[Evaluation of the efficacy of a leukocyte depletion filter].

We evaluated the efficacy of a leukocyte depletion filter (Pall RC 100) during operation. Clinically necessary blood was transfused to replace blood loss during the operation. Kinds of transfused blood and speed of transfusion were selected by clinical need. One leukocyte depletion filter was used at most for 4 units of transfused pack (200 ml). Blood samples were taken before and after the filtration to measure white blood cell (WBC), red blood cell (RBC), platelet and hematocrit. Blood samples before filtration and after filtration with white blood cell excluded, were examined by automated hematology analyzer (Coulter counter). White blood cell after filtration was counted by the hemacytometer method using Hauser chamber. The method of multiple linear regression was applied in order to estimate the removal rate of WBC and recovery rate of RBC. The independent variables were categorized in the following 3 sets: the age of transfused blood (day), duration of transfusion (min) and transfused volume (ml). Removal rates of WBC when 1, 2, 3 or 4 units were passed per filter, were 99.99% +/- 0.028%, 99.89% +/- 0.224%, 99.12% +/- 1.519% and 97.81% +/- 2. 866%, respectively. Removal rate of WBC when 4 units were passed per filter, was significantly lower compared with the rate when fewer units were passed. Recovery rates of RBC when 1, 2, 3, or 4 units were passed per filter, were over 99.5%, and there were no significant differences among 4 examined points. Only three variables, the age of transfused blood, duration of transfusion and transfused volume, showed a significant correlation with the removal rate of WBC.(ABSTRACT TRUNCATED AT 250 WORDS)