[Physiopathological alterations secondary to extracorporeal circulation in cardiac surgery].

Cardiopulmonary bypass (CPB) is one of the methods used in myocardial revascularization and can be associated with adverse events that are uncommon, but CPB induces high morbidity and mortality. Cardiac surgery and CPB activate a systemic inflammatory response characterized by tissular lesions, cells movements and blood flow toward the interstice where the harmful stimulus has begun, under the influence of the mediators. The systemic inflammatory response may be initiated during cardiac surgery by a number of processes, including blood contact with the foreign surface of the CPB apparatus, development of ischemia and reperfusion injury, and presence of endotoxemia. In the course of cardiac surgery using CPB, all three processes are present and contribute concurrently to the systemic inflammatory response. The term "systemic inflammatory response syndrome" (SIRS) has been proposed to describe an entity that continually overlaps with normal postoperative physiology. A frequent complication of SIRS is the development of organ dysfunction, including acute lung injury, shock, renal failure, and multiple organ dysfunction syndrome. Finally, long-term survival in patients developing SIRS may also be adversely affected. The purpose of this review is to examine and understand the pathological mechanisms for inflammatory response that occur following cardiopulmonary bypass.