haemoglobin 7: polycythaemia

Question 1

what is polycythaemia?

Answer 1

reduction in the amound of haemoglobin in a given volume of blood below what would be expected in comparison with a healthy subject of the same age and gender (by definition Hb is reduced, RBC & Hct also usually reduced)

Question 2

what are the causes of polycythaemia?

Answer 2

PSEUDO (reduced plasma volume) & TRUE (increase in total volume of red cells in circulation - caused by blood doping / overtransfusion, appropriately increased erythropoietin, inappropriate erythropoietin synthesis (eg by kidney tumour) / use, indepent of erythropoietin

Question 3

how would you investigate polycythaemia?

Answer 3

clinical history & physical examination (splenomegaly, abdo mass or cyanosis could be relevant)

Question 4

what is polycythaemia vera?

Answer 4

intrinsic bone marrow disorder, classified as a myeloproliferative neoplasm - causes hyperviscosity leading to vascular obstruction

Question 5

how could you treat polycythaemia vera?

Answer 5

remove blood (can be used to treat any extreme polycythaemia) / treat bone marrow disorder