemizygous males, as the G6PD gene is on the X chromosomes

16

Describe the blood film of someone with haemolytic anaemia caused by G6PD deficiency

Many irregularly contracted cells
Heinz bodies

17

What causes Heinz bodies?

Denatired DNA

18

Describe the aetiology of autoimmune haemolytic anaemia

Production of AutoIg-M which is directed at red cells
IgM recognised by splenic macrophages and phagocytosed, leading to loss of membrane and spherocytosis

19

Recall the 5 principles of diagnosis for haemolytic anaemia

1. Normachromic
2. Normacytic or macrocytic
3. Morphologically abnormal red cells
4. increased red cell breakdown
5. Increased bone marrow activity

20

Recall the aetiology of biliary system complications in haemolytic anaemia

Heamolysis > bilirubin production increased > jaundice + gall stones

21

What 2 things might be seen on the blood film of someone with haemolytic anaemia?

Spherocytes
Increased #reticulocytes

22

Recall the first line of treatment for haemolytic anaemia

Corticosteroids and other immunosuppressants

23

What measures are elevated in polycythaemia

HCt
Hb
Red cell count

24

WHat is the difference between pseudopolycythaemia and true polycythaemia?

Pseudopolycythaemia - results from decreased plasma vol
True polycythaemia - results from increased red cell number

25

Recall 4 possible causes of polycythaemia

1. Blood doping
2. Too much erythropoietin
3. Renal carcinoma
4. Abnormal bone marrow fx (eg polycythaemia vera)