Depletion of activated neutrophils by a filter during cardiac valve surgery

Purpose To determine whether inclusion of a neutrophil-specific filter into the extracorporeal circuit during open heart valve surgery alters postoperative outcomes. Methods Convenience sampling of 24 patients undergoing elective open heart valve surgery between July 1993 and June 1994. Patients were randomized to a neutrophil-specific filter (n= 11) or to a standard blood filter (n= 13) during cardiopulmonary bypass. Results Neutrophil-specific filter diminished (P < 0.02) the expression of CD 18, a neutrophil surface adhesion molecule, at 1 (84.5 ± 4.2 vs 94.8 ± 3.8%). 4 (80.0 ± 4.2 vs 95.1 ± 3.9%) and 24 hr (75.2 ± 4.2 vs 98.2 ±3.9%) post-operatively compared with standard filter. Total white blood cell count, neutrophil count, and proinflammatory cytokmes (IL-6, IL-8) were similar between groups at all times. Measured outcomes including: PaO 2 , cardiac index, ejection fraction, haemodynamic variables, use of motropes, spirometry (FEV FVC). and hospitalization duration were similar between groups. Conclusions Inclusion of the neutrophil filter during open heart valve surgery selectively depletes activated neutrophils. There were no other detectable differences between the two groups and the use of a neutrophilspecific filter in routine clinical practice for patients undergoing open heart valve surgery is not supported.