Inherited haemoglobin disorders Flashcards
What normally occurs to the haemoglobin chains at birth?
The gamma chains are replaced with beta chains
What are the physiological changes to the RBCs in sickle cell disease?
There are gene changes to the beta chains in the haemoglobin. It is a spectrum of disorders that have variable clinical presentations
Which ethnicities are most at risk of sickle cell?
Afrocaribean and asian
What screening and treatment is available for sickle cell?
There is routine screening both antenatal and neonatal, treatment provided is vaccinations and prophylactic penicillin when needed
What is vasoocculsive sickle crisis?
When small blood vessels are blocked by the sickle cells, this is very painful and can be serious
What treatment is required for a patient in sickle cell crisis?
Adequate pain relief, morphine not pethidine
LMWH if at risk of clotting
How do patients present with acute sick chest syndrome?
tachypnea, chest pain, fever, cough, hypoxia
Look for radiological evidence of consolidation
Need resp support and blood transfusion
What other systems does sickle cell commonly effect?
Causes stoke, resp problems and kidney problems
How does hydroxcarbamide (hydroxyurea) help with sickle cell?
It promotes fetal haemoglobin production and also slightly decreases bone marrow production of RBCs so will reduce number of sickle cells if getting occlusions
What is thalassaemia?
An autosomal recessive condition in which either alpha or beta chains are not produced properly
This causes a microcytic anaemia
Which thalassaemia is less severe?
Beta thalassaemia, alpha is only compatible with life if some alpha chains remain
In beta thalassaemia there are too many alpha chains and these replace the beta chains
How does thalassaemia present?
they are fine for the first 6 months as have fetal haemoglobin but then start to show symptoms as the haemoglobin changes to beta chains they will develop anaemia
What is the treatment for thalassaemia?
Treatment is blood transfusions every 2-4 weeks for life or a bone marrow transplant
With transplant comes risk of rejection and infertility
What is the risk of blood transfusions and how can this be prevented?
Iron overload is the risk and this can be countered by chelation therapy
This is usually with oral or subcut desferrioxamine but there are often compliance issues
High iron can cause pituitary and pancreas problems
What is the problem with iron overload from transfusions?
Causes endocrine problems so need sex hormone replacement and biphosphates
Also get cardiac problems from iron overload
