B7 Haemotology: Anaemias Flashcards
Name the six types of anaemia
Iron anaemia Megaloblastic anaemia Haemolytic anaemia Aplastic anaemia Sickle cell anaemia Thalassaemias
Symptoms and signs of anaemia
Why is skin colour not a reliable sign?
Shortness of breath Weakness Lethargy Tachycardia Skin colour determined by blood flow rather than Hb Nail bed and conjunctiva may be pale
In iron deficiency anaemia explain how input = output can be altered?
Input reduced (poor diet/surgical removal of stomach) Output increased (menstruation/GI bleeding ulcers) Demand increased (pregnancy)
In acute bleeding what are the expected changes blood counts
DECREASED ; Hb, Haemocrit, WBC, platelets
INCREASING : EPO
Normal iron stores
In chronic bleeding what are the expected changes to blood counts
DREASED ; HB, Haemocrit, MVC
INCREASED: Retics, EPO
Zero iron stores
Treatment of iron deficient anaemia
1 find and treat underlying cause e.g GI bleed
2 oral iron sulphate
3 prophylaxis in pregnancy
4 transfusion
What is renal anaemia ? How can it be treated?
A complication of CRF
Leads to normocytic anaemia
Treat with Fe and EPO injections
What is megaloblastic anaemia?
Rarer form of anaemia due to abnormal RBC maturation as a result of defective DNA synthesis
What is macrocytic megaloblastic anaemia ? Causes?
Red blood cells are larger than normal due to vit B12 or folate deficiency
Why is B12 important?
Essential co factor for purine and pyrimidine synthesis (DNA)
Draw Role of B12 cofactor diagram
…
Why is folate important?
essential for thymidylate synthesis (RDS in DNA synth as thymidine is a pyrimidine base
Methorexate case
Inhibits dihydrofolate reductase therefore folate regeneration impaired - treat with folic acid
What is pernicious anaemia?
Lack of intrinsic factor for absorption of B12 due to auto immune disease
What are haemolytic anaemias?
What is spherocytosis?
Increased rate of RBC destruction
Genetic - abnormal reduction in RBC membrane protein (spectrin) makes cells fragile
What is sickle cell anaemia?
Genetic, caused by SNP (single nucleotide polymorphism)
Abnormal Hb that forms insoluble crytals at low O2 and may block microcirculation –> Causes haemolytic anaemia
What is thalassaemias?
What doe the deletion of both alpha genes lead to?
Genetic
Reduced rate of alpha and beta globin units production many variations
Leads to death in uterus as only gamma 4 Hb is produced
One alpha gene deletion reduced RBC volume and haemocrit
What is aplastic anaemia?
what can this cause?
Insufficient production of RBC, WBCs and platelets
Absence of growth
= decreased resistance to infections, increased bleeding, increased tiredness
Treatment of aplastic anaemia
Immunosuppressants
Colony stimulating factors (increase WBC count)
Bone marrow transplant with a tissue match
What is polycythaemia?
RBC count is higher than normal
Increased Hb content and Haemocrit
Increased blood viscosity = poor perfusion
Signs and symptoms of polycythaemia
Ruddy appearance
Headaches
Blurred vision
Hypertension
