on 05-Aug-2015 (Wed)

Tags

#haematology #medicine

Question

What is the pathophysiology of Sickle-cell anaemia ?

Answer

• Production of abnormal globin chains.
• An amino acid substitution in the gene coding for the chain (Glu Val at position 6 ) results in the production of HbS rather than HbA.
• HbS polymerizes when deoxygenated, causing RBCs to deform, producing sickle cells, which are fragile and haemolyse, and also block small vessels
• ​HbA 2 and HbF are still produced.

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#haematology #medicine

Question

What virus causes the Aplastic crisis with sickle cell anaemia ?

Answer

parvovirus B19

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#haematology #medicine

Question

Who does a Sequestration crisis of sickle cell anaemia effect ?

Answer

Children as the spleen has not yet undergone atrophy

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#haematology #medicine

Question

What occurs in a Sequestration crisis of sickle cell anaemia ?

Answer

There is pooling of blood in the spleen ± liver, with organomegaly, severe anaemia and shock. Urgent transfusion is needed

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#haematology #medicine

Question

What are the possible complications of Vaso-occlusive ‘painful’ crisis in sickle cell anaemia ?

Answer

• Dactylitis
• Mesenteric Ischaemia
• Strokes and Seizures
• Avascular Necrosis
• Priapism ​​​​

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#haematology #medicine

Question

What is the pathphysiology behind Vaso-occlusive ‘painful’ crisis in sickle cell anaemia ?

Answer

Microvascular occlusion

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#haematology #medicine

Question

How long does the Aplastic crisis with sickle cell anaemia last ?

Answer

Usually self-limiting <2 wks

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#haematology #medicine

Question

What are the Complications of sickle cell anaemia ?

Answer

• Splenic infarction ( <2 yrs old, due to micro vascular occlusion, leading to susceptibility to infection)
• Poor growth
• Chronic renal failure
• Gallstones
• Retinal disease
• Iron overload or blood-borne infection after repeated transfusion
• Lung damage: Hypoxia, Fibrosis, Pulmonary Hypertension