Isovolemic hemodilution in erythrocytosis secondary to chronic obstructive lung disease

Patients with chronic obstructive lung disease often present with a combination of respiratory and circulatory insufficiency. In secondary erythrocytosis (polycythemia) blood viscosity rises and further impairs peripheral oxygenation. Against this background, a patient with acute exacerbation of a chronic respiratory disease with secondary erythrocytosis was treated with isovolemic hemodilution during two periods of hospitalization. During each of these two periods, hemodilution was achieved by removing 1 700 and 1750 ml blood, respectively, and replacing this simultaneously by infusing equal volumes of dextran 70 (Maacrodex). The patient's general condition improved, her dependence on supplementary oxygen drastically decreased and the blood gas values improved after hemodilution. The progress of the disease in this case suggests that the raised hematocrit rather than hypervolemia contributed to the patient's poor condition. It also illustrates that too intensive diuretic therapy in cardiac insufficiency with concomitant erythrocytosis can lead to hemoconcentration and thereby add to the strain on an already overloaded circulation.