
General Considerations and Causes
In the assessment of anaemia, factors to consider are:
- Is the anaemia the only haematologic abnormality?
- Is the reticulocyte response appropriate to the severity of the anaemia?
- If the reticulocyte count is raised, is there evidence of bleeding or haemolysis?
- If the reticulocyte count is not raised, then assess in relation to the MCV (see table below).
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MCV
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< 80
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Consider:
- Iron deficiency.
- Anaemia of chronic inflammation.
- Thalassemia.
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80 to 100
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Consider:
- Recent haemorrhage.
- Renal failure.
- Thyroid of other endocrine abnormality.
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> 100
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Consider:
- Alcohol excess.
- B12/folate deficiency.
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The anaemia may be primarily due to inadequate formation or excessive destruction, but remember acute blood loss. The main causes are listed in the following table.
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Causes of Anaemia
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Failure of production
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Decreased erythropoietin production
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Blood loss or excessive destruction
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- Acute bleeding.
- Thalassaemia, abnormal haemoglobins.
- Hereditary spherocytosis, elliptocytosis, pyropoikilocytosis.
- Red cell enzyme deficiencies e.g. G6PD, PK.
- Immune mediated red cell defects.
- Auto immune haemolytic anaemia - idiopathic, secondary, warm, cold.
- PNH.
- Microangiopathic haemolytic anaemia.
- Infections, burns, chemicals, drugs.
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Topic Code: 7933