33rd International Meeting of the German Society for Cardiovascular Engineering

OXYGENATOR TYPE AND BLOOD CELL TRAUMA IN CARDIAC SURGERY Objective: Blood cell trauma in cardiac surgery is mainly attributed to the use of the heart lung machine and the oxygenator. The optimization of oxygenator design and membrane technology (e.g., chemical properties of surface material), aiming at reducing the blood cell alterations, is an objective of current developments. Clinical evaluation of different oxygenators concerning alterations of blood cells and markers of organ function provide an appropriate level of complexity because various patient characteristics and operative data are involved. Our clinical research database enables us to study the impact of different oxygenator types on blood cells and markers of organ function in the homogenous group of elective coronary artery bypass grafting (CABG) patients. Materials and Methods: Prospective data from 4847 patients who underwent isolated CABG were collected, of which 282 had off-pump coronary artery bypass grafting (OPCAB). The blood cell parameters white blood cell (WBC) counts, platelet (PLT) counts, and red blood cell counts and the marker of organ function lactate dehydrogenase (LDH) and creatinine clearance (CC) were determined preand postoperatively. The changes of these parameters were analyzed among the 13-oxygenator type groups and compared with the OPCAB group. To account for individual differences in blood volume, flow rate, and bypass time, we introduced a formula to normalize blood alterations per transfer cycle across the oxygenator. Results: We could observe significant different blood cell alterations between the various oxygenator groups. The increase of WBC was positive correlated with LDH and negative with CC. The oxygenators with the least decrease in PLT had the highest WBC increase. Two manufacturer’s modifications in oxygenator surface material are observed to result in a trade off between induced WBC and PLT blood alterations. Conclusion: Cardiotomy suction blood separation had a clear effect on blood activation parameters. The cardiotomy suction blood separation enabled us to separate a main part of blood activation and prevent its negative effects. Further studies should prove whether retransfusion of cardiotomy suction blood without cell saver is indicated at all in routine CABG. B. Arnrich,* A. Albert,† J. Walter,* F. Schön,† M. Rothe,† J. Ennker† *Institute of Neuroinformatics, University of Bielefeld, Bielefeld, and †Clinic for Cardiothoracic Surgery, Heart Institute Lahr/Baden, Lahr, Germany JECT. 2004;36:286–293 The Journal of The American Society of Extra-Corporeal Technology