Sickle cell anemia

Question 1

Sickle-cell anaemia is an

Answer 1

autosomal recessive condition that results for synthesis of an abnormal haemoglobin chain termed HbS

Question 2

normal haemoglobin

Answer 2

HbAA

Question 3

sickle cell trait

Answer 3

HbAS

Question 4

homozygous sickle cell disease

Answer 4

HbSS

Question 5

Some patients inherit one HbS and another abnormal haemoglobin (HbC) resulting in

Answer 5

HbSC

Question 6

x

Question 7

x

Question 8

x

Question 9

x

Question 10

x

Question 11

x

Question 12

x

Question 13

x

Question 14

x

Question 15

x

Question 16

x

Question 17

x

Question 18

x

Question 19

x

Question 20

x

Question 21

x

Question 22

Sickle cell anaemia is characterised by periods of

Answer 22

good health with intervening crises

Question 23

types of crises are recognised?

Answer 23

thrombotic, ‘vaso-occlusive’, ‘painful crises’

acute chest syndrome

anaemic:
aplastic
sequestration

infection

Question 24

Thrombotic crises/ ‘vaso-occlusive’, ‘painful crises’ precipitated by ?

Answer 24

infection, dehydration, deoxygenation (e.g. high altitude)

Question 25

Thrombotic crises/ ‘vaso-occlusive’, ‘painful crises’ diagnosed ?

Answer 25

clinically

Question 26

infarcts occur in various organs including ?

Answer 26

bones (e.g. avascular necrosis of hip, hand-foot syndrome in children, lungs, spleen and brain

Question 27

Acute chest syndrome?

Answer 27

vaso-occlusion within the pulmonary microvasculature → infarction in the lung parenchyma

Question 28

cxr in acute chest syndrome ?

Answer 28

pulmonary infiltrates on chest x-ray

Question 29

chest syndrome Mx

Answer 29

pain relief

respiratory support e.g. oxygen therapy

antibiotics: infection may precipitate acute chest syndrome and the clinical findings (respiratory symptoms with pulmonary infiltrates) can be difficult to distinguish from pneumonia

transfusion: improves oxygenation

Question 30

Aplastic crises caused by

Answer 30

parvovirus

Question 31

Diagnosis of aplastic crisis ?

Answer 31

sudden fall in haemoglobin
bone marrow suppression causes a reduced reticulocyte count

Question 32

Sequestration crises clinical features ?

Answer 32

splenomegaly

Question 33

Monitoring of blood of sequestration crisis ?

Answer 33

increased reticulocyte count

Question 34

x

Question 35

x

Question 36

x

Question 37

Sickle cell patients should be started on long term

Answer 37

hydroxycarbamide - reduce the incidence of complications and acute crises