The International Journal of Artificial Organs / Vol. 17/ no. 10, 1994/ pp. 543-548 Gas Exchange and Artificial Lung Blood compatibility of two different types of membrane oxygenator during cardiopulmonary bypass in infants Y.J. GU, P.W. BOONSTRA, C. AKKERMAN, H. MUNGROOP, I. TlGCHELAAR, W. VAN OEVEREN Cardiothoracic Surgery and Anaesthesiology, University Hospital, Groningen - The Netherlands ABSTRACT: The contact of blood with the artificial extracorporeal circuit causes a systemic inflammatory response due to blood activation. In this study, we compared two different paediatric membrane oxygenators used for extracorporeal circulation: a hollow fibre membrane oxygenator (Dideco Masterflo 0-701, n=10), and a flat sheet silicone membrane oxygenator (Avecor Kolobow 800-2A, n=10). Blood compatibility was indicated by measuring complement activation as well as leukocyte and platelet activation. In patients perfused with a flat sheet membrane oxygenator, concentrations of complement split products C3a were significantly increased 30 minutes after the start of bypass (p<0.01), whereas only a mild increase of C3a was found in patients perfused with a hollow fibre membrane oxygenator. Leukocyte and platelet counts dropped uniformly in both groups after the start of bypass mainly due to hemodilution. Activetion of leukocytes and platelets identified by both plasma {3-glucuronidase and {3-thromboglobulin was similar in both groups. Infants perfused with a flat sheet membrane oxygenator received significantly more donor blood than those perfused with a hollow fibre oxygenator (p<0.05). These results indicate that when used during paediatric cardiopulmonary bypass, a flat sheet membrane oxygenator has a higher complement activity than a hollow fibre membrane oxygenator, which is probably due to the relatively larger blood-surface contacting area of the oxygenator. (lnt J Artif Organs 1994; 17: 543-8) KEY WORDS: Blood compatibility, Complement, Oxygenator, Paediatric, Cardiopulmonary bypass INTRODUCTION Patients undergoing cardiac surgery are suffering during the postoperative period from a general "whole body inflammatory response" resulting from the con- tact of blood with the artificial pump-oxygenator circuit (1-3). The activation and interaction among different humoral amplification systems and cell ele- ments in blood and the subsequent release of the inflammatory mediators often lead to postoperative cardiac, renal, as well as pulmonary dysfunctions (4- 10). The flat sheet membrane oxygenator is known to have the mildest blood activation property and the development of inflammatory response in patients in comparison with other types of oxygenator (10). However, this oxygenator system has a relatively large contact surface when used for paediatric cardio- pulmonary bypass (CPS). Therefore, it is of interest to study the blood compatibility when a smaller oxygenator system is used like that of the hollow fibre membrane oxygenator system (Dideco) with a flat sheet oxygenator system (Avecor) to examine their effects on complement, leukocyte and platelet activation, as well as the clinical performance of these two systems. © by Wichtig Editore, 1994 0391-3988/543-06 $03.00/0