The patient should receive supplemental oxygen. He probably has secondary erythrocytosis due to hypoxic lung disease and may benefit from oxygen therapy based on his documented hypoxemia (arterial PO₂ ≤55 mm Hg [7.3 kPa] or arterial oxygen saturation ≤88%). The erythropoietin level is elevated owing to hypoxemia, causing an erythrocyte mass. No splenomegaly is present on physical examination, and the lung examination suggests COPD.

Because of the patient's elevated erythropoietin level and hypoxemia, a bone marrow biopsy is not required to exclude polycythemia vera (PV). No leukocytosis, basophilia, or thrombocytosis is seen on laboratory studies, all of which are common in PV.

The JAK2 V617F activating mutation defines PV, and 95% of PV harbors this mutation, with the other 5% presenting with variations of the mutation. No JAK2-negative PV exists. However, JAK2 testing is expensive and is not required when a clear cause of secondary erythrocytosis is apparent.

The appropriate management of secondary erythrocytosis is control of the underlying cause. In most circumstances, therapeutic phlebotomy is not recommended for secondary erythrocytosis, because the increased erythrocyte mass is compensating for an unmet tissue oxygenation need.