Polycythaemia - Investigation and Referral Guidance
Refer through Choose and Book If
1) Haematocrit (
There are other features to suggest a myeloproliferative disorder
There is a recent thrombotic or embolic history
2) Haematocrit (
Platelet count ≥250 x109/l
There are NO causes of secondary or relative polycythaemia present
When all criteria in 2) are met our clinical advisory service (through C+B) will advise whether JAK2 and erythropoietin (epo) test should be performed before attendance. These tests require approval.
JAK2:a separate EDTA (full blood count style) specimen to haematology recording in the history that the test has been approved. JAK2 is positive in 95% of primary polycythaemia.
Epo: yellow top (biochemistry style)specimen to haematology.
It is usually driven by excess epo due to hypoxia, or rarely an epo producing tumour.
Chronic exposure to carbon monoxide including smoking
Sleep apnoea / massive obesity
Testosterone replacement, and anabolic steroid and erythropoietin misuse
Cyanotic heart disease or pulmonary shunt
Tumours include fibroids, renal cell carcinoma, hepatoma, and phaeochromocytoma
Relative(reduced plasma volume) is common.
Obesity with hypertension
Excess alcohol or dehydrating beverages (eg frequent strong coffee)
Primary(myeloproliferative)is rare (incidence 1 / 50,000) and is suggested by:
Pruritus after bathing
Raised RBCs but with hypochromic indices suggesting iron deficient polycythaemia
Platelet count > 400 x 109/l
Unexplained raised total white count.
Recommended initial examination and tests:
History and examination to distinguish potential primary and secondary causes as above.
FBC, repeating at 3 months if necessary
U+E, LFT, Urate, ferritin
The management of secondary polycythaemia is the management of the underlying disorder.
There is little evidence that COPD patients gain any objective benefit from venesection.
Venesection is not performed in cyanotic heart disease except at the request of the cardiologist.
Where testosterone replacement must be continued it is appropriate to refer for venesection.