Bedside filtration for white cell(WBC) reduction of red cell concentrates (RBCs) has been performed to reduce the workload of blood bank personnel. However, a high incidence of filtration failure with bedside filters was recognized by several
investigators. We therefore evaluated the efficiency of the bedside filter under various conditions that might be important variables such as temperature of the blood units, flow rate and possibly, filtration techniques performed. We used 29
bedside
filters (RCXL2, Pall Corporation, USA) and total of 58 units of CPDA-1 RBCs for this study. Thirty eight refrigerated RBCs were filtered at fast flow with or without mixing the blood cells in a bag to resuspend the possible blood cell aggregates.
And
another 20 units were filtered at slow flow (2 hours) with or withous mixing after 1 hour incubation at room temperature. Pre-, intra-, and post-filtration blood samples were collected and residual white cells were counted using Nageotte
hemocytometer.
A higher contamination of white cells was found in the units filtered after mixing at slow flow (mean 2.99×10E5/unit) than at fast flow(mean 1.31×10E5/unit) and in the units filtered at slow flow without mixing(mean 6.11×10E5/unit) than with
mixing(mean 2.46×10E5/unit). Our data suggested that filtration at slow flow decrease the efficiency of WBC reduction, especially after omitting the mixing process before filtration.
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