Haemoglobinopathies and Obstetric Haematology Flashcards Preview

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Flashcards in Haemoglobinopathies and Obstetric Haematology Deck (22):
1

What are the main haematological changes during pregnancy?

Plasma vol. expands by 50%
Red cell mass expands by 25%= haemodilution and decreased in relative MCH +/-anaemia
Increased requirement for Fe and folic acid
Leucocytosis- immature WBCs sometimes seen in peripheral blood
Thrombocytopenia
Hypercoaguable stage (liver increased production of clotting factors)

2

Overall, is pregnancy a hyper or hypo coagulable state?

Hypercoaguable- settles down 6-8 weeks after birth

3

Detection of what foetal haemaglobinopathy would prompt genetic counselling and the decision to terminate the foetus

Thalassamia major (B)

4

How is thalassaemia inherited?

Autosomal recessive

5

What are the most common single gene disorder

Thalassaemias

6

Why does alpha thalassamia have a worse prognosis than beta thalassaemia?

Alpha globin is present in adult and foetal haemoglobin

7

What are the lab findings for alpha and beta thalassaemia trait?

Microcytic, hypochromic RBCs with raised red cell count

8

Lifespan of sickle cells

10-20 days

9

What type of anaemia do you get in sickle cell disease?

Haemolytic anaemia

10

What type of mutation causes sickle cell disease?

Point mutation in the beta globin gene-

11

What is the result of the mutation in sickle cell disease?

Insolubility of HbS in deoxygenated state

12

4 clinical features of sickle cell disease

Vaso-occlusive crisis
Visceral suquestrian crisis
Aplastic crisis
Increased susceptibility to infection

13

Increased sickling and blockage of small vessels. Triggers include infection, dehydration, acidosis and deoxygenation. Hand- foot syndrome in children- infarction of metaphyses of small bones- pain and blistering

Vaso-occlusive crisis

14

Sickling with pools of RBCs in liver and spleen or lungs. Partly responsible for acute chest pain

Visceral sequestrian crisis

15

Follos B19 paravirus. Arrest of erythropoieisis is normal, but in HbS patients, rapidly causes severe anaemia.

Aplastic crisis

16

Treatment for sickle cell disease

Prophylactic vaccines
Folic acid
Hydration
Transfusion for severe anaemia
Oral hydroxycarbamide, increases Hbf and inhibits prothrombotic state, increases MCV
Stem cell transplant

17

Clincial features of thalassaemia major

Anaemia at 3-6 months when foetal to adult Hb chain occurs. Failure to thrive, infection, pallor, mild jaundice, bone marrow hyperplasia esp skull 'hair on end' appearance on x ray. osteoporosis= bone marrow expansion

18

Lab findings for thalassaemia major

20-60g/L Hb
low MCH
low MCV
Hypochromic, microcytic cells

19

Life expectancy for thalassaemia major

13 years

20

Treatment for thalassaemia major

Transfusion to suppress natural erythropoiesis.

21

Complications of treatment for thalassaemia major

No excretory mechanism for Fe, by 10-12 years- severe iron overload and toxicity.

22

Solution for iron toxicity

Iron chelation therapy-promotes excretion of iron in urine and faeces-subcutaneous desferrioxamine