Timing of leukocyte filtration during cardiopulmonary bypass

The effects of leukocyte filtration on the outcome of cardiac surgery with cardiopulmonary bypass (CPB) have been shown by numerous investigators. in the majority of cases a leukocyte filter is placed in the arterial line ins tead of a standard arterial line filter and used throughout CPB. However, p rotocols to optimize onset and duration of leukocyte filtration have not be en sufficiently evaluated to date. In this paper, current efforts to improv e such protocols are demonstrated and discussed. These efforts are based on studies of leukocyte pathogenicity during cardiac surgery. A first study ( double-blind randomized) was performed in routine coronary artery bypass gr aft (CABG) patients to evaluate whether short-term leukocyte filtration dur ing reperfusion by release of the aortic crossclamp would reduce reperfusio n-associated myocardial damage. Further data compare the efficacy of three different filtration concepts to reduce CPB- and/or reperfusion-associated leukocyte pathogenicity. Clinical endpoints, standard laboratory variables and functional in vitro assays are provided and discussed.