Definition
Usually associated with raised haemoglobin concentration or raised haematocrit.
Polycythemia may be spurious (diuretics, dehydration, alcohol etc) or secondary (eg associated with hypoxia). Primary myeloproliferative neoplasms (MPNs) may be associated with leucocytosis and thrombocytosis also.
C.M & L.W 31-07-23
Who to refer:
- Patients with a persistently raised venous haematocrit (Hct) for at least 2 months should be investigated.
- Please refer males with Hct > 0.52 and females with Hct > 0.48.
- If Hct doesn’t meet above values but low MCV with disproportionately high Hb/Hct, check serum ferritin. If ferritin low, this may represent an iron deficient polycythaemia vera, hence referral appropriate.
Urgent investigation of polycythaemia is required If there is a history of arterial thrombosis, or evidence of recent acute occlusive events.
Who not to refer:
- Patients who do not fulfil the above criteria.
- If severe hypoxia/lung disease, initial referral to respiratory physicians more appropriate.
How to refer:
SCI Gateway to the Department of Haematology WGH or St John’s Hospital.
Primary care investigations
- Serial FBCs at least 1 month apart.
- Serum ferritin.
- Pulse oximetry
- General evaluation for any possible contributory cause e.g. CXR, SpO2 if hypoxic pulmonary disease suspected.
