Effects of phospholipid-coated extracorporeal circuits on clinical outcome parameters and systemic inflammatory response in coronary artery bypass graft patients.

Introduction: The use of extracorporeal circulation (ECC) during coronary artery bypass graft (CABG) surgery is associated with a systemic inflammatory response due to the contact of blood with artificial surfaces. The clinical relevance of ECC-related systemic inflammation varies with the patient, and such inflammation may be accompanied by intermittent organ dysfunction and an increased catecholamine requirement. We investigated the effects of a new phospholipid coating system of ECC on systemic inflammatory response and clinical outcome following CABG.

Methods: Patients scheduled for CABG surgery were prospectively divided randomly into 2 patient groups: patients using noncoated ECC materials and patients using phospholipid-coated ECC materials. Clinical data measured perioperatively included hemodynamics, aortic clamp time, duration of bypass, time to extubation, catecholamine requirement, length of intensive care unit (ICU) stay, postoperative blood loss, and amount of blood transfused. In addition, blood samples were collected before cannulation and at 2, 24, and 48 hours postoperative. Cytokines (tumor necrosis factor alpha [TNF-alpha] and interleukin 10 [IL-10]) and P-selectin were measured with an enzyme-linked immunosorbent assay. Plasma nitrate/nitrite levels (NOx) were determined by the Griess reaction.

Results: A significant increase of TNF-a level was noted in the uncoated control group only. In the uncoated group, IL-10 levels significantly increased at 2 hours postoperative, whereas levels remained unchanged in the phospholipid coating group. P-selectin increased 2 hours postoperative in the uncoated group, and no significant changes were noted in the phospholipid coating group. At 24 hours postoperative, total plasma NOx production significantly increased in the phospholipid coating group but remained constant in the control group. No significant differences with respect to postoperative parameters (time to extubation, ICU stay, amount of bleeding, blood transfused, and catecholamine requirement) were observed.

Conclusions: Phospholipid coating significantly reduces the systemic increase in proinflammatory and anti-inflammatory cytokines and P-selectin. Despite the comparable clinical outcomes in this study, the observed significant reduction in systemic inflammatory parameter values suggests an improved biocompatibility of ECC materials when they are coated with phospholipids.