Anaemia: approach to a diagnosis Flashcards
What can be used to investigate anaemia?
History, examination, clinical context
FBC, reticulocyte count, blood film features, haematinics (ferritin, B12, folate), bone marrow biopsy, specialised tests (HbA2, HLPC)
How is anaemia broadly classified?
Decreased production e.g. hypoproliferative (reduced erythropoiesis) or maturation abnormality (ineffective erythropoiesis)
Increased loss or destruction of red cells e.g. bleeding or haemolysis
What should be looked for in a reticulocytosis?
If they are haemolysing then increased red cell destruction is seen - increased unconjugated serum bilirubin and increased urinary urobilinogen
Work hypertrophy of macrophage rich tissues i.e. splenomegaly
What should be suspected if there is a reticulocytosis and evidence of red cell breakdown products?
Haemolytic anaemia
How much can normal marrow increase red cell production?
3-4 fold
What is anaemia with a lesser reticulocyte response partly due to?
Impaired red cell production. Reticulocyte count should be appropriately increased for the degree of anaemia
What are the causes of hypochromic microcytic anaemia?
Iron deficiency - most common cause
Haem defects - lead poisoning, congenital sideroblastic anaemia
Globin defects - thalassaemia
What are the causes of macrocytic anaemia?
Nuclear maturation defects - B12/folate deficiency, myelodyspalsia
Apparent - agglutination
What are the causes of macrocytosis without significant anaemia?
Hypothyroidism, alcohol and liver disease
What are the causes of normocytic, normochromic anaemia?
Hypoproliferative cause:
- Marrow failure (drug induced, aplastic anaemia) Hypometabolic
- Marrow infiltration
- Renal impairment - failure of erythropoietin production
- Chronic disease (infective, inflammatory, malignant)
