Influence of lipid and leucocyte separation on patient inflammatory response during extracorporeal circulation

Objectives: Following initiation of extracorporeal circulation, a generalized inflammatory response is observed. In addition to traumatization of blood components, leucocyte activation and microemboli formation have been described as probable causative factors. Studies have shown that the separation of polymorphonuclear neutrophile granulocytes and lipid particles have had a positive effect on the clinical course. In a prospective, randomized study on 60 patients, we addressed the question whether the use of a reservoir equipped with leucocyte and lipid separators (Remowell, Eurosets, Milano, Italy) has an effect on postoperative inflammatory parameters, the serum lipid profile or the postoperative clinical course.

Methods: In a randomized prospective pilot study, 30 patients were included in one of two treatment groups. In the verum group, a reservoir equipped with a filter (Remowell, Eurosets) and in the control group, a conventional Reservoir (Admiral, Eurosets) was used for CBAG procedures. Blood samples were taken preoperatively, at the start of CPB, at the end of CPB, 2 to 6 hours postoperatively and on the first 3 postoperative days. Inflammatory markers (CRP, PCT, IL6, Lipids (triglycerides, VLDL, LDL) differenzial blood counts and the clinical course were documented.

Results: In-hospital mortality in both groups was 0%. Immediately following CBP, relevant differences in IL6 levels were observed. IL6 was lower in the Remowell group than in the control group (mean 43 ng/l and 74 ng/l, respectively; p = 0.05). For the remainder of the postoperative course, no significant differences were seen in either the inflammatory parameters (CRP, PCT, IL6) or the serum lipid profiles. Clinical data also revealed no advantages of leucocyte and lipid separation. Postoperative renal function (serum creatinine, urine output) and pulmonary function were equal in both groups. The incidence of postoperative delirium was also equal in both groups. Length of ICU stay and total in-hospital treatment times were equal in both groups as well.

Conclusion: Separation of lipid particles and leucocytes from suctioned blood was not advantageous when compared to conventional reservoirs in this setting.