Sickle Cell Anaemia Flashcards
What type of disorder is SCA?
Autosomal recessive
What is the main risk factor?
African descent
What happens in SCA?
There is an amino acid substitution in the beta chain resulting in a change from glu to val. This means HbS is produced
How does HbS cause sickling?
It polymerises when deoxygenated causing deformation
How do sickle cells cause problems?
They’re fragile, haemolyse and block small vessels
Where do vaso-occlusive crises often affect?
Bone marrow
What can trigger a vaso-occlusive crisis?
Cold, dehydration, infection, hypoxia
What is a sequestration crisis?
Pooling of blood in the spleen (and sometimes liver) that leads to severe anaemia and shock
What should you do if your patient is having a sequestration crisis?
Urgent transfusion
What investigations could you do?
Blood film, Sickle solubility test, Hb electrophoresis, blood count
What does Hb electrophoresis tell you?
It confirms diagnosis
What drug would you give if your patient has frequent crises?
Hydroxycarbamide
What are signs and symptoms of a crises?
Pain in hands and feet, long bone pain, cognitive defects in children, PH and chronic lung disease, splenic sequestration
What would the blood count be?
Hb 60-80g per L
Is sickle solubility test positive or negative?
Positive
