Does leukodepletion during elective cardiac surgery really influence the overall clinical outcome?

Aim: We examined the impact of leukocyte filtration during the entire bypass time on postoperative leukocytosis, perioperative hemorrhage and overall clinical outcome in patients undergoing elective cardiac surgery.

Methods: Eighty patients who electively underwent cardiac surgery were randomly allocated to a leukocyte depletion group (n=40) or a control group (n=40). In patients of the leukocyte depletion group an arterial line filter with leukocyte depleting capacity (Pall LG6) was applied instead of a standard arterial line filter. White blood cells and platelet count were estimated preoperatively and at various times postoperatively. Postoperative clinical outcomes were also recorded.

Results: Repeated measure analysis of variance between groups showed that leukocyte counts were significantly lower in the depletion group postoperatively (p=0.005) whereas no difference was found in the platelet counts (p=0.37). The catecholamine dose required at the time of weaning from cardiopulmonary bypass and during the first 12 postoperative hours was found to be lower in the leukodepletion group (p=0.027 and p=0.021, respectively). Furthermore leukodepleted patients showed a transient improvement in the oxygenation index (p=0.029) and a shorter period of mechanical ventilation (p<0.001). The incidences of postoperative complications were similar between the groups. No difference was observed in regard to postoperative blood loss (p=0.821) and amount of packed red blood cells required for transfusion during the first 24 hours (p=0.846). The duration of intensive care unit stay and of hospitalization were similar between the groups.

Conclusion: Leukocyte depletion contributes to early postoperative improvement in heart and lung function but does not influence significantly the overall clinical outcome of patients undergoing elective cardiac surgery.