Intro to Anaemia Flashcards
(24 cards)
What are the clinical signs of anaemia + cause?
Fatigue, weakness - reduced oxygen transport
Short of breath - reflex respiratory drive
Heart racing - reflex stimulation, palpitations
Pounding in head (increased cardiac output)
Pallor of mucus membranes
Feeling cold - peripheral circulation constricted
If + artery disease: angina, claudication, kidney dysfunction, confusion
Name two causes of microcytic hypochromic anaemia
Iron deficiency, thalassaemias
What will the blood film look like shortly after treatment of iron deficiency?
Double population (e.g. some small, underfilled cells, some normal in size + Hb content)
What is thalassaemia?
When alpha or beta globin peptides are reduced/absent
What are causes of megaloblastic anaemia? Outline pathogenesis.
Vitamin B12, folate deficiency. Both result in reduced synthesis of thymidine needed for DNA replication. S-phase of mitosis is slowed, therefore cells become larger than normal.
What are some more obscure causes of macrocytic anaemia?
Chronic liver disease
Alcohol abuse
Reticulocytosis
Pregnancy
Normal neonates (physiologically normal)
Drugs e.g. chemo drugs that interfere with folate or B12 metabolism
Why do we get anaemia in renal disease?
EPO deficiency!
What causes normocytic normochromic anaemia?
Bleeding + replacement with fluids –> dilutional anaemia
Anaemia of chronic disease
Anaemia in renal disease (EPO down)
Anaemia in cancer (ACD + bleeding + reduced responsiveness to EPO)
Outline the pathogenesis behind anaemia of chronic disease
Main mechanism: reduced iron avaliability, due to hepatic hepcidin (a peptide), which stops release of iron from stores and decreases iron absorption in the gut.
Phagocytosis of RBCs increased due to inflammation.
EPO production decreases + marrow less responsive.
Inflammatory cytokines can impair RBC proliferation.
What do we seperate haemolytic anaemia into?
Acquired and inherited
Name inherited causes of haemolytic anaemia
hereditary spherocytosis, G6PD deficiency, sickle cell anaemia, Hb E
What are acquired causes of haemolytic anaemia?
autoimmune, blood group antibody (e.g. wrong transfusion), infection e.g. malaria, drugs, physical damage e.g. burns, trauma
Anaemia of chronic disease vs anaemia of liver disease?
BOTH NORMOCYTIC, NORMOCHROMIC however…
CD - tends to microcytosis
Liver failure - tends to macrocytosis, cholesterol literally deposits on the RBCs
What will reticulocytes be in the following conditions:
1) following large haemorrhage
2) Iron deficiency
3) Megaloblastic anaemia
4) Renal failure
5) Haemolytic anaemia
1) low-normal
2) low-normal
3) low-normal
4) low-normal
5) increased
What is polychromasia?
e.g. more blue staining like reticulocytes, shows RBC production is increased e.g. haemolysis
How is a reticulocyte count performed?
By staining RNA remnants in red cells and counting positively stained cells
Features in the blood film of iron deficiency
Microcytic, hypochromic.
Target cells and pencil cells
What happens if you treat thalassaemia with iron?
No effect. In fact, iron is normal or raised in thalassaemia.
Why does anaemia of chronic disease fail to respond to iron therapy?
Through serum iron may be low, actual iron is high but HEPCIDIN from the liver is stopping release from stores. Need to treat underlying condition.
What is the main store of iron?
Macrophages. (which release iron to transferrin, a transport protein)
What is ESR?
Erythrocyte sedimentation rate, usually low as RBCs are -vely charged
What is meant by rouleaux formation?
stacking of RBCs, signifies inflammation which makes RBC negative charge partially neutralised
What are the main clotting proteins which increase ESR?
fibrinogen, immunoglobulins
How to treat anaemia in renal disease?
EPO injections 3x weekly
