Reducing the post-pump syndrome by using heparin-coated circuits, steroids, or aprotinin

Background: Cardiopulmonary bypass (CPB) induces a systemic inflammatory re sponse called 'post-pump syndrome'. As a part of a complex interaction betw een white cells and vascular endothelium, proinflammatory cytokines IL-6 an d IL-8 are part of a phased immune response that is also balanced by anti-i nflammatory cytokines such as IL-10. We compared the influence of heparin-c oated circuits, steroids, and aprotinin on these cytokines, looking for way s to reduce the syndrome. Methods: 40 patients with coronary artery disease (CAD) undergoing elective CABG were prospectively studied in four randomiz ed groups of 10. Group A received prednisolone pre- and postoperatively (2 x 250 mg), group B received aprotinin perioperatively (6 Mio. KIU). In grou p C, heparin-coated circuits ('Bioline' by Jostra) were used and in group D no special measures were taken (controls). Plasma levels of cytokines were measured before and during CPB and until 12h after surgery using an ELISA technique. Results: In group A IL-6 was significantly (p<0.05) suppressed i n contrast to the control group (A: peak at 4 h, 155 pg/ml vs. control: pea k at 8 h, 565 pg/ml). IL-8 was also suppressed (A: peak at 30', 22 pg/ml vs . control: peak at 30', 55 pg/ml). IL-10 level changed first and was marked ly upregulated in contrast to the control (A: peak at 30', 1600 pg/ml vs. c ontrol: peak at 30', 130 pg/ml; p<0.05). In group B (aprotinin) the cytokin e release was similar to group A. Using heparin-coated circuits (group C) a lso led to a significant (p<0.05) IL-10 upregulation (C: peak at 2 h, 1380 pg/ml) and IL-6 suppression (C: peak at 4 h, 290 pg/ml). IL-8 was not influ enced significantly. Conclusions: The results show a similar reduction of t he inflammatory cytokine release (IL-6 and IL-8 as markers) using early ste roid application and aprotinin in high dosage. Heparin coating reduces IL-6 and increases IL-10 release, whereas IL-8 is not affected. Further studies should investigate the effects of a combined application for reducing infl ammatory cytokine release and the post-pump syndrome.