Polycythaemia Flashcards
what are the different causes of polycythaemia?
relative i.e. dehydration
absolute - primary (polycythaemia vera) and secondary (COPD, chronic heart failure, OSAS)
how does secondary polycythaemia cause a raised haematocrit?
due to hyoxia which stimulates excessive erythropoeitin production
how does primary polycthaemia cause a raised haematocrit?
mutation in JAK 2
how does relative polycythaemia cause a raised haematocrit?
isolated decrease in plasma volume concentrates RBC therefore causing haematocrit to rise
what is haematocrit and what is the normal value in males and females?
% RBC within the blood
males 35-40%
females 30-35%
how would you treat secondary polycythaemia?
low flow oxygen to reduce hypoxia
how would you treat relative polycythaemia?
oral rehydration or IV fluids
how would you differentiate between true primary or secondary polycythaemia?
red cell mass studies
