Automated double red‐cell phlebotomy for the treatment of erythrocytosis

Abstract

Phlebotomy has been used as a primary method for the treatment of erythrocytosis. As a new phlebotomy method, we used an automated component collection system (Alyx, Fenwal), which has been used to obtain two units of leukoreduced red blood cells (RBCs) from donors. We evaluated the effectiveness of "double red-cell" phlebotomy (DRP) and compared it with conventional "whole-blood" phlebotomy (WBP). We have performed a total of 596 phlebotomies in 158 patients with erythrocytosis between June 2008 and November 2011. Forty patients underwent 84 DRPs and 118 patients underwent 512 WBPs. We removed 360-420 mL of RBCs in DRP and 360-600 mL of whole blood in WBP according to patient's total blood volume (TBV). Changes in hematologic parameters after phlebotomy were compared. DRP removed more RBC volume (399.4 ± 20.2 mL vs. 235.9 ± 29.8 mL, P < 0.05) and lowered more hematocrit than WBP (6.9% ± 2.3% vs. 3.0% ± 1.7%, P < 0.05). Hematocrit reduction per kilogram of body weight was higher by DRP than WBP (0.106% ± 0.043% vs. 0.039% ± 0.025%, P < 0.05). Mild adverse events occurred in 32.5% (13/40) during DRP and 4.2% (5/118) during WBP. DRP lowered more RBC mass than WBP by selectively removing more RBC volume with less TBV. DRP can be an effective and safe technique for the treatment of erythrocytosis.