Anaemias Flashcards
Give the normal haemoglobin reference ranges for males and females aged 12-70
Male = 140-180 Femal = 120-160
What test should be done if a patient’s blood film shows hypochromic, microcytic anaemia?
Serum ferritin level to test for iron-deficiency
What test should be done if a patient’s blood film shows normochromic, normocytic anaemia?
Reticulocyte count
What test should be done if a patient’s blood film shows macrocytic anaemia?
B12 and folate
also test bone marrow
What is the differential diagnosis for hypochromic, microcytic anaemia?
Iron deficiency (low serum ferritin)
Thalassaemia (normal or increased ferritin)
Sideroblastic anaemia (normal or increased ferritin)
Secondary anaemias
What is the differential diagnosis for normochromic, normocytic anaemia?
Marrow infiltration (e.g. leukaemia)
Marrow hypoplasia
Secondary anaemia
Acute blood loss (raised reticulocyte count)
Haemolytic anaemia (raised reticulocyte count)
What is the differential diagnosis for macrocytic anaemia?
Megaloblastic anaemia (B12/folate deficiency)
- Pernicious anaemia
- Gastric/ileal disease
- Dietary folate deficiency
Non-megaloblastic anaemia
- myelodysplasia
- marrow infiltration (e.g. leukaemia?)
- drug-induced
What is pernicious anaemia?
Megaloblastic anaemia caused by B12 deficiency.
Antibodies against intrinsic factor cause malabsorption of dietary B12.
Describe the red cell indices measured by blood tests
Red cell indices are automated measurements of red cell size and Hb content:
Mean cell volume (MCV) = cell size
Mean cell haemoglobin (MCH) = how much Hb is present
What test is done if a patient is thought to have acquired haemolytic anaemia?
Direct Antiglobulin Test (DAGT)
Positive = autoimmune haemolysis
Negative = non-immune haemolysis
What are the three classifications of congenital anaemias?
Membrane defects e.g. hereditary spherocytosis
Enzyme defects e.g. G6PD deficiency
Haemoglobin defects e.g. Thalassaemia and Sickle Cell
Give three rare anaemias that are caused by membrane defects
Hereditary elliptocytosis
Hereditary pyropoikilocytosis
Southeast Asian Ovalocytosis
Which form of thalassaemia is incompatible with life?
Alpha Thalassaemia –> no alpha chains
full name: Haemogenous alpha zero thalassaemia
What are the four classifications of thalassaemia?
Alpha
Beta - transfusion-dependent
Thalassaemia intermedia
Thalassaemia minor
Describe the general clinical features of anaemia
Fatigue and lethargy - often the only symptom Breathlessness, dizziness Conjunctival pallor Palpitations, chest pain Ankle swelling
Describe the clinical features of severe anaemia
Hypotension
Tachycardia
Tachypnoea
(Angina, weakness)
Which clinical features are specific to iron-deficiency anaemia?
Koilonychia
Angular stomatis
Which clinical features are specific to haemolytic anaemia?
Dark urine (haemoglobinuria)
Jaundice
Hepatosplenomegaly
Gallstones, leg ulcers (more severe/chronic cases)
Give an example of a megaloblastic anaemia. Which clinical features are specific to megaloblastic anaemia?
Pernicious anaemia "lemon tinge" - due to pallor + mild jaundice "sore tongue" - glossitis Neurological symptoms - paraesthesia - peripheral neuropathy Neuropsychiatric symptoms - irritability - depression - psychosis - dementia
What are the possible causes of iron-deficiency anaemia?
Low-iron diet
Malabsorption e.g. gastrectomy, coeliac disease
Blood loss e.g. menorrhagia, GI bleeding (GI symptoms should always be asked about when taking a history)
What is the most common cause of acquired haemolytic anaemia?
Auto-immune haemolytic anaemia
- body forms antibodies against its own red blood cells. Extravascular haemolysis (exaggeration of normal process)
Describe the approach to managing haemolytic anaemia
Support marrow function by giving folic acid
Correct the underlying cause e.g.
- immunosuppression
- treat trigger of autoimmunity (e.g. CLL)
- splenectomy (site of red cell destruction)
Consider blood transfusion
How is hereditary spherocytosis diagnosed?
Blood film - see spherocytes
negative DAGT
decreased EMA fluoroscopy
Describe the clinical presentation of G6PD deficiency
Episodic acute haemolysis
- follows an acute oxidative stressor
- prominant haemoglobulinaemia
