DEPLETION OF NEUTROPHILS BY FILTER DURING AORTOCORONARY BYPASS-SURGERY TRANSIENTLY IMPROVES POSTOPERATIVE CARDIORESPIRATORY STATUS

Study objective: To determine whether inclusion of a leukocyte specific filter into the extracorporeal circuit during aortocoronary bypass surgery alters postoperative cardiopulmonary function. Design: Randomized, double-blinded control trial. Setting: Tertiary care hospital. Patients: Convenience sampling of patients undergoing elective aortocoronary bypass between October 1992 and June 1993. Interventions: A total of 32 patients were randomized to a leukocyte specific filter (n = 16) or to a standard blood filter (n = 16) during the surgical procedure. Measurements and results: White blood cell count in the standard filter group (12.2 +/- 3.6 10(9)/L) was higher (p = 0.047) than in the leukocyte filter group (9.9 +/- 2.6 10(9)/L) at 4 h postoperatively but counts were similar (p = 0.063) at 24 h (10.8 +/- 2.7 vs 8.9 +/- 2.8 10(9)/L, respectively), Leukocyte activation assessed by chemiluminescence was similar between groups at all measurement periods. We noted transient improvements (p < 0.05) in intrapulmonary shunt (19 +/- 50% vs 24 +/- 9%) and mean blood pressure (85 +/- 8 vs 76 +/- 9 mm Hg, respectively) in the leukocyte filter group compared with the standard filter group, respectively. Otherwise there were no differences noted between groups. Conclusions: Inclusion of a leukocyte filter during cardiopulmonary bypass caused transient cardiorespiratory improvement that was lost within 24 h and did not offer any significant clinical benefits.