Low cardiac output syndrome in cardiac surgery

Abstract

Low cardiac output syndrome is one of the most common and serious complications in cardiac surgery and is associated with increased morbidity and mortality. Several prognostic features have been recognized, including preoperative, intraoperative risk factors and laboratory predictors. The pathophysiologic mechanisms of low cardiac output syndrome are not limited by ventricular systolic dysfunction only, diastolic dysfunction and valvular abnormalities also contribute to low cardiac output syndrome development. There is a broad spectrum of monitoring techniques during cardiac surgery, all of them are different in their invasiveness and reliability. Goal-directed hemodynamic therapy should be based on the most informative and accurate monitoring methods and its goal is to optimize the balance between oxygen delivery and consumption. Treatment of low cardiac output syndrome is intended to increase tissue oxygen delivery and prevent organ dysfunction providing adequate hemodynamic support. The first line of low cardiac output syndrome therapy, to be initiated as soon as the volume status is optimized, is the use of inotropes, vasopressors and vasodilators to improve contractility, preload and afterload. In the most severe cases the need of mechanical support might take place, including intra-aortic balloon pump, ventricular assist devices and extracorporeal membrane oxygenation.