Polycythaemia
Last updated: Friday, 28, January, 2011
| Causes | Appropriate Tests |
|---|---|
Review clinical findings, including history of smoking and diuretic therapy. Follow up FBC, blood film, red cell mass. | |
Relative polycythaemia The apparent erythrocytosis is due to reduced plasma volume, eg Dehydration, Diuretic therapy. | |
Stress polycythaemia (spurious polycythaemia) Gaisböck syndrome, associated with smoking and alcohol use. | May require measurement of blood volume to exclude absolute erythrocytosis. |
Absolute polycythaemia | Blood volume may be required to document absolute increase in red cell mass. Erythropoietin may be useful: increased levels in secondary erythrocytosis, low to undetectable levels in polycythaemia rubra vera. |
Chronic hypoxaemia | Blood gases/haemoximetry. See also Cyanosis. |
| See Smoking |
| |
Renal disorders | |
| See Cystic renal disease |
| See under Hypertension. |
| See under Renal cell mass. |
| See under Urinary tract obstruction. |
Tumours | |
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Primary haematological disorder | |
High affinity haemoglobin | Haemoglobin oxygen affinity, Haemoglobin electrophoresis; haemoglobin M. |
Review FBC, blood film, red cell mass. Bone marrow aspiration and trephine biopsy may sometimes be useful in documenting other features of a true myeloproliferative disorder. Presence "invitro" of the formation of spontaneous erythroid colonies (SEC's) in the absence of EPO is a sensitive but not specific finding in PRV. Low EPO is of high diagnostic specificity for PRV. Positivity for JAK-2 mutation confirms a myeloproliferative disorder. |
