Document presence of increased red cell mass

Document presence of increased red cell mass.
If normal, he has spurious/relative polycythemia
If increased, serum EPO levels must be measured.
If EPO levels are low/unmeasurable, patient likely has polycythemia vera.
If EPO levels are elevated, , need to differentiate between physiologic response to hypoxia and autonomous EPO production.
Mutation in JAK2 seen in 90-95% of polycythemia vera
Patients with low arterial O2 saturation must be evaluated for presence of heart/lung disease if not living in high areas.
Smokers with normal O2 saturation have elevated EPO due to CO displacement of O2
Smoker’s polycythemia: If COHb levels high
Non smokers with normal O2 saturation have abnormal hemoglobin that does not deliver to O2 to the tissues or source of EPO production that is not responding to normal feedback inhibition.
Further work-up depends on d/d of EPO producing neoplasms