PBL 4 - Anaemia Flashcards
Define anaemia (1 mark)
Anaemia is the condition when the haemoglobin level in the blood is below the reference level for
the age and sex of that individual
How is a normocytic anaemia differentiated from a microcytic anaemia? (2 marks)
A normocytic anaemia has a mean corpuscular volume (MCV) reading within the normal range of
80-96 fl (1 mark) whilst a microcytic anaemia has an MCV reading of <80 fl (1 mark) (some .
) State why some forms of anaemia do not respond to dietary iron supplements (1 mark) and (ii)
describe the features of the blood count that characterise these forms of anaemia
Megaloblastic anaemia is caused by impaired DNA synthesis, usually due to vitamin deficiency, specifically either vitamin B12 or folate deficiency, rather than iron deficiency (1 mark). [ Pernicious anaemia (megaloblastic anaemia) is due to a deficiency in vitamin B12 or folate not iron]. Megaloblastic anaemia is characterised by larger than normal red cells (MCV> 96 fl) (1 mark)
Explain (i) what is meant by the term reticulocyte (1 mark) and (ii) how reticulocytes are
differentiated from erythrocytes on a blood film (1 mark).
Reticulocytes are young non-nucleated red cells that still retain some RNA and are still able to
synthesize haemoglobin. (1 mark). They are slightly larger than mature red cells and have a
‘bluish” hue on a stained blood film, instead of the pinkish staining of mature erythrocytes. (1 m
How will the blood count of someone suffering from acute blood loss differ from someone
suffering from chronic blood loss? (
Acute blood loss leads to a normochromic, normocytic anaemia (1 mark), whereas chronic blood
loss will lead eventually to iron deficiency and a hypochromic, microcytic anaemia (1 mark).
) How is mean corpuscular volume normally calculated from standard blood measurements? (1
mark)
Divide haematocrit by red cell count Eg: 0.45/(5 x 1012) = (0.45)/5 x 10-12 =0.09 x 10-12 = 90 x
10-15 = 90 femtolitres
What is the function of haemoglobin? (2)
role is to transport
oxygen from the lungs to the tissues.
What are 3 physiological responses the body has to anaemia (3)
- Cardiac output increases - increased heart rate and stroke volume
- Peritubular cells increase EPO - to increase RBC production
- Kidneys retain salt and water - increase the intravascular volume
What are 3 causes of anaemia? (3)
bone marrow infiltration, inadequate marrow response due to deficiencies, inadequate EPO due to renal disease.
What MCV is microcytic, normocytic and macrocytic anaemia? What are the types of anaemia associated with each (3)
Microcytic - MCV <76fl - Iron deficiency - Thalassaemia - Chronic bleeding Normocytic - MCV 76-96fl - Haemolytic anaemia - Chronic disease Macrocytic - MCV >96fl - Meg- b12/folate deficiency - non-meg - pregnancy, alcohol/liver disease
What is the most common type of anaemia (1)
Iron deficiency anaemia
What is the difference between megablastic and non-megablastic anaemia? (2)
both macrocytic (>96fl) Megoblastic - B12 or folate deficieny, has hypersegmented neutrophils Non-megoblastic - no segmented neutrophils, alcohol/liver disease
What is the most likely diagnosis for patient 1,2 and 3? (3)
1 - iron deficiency anaemia
2 - Vitamin B12 deficiency anaemia (cause by pernicious anaemia, vegan)
3 - erythropoietin deficiency due to chronic renal failure (CRF)
How would you manage patient 1, 2, 3? (3)
1 - Oral ferrous sulphate 3x a day, colonoscopy + resection of the cancer
2 - regular, usually three monthly, intramuscular injections of
hydoxocobalamin (vitamin B12).
3 - Give EPO, haemodialysis, kidney transplant
What is atrophic glossitis, angular stomatitis? (2)
AG - smooth glossy tongue that is often tender/painful
AS - inflammation of one or both corners of the mouth
