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

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.

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.

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.

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.