Feasibility and rate of leucocyte depletion with a single leucocyte depletion filter during massive transfusion.

Background: The study examines the feasibility and rate of leucocyte depletion with a single leucocyte depletion filter in combination with the Level 1 heat exchanging infusion/transfusion device H-500/H-25i during massive transfusions.

Materials and methods: LeukoGuard-6 filters (LG-6) were manufactured to fit the infusion sets of the Level 1 H-500/H-25i. This modified device was used intraoperatively in six patients with severe haemorrhage. Following determination of the white cell counts (WCC) in each buffy coat poor red cell concentrate prior to administration, WCC were then obtained from blood sampled directly distal to the filter after the first and after the last red cell concentrate was given. Leucocytes were determined in the Nageotte chamber and then calculated to determine leucocytes/250 ml (therapeutic unit). Parameters of feasibility (time for preparation of the system, the amount of transfused red cell concentrates, time interval of transfusions) were recorded.

Results: The mean volume of red cell concentrates which were transfused and filtered by a single filter was 2,708 ml (S.D. +/- 797 ml) within a mean time interval of 42.5 min (S.D. +/- 26 min). With a mean WCC of 1.17 +/- 0.68 x 10(9) leucocytes/250 ml in the red cell concentrate prior to filtration the LG-6 achieved a log-3 reduction of leucocyte counts. During the transfusion the WCC distal to the filter increased on average by a factor of 3 (from 0.9 x 10(6) leucocytes/250 ml following the first blood unit to 2.7 x 10(6) leucocytes/250 ml following the last), but remained below 5 x 10(6).

Conclusion: Modification of the Level 1 H-500/H-25i system by incorporating the LG-6 leucocyte depletion filter provides a significant reduction of the WCC in the transfused red cell concentrates during massive transfusion. The rate of leucocyte depletion by a single leucocyte depletion filter achieves low leucocyte counts which are documented to be of therapeutical value. As the significance of leucocyte-reduced blood products for patients with haemorrhagic shock following trauma or major surgery has still to be elucidated, the presented device may be useful in the performance of future studies related to this subject.