Effect of Endotoxinemia on the Incidence of Postoperative Vasoplegia or Vasoplegic Shock Following Cardiothoracic Surgery Using Cardiopulmonary Bypass

Through previous research, it has been well established that cardiothoracic surgery using cardiopulmonary bypass (CPB) causes a systemic inflammatory response. This is in part due to the surgical trauma, the extracorporeal circulation and factors that come with it (e.g. blood contact with foreign surfaces, mechanical stress etc.), and ischemia. This inflammatory response is a key contributor to the incidence of vasoplegia and vasoplegic shock following these types of surgery - a common complication that in turn causes significant morbidity and mortality. Over the years, many factors that contribute to this reaction have been discussed. One potential explanation is the release of endotoxin into the bloodstream during CPB. Endotoxin is a molecule that is a part of bacteria which are native to the human gut. In healthy subjects, cell-barriers prevent release of relevant amounts of endotoxin into the blood stream. During major interventions, and especially during cardiac surgery with CPB, this barrier function is impeded, allowing endotoxin levels to rise and potentially exert detrimental effects. While previous studies have indicated that endotoxin may in fact be released into the bloodstream in significant concentrations, and there are some mechanistic explanations to how endotoxin may contribute to the resulting inflammation and vasoplegia, available studies have been small and the evidence is inconclusive. This study aims to show whether different blood-levels of endotoxin are associated with vasoplegia and vasoplegic shock in patients undergoing cardiac surgery with CPB.