Reducing the Post-Pump Syndrome by Using Heparin-Coated Circuits, Steroids, or Aprotinin

Abstract

Background: Cardiopulmonary bypass (CPB) induces a systemic inflammatory response called 'post-pump syndrome'. As a part of a complex interaction between white cells and vascular endothelium, proinflammatory cytokines IL-6 and IL-8 are part of a phased immune response that is also balanced by anti-inflammatory cytokines such as IL-10. We compared the influence of heparin-coated circuits, steroids, and aprotinin on these cytokines, looking for ways to reduce the syndrome. Methods: 40 patients with coronary artery disease (CAD) undergoing elective CABG were prospectively studied in four randomized groups of 10. Group A received prednisolone pre- and postoperatively (2x 250 mg), group B received aprotinin perioperatively (6 Mio. KIU). In group 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 12 h after surgery using an ELISA technique. Re-sults: In group A IL-6 was significantly (p<0.05) suppressed in contrast to the control group (A: peak at 4 h, 155 pg/ml vs. control: peak 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 markedly upregulated in contrast to the control (A: peak at 30', 1600 pg/ml vs. control: peak at 30', 130 pg/ml; p<0.05). In group B (aprotinin) the cytokine release was similar to group A. Using heparin-coated circuits (group C) also 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 influenced significantly. Conclusions: The results show a similar reduction of the inflammatory cytokine release (IL-6 and IL-8 as markers) using early steroid 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 inflammatory cytokine release and the post-pump syndrome.

Key words

Extracorporeal circulation - Post-pump Syndrome - Interleukins - Heparin coating - Steroids - Aprotinin