THE INFLAMMATORY RESPONSE TO CARDIOPULMONARY BYPASS

The inflammatory response to cardiopulmonary bypass is the product of a complex interplay of humoral and cellular components. Contact activa tion cascades, the complement system, and cytokines comprise the humor al elements and interact in such a way as to propagate their own casca des and to activate the cellular elements. Neutrophils and endothelial cells are the cellular components and become involved after their ''a ctivation'' by the humoral mediators. Neutrophil-endothelial cell adhe rence is the initial step of the cellular inflammatory response and is promoted by the expression of specific adhesion molecules on the surf aces of both of these cells leading to the emigration of neutrophils i nto the extravascular space where they release toxins that damage surr ounding tissues, The resulting organ dysfunction produces the clinical picture referred to as the ''postperfusion syndrome.'' Strategies to attenuate this response include the administration of corticosteroids, aprotinin, and anticytokine monoclonal antibodies, as well as various modifications of the bypass circuit. The existence of multiple pathwa ys to trigger this inflammatory response hampers efforts at its attenu ation and leaves much investigation to be done as the quest to underst and the body's inflammatory response to cardiopulmonary bypass continu es. Copyright (C) 1997 by W.B. Saunders Company.