The preparation of leukocyte-poor red cells from liquid stored blood: an evaluation of the Haemonetics 102 cell washing system.

An evaluation of the Haemonetics 102, an automated cell washing system, is presented. Although the system removes 68.4 +/- 14 per cent of the white blood cells from liquid stored blood, the percentage wash out is an unreliable mode of evaluation. The residual number of white blood cells per unit is 6.5 +/- 2.8 x 10(8), which is independent of the unit's size, age, and initial leukocyte count. The residual number of white blood cells is also not influenced by any of the modifications used in the study. Red blood cell loss averaged 16.3 per cent. A direct correlation exists between the initial red blood cell mass and the amount of cell lost. It is recommended that packed cell units which have a volume of less than 300 ml with hematocrits of 75 per cent or less be used to minimize excessive red blood cell loss. Recommendation as to the selection of units by an ideal age or the preparation of units prior to washing are not supported by these data.